Device and method for reaction force control using a variable elastic actuator for exoskeleton systems

Exoskeleton device with variable elasticity and adjustable actuators for joint reaction force control

This technology provides a kinematic mechanism that adjusts the stiffness and reaction force of exoskeleton joints in real-time using a variable elastic element (with elastic members placed between a rotatable outer rotor and a cross-shaped inner rotor) and an adjustable actuator.

Existing exoskeleton systems lack the means to precisely control joint haptic feedback (reaction force) to meet user requirements, which limits the wearer's comfort and the effectiveness of rehabilitation therapy.

This technology variably controls external reaction forces by adjusting the displacement of elastic members placed between an inner rotor connected to the joint axis and an outer rotor rotated by an adjustable actuator, while performing feedback control via torque sensors to reach target reaction force levels.

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Key Features:

• First and second link bodies connected to allow joint movement, and a joint axis constrained and connected only to the second link body
• A variable elastic element featuring elastic members sequentially arranged between an inner rotor connected to the joint axis and an outer rotor fixed to the first link body
• An adjustable actuator installed on the first link body that rotates the outer rotor to regulate the reaction force of the elastic members
• A control configuration that compares measured and target reaction force values to adjust the rotation count or speed of the outer rotor, thereby increasing or decreasing the reaction force

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