Digital Resistance-Map Generation for a Magnetorheological Damper Based Platform for Rehabilitation Applications

This paper introduces a methodology for generating digital resistance-map that can be utilized in an MR-Damper based robotic rehabilitation. Typically, in rehabilitation procedures, patients are getting involved in the recovery process of gradually training weak and damaged muscles by constraining motion in repetitive exercises. The whole purpose of robotic rehabilitation is to restrict body organ motion to the one prescribed by the therapist at the initial steps of treatment to avoid further damages to other weak muscles while focusing on recovering a particular muscle. MR-Dampers are semi-active actuators that can potentially be employed for this application. These dampers can be activated to produce high resistance to motion, and a platform that contains sufficient number of them can be manipulated to create regions of different resistance against motion. To apply this to the robotic rehabilitation, the motion recommended by the therapist should be converted to the resistance-maps that can be used by MR-Damper for implementation. To accomplish that, procedure of generating the digital resistance map is introduced and several digital resistance-maps are created. An MR-damper control methodology is also developed to activate the dampers. This controller relies on the accurate modeling of the MR-Damper. Bouc-Wen model is used for MR-Damper modeling. A 3-D platform containing three linear MR-Dampers is modeled using SimMechanics. 1-D and 2-D models are used to develop the idea and build up 3-D model. Several simulations are carried out to investigate the performance of the systems in generating the prescribed digital resistance-maps. The promising results of the simulations indicate that the method can be adopted for robotic rehabilitation purposes.