Decoupled three-rotational-degree-of-freedom parallel mechanism

Abstract

The invention relates to a decoupled three-rotational-degree-of-freedom parallel mechanism, which consists of a machine frame (1), a dynamic platform (3), a first motion branch chain (2a), a second motion branch chain (2b) and a third motion branch chain (2c), wherein the first motion branch chain (2a), the second motion branch chain (2b) and the third motion branch chain (2c) are fixedly connected between the machine frame (1) and the dynamic platform (3); and the axes of three rotation pairs of the first motion branch chain (2a) meet at the central point of the platform (3). As few motion pairs are used and all driving electric motors are arranged on the machine frame, the motion-decoupled spherical rotation parallel mechanism of the invention has the advantages of simple structure, convenient installation, small rotation inertia and quick motion response. In addition, the spherical rotation parallel mechanism of the invention has linear motion decoupling, easy calibration and simple control, thereby reducing development cost.

Description

technical field [0001] The invention belongs to the field of industrial robots, in particular to a parallel mechanism with three rotation degrees of freedom for the decoupling of wrist, shoulder and waist joints of robots. Background technique [0002] Industrial robots are usually composed of three parts: mechanical system, control system and intelligent system. The mechanical system is further divided into an actuator and a drive mechanism. The actuator is generally composed of a hand, a wrist, an arm, a waist and a frame. The robot wrist (wrist) is the connection part between the arm and the hand, the adjustment mechanism of the robot, and the most complicated part in the industrial robot manipulator. Wrists can be divided into single-degree-of-freedom wrists, two-degree-of-freedom wrists, and three-degree-of-freedom wrists according to the number of degrees of freedom. The wrist is at the end of the arm, and it is required to have a compact structure and light weight; ...

AI Technical Summary

Problems solved by technology

In the "sun tracking device based on spherical mechanism" reported in Chinese patent document CN03258423.7, a three-degree-of-freedom spherical mechanism is used, but its three rotations are fully coupled, that is, it cannot be decoupled; resulting in complicated control of the parallel mechanism and difficult calibration. And restrict the improvement of precision

The two-degree-of-freedom spherical mechanism proposed by US patent US00596699IA can only be decoupled instantaneously at the initial position, and cannot be decoupled at other positions

Literature [Hang Lubin, Wang Yan, Wu Jun, etc. Research on decoupling conditions of spherical parallel mechanism based on topology decoupling criterion [J]. Chinese Journal of Mechanical Engineering, 2005, Vol.41, No.9: pp28-32] proposed a Partially decoupled 3-RRR spherical rotation mechanism, but because the pose parameters still have weak coupling, controlling one pose parameter will cause other pose parameters to change at the same time

The literature on the invention of the three-degree-of-freedom spherical mechanism that can be decoupled has not yet been retrieved

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