A two-stage shock-absorbing ankle-foot integrated parallel low-impact walking foot mechanism and control method

Abstract

The invention discloses a two-stage vibration reducing ankle-foot integrated parallel low-impact walking foot mechanism and a controlling method, which can be used for effectively reducing foot-ground impact force and are capable of performing active control. The walking foot mechanism comprises a foot-leg connecting platform, a food end bottom connecting platform, three groups of moving pairs, three groups of revolute pairs and three groups of ball pairs, a lower platform simulates the foot end of a robot, the moving pairs are driving pairs, and are used for simulating legs of the robot, an anti-vibration pad, with frictional force, is inlaid in the lower surface of the food end bottom connecting platform, and is used as first-stage vibration reduction, the three groups of moving pairs are arranged in a mirror symmetry manner, and each group of moving pair comprise a hydraulic cylinder, a spring damper, a servo valve and a controller, wherein the spring damper sleeves a cylinder piston rod of the hydraulic cylinder, and is used as second-stage vibration reduction, so that the whole mechanism forms a lower-mobility parallel mechanism with a three freedom degree structure, and two rotational freedom along the directions of x and y and a translational freedom degree along the direction of z are realized. The mechanism and method provided by the invention have the advantages that the plan and control of the robot are flexible and reliable, and the stability is high.

Description

technical field [0001] The invention relates to a two-stage shock-absorbing ankle-foot integrated parallel low-impact walking foot mechanism and a control method. Background technique [0002] The mobile behavior of the footed robot has the characteristics of discontinuous support, which enables it to cross obstacles and ravines, adapt to various rough ground environments, and has very strong terrain adaptability. equipment form. The legged robot frequently collides with the ground during the walking process. The effective load of the foot is very different between the support phase and the swing phase, and more importantly, there is a very large shock. If it cannot be absorbed in a timely and effective manner, the instantaneous impact will be transmitted to the body of the legged robot, which will affect the walking stability and may cause damage to the mechanical system, especially in the high-speed dynamic gait mode. Most of the existing foot end adopts single-stage sp...

AI Technical Summary

Problems solved by technology

If it cannot be absorbed in a timely and effective manner, the instantaneous impact will be transmitted to the body of the legged robot, which will affect the walking stability and may cause damage to the mechanical system, especially in the high-speed dynamic gait mode.

Most of the existing foot end adopts single-stage spring damping mechanism, ankle-foot series connection, passive control or partial degree of freedom active control design. There are problems such as low ankle-foot stiffness, unadjustable foot-ground pressure area, and uncontrollable foot-ground contact angle. This leads to: 1) It is difficult to design the stiffness matching of the legs and feet, otherwise the foot-ground impact will be greatly transmitted to the body; 2) Even if the impact of the foot-ground contact on the body posture is passed through the top-level planning of the robot, the adjustment will fail due to the passive adaptation of the feet; 3) It is difficult to form the propulsion, deceleration and effective reflection of the foot end, which makes the control of the legged robot complex

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