Detection of stair dimensions for the path planning of a bipedal robot

This paper deals with the detection of the characteristics of stairs, i.e. the number of steps, the step height and the step width for online path planning of a bipedal robot. For the construction of a multi-purpose, mobile platform for service robot applications with special respect to the human environment, a biped is more advantageous than a wheel based robot. In the framework of our studies, the bipedal robot BARt-UH has been built and walking as well as the climbing of stairs have been realized. The environment of the robot is assumed to be structured, consisting of flat surfaces and stairs, but not known in advance. Therefore, a state transition algorithm for intelligent path planning of the robot is suggested. Further, a stereo vision module with a line laser is considered, in order to detect the stair dimensions. The necessary information is extracted from the projection of the line laser onto the stairs. To achieve this, three algorithms were implemented and a comparative study was carried out.