L1 Operator Curriculum

Five sections covering the foundational knowledge required to safely inspect and maintain BCR-monitored robots.

Section 1: Robot Safety Fundamentals

Safe operation near autonomous and semi-autonomous robots requires a different mental model than conventional industrial machinery. Robots can move unpredictably, restart from software commands without physical operator action, and apply significant forces at unexpected speeds.

LOTO Adapted for Robotic Systems

Lockout/Tagout (LOTO) procedures protect technicians from hazardous energy release during maintenance. Standard electrical LOTO applies fully to robots, but robotic systems add complexity:

• Stored mechanical energy: Springs, gas-charged actuators, and gravity-loaded arm positions retain energy after power cutoff. Always confirm all joints are at rest position or physically supported before working under or near them.
• Battery energy: Robot batteries remain hazardous after power-off. Lithium cells can discharge at high current even without a connected load. Battery isolation requires physical disconnection at the main battery connector, not just software shutdown.
• Software restart risk: Robots connected to a management system can restart remotely. Network isolation (disconnecting the robot from WiFi and Ethernet) must accompany physical LOTO.

Standard LOTO procedure for BCR-monitored robots:

1. Issue software stop via TechMedix dispatch interface.
2. Press hardware E-stop button (red, located on torso or base depending on platform).
3. Disconnect main battery connector.
4. Attach lockout hasp and tag with technician name and date.
5. Verify zero-energy state: attempt to power on (should fail), check all joint positions for stored energy.

Safe Approach Protocols

Humanoid robots (powered): Maintain a 2-meter exclusion zone from any humanoid robot that is powered on and not in a confirmed stopped state. The 2m radius accounts for maximum arm reach plus a 0.5m safety margin. Never stand directly in front of the face or chest camera as this can trigger motion responses.

Drones (armed): Maintain a 10-meter exclusion zone from any drone with motors armed, regardless of whether it is airborne. Propellers can inflict serious injury at any RPM above threshold.

Approaching a stopped robot: Approach from the side or rear where possible. Announce your presence verbally even though robots cannot hear — this is a procedural habit that prevents complacency.

E-Stop Hierarchy

The E-stop system has three layers, with hardwired taking highest priority:

1. Hardwired E-stop (highest priority): Physical red button wired directly to motor power contactor. Cannot be overridden by software. Forces all motors off within 10-50ms depending on platform.
2. Software E-stop: API command or TechMedix interface stop. Takes 100-500ms to execute due to software stack latency. Should not be relied upon for emergency stops.
3. Communication cutoff: Removing network connectivity causes robots to enter safe-stop mode after a configurable timeout (typically 3-10 seconds). Useful for remote situations but unreliable as primary emergency stop.

Situational Awareness

Always know the robot's current state before approaching:

• Check TechMedix alert panel for active faults before entering the work area.
• Note the robot's battery state of charge — low battery (<15%) can trigger unpredictable shutdown sequences.
• Confirm the robot is not in an active job or autonomous task. Check dispatch queue in TechMedix.

Section 2: Basic Mechanical Inspection

A thorough pre-deployment visual inspection catches the majority of preventable field failures. L1 operators perform this inspection before every deployment and after any incident.

Visual Inspection Checklist

Complete the inspection in a defined sequence to avoid skipping items:

Structural integrity:

• Inspect all visible joints for cracks, deformation, or unusual wear marks
• Check housing panels for fractures — especially high-stress areas at joint interfaces
• Verify all fasteners are present and show no signs of backing out (Loctite should be visible at thread exit)
• Inspect cable routing for pinch points, abrasion, or excessive bend radius (minimum 10x cable diameter)

Actuator condition:

• Rotate each accessible joint through a portion of its range while powered off — feel for grinding, catching, or binding
• Check harmonic drive output flanges for grease seepage (slight is normal, heavy seepage = overdue service)
• Listen for any dry or metallic sounds during manual articulation

Sensor integrity:

• Verify all camera lenses are clean and unscratched
• Check LiDAR apertures for contamination or physical damage
• Confirm IMU housings show no impact damage

Wear Indicators and Thresholds

Joint play (backlash):

• Nominal acceptable play on Unitree G1 knee: < 0.5 degrees
• Greater than 2 degrees of play = bearing wear — schedule for L2 inspection before next deployment
• Test by firmly grasping the limb above and below the joint and attempting to rock it perpendicular to the rotation axis

Lubrication status:

• Harmonic drive lubricant: Harmonic Grease SK-2 (specified by Unitree)
• Service interval: 500 hours of operation or 12 months, whichever comes first
• Visual indicator: grease should be visible at seal edges but not extruding heavily; dry or discolored = overdue

Torque verification:

• Critical fasteners should be torque-checked at each 250-hour service
• L1 operators verify fasteners are present and not obviously loose; L2+ technicians perform torque verification with calibrated tools

Section 3: Battery and Power Systems

Lithium-based batteries are the energy source for all current-generation humanoid robots and most drones. Safe handling requires understanding the electrochemistry, failure modes, and operating limits.

Battery Chemistry

LiPo (Lithium Polymer): Used in most drones and some light humanoid platforms. High energy density, fast discharge, but sensitive to puncture, overcharge, and deep discharge. Requires LiPo-rated charging equipment and storage bags.

Li-ion (Lithium-Ion): Cylindrical cells (18650, 21700 format). More robust than LiPo. Used in some humanoid platforms and many industrial applications. Lower risk of thermal runaway than LiPo under abuse conditions.

