Design and robust motion control of a planar hybrid manipulator for lower limb rehabilitation tasks

Abstract

Rehabilitation robotics had proved its importance in the medical field, newlinewhich had grown rapidly to deliver high dosage and intense physical training newlinefor patients with a loco-motor disorder caused by stroke. As per the National newlineSample Survey Organization (NSSO) survey of India, 27% of disabilities are newlinedue to loco-motor. This in turn, increases the need for rehabilitation followed newlineby rehabilitation robots. This research proposes a design and robust motion newlinecontrol of the 1P-2PRP hybrid planar manipulator for lower limb newlinerehabilitation treatments. The stationary system was designed for bed ridden newlinepatients where they have slight or no control over their lower limbs to newlineimprove the recovery in the early stages. At present, the commercial systems newlineavailable were having poor dynamic performance and no supportive or newlineorthosis systems. To overcome the above said issues hybrid planar newlinemanipulator was proposed with a robust motion control scheme. newlineThe proposed system was a hybrid planar manipulator with 1P-2PRP newlineconfiguration as an active part of the robotic based rehabilitation system and newlinethe orthosis with 3R configuration as passive orthosis support. The Hybrid newlinemanipulator has fused advantages of both serial and parallel manipulators. newlineThe therapeutic treatment of lower limb movements in the sagittal plane was newlinefacilitated by the active part of the manipulator to induce therapeutic motions newlineon the passive part (orthosis) that supports the patient as a Continuous Passive newlineMotion (CPM) device.The effectiveness and performance of the proposed system along with the robustness of the control system has been demonstrated using a scaled down fabricated real-time prototype. Further the performance and sensitivityof the proposed control has been analyzed for different range of working conditions. The clinically obtained gait data set was provided to the system to perform a passive range of motion control and verified the feasibility of newlineproposed rehabilitation robotic system. In addition, the clinical gait pattern newlinegeneration and tracking task