CN1861328A - Adjustable 3,4,5-SPS type parallel mechanism experiment bench - Google Patents

Abstract

The invention belongs to the field of robot and machinery manufacturing. It is characterized in that: 3, 4, 5 linear drive branches (3) are symmetrically distributed in a regular polygon between the upper platform (1) and the base (2), and one of the 4, 5 linear drive branches (3) Arranged at the center of the platform (1) and the base (2), the rest are symmetrically distributed in a regular polygon between the upper platform (1) and the base (2); each linear drive branch (3) has a ball pair at both ends. One end of the linear drive branch (3) is connected with the ring frame (5) to form a revolving pair, the ring frame (5) is connected to the bracket (6) to form a revolving pair, and the bracket (6) is connected to the bushing (7) to form a revolving pair. Two rotating pairs are orthogonal to each other to form a spherical pair; the degree of freedom of the spherical pair is changed with a horizontal pin (8) and a vertical pin (9). The invention can realize the experimental research of mechanism synthesis and motion analysis of the parallel mechanism with few degrees of freedom with variable degrees of freedom, variable configurations and variable motion forms. The invention has the characteristics of one machine with multiple types, variable degrees of freedom, relatively large working space, symmetrical structure and high motion precision. Various space parallel robots, parallel machine tools, micro robots and sensor elements can be designed.

Description

Adjustable 3, 4, 5-SPS Parallel Mechanism Experiment Platform

technical field

The present invention relates to the field of robots and machinery manufacturing.

Background technique

For the convenience of explanation, use (n, n=1, 2, 3, 4, 6) to represent the number of branches, and use (S, U, P, R) to represent the (ball pair, universal joint, moving pair, revolving pair), and their combination represents a branched kinematic chain structure.

Parallel robots have the characteristics of high structural rigidity, strong carrying capacity, light end mass, small inertia, and no accumulation of position errors. They are complementary to serial robots in application. The parallel robot mechanism with less than 6 degrees of freedom has relatively simple structure and easy control, and has become a research hotspot in the field of robotics and manufacturing. In recent years, Tsai's three-moving 3-UPU mechanism has won US Patent No. 5656905; Huang Zhen's 4-DOF 3-URU/SPS parallel mechanism and 5-DOF decoupling parallel robot structure have won Chinese patents 1335215A and 1311083A respectively ; Wang Jinsong's 4-DOF 2-to-2-transfer parallel robot mechanism, Huang Tian's 3-DOF spherical parallel mechanism, and Gao Feng's 5-DOF parallel micro-motion robot have also obtained Chinese patents 1267586A, 1439492A, and 1257770A respectively. These parallel mechanisms with few degrees of freedom have their own characteristics, but the motion sub-poses cannot be adjusted, so the kinematic characteristics of each parallel mechanism with few degrees of freedom are single, which is not conducive to the synthesis of mechanism experiments and the kinematic characteristics of parallel mechanisms with multiple configurations. Experimental Study. The existing theory of parallel mechanism cannot explain the redundant self-motion phenomenon of some parallel mechanisms with few degrees of freedom, and it is necessary to carry out relevant theoretical and experimental research.

Contents of the invention

The object of the present invention is to provide a parallel mechanism experiment platform with one machine, multiple types, high motion precision and adjustable degrees of freedom of 3, 4, 5. The invention has the characteristics of relatively simple mechanism, symmetrical structure, relatively large working space, variable model, adjustable motion sub-pose, variable degrees of freedom, and high motion precision. Adjusting the number of linear drive branches and the layout form can change the degree of freedom and configuration of the mechanism; under the premise of a given number of drive branches and layout form, appropriately increasing the constraints of the ball pair can transform the ball pair into a universal joint or a rotating joint. It can also change their attitudes, realize the construction of various parallel mechanism experiment platforms with few degrees of freedom, and carry out experimental research on their mechanism characteristics and motion characteristics.

This adjustable 3, 4, 5-SPS type parallel mechanism experiment platform is composed of an upper platform 1, a base 2 and 3, 4, 5 SPS type linear drive branches 3 connecting the upper platform 1 and the base 2. The feature is: each linear drive branch 3 has a ball pair at both ends, a linear drive mechanism and a stepping motor 4 form an SPS branch in the middle, its axis coincides with the center of the ball pair, and the linear drive branch 3 is driven by a stepping motor 4 It is composed of a linear moving drive device or a hydraulic linear moving drive device composed of a screw pair to realize linear drive movement; 3, 4, and 5 linear drive branches 3 are distributed symmetrically in a regular polygon between the upper platform 1 and the base 2, of which 4 , one linear drive branch 3 of the five linear drive branches 3 is arranged at the center of the platform 1 and the base 2, and the rest are symmetrically distributed in a regular polygon between the upper platform 1 and the base 2; each ball pair is composed of a ring frame 5 , bracket 6 and shaft sleeve 7, one end of the linear drive branch 3 is connected with the ring frame 5 to form a revolving pair, the ring frame 5 is connected to the bracket 6 to form a revolving pair, and the bracket 6 is connected to the shaft sleeve 7 to form a revolving pair. The pairs are orthogonal to each other to form a ball pair, the shaft sleeve 7 is fixedly connected with the upper platform 1 and the machine base 2; Appropriate constraints on the ball pair can restrict the rotation of one rotation pair of the ball pair, making the ball pair a universal pair with different orientations; it can also restrict the rotation of two rotation pairs of the ball pair, making the ball pair become a universal pair with different orientations. The rotating pair; thus, the experimental platform of various parallel mechanisms with few degrees of freedom is comprehensively constructed.

