Design and Manufacture of a Magnetorheological Brake System Applicable for Wheelchair Manipulations

Magnetorheological (MR) brake has been employed for a wide range of industrial applications such as automotive vehicles, robots, and haptic devices. In this article, we were mainly concerned with facilitating assistant devices for physically challenged people with the aid of developments in MR brake technology. Therefore, herein, an MR brake was manufactured for wheelchair handling capability. The main objective of this article was to design a low-weight brake that was capable of producing the necessary braking torque for handling or stopping a wheelchair. Numerical simulations based on the finite element method were employed to achieve the proper brake prototype. The main characteristics of the double disk MR brake obtained from numerical results were (i) 3 N.m braking torque when 120-turn coil current was 2 (Ampere. Turn), (ii) 9.5-kg weight, (iii) frustum shape coil design, and (iv) simple design with easy fabrication procedure. Thereafter, this prototype was manufactured, and an appropriate MR fluid was synthesized and utilized in the fabricated brake. The brake operation was examined, and the experimental results were compared with numerical ones. This comparison demonstrated that both results were in very good agreement with each other, which proved the validity of numerical and experimental procedures.