A Portable Variable Stiffness Unpowered Aided Exoskeleton Design

Long-term and long-distance walking, especially weight-bearing walking, can lead to a series of health problems, such as physical decline, muscle fatigue, and even muscle injury. In order to provide precisely walking support for users, our team studied the movement characteristics of normal people’s unilateral lower limbs from transition phase to support phase, the kinematic position relationship and energy conversion relationship of the human hip joint in different gait periods, and the internal cam mechanism is designed accordingly. Considering the individualized demand of user’s walking aid, a variable stiffness energy storage mechanism is designed, which can be adjusted according to user’s height. Through EMG test, it is proved that the mechanism has a good effect of assisted walking. The energy storage mechanism of unpowered aided exoskeleton is mainly composed of cam and roller follower. Compared with traditional energy storage mechanisms such as connecting rods, they are smaller in size and easier to wear, which provides some useful ideas for the human-friendly design of unpowered exoskeleton.