Robust Iterative Feedback Tuning Control of a Compliant Rehabilitation Robot for Repetitive Ankle Training

Abstract

Abstract-Robot-assisted rehabilitation offers benefits such as repetitive, intensive and task specific training as compared to traditional manual manipulation performed by physiotherapists. In this paper, a robust iterative feedback tuning (IFT) technique for repetitive training control of a compliant parallel ankle rehabilitation robot is presented. The robot employs four parallel intrinsically compliant pneumatic muscle actuators that mimic skeletal muscles for ankle's motion training. A multiple degreesof-freedom normalised IFT technique is proposed to increase the controller robustness by obtaining an optimal value for the weighting factor and offering a method with learning capacity to achieve an optimum of the controller parameters. Experiments with human participants were conducted to investigate the robustness as well as to validate the performance of the proposed IFT technique. Results show that the normalised IFT scheme will achieve a better and better tracking performance during the robot repetitive control and provides more robustness to the system by adapting to various situations in robotic rehabilitation.

Iterative Feedback Tuning-based Model-Free Adaptive Iterative Learning Control of Pneumatic Artificial Muscle

“…Weifeng Wu, Da Li, Wei Meng, Member, IEEE, Jie Zuo, Quan Liu, Qingsong Ai ankle rehabilitation robots [15]. In 2016, Marcel develop an IFT approach with robustness constraints [16].…”

Compliance adaptation of an intrinsically soft ankle rehabilitation robot driven by pneumatic muscles

“…1 [19,20]. This robot is actuated by four active PM links in parallel to realize the three rotational DoFs of the ankle joint, including dorsiflexion/plantarflexion, inversion/ eversion, and adduction/abduction, respectively.…”

Development of a New Robotic Ankle Rehabilitation Platform for Hemiplegic Patients after Stroke

“…Liu et al announced a 3-RSS/S parallel robotic platform associated with a virtual training environment, which employed servo motor to drive its parallel links [6]. Meng et al constructed a parallel structure ankle rehabilitation robot, where the patient's leg is fixed to the base of the robot; therefore, the robot can drive the patient's foot to generate relative movement using the ankle joint as the pivot center [7]. Muhammad and Shafriza presented a mechanical design and kinematic analysis of a parallel robot for ankle rehabilitation [8].…”