paper: New Control Functions - Drive System Testing

[Chris Fultz]

As part of our beta testing, we used the roboRIO for some drive system evaluation testing, capturing data not available through the 2014 control. We were testing 2, 4 and 6 CIM and 4 CIM+2mini-CIM drives and capturing data, including amperage and voltage.

Through this testing, we identified an operational effect of one of the control features that we felt would be good to share.

The new control disables output to the PWMs when the system voltage drops below 7V. This is a good feature as it helps keep the control and radio on-line.

However, operationally, this can cause the PWMs to cycle off and on as voltage recovers and then reduces if no change is made by the operator. Depending on the situation - pushing, lifting, etc. - the effect on the robot may be a non-event or may create a response that needs to be managed with software or by operator actions.

The attached paper describes the specific testing we were doing, and the results. It includes 2 charts that show graphically what was occurring.

As teams prepare to use the new control for 2015, we thought this was an interesting and different control response that would be worth sharing.