Chassis & Safety
Low-level drive and safety telemetry: wheels, odometry, IMU, bumper, and push handle.
Wheel State
{
"topic": "/wheel_state",
"control_mode": "auto", // auto/remote/manual
"emergency_stop_pressed": true, // Whether in emergency stop mode.
// Optional. Only supported by specific robot models.
// Some wheels have a release-wheels wire.
// This flag reflects whether the wire is active.
"wheels_released": true
}
Odom State
A debug topic, to visualize covariance of lidar odom。
{
"topic": "/odom_state",
"lidar_odom_reliable": true,
"lidar_odom_cov": [
0.000023889469957794063, -0.00002311983917024918, -0.00002311983917024918,
0.00005866867650183849
]
}
Fused Sensor State
{
"topic": "/fused_sensor_state",
"slipping": false,
"major_slipping": false,
"pushed": false,
"accelerability": 1,
"suggested_speed": 0.5,
"is_still": true, // Both odom_still and imu_still.
"odom_still": true, // Wheel encoder readings are zero or near-zero.
"imu_still": true // The integral of gyro readings over the last N seconds is below a threshold on all axes.
}
IMU State
Raw inertial data from the IMU sensor.
{
"topic": "/imu_state",
"calibrate_state": 0,
"calibrate_fail_reason": 0,
"temperature": 62.4,
"angular_velocity_standard_deviation_10s": [0.02175, 0.02393, 0.02442],
"angular_velocity_avg_10s": [0.00021, 0.00191, -0.00253],
"linear_acc_standard_deviation_10s": [0.00517, 0.00535, 0.00575],
"gyro_calibrating": true,
"gyro_bias": [0.00123, 0.00235, 0.00346], // current bias
// when gyro_calibrating is true,
// gyro_bias will move slowly towards it
"gyro_bias_target": [0.00457, 0.00568, 0.00679]
}
Bumper State
Since 2.9.0
The state of the bumper sensors around the robot.
{
"topic": "/bumper_state",
"front_bumper_pressed": false,
"rear_bumper_pressed": false
}
Push Handle State
{
"topic": "/push_handle_state",
"mode": "idle", // idle, push, drive
"left_activated": false,
"right_activated": false,
"calibrating": true // Optional. Only present when true
}