Hi, I am building a robot for the World Robot Olympiad with 2 34:1 Metal Gearmotor 25D HP 6V with Encoder driven by a Pololu Dual VNH5019 Motor Driver Shield for Arduino. My robot needs to reverse into a field wall 4-6 times per run to reset its odometry to a known position
What is the safest way to perform this wall backup maneuver without risking motor damage due to stalling?
My current plan is to reverse slowly and cut motor power the instant my encoders detect the wheels have stopped rotating.
Hello.
That approach sounds like it could be okay as long as the wheels actually stop when you drive into the field wall and do not slip. You could test that while monitoring the motor current using the VNH5019’s current sense output to make sure they are not drawing too much power. The current sense might also work as an alternative way to detect that you are touching the wall in case the wheels ever do slip.
Alternatively, you might consider adding something to your robot to act as a touch sensor that triggers when you touch the wall, like a limit switch. Depending on the precision required, you could also look into using a distance sensor that triggers when you are a particular distance from the wall instead of needing to actually touch the wall. One of the Pololu Digital Distance Sensors might be a good choice that is easy to implement.
- Patrick
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