NMC (Nickel Manganese Cobalt): Most advanced humanoid robot batteries, including Unitree G1. Balances energy density, cycle life, and safety better than older Li-ion chemistries.

State of Health (SoH) Indicators

SoH indicates remaining battery capacity relative to rated new capacity.

• SoH > 80%: Serviceable. Continue normal operation.
• SoH 70-80%: Marginal. Monitor closely. Schedule replacement at next maintenance window.
• SoH < 70%: Replace. Reduced range will affect robot mission completion.

Cell imbalance thresholds:

• Healthy pack: < 20mV imbalance between highest and lowest cell voltage
• Investigate at: > 50mV imbalance (indicates damaged cell or balancing circuit failure)
• Replace at: > 100mV persistent imbalance

Cell Voltage Ranges

Standard NMC cell specifications:

• Nominal voltage: 3.6 - 3.7V per cell
• Maximum charge voltage: 4.2V per cell
• Storage voltage: 3.8V per cell (ideal for long-term storage)
• Minimum discharge cutoff: 3.0V per cell (controller should cut off at 3.2V for safety margin)
• Deep discharge threshold: < 3.0V — cell may be damaged; assess before recharging

Charging Safety

• Never charge damaged, swollen, or excessively hot batteries
• Maintain visual monitoring during initial charge of any battery that has been discharged below 3.0V/cell
• Charge in a designated charging area away from flammable materials
• Set charge rate to 1C maximum for field charging; 0.5C preferred for long-term battery health
• Never leave batteries on charge unattended overnight without automatic cutoff

Section 4: TechMedix Dashboard Basics

TechMedix is the BCR fleet management and dispatch platform. L1 operators must be able to navigate the dashboard, interpret alerts, log findings, and escalate appropriately.

Fleet Health Overview

The main dashboard shows:

• Fleet health score: Aggregate 0-100 score across all monitored robots. Below 70 = investigate. Below 50 = immediate attention required.
• Active robot count: Robots currently online and reporting telemetry.
• Open jobs: Dispatch jobs assigned, en route, or onsite.
• Critical alerts: P1 alerts requiring immediate response.

Alert Severity Levels

TechMedix uses a three-tier alert priority system:

• P1 — Critical: Requires technician response within 2 hours. Examples: motor overtemperature, battery cell imbalance > 100mV, E-stop fault, joint position out of range. P1 alerts page the assigned technician immediately via SMS and email.
• P2 — Warning: Requires attention within 24 hours. Examples: elevated joint temperature (within normal range but trending up), battery SoH 70-80%, firmware version mismatch. P2 alerts appear in the dispatch queue.
• P3 — Informational: Schedule for next maintenance window. Examples: lubrication interval approaching, battery approaching 80% SoH, sensor calibration due.

Logging Requirements

Each L1 site visit requires a TechMedix log entry containing:

• Robot ID and site location
• Arrival and departure timestamp
• Battery SoH readings before and after service (if battery accessed)
• All inspection points completed (check against the platform's inspection template)
• Any anomalies found (describe symptom, not assumed cause at L1)
• Photos: minimum one pre-service and one post-service, plus close-up of any anomalies

Escalation Criteria

Escalate to L2 or above when:

• Any joint play exceeds 2 degrees
• Battery imbalance > 50mV
• Any unusual sounds during powered articulation
• Visual damage to actuator housings, cables, or sensors
• Any fault code not listed in the L1 field reference guide
• P1 alert that cannot be resolved by battery swap or E-stop reset

Section 5: Documentation and Compliance

Accurate field documentation protects technicians, fleet operators, and BCR's liability position. All documentation must be completed before leaving the service site.

Work Order Required Fields

Every TechMedix work order must contain:

• Work order ID (system-generated)
• Technician ID and certification level
• Robot ID and current firmware version
• Service type: inspection / repair / battery service / emergency response
• Arrival timestamp (GPS-verified if possible)
• Parts used: part number, quantity, serial number if applicable
• Findings: objective description of conditions found
• Actions taken: objective description of work performed
• Post-service validation: confirmation the robot passed post-service checks
• Departure timestamp

Photo Naming Convention

Photos uploaded to TechMedix must follow this naming format:

{ROBOT_ID}_{DATE_YYYYMMDD}_{SEQUENCE}_{DESCRIPTION}.jpg

Example: G1-TXA-007_20260402_001_PRE_SERVICE.jpg

Accepted description keywords: PRE_SERVICE, POST_SERVICE, ANOMALY, BATTERY, JOINT, SENSOR, DAMAGE

Incident Reporting

Any incident involving:

• Uncontrolled robot movement during service
• Injury to any person within 10 meters
• Property damage caused by the robot
• Dropped or mishandled battery
• Activation of fire suppression or evacuation

...requires an incident report filed within 4 hours via the TechMedix incident form and a direct call to the BCR operations line. Do not wait until the end of the work day.

Chain of Custody

When removing parts from a robot for transport (dead battery, failed sensor, etc.):

• Tag the part with the robot ID, removal date, and technician ID
• Photograph the part before removal and after installation of replacement
• Log the serial number of both the removed and installed part
• Transport defective parts in appropriate packaging (LiPo bag for batteries, anti-static bag for electronics)
• Return defective parts to the BCR parts depot within 5 business days