Hybrid Feedback Path Following for Robotic Walkers via Bang-Bang Control Actions

TL;DR

This paper presents a simple yet effective Bang-Bang control algorithm for guiding a robotic walking assistant along a planned path using minimal hardware, ensuring smooth user convergence and steady progress.

Contribution

The paper introduces a novel Bang-Bang control strategy utilizing only four saturated braking actions for path following in robotic walkers, reducing hardware complexity.

Findings

Effective path convergence demonstrated in simulations

Smooth user guidance achieved with minimal hardware

Robustness of control strategy in various scenarios

Abstract

We show a control algorithm to guide a robotic walking assistant along a planned path. The control strategy exploits the electromechanical brakes mounted on the back wheels of the walker. In order to reduce the hardware requirements we adopt a Bang Bang approach relying of four actions (with saturated value for the braking torques).When the platform is far away from the path, we execute an approach phase in which the walker converges toward the platform with a specified angle. When it comes in proximity of the platform, the control strategy switches to a path tracking mode, which uses the four control actions to converge toward the path with an angle which is a function of the state. This way it is possible to control the vehicle in feedback, secure a gentle convergence of the user to the planned path and her steady progress towards the destination.