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Preliminary Design Review

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Presentation on theme: "Preliminary Design Review"— Presentation transcript:

1 Preliminary Design Review
CanSat 2012 Preliminary Design Review Team IEEE UCSD CanSat 2012 PDR: Team 2134 (IEEE UCSD) 1

2 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Presentation Outline Introduction / Team Organization — Chris Warren Systems Overview — Chris Warren, Jeff Wurzbach Sensor Subsystem Design — Alex Forencich Descent Control Design — Jeff Wurzbach Mechanical Subsystem Design — Jeff Wurzbach Communication and Data Handling Subsystem Design — Alex Forencich Electrical Power Subsystem Design — Alex Forencich Flight Software Design — Chris Warren, Alex Forencich Ground Control System Design — Chris Warren, Alex Forencich CanSat Integration and Test — Jeff Wurzbach Mission Operations & Analysis — Chris Warren Management — Chris Warren Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 2

3 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Team Organization Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 3

4 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Acronyms AGL – Above Ground Level BPS – Barometric Pressure Sensor CAN – CanSat System CAR – Carrier Subsystem DCS – Descent Control System IMU – Inertial Measurement System LAN – Lander Subsystem MCU – Microcontroller Unit PCBA – Printed Circuit Board Assembly RTV – Room-temperature Vulcanizing Rubber FSW – Flight Software GSW – Ground Station Software OTA – Over the Air GCS –Ground Control Station Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 4

5 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Systems Overview Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 5

6 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mission Summary CanSat Objectives Successfully leave the Payload Envelope of the rocket Record and transmit telemetry every two seconds Passively control descent rate as specified Autonomously seperate into Carrier and Lander units at 91 meters above the ground Carrier Objectives Maintain a descent rate of 5 meters per second Record atmospheric and position data onboard Send recorded telemetry data to ground station Lander Objectives Land a large grade A hen's egg safely Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 6

7 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mission Summary (cont'd.) Selectable Objective Lander shall measure the force of impact on the ground at a sampling rate of 100 Hz This data will be stored onboard for post-processing Due to space and weight constraints, this is the easiest bonus objective to attempt External Objectives As a team, we wish to release as much open-source data, programming, and other system information as possible We will publish information and experimental findings that proved to be important and useful in our project This will serve as an aid and inspiration for other individuals/teams attempting similar system objectives Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 7

8 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Requirements – Cansat Mission ID Requirement Rationale Priority Children VM A I T D CAN-01 Total mass of Cansat shall not exceed 750 grams / be less than 400 grams (excluding egg) Mass is an expensive property concerning rockets and flight HIGH X CAN-02 Cansat shall fit inside payload envelope 130mm in diameter and 152mm in length Systems will have to be constructed around space available in a transport vessel CAN-03 No protrusions beyond the envelope of the rocket allowed until the Cansat is deployed Many cansats fail to eject properly, this will aid in ensuring a proper ejection CAN-04 The rocket airframe cannot be used to restrain any deployable parts of the Cansat The rocket is only for transport; systems must work independently MEDUIM CAN-05 The rocket airframe and payload sections shall not be used as a part of Cansat operations Systems must work independently MEDIUM CAN-06 The Cansat shall deploy from the rocket payload section Important to have a successful flight with proper telemetry CAN-07 The descent control system shall not use any flammable or pyrotechnic devices We will be launching in a fire-risk area CAR-06 LAN-06 DCS-04 CAN-08 Prior to lander deployment, Cansat shall descend as a single unit Competition Requirement CAN-09 Cansat descent rate shall be 10 m/s above 200 meters AGL, and 5 m/s below 200 meters AGL CAR-01 LAN-01 DCS-01 CAN-10 The Cansat (Carrier+Lander) shall separate at an altitude of 91 meters LAN-08 CAN-11 All descent control systems must be capable of handling a 30G shock force The deployment of recovery parachutes could tear apart the Cansat airframe if it is not strong enough CAR-03 LAN-03 DCS-05 Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 8

9 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Requirements – Cansat Mission (cont’d.) ID Requirement Rationale Priority Children VM A I T D CAN-12 Carrier and lander both shall include an audible locating device rated at 80dB or higher, independently powered with a dedicated power switch Cansat could be lost in the launch area after landing; audible locating is more reliable than visual in this situation HIGH CAR-09 LAN-10 X CAN-13 Cansat communications shall use the XBEE radio modules, with the NETID/PANID set to the team number, and the modules NOT in broadcast mode Reliable data handling and communications with no interference is key for this satellite flight CAN-14 Cansat shall not transmit telemetry until commanded by the ground control station Preserves onboard memory and battery life for mission critical data MEDIUM CAN-15 Ground station must be developed that shall display telemetry in real-time and in engineering units Prevents messy conversions or accidental miscalculations CAN-16 Ground control station antenna must be elevated a minimum of 3.5 meters Allows for clearer and more reliable radio transmissions CAN-17 Carrier and lander both shall have battery capacity to support a one-hour delay on the launch pad as well as flight time, with an external power control There is a good chance that there will be launch delays due to wind or other events; an external power switch will allow for easy power control without tearing apart the Cansat CAN-18 Cansat shall not use LiPo batteries Competition Requirement LOW CAN-19 Cansat fight hardware budget shall be limited to $1000 All projects must work within their approved budgets CAN-20 Cansat shall be launched within the assigned launch window Delays are costly, and must be avoided MEDUIM CAN-21 The Cansat and associated operations shall comply with all published field safety regulations Safety is key when dealing with rocket launches, projectiles, and possibly-free-falling objects Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 9

10 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Requirements – Carrier ID Requirement Rationale Priority Parents Children VM A I T D CAR-01 Average descent rate of Carrier after Cansat separation shall be 5 m/s Competition Requirement MEDIUM CAN-09 DCS-02 X CAR-02 Parachutes / parafoils shall be florescent pink or orange Aids visibility of the Carrier when in the sky DCS-06 CAR-03 Structure must support 10G acceleration force and 30G shock force, with the descent control attachment points to be easily inspected Structure must not deform under expected launch, flight, and descent forces HIGH CAN-11 CAR-04 Mechanisms must be able to maintain their configuration under any loading Structure must maintain its configuration in order to reliably work CAR-05 All electronic circuit boards must be properly mounted and enclosed/shielded from the environment Proper design and mounting of PCBs will ensure reliable electronic functioning CAR-06 Mechanisms must not use pyrotechnics or chemicals, and any use of heat must not be exposed to the outside environment We are operating in a fire-risk area; safety is key CAN-07 CAR-07 Contact information and identifying marks must be places on the Carrier structure In case the Carrier travels off-range, there is more of a chance of it being returned CAR-08 Telemetry must be transmitted every two seconds, and shall consist of GPS fix data, altitude from a non-GPS sensor, air temperature, and battery voltage Telemetry data is a large part of the competition CAR-09 Carrier shall activate an audible beacon only following landing, and for at least three hours thereafter After landing, visual contact will most likely be lost; audible contact will be much more reliable CAN-12 Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 10

