ATRS - A Technology-Based Solution to Automobility for Wheelchair Users

Abstract

In this paper, we present the Automated Transport and Retrieval System (ATRS). ATRS represents an alternative to van conversions for automobile drivers with lower body disabilities. It employs robotics and automation technologies that integrate into a standard mini-van or sport utility vehicle (SUV). At the core of ATRS is a “smart” wheelchair that navigates between the driver’s position and a powered lift at the rear of the vehicle - eliminating the need for an attendant. From an automation perspective, autonomously docking the wheelchair onto the lift platform presented the most significant technical challenge during system development. This was driven by geometry constraints, which limited clearance between the chair wheels and the lift platform rails. To solve this problem, we employed an LMS291 LIDAR in conjunction with an Extended Kalman Filter for reliable and accurate wheelchair localization. Coupled with a hybrid controller design, the system has proven to be exceptionally robust. This was validated through extensive simulation and experimental results, culminating in a three-day demonstration at the 2006 World Congress and Exposition on Disabilities where the system completed over 300 consecutive cycles without a failure.