**3. Mapping**

*3.1. Sensors*

The ATENA vehicle is equipped with a set of sensors located on the roof of the off-road car. The sensor set consists of three LiDAR sensors—Velodyne VLP-16 (sixteen layers, 100 m range), five Basler acA1920-48gc (50 fps at 2.3 MP resolution) cameras, and the Xsens MTi-G-710 IMU sensor.

LiDAR sensors are located on the roof of the vehicle in such a way as to create a synergy effect using all three sensors (Figure 6). The main central sensor is tilted by a dozen or so percent so that the cloud of points covers the shape of the road just in front of the ATENA vehicle. Two additional LiDAR sensors are placed on the roof divergently on the sides to form vertical lines of points, which enables better detection of horizontal objects such as barriers, fences, etc. The IMU sensor is placed in the geometric center of the vehicle.

**Figure 6.** Sensors on the roof of the vehicle with the ATENA system.

The present research data were collected using the ATENA core operating with the ROS package. One of the core functionalities of the ATENA program is the fusion of data from Velodyne LiDARs, information from the Xsens MTi-G-710 IMU sensor, and the odometry data from the CAN network of the vehicle. The system builds a 3D world model around the vehicle and creates a map as it moves. For the ATENA system, the model is built in a closed area limited to a square of 50 m × 50 m. To prepare a map of the surroundings, this limitation was turned off, which allowed building a full map of the surroundings around the building.

This work used the resulting point cloud (Figure 7). The point cloud was created by fusing data from the three LiDAR sensors and data from odometry (measurement on the wheels by the onboard system of a vehicle and information from the IMU sensor).

**Figure 7.** Point cloud built by the Łukasiewicz—PIAP ATENA demonstrator.