11 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Requirements – Lander ID Requirement Rationale Priority Parents Children VM A I T D LAN-01 Average descent rate of Lander after Cansat separation shall be 5 m/s Competition Requirement MEDIUM CAN-09 DCS-03 X LAN-02 Parachutes / parafoils shall be florescent pink or orange Aids visibility of the Lander when in the sky DCS-06 LAN-03 Structure must support 10G acceleration force and 30G shock force, with the descent control attachment points to be easily inspected Structure must not deform under expected launch, flight, and descent forces HIGH CAN-11 LAN-04 Mechanisms must be able to maintain their configuration under any loading Structure must maintain its configuration in order to reliably work LAN-05 All electronic circuit boards must be properly mounted and enclosed/shielded from the environment Proper design and mounting of PCBs will ensure reliable electronic functioning LAN-06 Mechanisms must not use pyrotechnics or chemicals, and any use of heat must not be exposed to the outside environment We are operating in a fire-risk area; safety is key CAN-07 LAN-07 Contact information and identifying marks must be places on the Lander structure In case the Lander travels off-range, there is more of a chance of it being returned LAN-08 Lander shall safely land a single large Grade A egg from 91 meters AGL CAN-10 LAN-09 Lander shall measure the force of impact with the ground at a rate of 100 Hz, with data stored onboard Bonus Objective LAN-10 Lander shall activate an audible beacon only following landing, and for at least three hours thereafter After landing, visual contact will most likely be lost; audible contact will be much more reliable CAN-12 Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 11

12 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Level CanSat Configuration Trade & Selection Stacked Module Design (Selected) Proven design Easily constructed Lower risk of binding during release phase 360° antenna coverage is straight forward to accomplish Sliding Module Design (Not used) Simple retention mechanism Higher sensitivity to tolerance stack up and misalignment Possible antenna occlusion due to asymmetric design Concentric Module Design (Not used) High complexity geometry Requires exotic PCB substrate to accommodate electronics If designed correctly center of mass will not change dramatically after release Parachute mount to inner module is simple, the outer module mount is comparatively complex Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 12

13 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Concept of Operations Pre-Launch Carrier Active Sleep Sleep Sleep Sleep Cansat will listen to XBEE, waiting for ground station to signal telemetry start MCU SENSOR (IMU / BPS / TMP) GPS OFF Active Sleep BUZZ XBEE Lander Active Sleep Sleep Sleep Sleep MCU SENSOR (IMU / BPS / TMP) GPS OFF Active BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 13

14 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
System Concept of Operations (cont’d) Launch Carrier Active Active Sleep Active MCU will cycle, pulling necessary information from SENSOR package. Data retrieval and storage will be interrupt-based MCU SENSOR (IMU / BPS / TMP) GPS OFF Sleep Active BUZZ XBEE Lander Carrier and Lander will have near-exact flight hardware. Telemetry data from both units will be separated and parsed by the ground station Active Active Active MCU SENSOR (IMU / BPS / TMP) GPS OFF Active BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 14

15 System Concept of Operations (cont’d)
Apex / Deployment Carrier Active Active Sleep Active SENSOR data still polled, stored onboard, and sent via XBEE MCU SENSOR (IMU / BPS / TMP) GPS OFF Sleep Active CanSat will fall out of payload envelope. Drag chute (resting inside payload bay) will release, keeping CanSat at required descent rate BUZZ XBEE Lander Active Active Active MCU SENSOR (IMU / BPS / TMP) GPS OFF Active BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 15

16 System Concept of Operations (cont’d)
Descent A Carrier Active Active Sleep Active SENSOR data still polled, stored onboard, and sent via XBEE. MCU SENSOR (IMU / BPS / TMP) GPS OFF Sleep Active BPS pressure altitude will be monitored BUZZ XBEE Lander Once altitude transitions past 200 meters AGL, the secondary drag chute attached to the Carrier will be released Active Active Active MCU SENSOR (IMU / BPS / TMP) GPS OFF Active BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 16

17 System Concept of Operations (cont’d)
Descent B Carrier Active Active Active SENSOR data still polled, stored onboard, and sent via XBEE. MCU SENSOR (IMU / BPS / TMP) GPS OFF Active BPS pressure altitude will be monitored BUZZ XBEE Once altitude transitions past 91 meters AGL, the Carrier and Lander will separate Lander Active Active Active MCU SENSOR (IMU / BPS / TMP) GPS OFF Active Lander chute will deploy during separation BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 17

18 System Concept of Operations (cont’d)
Landing / Post-flight Carrier Sleep OFF Active OFF Active SENSOR data still polled, stored onboard, and sent via XBEE. MCU SENSOR (IMU / BPS / TMP) GPS ON ON Sleep IMU (containing the accelerometer) will be monitored at 100 Hz BUZZ XBEE After impact data is stored, Buzzer will be turned on, sensor package will be turned off, and the MCU and XBEE will sleep Lander Sleep Active OFF OFF Active MCU SENSOR (IMU / BPS / TMP) GPS MCU and XBEE will wake periodically to ping the ground station ON ON Sleep BUZZ XBEE Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 18

19 Isometric view of the Complete CanSat
Physical Layout Isometric view of the Complete CanSat (covers not shown) Sectioned Front view of the Complete CanSat (covers not shown) 127mm 145mm Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 19

20 Carrier (cover not shown) Lander (cover not shown)
Physical Layout Carrier (cover not shown) Lander (cover not shown) Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 20

21 Front view of Carrier (cover shown) Carrier (cover shown)
Physical Layout Front view of Carrier (cover shown) Carrier (cover shown) Note: Lander cover design is incomplete. Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 21

22 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Launch Vehicle Compatibility CanSat (Carrier + Lander) will be inserted into the payload envelope upside-down, with the initial drag chute closest to the base of the rocket stack This allows the CanSat to fall out in the proper orientation The CanSat dimensions will be within the required envelope, and will have a factor of safety built in such that the CanSat will fall out smoothly 127mm 145mm We have ordered and received a LOC/Precision Minie-Magg rocket body We will use this prior to our flight to ensure proper CanSat – Rocket integration and fit Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 22

