A variable stiffness joint hydraulic drive system for an exoskeleton robot

Abstract

The invention relates to the field of hydraulic drive systems, in particular to a variable stiffness joint hydraulic drive system for an exoskeleton robot, comprising a left leg variable stiffness joint drive system and a right leg respectively used to drive a left leg and a right leg and have the same internal structure Variable stiffness joint drive system, the drive system includes a hydraulic power module and a joint drive module that assists driving the human body to walk. The invention uses a distributed power source to replace the centralized hydraulic power source in the exoskeleton backpack, and solves the problem of the centralized hydraulic power source. and the risk of oil leakage caused by many oil pipe joints, reducing the complexity of system control, and decomposing the centralized hydraulic power source into distributed hydraulic power sources, which can replace the load-bearing backpack often found in hydraulically driven lower extremity exoskeletons. Backpacking makes the overall structure more concise.

Description

technical field [0001] The invention relates to the field of hydraulic drive systems, in particular to a variable stiffness joint hydraulic drive system for an exoskeleton robot. Background technique [0002] With the aging of the population in my country, the increase in the number of strokes, and the frequent occurrence of traffic accidents, the number of patients with lower extremity motor dysfunction is increasing. Therefore, the wearable lower limb exoskeleton robot, as an intelligent device that can assist the movement of the lower limbs of the human body, has become the demand of social development. [0003] At present, the joint driving methods of lower limb exoskeleton robots mainly adopt motor driving and hydraulic driving. Motor drive is the most widely used driving method in the current research on lower extremity exoskeletons. It is usually arranged in the direction parallel to the leg members of the lower extremity exoskeleton, and the motion transmission is r...

AI Technical Summary

Problems solved by technology

However, matching a hydraulic base station at each joint of the lower extremity exoskeleton increases the complexity of the joints, and the distributed power source is only composed of a motor, a pump, and an oil tank, and the flow rate of the hydraulic cylinder is controlled by the speed of the motor, which reduces the control accuracy of the hydraulic system

Chinese Patent No. 201310137055.2 "A Highly Integrated Hydraulic Drive Unit Structure" discloses a highly integrated double-rod hydraulic cylinder, which integrates servo valves, oil circuit connecting blocks, force sensors and displacement sensors into the hydraulic cylinder, shortening the The distance between the servo valve and the hydraulic cylinder is increased, but because the hydraulic base station is not integrated, the entire exoskeleton system still uses a single hydraulic base station, with many oil pipes and oil pipe joints, and the risk of oil leakage still exists

At the same time, in the above four patents, a double oil port hydraulic cylinder is used, and the rigidity of the hydraulic cylinder cannot be adjusted.

In the ground contact and bounce phases of the exoskeleton walking process, the soles of the human body contact the ground quickly, and the hydraulic cylinder cannot be flexibly adjusted according to the external load, which will cause the human body to touch the ground or bounce up stiffly, making the human body uncomfortable for walking

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