1. Ultrasonic Tracking System Group # 4 Bill Harris Sabie Pettengill Enrico Telemaque Eric Zweighaft

2. Introduction What is our project? What is our project? Pan and tilt implemented system tracking an ultrasonic beacon which sends a signal to 3 ultrasonic receivers, is carried around the room by a team member Pan and tilt implemented system tracking an ultrasonic beacon which sends a signal to 3 ultrasonic receivers, is carried around the room by a team member How does it work? How does it work? The signal coming from an ultrasonic transmitters is measured at three different locations The signal coming from an ultrasonic transmitters is measured at three different locations The difference in the time the signal is received at each sensor is used to calculate a distance relationship The difference in the time the signal is received at each sensor is used to calculate a distance relationship Why is this project practical? Why is this project practical? Mitsubishi Motor company uses a similar design in their automobiles for a collision avoidence system Mitsubishi Motor company uses a similar design in their automobiles for a collision avoidence system Various pest and animal repellent systems use ultrasonic waves for tracking and repelling. Various pest and animal repellent systems use ultrasonic waves for tracking and repelling.

3. Objective Simulation of pan & tilt system used as a cost efficient method to determine: Simulation of pan & tilt system used as a cost efficient method to determine: Motor required to drive system Motor required to drive system Gear, belt and pulley combination needed Gear, belt and pulley combination needed Response of system to motor, gear, belt and pulley Response of system to motor, gear, belt and pulley Maximum performance variables for system Maximum performance variables for system Rough estimate of system response to sample payload Rough estimate of system response to sample payload Chance to show that we were paying attention in all those math classes Chance to show that we were paying attention in all those math classes

4. Specifications The system will track objects between 2 and 10 meters from the array The system will track objects between 2 and 10 meters from the array The system will track objects between 0 and 2 meters off the ground The system will track objects between 0 and 2 meters off the ground The system will track items within.5 degree of accuracy (within 10 cms of the object with beacon) The system will track items within.5 degree of accuracy (within 10 cms of the object with beacon) The system must be able to track the beacon at the speed of a human walking (.64 rad/sec) The system must be able to track the beacon at the speed of a human walking (.64 rad/sec)

5. Major Change in Design With our previous sensor structure, there was not a large enough motor that could handle the torque With our previous sensor structure, there was not a large enough motor that could handle the torque We decided make a more compact sensor structure which allowed us to go with a much smaller motor in the Pittman 8000 series. We decided make a more compact sensor structure which allowed us to go with a much smaller motor in the Pittman 8000 series. The sensor structure was made L shaped instead of T shaped to allow for a simpler timer circuit The sensor structure was made L shaped instead of T shaped to allow for a simpler timer circuit

6. Motor Pittman GM8724S017 Pittman GM8724S017 19.5:1 internal gearing ratio 19.5:1 internal gearing ratio Encoder mounted directly to rotor increases accuracy of encoder (encoder is not geared down) Encoder mounted directly to rotor increases accuracy of encoder (encoder is not geared down) External transmission gives additional reduction ratio of 3:1 External transmission gives additional reduction ratio of 3:1

7. Motor Pittman GM8724S017 Pittman GM8724S017 Larger gearing ratio does not allow us to meet our speed requirements Larger gearing ratio does not allow us to meet our speed requirements Smaller gearing ratio does not allow us to meet our torque requirements Smaller gearing ratio does not allow us to meet our torque requirements Gains must be chosen carefully to remain inside the feasible range for both speed and torque Gains must be chosen carefully to remain inside the feasible range for both speed and torque

8. Motor SimulationSimulation Sinusoidal inputSinusoidal input Frequency of 0.63 rad/sFrequency of 0.63 rad/s

9. Motor Speed vs. Torque plotSpeed vs. Torque plot Shows that motor is well within limits, as long as gains are kept at reasonable levelsShows that motor is well within limits, as long as gains are kept at reasonable levels

