2 Commits

Author SHA1 Message Date
d8b25bad77 feat: VESC CAN odometry for nav2 (Issue #646)
Replace single-motor vesc_odometry_bridge with dual-CAN differential
drive odometry for left (CAN 61) and right (CAN 79) VESC motors.

New files:
- diff_drive_odom.py: pure-Python kinematics (eRPM→wheel vel, exact arc
  integration, heading wrap), no ROS deps, fully unit-tested
- test/test_vesc_odometry.py: 20 unit tests (straight, arc, spin,
  invert_right, guard conditions) — all pass
- config/vesc_odometry_params.yaml: configurable wheel_radius,
  wheel_separation, motor_poles, invert_right, covariance tuning

Updated:
- vesc_odometry_bridge.py: rewritten as VESCCANOdometryNode; subscribes
  to /vesc/can_61/state and /vesc/can_79/state (std_msgs/String JSON);
  publishes /odom and /saltybot/wheel_odom (nav_msgs/Odometry) + TF
  odom→base_link with proper 6×6 covariance matrices
- odometry_bridge.launch.py: updated to launch vesc_can_odometry with
  vesc_odometry_params.yaml
- setup.py: added vesc_can_odometry entry point + config install
- pose_fusion_node.py: added optional wheel_odom_topic subscriber that
  feeds DiffDriveOdometry velocities into EKF via update_vo_velocity
- pose_fusion_params.yaml: added use_wheel_odom, wheel_odom_topic,
  sigma_wheel_vel_m_s, sigma_wheel_omega_r_s parameters

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-17 09:54:19 -04:00
c76d5b0dd7 feat: Multi-sensor pose fusion node (Issue #595)
New package saltybot_pose_fusion — EKF fusing UWB+IMU absolute pose,
visual odometry velocity, and raw IMU into a single authoritative pose.

pose_fusion_ekf.py (pure Python, no ROS2 deps):
  PoseFusionEKF — state [x, y, θ, vx, vy, ω], 6-state EKF.
  - predict_imu(ax_body, ay_body, omega, dt): body-frame IMU predict step
    with Jacobian F, bias-compensated accel, process noise Q.
  - update_uwb_position(x, y, sigma_m): absolute position measurement
    (H=[1,0,0,0,0,0; 0,1,0,0,0,0]) from UWB+IMU fused stream.
  - update_uwb_heading(heading_rad, sigma_rad): heading measurement.
  - update_vo_velocity(vx_body, omega, ...): VO velocity measurement —
    body-frame vx rotated to world via cos/sin(θ), updates [vx,vy,ω] state.
  - Joseph-form covariance update for numerical stability.
  - Dual dropout clocks: uwb_dropout_s, vo_dropout_s (reset on each update).
  - Velocity damping when uwb_dropout_s > 2s.
  - Sensor weight parameters: sigma_uwb_pos_m, sigma_uwb_head_rad,
    sigma_vo_vel_m_s, sigma_vo_omega_r_s, sigma_imu_accel/gyro,
    sigma_vel_drift, dropout_vel_damp.

pose_fusion_node.py (ROS2 node 'pose_fusion'):
  - Subscribes: /imu/data (Imu, 200Hz → predict), /saltybot/pose/fused_cov
    (PoseWithCovarianceStamped, 10Hz → position+heading update, σ extracted
    from message covariance when use_uwb_covariance=true), /saltybot/visual_odom
    (Odometry, 30Hz → velocity update, σ from twist covariance).
  - Publishes: /saltybot/pose/authoritative (PoseWithCovarianceStamped),
    /saltybot/pose/status (String JSON, 10Hz).
  - TF2: map→base_link broadcast at IMU rate.
  - Suppresses output when uwb_dropout_s > uwb_dropout_max_s (10s).
  - Warns (throttled) on UWB/VO dropout.

config/pose_fusion_params.yaml: sensor weights + dropout thresholds.
launch/pose_fusion.launch.py: single node launch with params_file arg.
test/test_pose_fusion_ekf.py: 13 unit tests — init, predict, UWB/VO
  updates, dropout reset, covariance shape/convergence, sigma override.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-14 15:00:54 -04:00