A novel ankle rehabilitation device based on a reconfigurable 3-RPS parallel manipulator

Abstract

This paper deals with the constraint-based design, optimum design and reconfiguration strategy of a 3-RPS parallel manipulator. Some design conditions related to the base and moving-platform design parameters and the three degree of-freedom operation modes are derived. A 3-RPS parallel manipulator with two types of operation modes is generated by following those conditions. Due to its potential advantages, this manipulator is used as an ankle rehabilitation device which can cover the ankle joint motion. To derive the optimum parameters, kinematic optimization is conducted by initially parametrizing the orientation workspace and it turns out that its orientation workspace is not symmetrical. The singularity loci are traced in its orientation workspace. A performance index, named Maximum Inscribed Circle Diameter (MICD) is presented to assess the maximum tilt of the moving-platform for any azimuth angle. The distributions of MICD are plotted in the design space for different moving-platform heights. The optimum region with regard to MICD is obtained. It is noteworthy that the evolution of MICD as a function of movingplatform height in both operation modes is the opposite. Therefore, a reconfiguration strategy is proposed to ensure the moving-platform working above the minimum required orientation for any moving-platform height.

Design and Experimental Research of 3-RRS Parallel Ankle Rehabilitation Robot

“…MICD (maximum internal connecting circle radius) performance metrics were analyzed for different motion states. Structural optimization was performed to ensure the output [22]. Florida International University has designed an ankle rehabilitation device based on pneumatic artificial muscle actuation.…”

Control Design for CABLEankle, a Cable Driven Manipulator for Ankle Motion Assistance

“…Hence, in this regard, robotics has been involved in rehabilitation therapy to constantly monitor the patient and help in movement execution [9][10][11]. Most of the past robotic designs are based on a static platform design, where a non-portable device requires the patient to keep his foot on a grounded platform (usually while sitting down) to perform rehabilitation [12][13][14][15][16][17][18][19][20][21]. A similar design involves a mechanism driven by pneumatic muscles to help exercise a single leg [22,23].…”

Geometric Constraint-Based Reconfiguration and Self-Motions of a Four-CRU Parallel Mechanism

“…Later, the translational parts of the Study's kinematic mapping were modified to identify the workspace transition of the 3-(rR)PS metamorphic parallel mechanism [16,17]. The same method was employed in [18] to synthesize the design parameters for medical purposes [19,20,21]. The Cayley parametrization was implemented in [22] to determine several extra modes of the 4-UPU parallel mechanism.…”