23 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Launch Vehicle Compatibility This rendering shows the Cansat assembly inside the specified reference payload envelope Presenters: Chris Warren Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 23

24 Sensor Subsystem Design
Alex Forencich CanSat 2012 PDR: Team ### (Team Name) 24

25 CanSat 2012 PDR: Team ### (Team Name)
Sensor Subsystem Overview Subsystem Component Chosen Purpose ALT DEV-100/BMP085 Measure barometric pressure TEM Measure open-air temperature ACL DEV-100/ADXL345 Measure acceleration GYR DEV-100/ITG-3200 Measure rotation rate MAG DEV-100/HMC5883L Measure heading GPS MT3329 Calculate Altitude, Latitude, Longitude, and Time SCP DEV-100/ATMEGA328P Coprocessor to assist in sensor data acquision and processing Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 25

26 CanSat 2012 PDR: Team ### (Team Name)
Sensor Subsystem Requirements ID Requirement Rationale Priority Parent VM A I T D SEN-01 Telemetry shall be displayed at GCS Competition requirement HIGH X SEN-02 Position shall be recorded via GPS Altitude shall be recorded via non-GPS sensor SEN-03 Air temperature shall be recorded SEN-04 Accelerometer shall measure impact force SEN-05 Accelerometer shall be sampled at a minimum of 100 Hz SEN-06 GPS shall operate at 3.3 volts Hardware requirement MEDIUM EPS-04 SEN-07 IMU sensors shall operate at 3.3 volts EPS-07 Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 26

27 CanSat 2012 PDR: Team ### (Team Name)
Carrier GPS Trade & Selection Model Power Channels Accuracy Mass Frequency MT3329 3.3V/42mA 66 2.5m 6g 10Hz LS20031 3.3V/41mA 10m 9g 5Hz Venus634FLPx 3.3V/28mA 14 <2.5m 2g Selection: MT3329 Extremely compact and lightweight Internal antenna High update rate Binary protocol support for efficient storage and transmission of GPS data with no reprocessing Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 27

28 CanSat 2012 PDR: Team ### (Team Name)
Carrier Non-GPS Altitude Sensor Trade & Selection Model Voltage/Current Range Accuracy Mass Interface BMP085 3.3V/5A 30kPa-110kPa 100Pa .09g I2C MPL115A1 (3.3V or 5V)/10A 50kPa-115kPa 1000Pa <1g SPI SCP1000 3.3V/25A 30kPA-120kPa 1.5Pa Selection: BMP085 Extremely compact and lightweight Very accurate Built in pressure sensor Included in Mongoose IMU board Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 28

29 CanSat 2012 PDR: Team ### (Team Name)
Carrier Air Temperature Trade & Selection Model Voltage/Current Range Accuracy Mass Interface BMP085 3.3V/5A -40 to +85°C ±0.1°C <1g I2C TMP36 (3.3V/5V)/50A –40°C to +125°C ±1°C Analog DS18B20 (3.3V/5V)/NA –55°C to +125°C ±0.5°C Digital Selection: BMP085 Extremely compact and lightweight Very accurate Built in temperature sensor Included in Mongoose IMU board Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 29

30 CanSat 2012 PDR: Team ### (Team Name)
Lander Altitude Sensor Trade & Selection Model Voltage/Current Range Accuracy Mass Interface BMP085 3.3V/5A 30kPa-110kPa 100Pa .09g I2C MPL115A1 (3.3V or 5V)/10A 50kPa-115kPa 1000Pa <1g SPI SCP1000 3.3V/25A 30kPA-120kPa 1.5Pa Selection: BMP085 Extremely compact and lightweight Very accurate Built in pressure sensor Included in Mongoose IMU board Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 30

31 CanSat 2012 PDR: Team ### (Team Name)
Lander Impact Force Sensor Trade & Selection Model Voltage Current (active/sleep) Range Frequency Interface ADXL345 3.3V 40A/.1A 2, 4,8,16g 3200Hz I2C MMA7361 440A /3A 1.5, 6g 400Hz (x,y) 300Hz (z) Analog SCA3000 A No Sleep Mode 2g 300Hz SPI ADXL320 3.3V/5.0V A 5g 500Hz Selection: ADXL345 Extremely compact and lightweight Very accurate Included in Mongoose IMU board Presenter: Name goes here CanSat 2012 PDR: Team ### (Team Name) 31

32 Descent Control Design
Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 32

33 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Descent Control Overview Carrier and Lander descent control will be accomplished with a parachute. A hemispherical or an elliptical configuration shall be used ration to minimize mass, material, and volume. A spill hole may be used for improved stability. Rip-stop Nylon fabric will be used cut into gores and stitched into desired geometry. Nylon cords will be used for suspension lines Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 33

34 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Descent Control Requirements ID Requirement Rationale Priority Parents Children VM A I T D DCS-01 CanSat descent rate shall be 10 m/s above 200 meters AGL, 5 m/s below 200 meters AGL Competition Requirement MEDIUM CAN-09 X DCS-02 Carrier descent rate shall be 5m/s after separation CAR-01 DCS-03 Lander descent rate shall be 5m/s below 91 meters AGL LAN-01 DCS-04 Descent control system shall not use and flammable or pyrotechnic devices Safety is key, as we are launching in a fire-risk area HIGH CAN-07 DCS-05 All descent control systems must be capable of handling a 30G shock force The deployment of parachutes must not teat apart the CanSat structure CAN-11 DCS-06 Parachutes / parafoils shall be florescent pink or orange High visibility of descending carrier and lander CAR-02 LAN-02 Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 34

35 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier Descent Control Strategy Selection and Trade Material Selection – Rip Stop Nylon Lightweight Strong– proven to hold up humans when skydiving Easy to work with Bright orange is easily procured We used nylon in last year’s competition Parachute design performed marginally well Flaws in last year’s implementation Edges of the parachute crept up the shroud lines Packing error caused the canopies to collapse during release phase Using data / experience from last year to design and fabricate higher performance descent control parachutes Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 35

36 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Lander Descent Control Strategy Selection and Trade Using Rip Stop Nylon for Lander descent control It makes sense for us to use only one material Simplifies manufacturability Nylon, as stated before, is proven to work Bright pink selected for Lander descent control parachute Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 36

37 Descent Rate Estimates
Assumptions Maximum system mass of 750 g Mass split equally between Carrier and Lander Mass of egg neglected for estimations Pieces falling at terminal velocity Air density at standard temperature and pressure Configurations Estimates Since mass of Carrier + Lander is double that of just the Carrier (or Lander), we can assume that the descent speed of the combined configuration is double that of the single pieces Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD)

