Single Laser Bidirectional Sensing for Robotic Wheelchair Step Detection and Measurement

Abstract

Research interest in robotic wheelchairs is driven in part by their potential for improving the independence and quality-of-life of persons with disabilities and the elderly. Moreover, smart wheelchair systems aim to reduce the workload of the caregiver. In this paper, we propose a novel technique for 3D sensing of the terrain using a conventional Laser Range Finder (LRF). We mounted this sensing system onto our new six-wheeled robotic step-climbing wheelchair and propose a new step measurement technique using the histogram distribution of the laser data. We successfully measure the height of stair steps in a railway station. Our step measurement technique for the wheelchair also enables the wheelchair to autonomously board a bus. Our experiments show the effectiveness and its applicability to real world robotic wheelchair navigation.