Digital Twin Guide
Knowledge Guides /How do you calibrate a robot digital twin, and why does its motion fail to match?
Last updated: · New Horizon Digital Outsourcing Team
Check coordinates, geometry, joint definitions, and time synchronization layer by layer before addressing dynamics parameters. Identical appearances can conceal different base orientations, zero positions, or joint signs and cause substantial motion errors. Manually dragging models into visual alignment does not replace an auditable calibration process.
Check coordinate and joint conventions first
- Record world, base, joint, and sensor coordinate frames and units. Check each joint's positive direction, zero position, and limits under low-risk conditions, including possible confusion between degrees and radians. For mobile robots, also distinguish odometry and map references; two localization sources must not simultaneously overwrite the same state.
Time is also part of calibration
- Position data needs acquisition timestamps, not just reception timestamps. Record transmission delay, processing time, and rendering time separately to avoid mistaking latency for geometric error. During disconnection, explicitly show that the state is stale instead of presenting the last frame as live data.
Increase model fidelity progressively
- Align static poses and kinematic trajectories first, then identify dynamics parameters such as mass, friction, and actuator response. Choose complexity according to the application. A monitoring twin may not need contact-force prediction, whereas control verification requires corresponding evidence.
How should acceptance records be created?
- Select multiple poses, speeds, and task segments, and report error distributions, synchronization losses, and recovery from anomalies. Retain calibration configurations, measurement bases, and replayable logs. Comparisons cover only measured conditions; one aligned trajectory cannot establish accuracy across all operating conditions.