38 Descent Rate Estimates (cont’d)
Thus, we have decided to use the same parachute for both halves of the Cansat assembly This will simplify design and manufacturability However, since our CAD model has not yet been refined, we have not focused on nailing down the descent control design The governing equations for parachute decent are well documented The final mass budget we get from our final CAD design will drive those equations, the solution of which will be our finalized parachute design All we really need is the parachute dimensions from those equations to move forward Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD)

39 Descent Rate Estimates (cont’d)
Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD)

40 Mechanical Subsystem Design
Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 40

41 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mechanical Subsystem Overview Summary Carrier design overview Lander design overview Egg Container and Protection System overview PCBAs and electrical components Material Selections The modules, the carrier and the lander, are stacked on top of each other. There is a retainer bracket to hold the main parachute down unit it is deployed. The egg is contained inside of a rubber and foam protective jacket. There is a plastic shell holding the egg package to the lander module The circuit board assemblies are common to both modules. The are discreet antenna mounting assemblies in each module. The carrier-lander interface is held by a latch assembly that is actuated by a rotary solenoid. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 41

42 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mechanical System Requirements ID Requirement Rationale Priority Parents Children VM A I T D MEC-01 Structure must support a 10G load The Cansat must not deform; it must stay strong throughout the mission HIGH X MEC-02 Structure must support a 30G shock force Parchute deployment can be violent MEC-03 Structure must have an enclosure Protects electronic components; adds strength MEDIUM MEC-04 Cansat structure must have a mass between 400 and 750 grams Mass is a valuble “resource” in space misions Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 42

43 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Lander Egg Protection Trade & Selection Selection: Neoprene Rubber and Expanding Foam (formed in the field, around egg to be launched) Material Cost Weight Comments Closed Cell Foam (thin) Medium Low Observed effectiveness is low (used in last year’s scheme) Neoprene Rubber High Whole sheets are very costly Polystyrene Beads N/A (left over from last year) Observed effectiveness is low Expanding Foam Medium-High Expanding foam to be contained so that it does not stick to the egg or container the egg is in. Peanut Butter Almost as dense as water. Eliminated as the primary cushion material due to high density Initially considered peanut butter, based on recommendation of a friend who won an egg drop contest using an egg protector made of peanut butter. The problem is weight. The system used last year didn’t work at all. The foam beads need a lot more room than we have for an egg protector, and all of the other parts. We considered Great stuff foam sprayed into a plastic bag and used to make a custom shape to protect the egg. Drying time is an issue. Presently considering shipping foam due to it’s fast setup time. The neoprene is the absorb shocks that the expanding foam does not absorb. This may be replaced with peanut butter. The selection modeled in CAD is based on expanding foam and neoprene. It’s performance under shock loads has not been simulated yet. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 43

44 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mechanical Layout of Components Trade & Selection Principle metric for judging materials is workability. This metric is key based on last year’s experiences of building the structures at the last minute Parts have to machine-able with the tooling we have on hand Table below shows the metrics considered and a brief description of the metric DFM considered from the start of the design. Materials considered 6061-T6 alloy Al 7075-T6 alloy Al 3003 alloy Al Inconel 625 Carbon Fiber/other composites 3003 alloy Al was picked because it is not a hardened metal, free machining, easy to find (Home Depot Carries 20ga sheets of it) and it takes bends well. 6061-T6 and 7075-T6 are both hardened alloys. They are difficult to bend (they have a habit of tearing at the bend line). They can be bought in annealed versions, but they have to be heat treated to have a reasonable gain over 3003. Inconel 625 is too expensive, but nevertheless very sexy. Carbon Fiber/other composites: hard to machine. Requires extra care while machining to control dust. Dust is conductive, fine and makes hands very itchy. It does offer very desirable strength characteristics on paper, but the difficulty machining it and its high cost make it a poor choice for this application Material Workability Cost Strength/Weight Other Name of the material Overall ease of machining and forming processes Cost of the raw material Strength of the material divided by its weight. Notes and comments Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 44

45 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mechanical Layout of Components Trade & Selection Material Workability Cost Strength/Weight Other 6061-T6 Alloy Aluminum Medium Low-Medium Tears easily when bent 7075-T6 Alloy Aluminum 3003 Alloy Aluminum Easy-Medium Low Used last year Carbon Fiber/Other Composites High Dust is very annoying Nickel Based Alloys (such as Inconel) Difficult Astronomical No prior knowledge of working with material High Impact Polystyrene Easy For use on non structural parts. No prior experience with vacuum forming process Expanding Foam Medium (messy) Medium-High N/A (used for cushioning) Expanding foam to be contained so that it does not stick to the egg or container the egg is in. Peanut Butter Almost as dense as water. DFM considered from the start of the design. Materials considered 6061-T6 alloy Al 7075-T6 alloy Al 3003 alloy Al Inconel 625 Carbon Fiber/other composites 3003 alloy Al was picked because it is not a hardened metal, free machining, easy to find (Home Depot Carries 20ga sheets of it) and it takes bends well. 6061-T6 and 7075-T6 are both hardened alloys. They are difficult to bend (they have a habit of tearing at the bend line). They can be bought in annealed versions, but they have to be heat treated to have a reasonable gain over 3003. Inconel 625 is too expensive, but nevertheless very sexy. Carbon Fiber/other composites: hard to machine. Requires extra care while machining to control dust. Dust is conductive, fine and makes hands very itchy. It does offer very desirable strength characteristics on paper, but the difficulty machining it and its high cost make it a poor choice for this application Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 45

46 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Material Selections 3003 Aluminum sheet metal Easy to work with (machines easily, takes bends well) Readily available (carried by Home Depot and other local vendors) Good strength to weight ratio 40 mil High Impact Polystyrene Vacuum formable Allows low weight non-structural and low strength parts to be made Low density foam Low weight Easily custom formable Readily available Neoprene/similar Rubber Good shock absorption Moderate weight Augments the expanding foam Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 46

47 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier-Lander Interface Operational Model 4 locking tabs hold the lander to the carrier The carrier has a plate that turns and releases the locking tabs. There are alignment tabs and pins that ensure the Lander does not rotate with the Carrier Rotation is accomplished by rotary solenoid Considering swapping a servo in to save weight. Parachute for the lander will be stowed to the side of the lander Pulled out during the separation phase by a drag line taped to the Carrier Stowed here to prevent damage from moving parts Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 47

