Related Experiment Video
Updated: Aug 8, 2025
10:02
FIM Imaging and FIMtrack: Two New Tools Allowing High-throughput and Cost Effective Locomotion Analysis
Published on: December 24, 2014
11.8K
Highly-time-resolved FMCW LiDAR with synchronously-nonlinearity-corrected acquisition for dynamic locomotion
Optics Express
|March 2, 2023
Summary
This study introduces a novel Frequency-Modulated Continuous-Wave (FMCW) LiDAR system capable of sub-millisecond acquisition rates for precise robotic motion tracking. The system achieves high-speed, accurate measurements of velocity and acceleration in dynamic legged robots.
Area of Science:
- Robotics
- Sensor Technology
- Optical Engineering
Background:
- Dynamic legged robots require precise, high-time-resolved tracking of motion parameters like position, velocity, and acceleration.
- Frequency-modulated continuous-wave (FMCW) laser ranging offers precise short-distance measurements but faces limitations in acquisition rate and modulation linearity.
- Previous research has not achieved sub-millisecond acquisition rates or wide-bandwidth nonlinearity correction for FMCW LiDAR.
Purpose of the Study:
- To develop and demonstrate a highly time-resolved FMCW LiDAR with synchronous nonlinearity correction.
- To achieve a high acquisition rate for capturing rapid movements in dynamic robots.
- To validate the system's performance in tracking the trajectory of a jumping robot.
Main Methods:
- Implemented synchronous nonlinearity correction for FMCW LiDAR using a symmetrical triangular waveform to synchronize measurement and modulation signals.
- Achieved a 20 kHz acquisition rate by synchronizing laser injection current signals.
- Linearized laser frequency modulation through resampling over 1000 interpolated intervals within 25 µs up-sweeps/down-sweeps, adjusting the measurement signal over 50 µs periods.
Main Results:
- Demonstrated a 20 kHz acquisition rate, matching the laser injection current's repetition frequency for the first time.
- Successfully tracked the foot trajectory of a jumping single-leg robot.
- Measured peak velocities up to 7.15 m/s and accelerations up to 365 m/s² during the jump, with impact accelerations reaching 302 m/s².
Conclusions:
- The developed FMCW LiDAR system provides unprecedented time resolution and accuracy for dynamic robotic motion analysis.
- The system successfully captured extreme motion dynamics, including accelerations exceeding 30 times gravity, in a jumping robot.
- This technology enables new possibilities for high-performance robotic locomotion and dynamic analysis.
