Template:UGC-PositionControllerSettings

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PositionController Settings

There are a number of settings that can be adjusted to customize the position controller. You can save these variables into the program so you don't have to re-enter them manually (NOTE: This does not store the settings on the {{{1}}}, it simply saves them inside the control panel program, so you'll have to re-enter them if it's used on another computer).

Kp, Ki, and Kd

You can set the control parameters Kp, Ki, and Kd in order to change the behavior of the control loop. For more information on how each of these three tuning parameters affect the control loop, see “Control Loop Parameters ”.

Velocity and Acceleration

Velocity is how fast the motor will move to the target position, and acceleration controls how quickly the motor will reach its velocity and how quickly it will slow down. These values are measured in position per second and position per second squared, and position by default is measured in encoder pulses.

Rescale Factor

If you want position to be measured in another unit (degrees, for example), you can set the rescale factor. For more information on choosing the correct rescale factor, see “Setting the Rescale Factor”.

Deadband

Sometimes the motor will oscillate back and forth across the target position when holding position. Adding a deadband will widen the target position so the motor will stop when it gets within the target position plus or minus the deadband.

Current Limit

Setting the current limit gives you control over how much power is being supplied to the motor. Generally, we advise that you set the current limit to your motor’s specified coil current.

Fan Mode

This turns the cooling fan on and off. Setting it to auto will result in the fan turning on only when the temperature sensor detects rising board temperatures.

Encoder IO Mode

Changes between different encoder modes based on your encoder’s circuitry. For more information see the Encoder Primer.

Current Regulator Gain

Depending on power supply voltage and motor coil inductance, the current through the motor can change relatively slowly or extremely rapidly. A physically larger DC Motor will typically have a lower inductance, requiring a higher current regulator gain. A higher power supply voltage will result in motor current changing more rapidly, requiring a higher current regulator gain. If the current regulator gain is too small, spikes in current will occur, causing large variations in torque, and possibly damaging the motor controller. If the current regulator gain is too high, the current will jitter, causing the motor to sound 'rough', especially when changing directions.