Killswitch

For the IGVC competition, we'll need a wireless and hardwired E-STOP.

Requirements

Following is an excerpt from the IGVC rules on emergency stops:

Mechanical E-stop location: The E-stop button must be a push to stop, red in color and a minimum of one inch in diameter. It must be easy to identify and activate safely, even if the vehicle is moving. It must be located in the center rear of vehicle at least two feet from ground, not to exceed four feet above ground. Vehicle E-stops must be hardware based and not controlled through software. Activating the E-Stop must bring the vehicle to a quick and complete stop.

Wireless E-Stop: The wireless E-Stop must be effective for a minimum of 50 feet. Vehicle E-stops must be hardware based and not controlled through software. Activating the E-Stop must bring the vehicle to a quick and complete stop. During the competition performance events (Autonomous Challenge and Navigation Challenge) the wireless E-stop will be held by the Judges.

A new requirement for 2011 is a kill switch indicator light. The light will be on when the robot is active, and flashing when it in autonomous mode. This will be controlled with the monitoring system.

Solution

We are working on a new system that uses the C1101 transceiver to allow for longer range, smaller remote size and better battery life. This system is being build currently, and should be installed on the robot during Spring Quarter, 2011. This new system is also a bit more failsafe, as it will physically disconnect the motor controllers from the computer when the robot is killed.