Description of drawings

In Figure 1, Figure 2 and Figure 3, 1. Moving platform, 2. Base, 3. Linear drive branch, 4. Stepping motor, 5. Ring frame, 6. Bracket, 7. Shaft sleeve, 8. Horizontal Pin, 9. Vertical pin.

Detailed ways

Example 1

Fig. 1 is the first embodiment disclosed by the present invention, the three SPS linear drive branch kinematic chains have the same structure, and the upper platform 1 and the base 2 are symmetrically distributed in an equilateral triangle, and each linear drive branch 3 has a ball pair at both ends, There is a linear drive mechanism and a stepper motor 4 in the middle, the axis of which coincides with the center of the ball pair, and is driven by the stepper motor 4 to realize the telescopic movement of the linear drive branch 3 . The ball pair is composed of three rotating pairs whose axes are orthogonal; the horizontal pin 8 and the vertical pin 9 are used to limit the rotation of the two rotating pairs in the ball pair, and the three ball pairs connected to the moving platform 1 are turned into rotating pairs to form a An experimental platform for a 3-SPR parallel mechanism with 3 degrees of freedom.

Example 2

Fig. 2 is the second embodiment disclosed by the present invention, differs from the first embodiment in that there are 4 SPS type linear drive branches, and the upper platform 1 and the base 2 are symmetrically distributed in a regular quadrilateral; The vertical pin 9 restricts the rotation of the two rotating pairs in the ball pair, and turns the two adjacent ball pairs connected with the moving platform 1 into rotating pairs to form a 2-SPS/2-SPR parallel mechanism experiment platform. The degrees of freedom are 4.

The adjustable 3, 4, 5-SPS type parallel mechanism two experimental platforms, in addition to the characteristics of high rigidity and high load capacity of the parallel mechanism, also has the characteristics of relatively simple mechanism, symmetrical structure, high motion precision and good adjustability. They can be used in the experimental research of mechanism synthesis and motion analysis of various parallel mechanisms with few degrees of freedom, and can also be used to design space parallel robots, parallel machine tools, micro robots and sensor components for various purposes.

Claims (3)

1. one kind adjustable 3,4,5-SPS type parallel mechanism experiment bench, by 3 of upper mounting plate (1), pedestal (2) and connection upper mounting plate (1) and pedestal (2), 4,5 linear drives branches (3) form, it is characterized in that: 3,4,5 linear drives branches (3) are regular polygon and are symmetrically distributed between upper mounting plate (1) and pedestal (2), wherein, and 4,1 linear drives branch (3) of 5 linear drives branches (3) is arranged in the center of platform (1) and pedestal (2), and all the other are regular polygon and are symmetrically distributed between upper mounting plate (1) and pedestal (2); There is the ball pair at each linear drives branch (3) two ends, and there are 1 straight line driving mechanism and 1 stepper motor (4) in the centre, and its axis overlaps with the ball sub-center.

2. according to claim 1 adjustable 3,4,5-SPS type parallel mechanism experiment bench is characterized in that: straight line mobile drive deivce or hydraulic linear mobile drive deivce formation that linear drives branch (3) is made up of stepping motor (4) and screw pair.

3. according to claim 1 and 2 described adjustable 3,4,5-SPS type parallel mechanism experiment bench, it is characterized in that: each ball pair is made up of ring stand (5), support (6) and axle sleeve (7), drive branch's one end (3) and connect the formation revolute pair with ring stand (5), ring stand (5) connects the formation revolute pair with support (6), and support (6) connects the formation revolute pair with axle sleeve (7), 1 ball pair of the mutually orthogonal formation of these 3 revolute pairs, axle sleeve (7) is connected with upper mounting plate (1) and support (2); Lateral pin (8) is set on the support (6), vertical pin (9) is set on axle sleeve (7), the ball pair is applied suitable constraint, can limit 1 revolute pair of ball pair and rotate, make the ball pair become the universal pair of different azimuth with lateral pin (8) or vertical pin (9); Also can limit 2 revolute pairs of ball pair and rotate, make the ball pair become the revolute pair of different azimuth; Thus, the various lower-mobility parallel mechanism experiment bench of synthesis structure.

Images