Warman 2015 University of Technology Sydney A. Gillmore B. Potts T. Dalyell S. Abid D. Brown
Warman 2015University of Technology Sydney
A. Gillmore B. Potts T. Dalyell S. Abid D. Brown
Brief outline of activities and decisions
• Brainstorming- Device collecting 6 balls with path straight down the track- Suction cups
• Concept- Keeping the design simple - Collect and store 3 balls before continuing to the next three- Aiming for biggest storage pit due to minimal point difference
• Design - Dagu Rover 5 tracked chasis- 2 DC motors with 4 encoders- 2 Servos operating collection arm
• Production- Laser cut sheet acrylic (3/4.5mm)- Different sized spacers to control ball arm height
• Testing- Ahead of fabrication schedule allowed us maximum track testing time- Laser cut starting jig with adjustable spacers
• Execution- Followed from testing
Project and device requirements
• Collect 1-6 balls put in 1 of 3 storage pits; • Off the shelf kits not allowed; • Start button can not impart motion; • 120 second set up time, 120 second run time; • No contact with robot after start; • Wireless communication prohibited; • 6kg, 400mm cube restriction; • Robot must stop moving after completing the course.
Detailed explanation of the device
• Prototype 1 - Tolerance issues- Group discussion following testing we decided to continue brainstorming another idea as we had plenty of time remaining
Concept Design
Detailed explanation of the selected device
• Final Prototype - Dagu Rover 5 Tracked Chassis
Concept Design
Detailed explanation of the selected device
• Final Prototype - Mechanical linkages to operate the gates - Arm is connected through cantilever under the Dagu
Concept Design
Detailed explanation of the selected device
• Design Mechanics - Two Servo motors;1 for Ball gates and a second to keep the collector arm within the 400mm requirement
• Meeting the design requirements - Start button correctly installed - Dagu max speed was 25cm/s allowing plenty of leeway to fit within time limit- Total system weighed under 3kg - Total system was within 400mm Cube due to folding arm design
Two key issues overcome by the team
• Driving Straight
• Encoder resolution
• Physical design of Robot
• PID controller code modification
• Starting position
• 1 degree of inaccuracy at start resulted in 35mm East west variation at 2m
• Laser cut starting jig with adjustable spacers
Videos
5 Balls collected and stored in the large pit
Event day
Final Device Analysis• Rules/requirements met
• No combustion/Aerial systems
• 1 button push start
• Met all size and weight (final weight -> 2.8kg) restrictions
• Device Weaknesses
• Tracked chassis, encoder resolution, starting position could be refined
• Improvements
• IR sensors to detect edge and drive robot straight
• Replace tracked chasis with rear wheels and front castor
• Positives
• Build quality
• Collection mechanism if positioned properly never failed
• Speed
• Team time management (8am lab sessions, early prototyping)