48 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier-Lander Interface Parts Carrier Parachute Foundation Mounting Nuts and Washers Rotary Solenoid Alignment Bracket Release Tabs 4 locking tabs hold the lander to the carrier. The carrier has a plate that turns and releases the locking tabs. There are alignment tabs and pins that ensure this setup will release the lander. Presently the rotational motion is accomplished via a rotary solenoid, but it will probably be changed to a servo because of the reduced weight and increased range of travel. Rotating Arm Lander Top Plate Planned Alignment Pins on Lander (not modeled yet) Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 48

49 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier-Lander Interface Operation Part Planned Motion of the Solenoid and Arm The solenoid turns CCW and moves the rotating arm. The planned alignment pins prevents the Lander from rotating with rotating arm. The release tabs are loose their support and gravity pulls the lander away from the carrier. Parachute for the lander will be stowed to the side of the lander and pulled out during the separation phase This keeps the chute away from the moving parts (preventing damage). There will be a drag line taped to the carrier with cheesy tape. This will start the process of parachute deployment. The drag from the line and partially inflated canopy should do the rest. This will be verified via testing. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 49

50 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier-Lander Interface Parachute Storage Parachute wrapped around the enclosure. Parachute for the lander will be stowed to the side of the lander and pulled out during the separation phase. This keeps the chute away from the moving parts (preventing damage). There will be a drag line taped to the carrier with cheesy tape (magic tape, scotch, etc). This will start the process of parachute deployment. The drag from the line and partially inflated canopy should do the rest. This will be verified via testing. Drag line (yellow) taped to the bottom of the Carrier Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 50

51 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Structure Survivability Trades PCBAs mounted with 4-40 hardware to core structures Lander: Mounted to Egg Protection Cup Carrier: Mounted to Parachute Foundation PCBAs will be covered with enclosures made from high impact polystyrene on both Lander and Carrier Enclosures will cover entire module. Batteries adhered to PCBAs with zip tie and adhesive based RTV GPS will be secured with adhesive based RTV to top of enclosure (not modeled in CAD yet) Electronics are mounted to PCB. The PCBs in the Carrier are mounted to the Parachute foundation and will be used to help stiffen the foundation against shock loads The mounts for the Lander PCBs are TBD at this time. The PCBs mount to the side of the egg protection system’s plastic cover. They will be mounted with screws. This has not been modeled yet. The PCBs for both flight units are the same design and layout. The CR123A battery is mounted to the board with soldered wires and a cable tie. RTV or epoxy will be used to further secure the battery in place. This is not yet shown in the CAD model. The entire module will be enclosed by a vacuum formed high impact polystyrene cover. The starting thickness of the material, before forming, is 40mil. It is modeled as 40mil thick, but it will be significantly thinner due to elongation in the forming process. We have not calculated the actual thickness yet. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 51

52 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Structure Survivability Trades 10G Acceleration and 30G shock force verification Conduct FEA simulations in Solidworks to verify. Requires a more complete CAD model than we presently have. Learning How to use the bolt and screw joint modeling feature Electronics are mounted to PCB. The PCBs in the Carrier are mounted to the Parachute foundation and will be used to help stiffen the foundation against shock loads The mounts for the Lander PCBs are TBD at this time. The PCBs mount to the side of the egg protection system’s plastic cover. They will be mounted with screws. This has not been modeled yet. The PCBs for both flight units are the same design and layout. The CR123A battery is mounted to the board with soldered wires and a cable tie. RTV or epoxy will be used to further secure the battery in place. This is not yet shown in the CAD model. The entire module will be enclosed by a vacuum formed high impact polystyrene cover. The starting thickness of the material, before forming, is 40mil. It is modeled as 40mil thick, but it will be significantly thinner due to elongation in the forming process. We have not calculated the actual thickness yet. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 52

53 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget Table(s) providing the following: Mass of all components Mass of all structural elements Sources/uncertainties – whether the masses are estimates, from data sheets, measured values, etc. Total mass Margins Must clearly distinguish between carrier and lander masses Include allocated mass for egg payload Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 53

54 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Carrier, Lander, Egg and Margin) Module Estimated Mass (grams) Percent of System Mass Carrier 300.71 40% Lander 217.78 29% Margin/unallocated 231.51 31% Egg 63.19 N/A Note 1: Margin/unallocated mass accounts for parts not yet modeled. This number will change as the design matures. Note 2: Egg model was created last year. Measurements of eggs purchased in the past 30 days validates the model, with margin. Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 54

55 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Electronics) Electronics Estimated Mass (grams) Notes PCBA-CPU 37.18 Includes CR123A Battery PCBA-Sensor GPS 15 Manufacturer’s Website. Mass not captured in Integrated CAD model. Xbee 3 Manufacturer’s Website. Mass partially captured in Integrated CAD model. Antenna 4 Average mass of 4 units. PCBA-RF Power Divider 2 Estimate based on density of FR4 substrate and estimated dimensions of PBCA. Mass not captured in Integrated CAD model. Note: Electronics configuration is identical on the Lander and Carrier Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 55

56 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Wiring and Interconnects) Electronics Estimated Mass (grams) Notes Carrier Interconnects 50 Target Value Lander Interconnects Note: Final weight of interconnects will be driven by the CAD model Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 56

57 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Carrier Structure) Electronics Estimated Mass (grams) Notes Baseplate 54 CAD Model estimate from material properties Parachute Foundation 15 Servo 9 Manufacturer’s Website Parachute Retention Mechanism 23 Release Mechanism 75 Antenna Bracket (x2) 1.2 CAD Model estimate from material properties. Given mass is for both brackets Fasteners 30 Target value. Not Captured in the CAD model yet Enclosure/Cover 40 Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 57

58 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Lander Structure) Electronics Estimated Mass (grams) Notes Baseplate 31 CAD Model estimate from material properties Parachute Foundation 16 Top Plate 27 Manufacturer’s Website Release Tabs (x4) 10 CAD Model estimate from material properties. Mass given is for all 4 parts Antenna Bracket 1 Fasteners 30 Target value. Not Captured in the CAD model yet Enclosure/Cover 40 Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 58

59 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mass Budget (Egg Protection) Electronics Estimated Mass (grams) Notes Cover 19 CAD Model estimate from material properties Neoprene 32 Foam Half (x2) 1.7 CAD Model estimate from material properties. Given mass is for both brackets PCBA Mounts 10 Target value. Not Captured in the CAD model yet Carrier is grams, estimated from existing CAD model Lander is grams, estimated from existing CAD model Total is grams, estimated from existing CAD model Egg is modeled at grams CAD model estimate for the CPU electronics is grams (incld 1 CR123A battery) PCB material is estimated from volume and the density of E type fiberglass, as used in the SW materials lib. CR123A battery mass is based on data found on internet: Xbee weight is not accounted for fully. electronic components are not accounted for yet. CAD model estimate for the Sensor electronics is grams (incld 1 CR123A battery) Solenoid mass is from direct measurement. Structural elements are modeled for geometry, weight and strength by using the SW materials lib. Egg Model is the same as was used last year. This model has been proven by data gathered this year and performance last year. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 59

