Variable-stiffness joint with symmetrical compression springs

Abstract

The invention provides a variable-stiffness joint with symmetrical compression springs, and belongs to the field of bionic robots. The variable-stiffness joint comprises a base, a joint connecting rod, a position motor, a stiffness motor and a stiffness adjusting module, the stiffness adjusting module is composed of rollers and symmetrical structures comprising cam discs and the springs, the rollers are connected onto a roller retainer, the position motor is fixed on the base, the output end of the position motor is connected with the roller retainer, the stiffness adjusting module is arrangedon the base, the joint connecting rod is fixedly connected with one cam disc, the stiffness motor is fixedly connected with the joint connecting rod, and the output end of the stiffness motor is connected with the other cam disc. The variable-stiffness joint structure composed of the rollers, and the cam discs and the springs which are symmetrically arranged on the two sides is adopted, the structure is simple and reliable, the size is small, the same flexible effect can be achieved through forward driving and reverse driving, the advantages of being large in output torque and wide in rigidity adjusting range are achieved, and the variable-stiffness joint can be applied to various different occasions as a modular design.

Description

technical field [0001] The invention belongs to the field of bionic robots, in particular to a symmetrical compression spring type variable stiffness joint. Background technique [0002] Soft robot is a kind of robot with human-like muscle characteristics and variable stiffness. The soft robot obtains flexibility through the joints, in which the position motor drives the joint movement, and the stiffness motor adjusts the joint stiffness. The quality of the variable stiffness joint directly affects the soft robot. performance. [0003] The Chinese invention patent with the publication number CN105328711A discloses a modular variable stiffness joint, which uses a torsion spring as an elastic element, and uses a pulley mechanism and a rope drive to reduce the space occupied by the driving parts, and has the advantages of small size and high integration. Advantages, it is suitable for applications such as exoskeleton joints, but due to the limited torsion spring characteristic...

AI Technical Summary

Problems solved by technology

[0003] The Chinese invention patent with the publication number CN105328711A discloses a modular variable stiffness joint, which uses a torsion spring as an elastic element, and uses a pulley mechanism and a rope drive to reduce the space occupied by the driving parts, and has the advantages of small size and high integration. Advantages, suitable for applications such as exoskeleton joints, but due to limited torsion spring characteristics, resulting in a narrow range of adjustment stiffness and low output torque

The Chinese invention patent with the publication number CN105108771A discloses a variable stiffness robot joint structure, which designs a stiffness adjustment mechanism based on the variable lever principle, uses a leaf spring as an elastic element, and realizes stiffness adjustment by changing the fulcrum of the lever, with a wide range of stiffness adjustment , but there are problems such as low energy utilization efficiency, low integration and high control difficulty due to complex actuators

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