encoder_calc

Encoder Calibration Tools

This project is to calculate wheel encoder intrinsic(wheel radius and track) with gnss and gyro Result shows in the picture.

Installation

1. Install dependecies: sudo apt install libgeographic-dev

Run

1. Build the package: catkin build encoder_calc
2. Run the code rosrun encoder_calc encoder_calc
3. Visualization demo.rviz to visual encoder and gps path(encoder path calculate from default parameters)
4. Run the ROSbag rosbag play ugv_parking00.bag -r 20
5. Call Servicerosservice call /encoder_result/cali_encoder
6. Obtain the calibration result. Example: 0.218323 0.218349 0.783034 -1.0585 -0.274179 -0.845402 (radius_left, radius_right, track, gnss_yaw_2_wheel) in the terminal the visualize the refine encoder path in rviz

Notice

1. use gps cov <0.5 and add gps data per 0.5m for calibration(edit this value in main.h).
2. yaw angle calculate from imu (imu of 3dm is downward, imu_yaw -= w * delta_t, use "+=" for upward imu )
3. set the extrinsic between gps and wheel in "gps2wheel" and edit corresponding gps topic

Results

Contributors

Mr.Xupeng Xie and Mr.Yilong Zhu from the Hong Kong University of Science and Technology