Designing and tuning a brake assistant for omnidirectional wheels

Abstract

Although the invention of the special wheels that move omnidirectional vehicles dates back to the seventies, advances in mechatronics, and control technology keep them constantly on the drawing table of engineers working with mobile robots. The need for eliminating human error becomes ever so obvious when human operators are managing expensive and/or powerful machinery, as the cost of failure can be very high. Omnidirectional platforms are not immune to human error either, however due to their unique working principle they require customized methods. This article presents a trajectory controller for omnidirectional transport robots that is able to correct their trajectory during braking even when high disturbances are present. A method for tuning the controller to achieve a desired behavior is presented. The results are demonstrated by simulation, in Modelica-Dymola environment.