Finalize Motor Controller

[justinnuwin]

Drafting PR from MSP430+HerculesFSW motor controller code review with @SchwartzCode.

Terminology

Motor Controller: MSP430
MotorControllerComponent: Hercules FSW

Important Notes

• Hercules handles orientation of motors — Justin
• No method to steer in FSW — Justin
• Should definitely have a way to bypass P-I controller with open-loop control of motors — Jonathan
• Figure out how telemetry is going to be updated in the Motor Controller-MotorControllerComponent state machine — Ground, FSW, Motor Controller
• C&TL MotorControllerComponent Telemetry Units+Type don’t match the commanded — Ground, FSW, Motor Controller
• C&TL MotorControllerComponent Telemetry Speed doesn’t include angular movement — Ground, FSW, Motor Controller

Questions

• Are all motors always going to be driven abs value of expected # tick? (i.e. support differential steering) — Connor/Jonathan
• What is the CURRENT_POSITION and CURRENT_SPEED RO registers used for (Motor Controller executes immediately so there is no time to read these registers)? — Justin/Jonathan
• Goes back to what we want the telemetry to represent: snapshot in time, or state of Motor Controller over time? — Connor/Justin/Jonathan
• Do we want additional telemetry for internal state of PI controller (potentially over time)? — Connor/Jonathan
• Do we need a flag for convergence (to let operator know when movement is complete/are we going to poll CURRENT_SPEED and CURRENT_POSITION? — Jonathan/Justin
• Can the Motor Controller detect that its latched in a continuous driving when we don’t want to (due to SEU or sensor failure)? No, but it will be soon. — Jonathan

@SchwartzCode to PR motor control branches into this branch for staging & testing to merge with fprime-fsw/staging.

[justinnuwin]

Meeting Updates

@justinnuwin @SchwartzCode @zCoCo

• It could be helpful to be able to downlink I-error to detect integral wind-up (or Jonathan could implement automatic mitigations for this).
• Drifting on the moon: very unlikely (not flight critical), but @zCoCo could give us a function for radius and arc-length to easily implement differential steering.
• Acceleration and Deceleration registers may be unused for flight

C&TL Motor Controller Telemetry Units

Speeds: Deprecate because these readings are totally useless since we are downlinking the raw encoder readings already (can likely stream encoder values @ >100Hz with current bandwidth) -> Will perform this calculation on ground
Encoder Displacements: encoder ticks

@SchwartzCode 's Motor Control Updates

Flag For Convergence: Use status register -> Telemetry
Fault registers & Control Registers formalized
Output correct (and more simple units) for telemetry

Plans for Motor Receipt

• No frying SBCs
• Individual Motor Tests
• Command all 4 motors simultaneously (forward & turning)
• Telemetry from all 4 motors simultaneously
• Navigation command WITH CAMERAS

[justinnuwin]

Pre-Code Review Motor Control Test

Motor Control Code 503c121

Updates that have been tested

• Continuous drive test successful with 4 motors & test pattern going forward, backward, turning left, and turning right at different speeds (SBC H#1)
• Motors seemed to be moving in the correct direction (forward has 2 motors spinning opposite the other 2, turning has them all spinning the same way)
• Open Loop Fully Integrated (Hercules can set this with common flag for all motors)
• Execute Command register implemented - bit needs to be set to start the movement
• Position converged flag implemented (Hercules will not send another move command until current position converged)
• Added timeout for position converged (on MSP430): after 2 min the position converged flag will be set in addition to the timeout flag in the fault register (tested with a move command speed 10, 3 EM1 motors & 1 EM4 motor where the EM4 motor stalled and after 2 min the position converged flag was set -> did not check fault)

Outstanding TODOs

• Hercules should also have a timeout for position converged (slightly longer than MSP430 2min)
• Resetting MotorControllers via Watchdog
• General Motor Controller code (MSP430) code cleanup
• Hercules checking fault registers and resolution
• Measure the 2min MSP430 timeout for position converged (test distance 100cm in open loop (slow) mode -> time out after 2min 12s)
• Test setting PID gains
• Verify angular movement conversion (angular -> linear movement conversion)
• What to do with Hercules stop command (send immediately or wait for convergence)?
• Hercules should implement critical section when setting execute command
• Finalize the remaining Hercules TODOs

[SchwartzCode]

Looks good so far, going to sift through code and populate code review google sheets