DESIGN AND MANUFACTURE OF CONTROL SYSTEM FOR A LOWER LIMB SIT-TO-STAND EXOSKELETON FOR PARAPLEGIC PATIENTS

• Main Author: Pasaribu, Rainhart
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/47184
• Institution: Institut Teknologi Bandung

In Indonesia, the number of people with lower limb disability, which is called paraplegia, is increased every year. Generally, paraplegic patients have a higher risk of suffering from another muscular disorder because there is no contraction of the paralyzed muscles. To prevent this issue, an assistive device to trigger contraction of the lower limb muscle is required. One of the most desired movements to be regained by the paraplegic patients is sit-to-stand movement. Therefore, it is required to develop a sit-to-stand assistive device with relatively low in cost. This research is focused on the design, manufacture, and testing of a control system applied to an active exoskeleton which is functioned as a sit-to-stand and stand-to-sit assistive device. The control system is designed so that the actuated hip and knee joints in the exoskeleton can rotate based on the joint angle reference of sit-to-stand movement. A biomechanical analysis of sit-to-stand movement is conducted to the load torque in hip and knee joints which is required for actuator selection. A closed-loop PD controller is designed based on mathematical model of the actuators. Electrical system and user-interface are designed and manufactured as well. The exoskeleton has been tested through subject test and motion capture test. The subject test results show that the exoskeleton can successfully assist subject to perform sitto-stand and stand-to-sit movement based on the given trajectory of hip and knee joints. However, the motion capture test results show that there are differences between the joint angle measured by encoder and the actual joint angle measured by motion capture.