60 Communication and Data Handling Subsystem Design
Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 60

61 CDH Overview Carrier Transponder Ground Station Computer XMEGA XMEGA XBee XBee Lander XMEGA XBee XBee XMEGA processors in Carrier and Lander will packetize telemetry data for transmission via the XBee radios Transponder XMEGA will process received packets and pass them to the ground station computer via RS485 Multiple ground receive radios with overlapping antenna patterns allow for seamless sky and long range ground coverage Ground station software will format and display data in real time Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 61

62 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CDH Requirements ID Requirement Rationale Priority Parent VM A I T D CDH-01 Radios used shall be Digi XBP24-AUI-001 and XBP24-ASI-001 Competition requirement HIGH CAN-13 X CDH-02 Communications shall be carried out through the XBee API Necessary for robust packetized telemetry XBee PAN ID shall be the team number, 2134 Competition requirement, necessary to prevent interference CDH-03 Telemetry data shall be transmitted at a rate of 0.5 Hz CAR-08 CDH-04 Telemetry data shall be backed up on board in real time Accurate analysis of flight data CDH-05 Primary processor shall be Atmel ATXMEGA128A1 running at 32 MHz Internal oscillator and lots of serial IO for communicating with internal peripherals MEDIUM CDH-06 Auxillary sensor processor shall be Atmel ATMEGA328P running at 16 MHz On integrated IMU board, offload sensor data acquisition and processing Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 62

63 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Processor & Memory Trade & Selection Model Voltage Clock SRAM UART / I2C / SPI Flash ATXMEGA128A1 3.3 V 32 MHz 8 KB 8 / 4 / 4 128 KB ATMEGA328 16 MHz 2 KB 1 / 1 / 1 32 KB AT91SAM7X512 3.3V 55 MHz 2 / 1 / 2 512 KB Selection: XMEGA128A1 for communications processing, MEGA328 for sensor processing Easy to use, widely available, open source toolchain XMEGA has numerous serial ports for comms, data acquisition, control, and logging IMU board contains an ATMEGA328, convenient for off-loading high rate sensor data acquisition and processing Interrupt support allows for easy multitasking Low power Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 63

64 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier Antenna Trade & Selection Model Gain Center F BW Length Weight ANT-2.4-CW-RH 2 dBi 2.45 GHz 80 MHz 27 mm 4 g GW 50 MHz 109 mm unknown W5001 1.5 dBi 128 mm Selection: ANT-2.4-CW-RH Very small size, light weight, economical Low gain Correct frequency band Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 64

65 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Radio Configuration Radios will be configured in API mode Radio PAN ID will be set to the team number Radio configuration parameters will be stored in nonvolatile memory making them immune to unexpected resets Radio data frames will be encapsulated in XBee transmit request packets and sent to the XBee radio for transmission XBee radio will be connected to a buffered, interrupt driven USART in the XMEGA controller to enable efficient asynchronous transfers of packet data while allowing minimally interrupted processing Packets for transmission will be enabled or disabled based on internal mission phase selection Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 65

66 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier Telemetry Format Data will be sent in packet format Data frames will be encapsulated inside ZigBee packets Data frames will include high precision timestamps, source, and type information Data frames will have different formats for different sensors Data will be transmitted in binary to conserve transmitted wireless data Communication to ZigBee module will take place at baud Radio data rate will be baud Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 66

67 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Activation of Telemetry Transmissions Telemetry transmissions will be controlled as part of a mission phase state machine State change will be triggered by onboard interpretation of sensor data in addition to command packets sent by the ground station software Data will be logged before and during telemetry transmission during all phases of flight Radios and sensors will enter a low power state after landing to preserve battery life Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 67

68 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Locator Device Trade & Selection Model Frequency Impedence Mass CEM-1203 2 kHz 42 Ohm 1.4g COM-09151 Unknown 8 Ohm 10g ZSP99023A 400 Hz-8 kHz 4 Ohm >30g Selection: CEM-1203 Produces audible sound Much smaller and lighter than alternative speakers FSW onboard carrier will enable buzzer once the lander mission phase has switched from descent to landed State change should be triggered by sensor data, but could be manually actuated by a radio command Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 68

69 Electrical Power Subsystem Design
Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 69

70 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
EPS Overview Components require 3.3 volts Chose 3.7 volt RCR123A 880 mAh Li-Ion cells 2 series cells, 7.4 volts total Carrier components include: XBee Radio XMEGA CPU GPS IMU 328/Acc/Gyro/BPS Temperature Sensor Release Solenoid Servo Buzzer Lander components include: XBee Radio XMEGA CPU GPS IMU 328/Acc/Gyro/BPS Temperature Sensor Servo Buzzer Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 70

71 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
EPS Requirements ID Requirement Rationale Priority Parent VM A I T D EPS-01 High efficiency switching regulator will generate 3.3 volts from batteries Hardware Requirement HIGH X EPS-02 XMEGA MCU shall operate at 3.3 v MEDIUM EPS-03 XBee radio shall operate at 3.3 v EPS-04 MTK GPS shall operate at 3.3 v EPS-05 Parachute release servo shall operate at 3.3 v EPS-06 Separation solenoid shall operate at 35 v provided by a step-up converter EPS-07 IMU module shall operate at 3.3 v Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 71

72 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier Electrical Block Diagram 7.4v Li-Ion Pack 3.3 V Switcher XMEGA XBee Servo Step up switcher Solenoid Actuator Micro SD Buzzer IMU Carrier will be put in sleep mode with a pin actuated switch Verification will be an on board LED in addition to XBee radio packets Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 72

73 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Lander Electrical Block Diagram 7.4v Li-Ion Pack 3.3 V Switcher XMEGA XBee Servo Micro SD Buzzer IMU Lander will be put in sleep mode with a pin actuated switch Verification will be an on board LED in addition to XBee radio packets Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 73

74 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Power Budget Device Source Typ. I (A) Max I (A) Stdby I (A) Qty Total Typ. I Total Max I Total Stdby I V Typ. P (W) Max P (W) Stdby P (W) xmega Logic 3.3 0.022 0.0095 1 3.3 0.0726 mega368 0.006 0.0015 0.0198 led 0.01 0.02 4 0.04 0.08 0.132 0.264 max3468 0.004 0.0132 adxl345 hmc5883l Ps-itg-3200 0.0066 bmp085 XBee Radio Radio 3.3 0.148 0.25 0.015 0.4884 0.825 0.0495 MTK GPS 0.042 0.053 0.1386 0.1749 Power figures drawn from datasheets Maximum values used for current and minimum values used for efficiency for worst case calculation Assuming radio typically transmits 50% of the time (overestimate) Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 74

