July 8, 2025

Humanoid Robot Diagnostic Procedures Manual

PHASTLabs Training Materials Safety Protocol – MANDATORY BEFORE ALL PROCEDURES LOCKOUT/TAGOUT (LOTO) Procedure 1. JOINT ACTUATOR DIAGNOSTIC PROCEDURE Symptoms: Diagnostic Steps: Step 1: Visual Inspection Step 2: Mechanical Testing Step…

PHASTLabs Training Materials

Safety Protocol – MANDATORY BEFORE ALL PROCEDURES

LOCKOUT/TAGOUT (LOTO) Procedure

Power Down Sequence
- Initiate software shutdown through control interface
- Wait for all actuators to reach zero position
- Disconnect main power supply
- Lock out power source with padlock and tag
Energy Verification
- Test all actuators for residual motion
- Check capacitor discharge (wait minimum 10 minutes)
- Verify emergency stop systems are engaged
- Confirm all pneumatic/hydraulic systems are depressurized
Personal Safety Equipment
- Safety glasses, non-slip shoes
- ESD wrist strap for electronic components
- Insulated tools for electrical work

1. JOINT ACTUATOR DIAGNOSTIC PROCEDURE

Symptoms:

Irregular movement patterns
Excessive noise during operation
Joint position drift
Reduced torque output
Overheating

Diagnostic Steps:

Step 1: Visual Inspection

Check for: Physical damage, loose connections, fluid leaks
Document: All visible abnormalities with photos
Tools: Flashlight, magnifying glass, camera

Step 2: Mechanical Testing

Manual Range of Motion Test
- With power OFF, manually move joint through full range
- Note any binding, grinding, or irregular resistance
- Compare to manufacturer specifications
Backlash Measurement
- Use dial indicator to measure gear backlash
- Acceptable range: <0.5° for precision joints
- Record readings at multiple positions

Step 3: Electrical Testing

Motor Resistance Test
- Disconnect motor cables
- Measure phase-to-phase resistance with multimeter
- Compare to manufacturer specifications (typically 2-8 ohms)
Encoder Verification
- Check encoder cable continuity
- Verify 5V power supply to encoder
- Test encoder signal integrity with oscilloscope

Step 4: Functional Testing

Position Accuracy Test
- Command joint to specific positions
- Measure actual position with external reference
- Acceptable error: ±0.1° for precision applications
Torque Output Test
- Apply known load to joint
- Measure actual torque vs. commanded torque
- Record temperature rise during test

Common Failures & Solutions:

High resistance readings → Replace motor windings
Encoder signal noise → Check cable shielding, replace encoder
Excessive backlash → Replace gear reduction assembly
Overheating → Check thermal paste, verify cooling system

2. POWER SYSTEM DIAGNOSTIC PROCEDURE

Symptoms:

Unexpected shutdowns
Reduced operating time
Charging issues
Voltage fluctuations
Thermal alerts

Diagnostic Steps:

Step 1: Battery Pack Assessment

Voltage Testing
- Measure total pack voltage (should be within 5% of nominal)
- Check individual cell voltages (variance <0.1V between cells)
- Test under load condition
Capacity Testing
- Perform controlled discharge test
- Measure amp-hours delivered vs. rated capacity
- Document capacity degradation percentage

Step 2: Charging System Verification

Charger Output Test
- Verify charger voltage and current output
- Check for proper charge termination
- Test charge balance circuits
Thermal Management
- Monitor battery temperature during charge/discharge
- Verify cooling fan operation
- Check thermal sensors and cutoff circuits

Step 3: Power Distribution Testing

Voltage Regulation
- Test all voltage rails (12V, 5V, 3.3V systems)
- Check regulation under varying load conditions
- Verify backup power systems
Current Monitoring
- Measure current draw of major subsystems
- Identify any excessive current consumption
- Check for short circuits or ground faults

Critical Thresholds:

Battery voltage drop >20% → Replace battery pack
Cell voltage imbalance >0.2V → Replace faulty cells
Charging current <80% of rated → Service charging system
Operating temperature >60°C → Check thermal management

3. SENSOR SYSTEM DIAGNOSTIC PROCEDURE

Symptoms:

Inconsistent sensor readings
Navigation errors
Object detection failures
Balance instability
Environmental awareness issues

Diagnostic Steps:

Step 1: Vision System Testing

Camera Calibration Check
- Use calibration target with known dimensions
- Verify image distortion correction
- Check focus across full field of view
Image Quality Assessment
- Test in various lighting conditions
- Check for dead pixels or sensor degradation
- Verify color accuracy and white balance

