A device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism

Abstract

The application belongs to the technical field of robots, and discloses a device for visualizing the instantaneous rotation axis trajectory of a spherical 4R mechanism connecting rod, which comprises a fixed platform and a movable platform, two motion branch chains are arranged between the fixed platform and the movable platform, the fixed platform is provided with a first rotation pair and a fourth rotation pair, the first rotation pair is provided with a rotating motor, and the motion branch chains comprise a first branch chain and a second branch chain. The device is used for drawing the instantaneous rotation axis of the spherical 4R mechanism connecting rod, can be used to study the change of the instantaneous rotation axis of the spherical 4R mechanism connecting rod, and solves the problem that the instantaneous rotation axis of the spherical 4R mechanism connecting rod needs to be drawn through software programming at present, the process is complex, and it is not easy to intuitively represent the relationship between the mechanism position and the instantaneous rotation axis.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot technology, in particular to a device for visualizing the instantaneous rotation axis trajectory of the connecting rod of a spherical 4R mechanism. BACKGROUND

[0002] Mechanisms with rotational motion mode have good dynamic performance, high precision, etc., and are widely used in bionic joints, pointing and positioning mechanisms. Spherical 4R mechanisms are widely used in some key structures in industrial production. Analyzing the instantaneous rotation axis of the connecting rod can obtain the kinematic characteristics of the mechanism, which has certain significance for optimizing the structural parameters of the mechanism.

[0003] Currently, existing three-dimensional modeling software can track the trajectory of a point on the connecting rod as the mechanism moves. For example, the connecting rod curve trajectory of a point on the connecting rod can be directly drawn by three-dimensional modeling. However, since the instantaneous rotation axis of the connecting rod is not fixed on the connecting rod, the existing three-dimensional software cannot draw the instantaneous center trajectory of the connecting rod. Programming and solving through mathematical calculation software require a certain foundation in mechanism kinematics analysis and programming. It is relatively complex and tedious to draw the instantaneous center trajectory of the connecting rod. The variation of the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism can be studied. Currently, the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism needs to be drawn through software programming, which is complex and not easy to intuitively represent the relationship between the mechanism position and the instantaneous rotation axis. SUMMARY

[0004] To achieve the above purpose, the technical scheme adopted by the present application is:

[0005] A device for visualizing the instantaneous rotation axis trajectory of the connecting rod of a spherical 4R mechanism, comprising a fixed platform and a moving platform, two motion branch chains are arranged between the fixed platform and the moving platform, the fixed platform is provided with a first rotation pair and a fourth rotation pair, the first rotation pair is provided with a rotation motor, the motion branch chain comprises a first branch chain and a second branch chain;

[0006] The first branch chain comprises a second connecting rod, the second connecting rod is connected with the moving platform through a fifth rotation pair, the second branch chain comprises a fourth connecting rod and a sixth connecting rod, one end of the sixth connecting rod is provided with a rotation pair, the sixth connecting rod is connected with the fourth connecting rod through a seventh rotation pair, the fourth connecting rod is connected with the moving platform through a sixth rotation pair, the second connecting rod is connected with a fifth connecting rod through a second rotation pair, the sixth connecting rod is connected with the fifth connecting rod through a third rotation pair, and one end of the moving platform is fixedly connected with a light beam emitter.

[0007] Further, the rotation axis of the fifth rotation pair is perpendicular to the rotation axes of the first rotation pair and the second rotation pair.

[0008] Further, the rotation axis of the seventh revolute pair is perpendicular to the rotation axes of the third revolute pair and the fourth revolute pair.

[0009] Further, the rotation axes of the first revolute pair, the second revolute pair, the third revolute pair, the fourth revolute pair, the fifth revolute pair, the sixth revolute pair and the seventh revolute pair all pass through the point O of the coordinate system.

[0010] Further, the axis of the sixth revolute pair is always perpendicular to the axis of the fifth revolute pair.

