1. Lunabotics Positioning System Proposal
UAH Lunabotics Team
January 11, 2013
Mark Becnel
Ethan Hopping

2. What is Lunabotics?
Competition Goal: Create a remotely operated excavator capable of mining and depositing a minimum of 10kg of lunar simulant in 10 minutes
Excavator must navigate from a starting position across an obstacle region to a mining region
Excavator must extract regolith, return across obstacle area, and deposit regolith in a bin
Points are awarded or deducted for a variety of factors including mass of regolith collected
Links to full rules can be found at:
Introduce purpose of Lunabotics. Discuss basic rules

3. The Competition Arena
Graphic aid for explaining competition goal

4. Feasibility Assessment
Where Are We?
Conceptualization
Research Completed
Numerous navigation and harvesting systems were researched and considered
Other team’s solutions were researched
Ideas were discussed and debated in a team environment
Feasibility Assessment
Analysis Completed
Based on research, the team decided to proceed with a wheeled chassis using an excavation system based on the mechanical design of a snow blower.
Preliminary Design
Ongoing
Certain systems, such as the excavation system, have been designed
Electrical and software systems still in development
Positioning system still in development
Fabrication & Testing
A “test platform” has been developed for testing of software and mechanical systems. This platform is close to completion.
Final Lunabot fabrication is to be completed
Bring audience up to speed on what has been done and what is yet to be done…Lead into the need for a positioning system.

5. Importance of the Positioning System
Bonus points are given to teams with excavators capable of operating autonomously.
500 bonus points awarded to teams with excavators that complete the competition with no human interaction other than starting and stopping the excavator.
The size of this bonus is substantial enough to be a deciding factor for winning the competition.
To operate autonomously, the excavator must have a method of determining position within the competition arena.
Position acquisition must occur quickly 1Hz or faster
Must be able to determine position within region approximately the size of a tennis court, accurate to 10cm or less.
Excavation process must not interfere with position acquisition

6. Proposed Positioning System
Determine excavator position using triangulation with two rotating Doppler radios.
Two Doppler radios are attached to the Lunabin
Radios transmit directional/reflector angle
Receiver on excavator records reflector angle and signal strength
Signal strength “peaks” when reflector is pointed directly at excavator
By determining when signal strength rises above a threshold, excavator can determine angle to each radio
Triangulation can be used to determine position within arena
To the best of our knowledge, no other team has used radio positioning—this is a unique and original concept for the Lunabotics competition

7. 50 degrees
75 degrees
100 degrees
125 degrees
50 degrees
75 degrees
100 degrees
125 degrees
Lunabin
Transmitter
Transmitter
Robot

8. Receiver Example If threshold is signal strength of 6
Angle
Signal
Signal 50 4 2 51 5 52 6 53 7 3 54 8 55 56 57 58 59 60 61 62 63
If threshold is signal strength of 6
Transmitters 2 meters apart
Angle to #1 is (52+56)/2 = 54
Angle to #2 is ( )/2 = 58

9. Proposed Hardware Receiver (on excavator) Doppler Radio Atmel RZ600
Use spinning directional antenna
Hardware to be determined

10. Software & Positioning System Integration
Radios
Positioning System PC
Use MATLAB to determine excavator position and direction within arena
Send position and angle to MCU via serial
Remote Operator
Sends stop and start commands
Monitors system health
Control excavator (if necessary)
MCU
Interpret position data from PC
Use data to control mechanical systems
Monitor basic system status (power usage, battery life, etc.)
Report system status to operator
Mechanical Systems (drivetrain, excavator, hopper, etc.)