Title :
Adaptive torque control of electro-rheological fluid brakes used in active knee rehabilitation devices
Author :
Nikitczuk, Jason ; Das, Abhimanyu ; Vyas, Harsh ; Weinberg, Brian ; Mavroidis, Constantinos
Author_Institution :
Dept. of Mech. & Ind. Eng., Northeastern Univ., Boston, MA
Abstract :
This paper describes the development of an adaptive nonlinear PI torque control for electro-rheological fluid (ERF) based variable resistance brakes that are used in compact and portable rehabilitation devices. The electrorheologic fluid (ERF) brake concepts are introduced and previous work performed with a non-linear PI control on ERFs is tested and analysed. The response of ERF brake systems to this non-linear PI torque control, that utilizes an inverse model, is enhanced through the addition of two key components, a step logic function and an adaptable B-spline based algorithm. The description of each is provided along with tests verifying their effectiveness. In addition, the controller´s response to disturbances is provided. The effectiveness of the control is validated through testing on two different electro-rheological fluid based brakes
Keywords :
PI control; adaptive control; brakes; electrorheology; medical robotics; nonlinear control systems; patient rehabilitation; torque control; active knee rehabilitation devices; adaptable B-spline based algorithm; adaptive torque control; electro-rheological fluid brakes; linear PI control; nonlinear control systems; resistance brakes; step logic function; Adaptive control; Inverse problems; Knee; Logic functions; Performance analysis; Performance evaluation; Pi control; Programmable control; Testing; Torque control;
Conference_Titel :
Robotics and Automation, 2006. ICRA 2006. Proceedings 2006 IEEE International Conference on
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-9505-0
DOI :
10.1109/ROBOT.2006.1641743