walker_control/plans/remove-stall-detection-branch.md

Branch: feature/remove-stall-detection

Summary

Removed all stall detection logic to collect clean current data with new beefy PSU before reimplmenting simpler stall detection.

Problem

The original stall detection was overly complex with:

• Delta-based spike detection with EMA averaging
• Under-current detection
• Repeated spike detection for oscillating patterns
• Multiple timing thresholds and stabilization periods
• 16 configuration parameters

This complexity was trying to compensate for a weak PSU that couldn't provide enough current, causing unreliable stall detection.

What Was Removed

config.h

• STALL_DELTA_THRESHOLD
• STALL_EMA_ALPHA
• STALL_EMA_BASELINE
• STALL_STABILIZE_MS
• STALL_CONFIRM_MS
• DISABLE_STALL_DETECT
• STALL_UNDERCURRENT_THRESHOLD
• STALL_UNDERCURRENT_MS
• STALL_CANDIDATE_COUNT
• STALL_CANDIDATE_WINDOW_MS

motor.h / motor.cpp

• checkStall() function (~115 lines)
• resetStallDetection() function
• isStalled() method
• setStallCallback() method
• getPingpongStallReturn() method
• All stall-related member variables

webserver.cpp

• Stall warning UI banner
• "Return on stall only" checkbox
• stalled and ppStallReturn from status JSON

main.cpp

• onMotorStall() callback function

What Was Added

• CURRENT_LOG_INTERVAL_MS config (100ms)
• Frequent current logging: CURRENT: R=%.2fA L=%.2fA dir=%d spd=%d
• "Motor: STOPPED (manual)" message

Current Data Analysis

See src/current_loggin.log for sample data.

Running Current (motor moving freely)

• Range: 0.67A - 2.64A
• Average: ~1.5-2.0A

Stall Current (motor blocked at end stop)

• Range: 16.8A - 21.0A
• Average: ~17-18A

Key Observations

1. Clear separation: Running ~2A vs Stall ~17A = 8.5x difference
2. Fast transition: Stall spike happens within 1-2 samples (100-200ms)
3. Initial spike: Can see 3.77A or 5.35A briefly before full stall current
4. Gradual decay: Stall current trends down slightly over time (~21A → ~17A)

Next Step: Simple Stall Detection

Based on the clean data, implement a simple threshold-based stall detection:

Proposed Algorithm

IF motor is running (dir != 0 AND speed > 0):
    IF active_current > STALL_THRESHOLD for STALL_CONFIRM_SAMPLES:
        STALL DETECTED

Proposed Config (much simpler)

#define STALL_THRESHOLD 8.0f      // Amps - midpoint between 2A run and 17A stall
#define STALL_CONFIRM_SAMPLES 3   // Debounce: 3 samples = 300ms at 100ms interval

Why This Should Work

• With beefy PSU, running current is stable ~2A
• Stall current is clearly ~17A+
• No need for EMA averaging or complex spike detection
• Simple threshold + debounce is enough

Files Changed

File	Lines Removed	Lines Added
config.h	16	2
motor.h	26	0
motor.cpp	180	1
webserver.cpp	50	5
main.cpp	12	1
Total	284	9