Intelligent bimanual rehabilitation robot with fuzzy logic based adaptive assistance

Functional recovery of an impaired limb could be achieved effectively using rehabilitation robots. Most studies focus on unilateral robots. However, bimanual rehabilitation robots promote inter-limb coordination which is specially useful for stroke patients. Existing rehabilitation machines designed for resistance training do not follow the profile of the human arm torque curve as for the human biomechanics. Therefore the resistance exercise may become an inefficient workout as the patient may use biomechanical advantage at certain angles. Ideally, a rehabilitation robot should provide low impedance or assistance when the patient is unable to work against the resistance. This paper proposes a novel impedance controlled bimanual robot with fuzzy logic based adaptive assistance. The proposed controller is tested with two options. Torque is controlled using the Reaction Torque Observer (RTOB). Results show the applicability of the proposed method.