Max Speed Problem on MCP236

Questions about using encoders with the Roboclaw product line
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Basicmicro Support
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Re: Max Speed Problem on MCP236

Post by Basicmicro Support »

1. Run the motors using the PWM settings screen and graph the results. This is duty controlled so PID settings will have no effect. Maximum speed shown at maximum duty is the actual maximum speed of hte motor(s) under the tested load. Note this speed is also the QPPS of the motor.

2. When using speed control you can NOT reach the same maximum speed as that shown when just running open loop. Not and still have accurate speeds. Assume a maximum of 80% of the open loop maximum speed

3. After setting up the PID run the same test using the Velocity Settings screen. Test up to about 80% of QPPS. If you cant get to 80% QPPS under velocity control then your tuned PI values need some adjustment. This is assuming the same load you tested under 1.

4. The voltage output of a motor driver will never reach the voltage imput. There are losses in a lot of places and the is a minimum off time required for boost circuits to drive the high side mosfets. In general you can reach around 95% the input voltage, under no load, on the output.

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