Extrinsic calibration of sensors mounted on a vehicle

A vehicle comprising:

• an inertial measurement unit (IMU);
• a light detection and ranging device (LIDAR), wherein the LIDAR is configured to scan an environment of the vehicle;
• one or more processors;
• and
• data storage storing instructions that, when executed by the one or more processors, cause the vehicle to perform operations comprising:
• obtaining first sensor data collected, by the IMU and the LIDAR, while the vehicle is aligned in a first yaw direction, wherein the first sensor data comprises a first scan of the environment performed by the LIDAR;
• obtaining second sensor data collected, by the IMU and the LIDAR, while the vehicle is aligned in a second yaw direction, wherein the second sensor data comprises a second scan of the environment performed by the LIDAR;
• determining first pitch and roll misalignments of the IMU relative to the vehicle based on the first sensor data and the second sensor data,
• determining second pitch and roll misalignments of the LIDAR relative to the IMU based on the first sensor data and the second sensor data, wherein determining the second pitch and roll misalignments of the LIDAR relative to the IMU comprises determining a matrix that represents rotational offsets between the first scan of the environment performed by the LIDAR and the second scan of the environment performed by the LIDAR;
• and
• determining third pitch and roll misalignments of the LIDAR relative to the vehicle based on (i) the first pitch and roll misalignments and (ii) the second pitch and roll misalignments.

A method comprising:

• obtaining, from an inertial measurement unit (IMU) mounted on a vehicle and a light detection and ranging device (LIDAR) mounted on the vehicle and configured to scan an environment of the vehicle, first sensor data collected while the vehicle is aligned in a first yaw direction, wherein the first sensor data comprises a first scan of the environment performed by the LIDAR;
• obtaining, from the IMU and the LIDAR, second sensor data collected while the vehicle is aligned in a second yaw direction, wherein the second sensor data comprises a second scan of the environment performed by the LIDAR;
• determining first pitch and roll misalignments of the IMU relative to the vehicle based on the first sensor data and the second sensor data;
• determining second pitch and roll misalignments of the LIDAR relative to the IMU based on the first sensor data and the second sensor data, wherein determining the second pitch and roll misalignments of the LIDAR relative to the IMU comprises determining a matrix that represents rotational offsets between the first scan of the environment performed by the LIDAR and the second scan of the environment performed by the LIDAR;
• and
• determining third pitch and roll misalignments of the LIDAR relative to the vehicle based on (i) the first pitch and roll misalignments and (ii) the second pitch and roll misalignments.