Step 2: Inertial Measurement Unit (IMU) Testing

Static Testing
- Place robot on level surface
- Verify accelerometer reads 1g on vertical axis
- Check gyroscope reads zero when stationary
Dynamic Testing
- Rotate robot through known angles
- Verify gyroscope integration accuracy
- Test response time and noise levels

Step 3: Force/Torque Sensor Testing

Zero Offset Verification
- With no external forces, verify zero reading
- Check for drift over time
- Calibrate if offset exceeds ±2% of full scale
Linearity Testing
- Apply known loads across sensor range
- Verify linear response within ±1% accuracy
- Check for hysteresis effects

Step 4: Environmental Sensor Testing

Temperature Sensors
- Compare readings to reference thermometer
- Test across operating temperature range
- Verify response time to temperature changes
Proximity Sensors
- Test detection range with standard targets
- Verify response to different materials
- Check for electromagnetic interference

Sensor Calibration Procedures:

IMU Calibration: 6-position static calibration
Camera Calibration: Checkerboard pattern method
Force Sensor: Multi-point load calibration
Temperature: Two-point calibration (ice point + boiling point)

4. CONTROL SYSTEM DIAGNOSTIC PROCEDURE

Symptoms:

Erratic movement patterns
Communication timeouts
Software crashes
Servo instability
Real-time performance issues

Diagnostic Steps:

Step 1: Communication Testing

Network Connectivity
- Test ping response times between control modules
- Check for packet loss or latency issues
- Verify bus topology and termination
Protocol Verification
- Monitor bus traffic with protocol analyzer
- Check for communication errors or retries
- Verify message timing and synchronization

Step 2: Control Loop Analysis

PID Parameter Verification
- Review gain settings for each joint
- Test step response characteristics
- Check for oscillation or instability
Real-time Performance
- Monitor control loop timing
- Check for missed deadlines or jitter
- Verify CPU utilization levels

Step 3: Software Diagnostics

Log File Analysis
- Review system logs for error messages
- Check for memory leaks or resource exhaustion
- Identify recurring fault patterns
Performance Monitoring
- Monitor CPU, memory, and disk usage
- Check for thermal throttling
- Verify real-time operating system performance

Performance Benchmarks:

Control loop frequency: 1kHz minimum
Communication latency: <10ms for critical systems
CPU utilization: <70% during normal operation
Memory usage: <80% of available RAM

5. INTEGRATED SYSTEM DIAGNOSTIC PROCEDURE

Symptoms:

Inconsistent overall performance
Intermittent failures
Coordination problems between subsystems
Unexpected behavior patterns

Diagnostic Steps:

Step 1: System Integration Testing

End-to-End Functionality
- Test complete task sequences
- Verify sensor-to-actuator response chains
- Check inter-system communication
Timing Analysis
- Measure response times for complex operations
- Check for race conditions or deadlocks
- Verify synchronization between subsystems

Step 2: Performance Profiling

Resource Utilization
- Monitor system-wide resource usage
- Identify bottlenecks or contention points
- Check for resource leaks or inefficient algorithms
Behavioral Analysis
- Compare actual vs. expected behavior
- Test edge cases and failure scenarios
- Verify graceful degradation capabilities

Step 3: Environmental Testing

Operating Conditions
- Test performance across temperature range
- Verify operation in different environments
- Check electromagnetic compatibility
Stress Testing
- Run extended operation cycles
- Test maximum load conditions
- Verify thermal and mechanical limits

DOCUMENTATION AND REPORTING

Required Documentation:

Test Setup Description
- Equipment used, environmental conditions
- Software versions, configuration settings
- Personnel involved and their qualifications
Measured Results
- All numerical measurements with units
- Pass/fail criteria and actual results
- Any deviations from expected performance
Failure Analysis
- Root cause identification
- Contributing factors
- Recommended corrective actions
Maintenance Recommendations
- Preventive maintenance schedule
- Component replacement intervals
- Monitoring recommendations

Report Format:

Executive Summary: Key findings and recommendations
Detailed Results: Complete test data and analysis
Trending Data: Historical performance comparisons
Action Items: Specific steps for resolution

EMERGENCY PROCEDURES

Immediate Actions for System Failures:

Activate Emergency Stop
Isolate Power Sources
Document Failure Conditions
Notify Supervision
Secure Work Area

Never Attempt to:

Override safety systems
Work on energized equipment
Modify manufacturer programming without authorization
Ignore environmental hazards

This manual serves as a foundation for PHASTLabs training programs. Always refer to manufacturer-specific procedures and local safety regulations.