ControlsIntermediate
Velocity PID for Intake and Shooter Wheels
Velocity control is about holding speed under load, not merely sending a motor percentage.
Site connection
The 2024 robot used velocity PID loops for intake and shooter mechanisms.
Visual model
Speed response to a setpoint
Change gain and damping to see why a wheel can overshoot, undershoot, or settle.
Interactive
PID tuning changes speed, overshoot, and settling
Why Percent Output Is Not Enough
A shooter wheel slows when it contacts a game piece. A fixed motor percentage cannot know that happened.
Velocity feedback measures actual wheel speed and pushes the motor harder when the measured speed falls below target.
Feedforward plus Feedback
Many mechanisms use feedforward for the expected voltage and PID feedback for correction. The feedforward gets close; the feedback cleans up error.
Common Pitfalls
- Tuning shooter speed with no game piece interaction.
- Ignoring sensor units and loop period.
- Using position PID constants for velocity control.
Quick check
Quiz
What is the measured variable in velocity PID?
- Wheel speed
- Robot color
- Field pose only
- Match time
Velocity PID compares target speed with measured speed.