Section: New Results

Step detection for Personal Mobility Vehicles

Participants : Evangeline Pollard, Joshué Pérez Rastelli, Fawzi Nashashibi.

Personal Mobility Vehicles (PMV) is an important part of the Intelligent Transportation System (ITS) domain. These new transport systems have been designed for urban traffic areas, pedestrian streets, green zones and private parks. In these areas, steps and curbs make the movement of disable or mobility reduced people with PMV, and with standard chair wheels difficult. In this work, a step and curb detection system based on laser sensors has been developed. This system is dedicated to vehicles able to cross over steps, for transportation systems, as well as for mobile robots. The system is composed of three laser range finders. Hokuyo UTM 30 LX devices were chosen for their large detection angle (${270}^{\circ }$) and their high angular resolution ($0.{25}^{\circ }$) and range (30m).

Two laser sensors dedicated to the step detection have a vertical orientation in order to scan the altitude profile of the environment over two lines of sight and the third one, with a vertical orientation is dedicated to obstacle detection.

The step detection process is thus based on the study of the first derivative of the altitude and highlights the use of a new algebraic derivative method (Alien) adapted to laser sensor data. The system has been tested on several real scenarios. It provides the distance, altitude and orientation of the steps in front of the vehicle and offers a high level of precision, even with small steps.