10. Controller By intuitive adjustment of gains, a reasonable response was obtained By intuitive adjustment of gains, a reasonable response was obtained But “guessing” is not a valid design approach But “guessing” is not a valid design approach

11. Controller SISO Design tool was used SISO Design tool was used Linearized model was obtained using the linearlization routines provided Linearized model was obtained using the linearlization routines provided Alternatively, the “linmod” command could be called to create a linear State Space model from the Simulink Diagram Alternatively, the “linmod” command could be called to create a linear State Space model from the Simulink Diagram This allows the designer to view pole/zero locations, bode plots, AND response plots all at the same time, and adjust poles, zeros, and gains in any of these formats This allows the designer to view pole/zero locations, bode plots, AND response plots all at the same time, and adjust poles, zeros, and gains in any of these formats

12. Controller SISO WindowStep Response Overshoot is very undesirable

13. Controller SISO WindowStep Response PM = 98.2° GM = Inf. Zero overshoot, 1% e ss

14. Notes on Controller Because of assumptions made in order to linearize the system, this controller does not perform perfectly on the non-linearized model, so some adjustments will have to be made during assembly and testing Because of assumptions made in order to linearize the system, this controller does not perform perfectly on the non-linearized model, so some adjustments will have to be made during assembly and testing We may wish to add an Integral term later to cancel the 1% overshoot We may wish to add an Integral term later to cancel the 1% overshoot Does not seem necessary now- it would only hurt our transient response, and require more torque and speed from the motor Does not seem necessary now- it would only hurt our transient response, and require more torque and speed from the motor

15. Justification for Sensor Parts Given the cost of larger motors, needed to have a design with a small moment of inertia Given the cost of larger motors, needed to have a design with a small moment of inertia The higher the clock frequency of timer circuit, the smaller our sensor structure has to be The higher the clock frequency of timer circuit, the smaller our sensor structure has to be The cheapest TTL components had a maximum functional frequency of 5 MHz The cheapest TTL components had a maximum functional frequency of 5 MHz Chose an oscillator accordingly Chose an oscillator accordingly

16. Cost Pan and Tilt Parts Total $478.64 Part Part # QuanityPrice Total $$ MotorGM8724S0172192.86385.72 Gear (large) A 6A 6- 75NF01812 215.1530.30 Gear (small) A 6A 6- 25DF01806 27.7615.52 Carbon Fiber T155-5143.4043.40 Timing Belt A6Z16-C01821.863.70

17. Additional Costs Total Amount for Timing Circuit and Sensors: $46.52 Total Cost for project: $533.84

18. February Week 2Week 3Week 4 Hardware Placing parts and payload on CAD drawings to calculate P,I,M values for Matlab simulation (Bill, Sabie) Hardware - CAD designed payload added to Ben’s CAD drawings system and edited P,I,M values are calculated (Eric, Sabie) Final design specifications are met (All members) Parts are ordered (Eric, Sabie) Software Simulation of pan and tilt system to obtain feasibility and performance of test motor with a test payload (Bill) Final Motor feasibility simulation with payload on pan and tilt system (Bill, Enrico) Testing of control system’s ability to track a signal using amplitude, or distance and time measurements (All members) Reports Presentation writeup (Enrico Eric) Proposal writeup (Sabie, Enrico) TBD

19. March Weeks 1-2Week 3Week 4 Hardware Sensor development with focus on time\distance relationship (Eric, Sabie) Encoder and amplifier properties researched (Bill, Enrico) Design model assembled (Enrico, Sabie) Sensor assembly (Bill, Eric) Further tolerance testing of physical equipment Software Current Feedback control analyzing and testing to find proper gains for accurate tracking (Bill, Enrico) Encoder and amplifier properties simulated (Eric, Sabie) Testing and fine tuning of control feedback system (Bill, Sabie) Sensor testing with system (Enrico, Eric) Test mechanics of system in terms of motion (Bill, Enrico) Test mechanics of system in terms of tracking (Eric, Sabie) Reports Progress Report (All members) TBD