A Compact Variable Stiffness Series Elastic Actuation Joint

Abstract

The invention discloses a compact variable-stiffness tandem elastic actuated joint which comprises an upper arm part, a driving part, a forearm part, a stiffness regulation part and an angle sensor. Aworm gear and a reel are fixed to a bolt together through mounting keys, worm gear transmission is introduced, and the use of a gear reducer is reduced, so that the joint has small size and a compactstructure and achieves the purpose of miniaturization design. The compact variable-stiffness tandem elastic actuated joint can realize bidirectional flexibility, and the joint stiffness K is equal to4kR2, wherein K is the joint stiffness, k is individual spring stiffness, and R is the radius of a wire lot of the reel. The joint stiffness can be calculated accurately. Two groups of springs are used, the requirement on the spring stiffness is lower than that of one group of springs, and the spring size can be reduced and the joint size is further reduced. The springs are arranged on the two sides of the reel, which is good for balance of internal and external side force.

Description

technical field [0001] The invention belongs to the technical field of machinery, and in particular relates to a compact variable stiffness series elastic drive joint for a robot. Background technique [0002] In order to achieve precise control of position and speed in the workspace and ensure rapid motion response, traditional robots mostly use rigid joints. However, with the continuous popularization of robot applications, the interaction between robots and the environment and humans is becoming more and more extensive, so robots need to have certain flexibility and safe interaction capabilities. In 1995, Gill A.Pratt of the Massachusetts Institute of Technology proposed the concept of a series elastic driver. He connected an elastic element in series between the motor drive end and the load end. On the one hand, the elastic element can be used as a transmission for measuring the output force (moment). Inductive elements can transform the force control problem into posit...

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Problems solved by technology

[0003] In order to solve the problem of robot control compliance and safe interaction, many structural forms of series elastic actuators have been developed. For example, Chinese Patent No. 201420688785.1 discloses "a quadruped robot based on series elastic actuators", and proposes a A flexible output mechanism composed of 8 compression springs, the joint structure is relatively compact, but the joint stiffness is an approximate value, and the variable stiffness has not been realized; Chinese Patent No. 201410070478.1 discloses "a flexible joint with hybrid control", using wire-cut elastic body As an elastic element, the torque can be indirectly measured by measuring the torsion angle of the elastic body, which can reduce the joint size very well, but the stiffness curve of the elastic body is not linear.

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