**3.1 Perception system**

In this study, we have three main perception sensors: one RGB-Depth camera (Intel Real Sense—D435i) that provides point cloud data with 87° × 58° × 95° field of view and 10 m range; one industrial relatively expensive 2D Lidar (SICK LMS151) that has 270° field of view, maximum 50 m range, and 50 Hz scan rate; and one low-cost Lidar (RPLIDAR-A2M6) that has 360° field of view, maximum 18 m range, and 15 Hz scan rate.

The aim is to analyze the performance of these different characteristic sensors on global mapping, local mapping, tracking, and localization. Some of these sensors can be removed from the system or can be used together depending on their perception performance. The angle of RGB-D camera can be adjusted manually. **Figure 3** shows these sensors that are mounted on the chair, using appropriate mechanical parts which are designed for the chair specifically.
