A Compatible Design of a Passive Exoskeleton to Reduce the Body–Exoskeleton Interaction Force

Abstract

In the research and development of a passive exoskeleton, the body–exoskeleton coupling mode is a key point to reduce the interaction force and realize the efficient assistance of the exoskeleton. The purpose of this paper was to explore a cooperative movement mode between human and passive exoskeleton for reducing the body–exoskeleton interaction force. Firstly, through the research of the body–exoskeleton interactive mode, we analyzed the kinematic and dynamic constraint of the exoskeleton and established a dynamic model of the body–exoskeleton system. On this basis, the characteristic of the body–exoskeleton interaction force was analyzed; then, we put forward a mode that uses human gravity and load weight to maintain the stability of the exoskeleton’s movement to achieve the goal of reducing the interaction force. Based on the human–exoskeleton integrated mode, we constructed a mechanical model and simulated the change in interaction force in this mode; the simulation results showed that the interaction force at the lower leg was 98.5% less than that of the pure mechanical exoskeleton. Finally, we developed a prototype that was made of plastic parts and finished the experiment by walking with a load of 30 kg. The experimental results showed that this mode reduced the body–exoskeleton interaction force by 65.1%, which verified the effectiveness of the body–exoskeleton coupling mode preliminarily. The research results provided a new analytical approach for the design of a passive exoskeleton, and its improvement effect could be extended from the lower leg of the body–exoskeleton to the thigh or trunk, and guide the design of a passive exoskeleton.

Hierarchical Classification of Subject-Cooperative Control Strategies for Lower Limb Exoskeletons in Gait Rehabilitation: A Systematic Review

“…Augmentation exoskeletons are a type of technology that is designed to enhance the functional capabilities of individuals, even those who are otherwise healthy. These devices use advanced tracking technology, such as admittance/impedance control, to monitor the trajectory of the user's limbs and increase the power output of the range of functions they are designed to augment [16][17][18]. To achieve this, augmentation exoskeletons typically utilize high power-to-weight ratio actuators such as pneumatic actuators and series elastic actuators (SEAs).…”

Position control of electro-hydraulic servo system using active disturbance rejection control for upper-limb exoskeleton

“…Upper-limb exoskeleton robots are generally applied in a variety of different fields, such as rehabilitation robots [1][2][3], assistive robots [4][5][6], human amplifiers [7,8] and other uses. Robotic exoskeleton is the complex multi-input and multi-output (MIMO) with time varying dynamics and highly coupled nonlinear [9]. Compared with industrial manipulators, exoskeletons suffer severe kinematic and dynamic uncertainties and external disturbances.…”

Optimizing Exoskeleton Design with Evolutionary Computation: An Intensive Survey

“…Tracked movements can be visually expressed in virtual environments [8] or used as the controller reference for a secondary robotic device during teleoperation tasks [9]. Alternatively, passive exoskeletons can distribute the weight of heavy objects on anatomical joints more equally to avoid potential injuries [10]. When equipped with batteries and actuators, namely active exoskeletons, they are used to augment and improve users' physical capabilities; examples range from performing heavy workload tasks [11] and completing sports activities [12] to assisting patients with physical/neurological disabilities while performing activities of daily living [13].…”