Different approaches for sensor calibration for autonomous vehicles
For the development of semi-automated or automated trucks, the calibration of the "eyes" of a vehicle is an important success factor. High accuracy of the various sensors and systems used as "vehicle eyes" is important and necessary, since even the smallest errors and deviations can have a major impact with increasing distance. In current projects the team of ServiceXpert Gesellschaft für Service-Informationssysteme is working on the setup and commissioning of a calibration area for trucks with lidar and camera calibration.
The calibration is performed for cameras and lidar systems. The lidar systems capture the geometry of the calibration area in form of a point cloud. The cameras pick up mounted markers in the calibration area. The calibration data of both systems are recorded during the slow forward and backward movement of the test carrier through the calibration area. The recorded sensor data are processed by a MATLAB software in a downstream process. Individual frames of the measurement data are evaluated and, using an Iterative Closest Point (ICP) algorithm, the rotations and translations of the individual sensors with respect to the vehicle coordinate system are calculated. The results are correction or adaption values for each individual sensor, which are stored in the vehicle configuration file. With these adapted values the vehicle can be positioned exactly.
The project includes the planning, setup and commissioning of the calibration area for different test vehicle types. The setup consists of mechanical work and of the virtual design of the calibration range, which is tested on the basis of test vehicle models (incl. sensor technology). This procedure ensures that the calibration area meets all requirements of the sensors regarding field of view and detection of the room geometry.
The engineers of ServiceXpert always work in projects with the current state of the art and continuously expand their know-how, e.g. through internal R&D projects. With this method, the team has already been able to successfully and profitably support numerous customers in the development of individual solutions and complete systems.
ServiceXpert, an ESG-Group company, employs over 85 staff in Hamburg and Munich. ServiceXpert is a Europe-wide operating system and software house with a focused service portfolio for Lifecycle management of EE information for leading manufacturers of commercial vehicle and their supplier industry.