Purpose

Design a function that optimizes 0–60 mph acceleration by adjusting torque output based on slip ratio.

• Optimal slip ratio ≈ 7% (commonly 5–10% depending on car).
• If slip ratio exceeds optimal → decrease torque
• If slip ratio falls below optimal → increase torque

Algorithm Overview

Initial Function

• Validate and reset PID gains and internal PID state.
• Obtain constants (max torque, optimal slip target).
• Initialize launch control button to false (inactive until pressed).

Pre-Launch Phase

• Open loop torque ramp over 500ms, capped at 60% of CAPPED_MOTOR_TORQUE
• Transitions to Post-Launch when freeSpeed > 0.1 mph, resets PID on transition
• If Pre-Launch exceeds 2 seconds → exit to OPEN_LOOP

Post-Launch Phase

1. Check button state
   • If not pressed → output driver torque normally.
2. Wheel speeds
   • Controlled speed: rear wheel with higher speed.
   • Free rolling speed: front wheel with lower speed.
3. Slip Ratio
   • slip = (controlledSpeed - freeRollingSpeed) / freeRollingSpeed
4. Torque Logic

• If slip < 0.07 → increase torque.
• If slip > 0.07 → decrease torque.

5. PID Correction

• Use PID::computePID() for correction.
• Add correction to driver torque.

6. Clamp Torque

• If corrected torque > max → clamp to maxTorque.
• If < 0 → clamp to 0 Nm.

Implementation Details

LAUNCH_STATE_ON PRE_LAUNCH (0 → 0.1 mph)

1. Get front wheel speeds (MPH), take slower as freeSpeed
2. Check if elapsed time > 2s → exit to OPEN_LOOP
3. If freeSpeed > 0.1 mph → transition to POST_LAUNCH, reset PID
4. Ramp torque linearly over 500ms, capped at 60% of CAPPED_MOTOR_TORQUE

POST_LAUNCH (0.1 mph → launchTargetSpeed)

1. Compute controlledSpeed from motor eRPM × rpmConversion × wheelRadius
2. Compute slip ratio = (controlledSpeed - freeSpeed) / freeSpeed
3. PID outputs correction, add to normalized realTorque
4. Multiply by CAPPED_MOTOR_TORQUE
5. Clamp target between minTorque and CAPPED_MOTOR_TORQUE
6. If freeSpeed > launchTargetSpeed → exit to OPEN_LOOP, reset PID.

LAUNCH_STATE_OFF

• Wait for:
• Motor speed = 0
• Launch button activated
• Then activate launch control (FSAE requires button activation — must update logic).

FAULT State

• Triggered by irregular wheel speeds or invalid conditions.

TESTING PLAN

Constants:

slipTarget = 0.7f

minTorque = 0.0f

maxTorque = 260.0f

wheelRadius = 0.35f

rpmConversion = 0.3f

INTEGRAL_MAX = 20.0f

INTEGRAL_MIN = -20.0f

launchTargetSpeed = 10.0f