Robot Lab

San Jose State University

Charles W. Davidson College of Engineering

December 3, 2015

E10 Section 14

Professor Smita Duorah

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Group 2

Kasey Leong

Nathan Luc

Eduardo Luna

Andy Ma

Sabrina On

Dominic Scalero

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Introduction

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Purpose/Goal: To build a successful robot, using components from electrical, mechanical, and programming.

Tasks: Robot must find the red beacon, turn it off, find the green beacon, and move it out of the arena as fast as possible; should be under 2kg

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Design of the robot - Circuit Board

• resistors, capacitors, sockets for integrated circuits, LEDs, transistors, connectors, infrared detectors, fuse holder
• polarized: capacitors, LEDs
• failed circuit board

Design of the robot-body

• Used design of base given in instructions
• 4 wheel design
• elevated platform for the main arm
• one limit switch directly in the center of robot
• slightly elevated circuit board
• caging in the back to hold the battery in place

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Design of Robot - Bumper Arms

• 2 extended arms
• 2 braces to position the beacons
• 2 bumpers: one on each of the extended

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Design of the Robot- ARm

Final Arm was single motor claw that deactivated the red beacon and secured the green beacon

• L-shape arm
• lightweight
• styrofoam on palm of the claw
• three claws in the front
• U-Shaped extension

Programming - Unique modifications

• Lowered rotational speed when searching for beacon to make it easier to pick up signal
• Increased beacon approach speed
• Lowered ambient_level

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• Arm drops repeatedly until red beacon turns off
• Using condition (PD_Sum > 200)

[arm lowers and rises]

Programming - User Functions

• Bumper: placed in while loop when searching for beacon/exit
• checks if either bumper is pressed, and if so, runs the user function back_up, then rotates approx. 90°

Programming - User Functions

• back_up: placed in Bumper, and after turning off red beacon
• moves in reverse for .5 sec
• used in multiple places in the program, so it was given its own function

Programming - Main

• used four states
• state 1: locate red beacon
• state 2: deactivate red beacon
• state 3: locate & secure green beacon
• state 4: exit arena

• escape plan:
• move forward continuously
• constantly check for signal from bumper
• when bumper is pressed, back up, rotate ~90°, and continue moving forward
• should escape within 4 rotations

Performance

• on the third trial, able to complete all tasks in 32 seconds
• robot weighed: 1.895 kg, which was under the criteria of 2.0 kg.

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Hardware issues

• bad motor
• bad servo
• battery issues
• bad controller

Design Errors

• Could not properly secure the green beacon
• Arm missed button on red beacon
• Later, bounced on red beacon
• Various iterations of arm design
• Loose bolts

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Recommendations

• Keep a fully charged spare battery in hand
• If using a heavy arm then use a motor rather than a servo
• Testing too much can burn out motors
• Meet often with group
• Keep all possible causes in

mind when troubleshooting

• Be open minded!!!!

Conclusion

• A lot of troubleshooting/design changes
• Servo to Motor
• Group worked hard
• Successful Robot on the last attempt
• Fastest Robot

References

• http://perch.roberts.edu/wp-content/uploads/2015/10/dead-battery.jpg
• http://www.robotmarketplace.com/products/images/store_vexservo.jpg
• http://www.vexrobotics.com/wiki/images/6/6d/VEXMicrocontrollerV05.JPG
• https://pixabay.com/p-157437/?no_redirect
• http://engineering.sjsu.edu/e10/wp-content/uploads/RobotProjectGuidelines-F14.pdf

Thanks for listening