75 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Power Budget Rail Name Source Voltage Efficiency Typ. Load P Max Load P Stdby Load P Typ. P Max P Stdby P Typ. Load I Max Load I Stdby Load I Logic battery 7.4 1 0.985 1.546 0.134 0.133 0.208 0.0182 Logic 3.3 3.3 0.9 0.260 0.392 0.0719 0.288 0.435 0.0799 0.0787 0.118 0.0217 Radio 3.3 0.627 0.999 0.0495 0.696 1.111 0.055 0.19 0.303 0.015 Source Voltage Typ. P Max P Stdby P Typ % Max % Stdby % Approx P Capacity Ah Capacity Wh Typ. Life (h) Max Life (h) Stdby Life (h) Approx Life Logic Battery 7.4 0.985 1.546 0.134 1 0.25 8 0.254 0.88 6.512 6.607 4.210 48.264 24.567 Power figures drawn from datasheets Maximum values used for current and minimum values used for efficiency for worst case calculation Figures include 15 minutes at max current draw, 1 hour regular telemetry transmission, and 8 hours standby Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 75

76 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Power Source Trade & Selection Model Voltage Capacity Weight Dimension Type 16340 (CR123A) 3.7 V 880 mAh 17 g 16 x 34mm Li-ion 14500 (AA) 800 mAh 16.2 g 14 x 50mm 9 volt 9 V 565 mAh 47 g 49 x 27 x 18 mm Alkaline Selection: Li-ion cell Physically short so easier to fit into CanSat body Large capacity cylindrical cell Relatively easy to obtain Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 76

77 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Battery Voltage Measurement Trade & Selection Battery voltage measurements will be made with a voltage divider The output of the divider will be connected to an analog input of the XMEGA MCU ADC has 12 bits of resolution Carrier and lander use same measurement method Presenter: Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 77

78 Flight Software Design
Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 78

79 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
FSW Overview FSW will be essentially the same for both the Carrier and Lander While the Carrier and Lander will function separately, the code running on each will be taking care of roughly the same things, however: The Carrier will be the only subsystem monitoring barometric pressure altitude, and will be controlling the release of drag chutes and system separation The Lander will be more of a data-logging unit, as it has no separation or chute release Lander shall record impact forces at 100 Hz FSW will be written for the Atmel XMEGA processor Based off of the C programming language Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 79

80 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
FSW Requirements ID Requirement Rationale Priority Parents Children VM A I T D FSW-01 Software shall control the gathering and sending of telemetry data over the Zigbee protocol CARRIER ONLY – Competition Requirement; Ensures the availability of necessary flight data HIGH X FSW-02 Software shall store any telemetry data onboard for post-processing and risk reduction Storing the data sent to ground onboard as well reduces the risk of lost flight data FSW-03 Software shall control the release and control of descent control methods Control of descent speed is necessary for a successful flight FSW-04 Software shall measure impact force at a rate of 100 Hz LANDER ONLY – This is our chosen bonus objective MEDIUM FSW-05 Both instances of software (Carrier and Lander) shall operate independently and autonomously Following the physical separation of subsystems, the Carrier and Lander must operate on their own for the flight to be a success Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 80

81 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat FSW Overview Our plan for the flight software is an interrupt-driven state machine It isn’t terribly efficient to outline this program style with a standard flowchart This state machine will change its behavior based mainly on its altitude read from the pressure sensor It will also “begin” its flight sequence from a command sent from the ground control station to initialize telemetry Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 81

82 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Carrier CanSat FSW Overview The Carrier FSW states are as follows: Pre-Launch Carrier listens for “Telemetry Go” signal from ground station Launch Carrier polls sensor packages for GPS location, pressure altitude and other telemetry Deployment Sensors are still polled, Carrier now waits for pressure altitude checkpoints Descent Carrier releases main descent chute at 200 meters AGL Carrier separates from Lander at 91 meters AGL Landing / Post-Flight Sensor data continues to be polled until landing on ground Carrier will then relay the final GPS location, turn on the buzzer, and go into sleep mode waiting for signals from ground station Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 82

83 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Lander CanSat FSW Overview The Lander FSW states are as follows: Pre-Launch Lander listens for “Telemetry Go” signal from ground station Launch Lander polls sensor packages for GPS location, pressure altitude and other telemetry – sensor packages are polled continuously until the Landing / Post- Flight state Deployment Sensors are still polled Descent Landing / Post-Flight Sensor data continues to be polled until landing on ground Lander records impact force data at 100 Hz and stores data onboard Lander will then relay the final GPS location, turn on the buzzer, and go into sleep mode waiting for signals from ground station Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 83

84 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Software Development Plan We are already in the process of writing our flight software We have obtained and are using XMEGA development boards to test and prototype our code We are using Git as source control to allow team members to write, edit, and maintain our software independentlya We plan to test our code after major changes Tests will occur many times throughout our software development stage Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 84

85 Ground Control System Design
Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 85 85

86 GCS Overview Antenna mast w/ guy wires Spare parts Signal router
Laptops Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 86

87 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
GCS Requirements ID Requirement Rationale Priority Parents Children VM A I T D GCS-01 Antenna shall be 3.5 meters above the ground (or greater) Allows for clearer / more reliable signal transmission HIGH X GCS-02 Communications shall use the XBEE module, with PANID set to the team number Prevents crosstalk between different teams / systems GCS-03 GCS User Interface will allow for real-time viewing of telemetry data The ability to view real-time data allows for a better understanding of the mission at hand MEDIUM GCS-04 GCS will communicate with both the Carrier and Lander units Gives a better picture of the mission by capturing data from two sources Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 87

88 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
GCS Antenna Trade & Selection The antenna mast will consist of 1.5” (diameter) fiberglass/aluminum poles in 4 foot sections This is easily obtainable from various military surplus sources The mast will be feet tall We will use three antennas One 3dBi antenna One 8dBi antenna One patch antenna We have chosen these three antennas due to the various signal ranges and strengths they give us We will be able to automatically select the strongest signal Antenna mast: The antenna mast consists of 1.5” fiberglass and/or aluminum poles in 4’ sections. These are military surplus and sold by a number of vendors on ebay and elsewhere. The mast will be feet tall (wind dependent) Tripod base. 3 guy lines Baseplate anchored into ground with 4 spikes (12” long) documentation on the internet suggests that the mast can be setup by 1 person Weather station on the top of the mast with an anemometer. Weather station reports the ground station software. Plastic pipe used to hold antennae apart from each other. Plastic NEMA rated enclosure hold transceiver electronics at top of tower 3dBi antenna on let side, patch in the middle, 8dBi antenna on the right. Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 88

