Design and Dynamic Modelling of Knee Exoskeleton for Disabled People through ADAMS-Simulink Co-simulation

Abstract

This paper is written to outline the progress and findings of an undergraduate research project aimed at the designing and modelling of an exoskeleton design of the knee joint for rehabilitation and gait support. It focuses on the rehabilitation potential of the proposed exoskeleton design on patients with Hemiplegia and Monoplegia conditions with the objective of seeking a feasible, simple means of joint actuation to reduce the complexity of the design. Exoskeleton designs are able to provide rehabilitation and improve the overall quality of life of disabled people globally. However, a common issue found almost everywhere is the costly nature of the exoskeletons that are available in the market now as they are exclusive devices, which makes them inaccessible and impractical to the general public, especially in developing countries. Initially, the paper focuses on the review of relevant literature and previous research and evaluating the designs that have been developed as of now. A thorough analysis of the work done by previous researchers and companies was conducted to gather data on the underlying engineering principles and techniques used for the exoskeleton development as well as any limitations or restrictions to the process. Conceptual designing of the possible solutions was developed using the understanding and knowledge gathered during the literature review. The selection of the best solution was based on the analysis of the pros and cons of all the solutions. The chosen design, utilising a 4-bar mechanism, was then modelled using SolidWorks software to provide a clear visualisation of the system. The kinematic and dynamic analysis of the mechanism was evaluated to analyse the possibility of using the proposed exoskeleton design by replicating the model in ADAMS multibody software. The dynamic analysis was conducted by using the co-simulation platform between ADAMS and Simulink to enable the addition and control of feedback loops within the system. The results of the analysis show that the design can achieve the required motions of the human gait cycle, especially during the swing phase of the gait cycle. The analysis of the actuation torques and reaction forces on the human body showed that an acceptable torque range was possible during the swing phase of the gait cycle.