A walking assistive device with intention detection using back-driven pneumatic artificial muscles

In this paper, a pneumatically-driven walking assistive device is proposed. Since the structure of the exoskeleton is different from users´ legs, it is not required to attach the exoskeleton links to the user´s knee and adjust the length of the links. McKibben type pneumatic artificial muscles are adopted as the actuators, realizing back-drivability. We proposed a control method with the detection of the walking intention of the user using air pressure sensors isolated from the device itself, without attaching sensors to the user. The actuators are pre-pressurized and then the difference of the pressure is monitored and used as the trigger to starting the assist. Experimental results show the effectiveness of the proposed system and the intention detection method.