89 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
GCS Software Telemetry will be displayed via live graphs drawn on screen No commercial packages will be used in the GCS We wish to keep this design purely open-source Allows more fine control of our software Data from the antenna array will be directly logged to SD card Data will also be logged to a simple text file on the laptop(s) Command interface will be built into the telemetry viewer and data logger We wish to create a unified user interface Presenters: Chris Warren Alex Forencich CanSat 2012 PDR: Team 2134 (IEEE UCSD) 89

90 CanSat Integration and Test
Jeff Wurzbach CanSat 2012 PDR: Team ### (Team Name) 90

91 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Integration and Test Overview 3D CAD Model integration prior to fabrication of parts Integrated system tests on flight unit representative parts Testing of flight representative radio configurations with ground station setup (small scale tests have been completed already). Long term (hours to days) testing of software systems to ensure stability Progressive testing during production to ensure problems are identified prior to installation into CanSat. Design reuse wherever possible Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 91

92 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Integration and Test System and Subsystem Integration Systems Integration prior to fabrication via “In the box design” Design system in Solidworks prior to fabrication and detailed design of the flight PCBAs to ensure that all components fit and mass budgets are observed 3D CAD allows immediate feedback on system level impacts of changes Use/Creation of accurate 3D models in Solidworks ensures that our team meets specs Proven method used last year and by other IEEE UCSD projects Design validated as a whole before production begins via simulations in Solidworks Technical Drawings made for dimensional verification of fabricated parts to the 3D CAD model. Parallel development of hardware and software systems by using non-flight unit prototypes Identifies electronic interface issues before long lead items are purchased. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 92

93 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Integration and Test Integrated System testing Fully Integrated System Testing Drop testing—Drop Cansat from 6th floor Service elevator balcony down to the east loading dock (6+ story drop) Checkout operation of separation method Checkout operation of main parachute retainer Checkout landing software sequence Overall structural checkout of design Long distance radio testing Setup Ground station mast on Warren field Move CanSat away from mast until the connection drops. Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 93

94 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Integration and Test Module/Major Subassembly Level Testing Module Level Testing Assembled modules tested for basic functionality prior to integration into CanSat Assembly Each module to be drop tested to ensure that each DCS performs as expected GPS testing accomplished by long term logging tests (road trip). Major Subassembly Testing Shared configuration of electronics between Lander and Carrier Sensors system tested for electrical functionality after soldering into PCBA Software tested by running the system for long periods to verify logging tests, long term system stability (no counter overflows, etc), and battery life testing. Software updates can be completed OTA using xboot boot loader xboot installed on all microcontrollers in the system (flight and ground) Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 94

95 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Integration and Test Test Equipment Electronics testing accomplished with standard test equipment Oscilloscope Voltmeter Debugging terminal on computer Mechanical parts verified via measurement and inspection against CAD model Calipers Ruler Scale Many tests can be completed with sensors on board the CanSat modules. Data logging code within FSW is already verified GPS testing is underway Presenter: Jeff Wurzbach CanSat 2012 PDR: Team 2134 (IEEE UCSD) 95

96 Mission Operations & Analysis
Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 96

97 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Overview of Mission Sequence of Events Arrive at launch Site Check in with Flight Line Judge Weigh Cansat Perform fit-check of CanSat using sample payload Receive Egg Receive Rocket Payload Prep and test CanSat for flight Wait for launch window Request flight from Flight Coordinator Set up CanSat on launch pad Give Flight Coordinator “GO” for launch Monitor Telemetry of descent following Rocket Separation Update Flight Day scoring card Coordinate CanSat recovery with Flight Line judge and Field judges Recover CanSat ONLY when final approval is given by Field judge Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 97

98 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Mission Operations Manual Development Plan Development of our Operations Manual has only somewhat begun We have only included the basic launch day requirements and activities included in the Competition Guidelines As the team progresses through our final design plans and begins on the testing, verification, and manufacture phases of this project, we will add to our Operations Manual any interesting, important, and/or useful things we come across Ideally, by our demo flight, the Operations Manual will be the ultimate guide to running, repairing, and managing our project This “ultimate guide” will be a great addition to our plan to release our project data as open-source Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 98

99 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Location and Recovery Upon landing onboard buzzers will activate for 3 hours Carrier can be found by the last GPS location transmitted over the Xbee radios While one team member stays behind at the ground station, two people will become “scouts”, using any data relayed over handheld/shortwave radios Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 99

100 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Management Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 100

101 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Budget – Hardware Model Cost (US Dollars) SCP1000 (x2) 25.00 CR123A (x4) 8.00 Buzzer (x2) 15.00 IMU (x2) 200.00 XBEE Module (x2) 70.00 GPS Module (x2) 74.00 Power divider (RF) (x2) 20.00 Casing (exterior) UNK Micro-servo 12.00 Casing (other) 50.00 (allocated) Descent Control Egg Protection 20.00 (allocated) Custom PCB 100.00 Total: 644.00 Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 101

102 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
CanSat Budget – Other Costs Travel and Other Costs Item Cost (US Dollars) Flight Hotel and Car $2400 (Estimate) Food $720 (Estimate) Prototyping $400 (Estimate) Total $3520 (Estimate) Ground Station Costs Item Cost (US Dollars) XBEE Modules $70.00 Antenna $30.00 Computers $0.00 Software Miscellaneous Other $50.00 Total $150.00 Total Budget Costs Total Budget Cost (US Dollars) Cansat $644 Ground Station $150 Travel & Other $3520 Total $4314 Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 102

103 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Program Schedule Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 103

104 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Program Schedule (cont’d) Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 104

105 CanSat 2012 PDR: Team 2134 (IEEE UCSD)
Conclusions Major Accomplishments Mechanical design is essentially finalized Only a few minor details need to be worked out before we enter the prototyping and manufacturing phases Radio communications are proven in the lab Need trials in the field to test fully Major Unfinished Work Need to finalize plans for descent control Need to work on flight software Need to finalize the design, and test, our ground station setup Why We’re Ready for The Next Step We have a very dedicated team Energy and motivation to move forward We have the history and experience to take this project to the next level and beyond Presenter: Chris Warren CanSat 2012 PDR: Team 2134 (IEEE UCSD) 105


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