[0011] Further, the axis of the sixth revolute pair is always perpendicular to the axis of the seventh revolute pair.

[0012] Further, the instantaneous rotation axis of the fifth connecting rod coincides with the rotation axis of the sixth revolute pair.

[0013] Further, the light beam emitted by the light beam emitter has a light ray coinciding with the axis of the sixth revolute pair.

[0014] Further, the light ray of the light beam coincides with the instantaneous rotation axis of the fifth connecting rod, and the direction of the light beam changes in space with the movement of the mechanism.

[0015] Further, the first revolute pair, the fifth revolute pair, the sixth revolute pair, the seventh revolute pair and the fourth revolute pair form a 5R spherical loop, and the structural parameters of the 5R spherical loop are selected so as not to limit the rotation angle of the first revolute pair and the fourth revolute pair in the spherical 4R mechanism loop formed by the first revolute pair, the second connecting rod, the second revolute pair, the fifth connecting rod, the third revolute pair, the sixth connecting rod and the fourth revolute pair.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The parallel mechanism for drawing the instantaneous rotation axis of the connecting rod of the instantaneous spherical 4R mechanism can be used to study the change of the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism, and solves the problem that the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism needs to be drawn by software programming at present, which is complex and not easy to intuitively represent the relationship between the mechanism position and the instantaneous rotation axis. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 is a schematic diagram of the overall planar structure of the present application.

[0020] Reference signs: 1, fixed platform; 2, second connecting rod; 3, movable platform; 4, fourth connecting rod; 5, fifth connecting rod; 6, sixth connecting rod; 7, light beam emitter; 8, light beam;

[0021] R1, first rotary pair; R2, second rotary pair; R3, third rotary pair; R4, fourth rotary pair; R5, fifth rotary pair; R6, sixth rotary pair; R7, seventh rotary pair. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0024] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In addition, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" are only used for descriptive purpose and cannot be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0027] Embodiments

[0028] With reference to the accompanying drawings Figure 1 The purpose of the present application is to solve the above-mentioned technical problems, and provide a device for visualizing the instantaneous rotation axis trajectory of the connecting rod of a spherical 4R mechanism, comprising a fixed platform 1 and a moving platform 3, two motion branch chains are arranged between the fixed platform 1 and the moving platform 3, the fixed platform 1 is provided with a first rotation pair R1 and a fourth rotation pair R4, the first rotation pair R1 is provided with a rotating motor, the motion branch chain comprises a first branch chain and a second branch chain;

[0029] The first branch chain comprises a second connecting rod 2, the second connecting rod 2 is connected with the moving platform 3 through a fifth rotation pair R5, the second branch chain comprises a fourth connecting rod 4 and a sixth connecting rod 6, one end of the sixth connecting rod 6 is provided with a rotation pair, the sixth connecting rod 6 is connected with the fourth connecting rod 4 through a seventh rotation pair R7, the fourth connecting rod 4 is connected with the moving platform 3 through a sixth rotation pair R6, the second connecting rod 2 is connected with a fifth connecting rod 5 through a second rotation pair R2, the sixth connecting rod 6 is connected with the fifth connecting rod 5 through a third rotation pair R3, one end of the moving platform 3 is fixedly connected with a light beam emitter 7.

[0030] The rotation axis of the fifth rotation pair R5 is perpendicular to the rotation axes of the first rotation pair R1 and the second rotation pair R2; the rotation axis of the seventh rotation pair R7 is perpendicular to the rotation axes of the third rotation pair R3 and the fourth rotation pair R4; the rotation axes of the first rotation pair R1, the second rotation pair R2, the third rotation pair R3, the fourth rotation pair R4, the fifth rotation pair R5, the sixth rotation pair R6 and the seventh rotation pair R7 all pass through the coordinate system O point; the axis of the sixth rotation pair R6 is always perpendicular to the axis of the fifth rotation pair R5; the axis of the sixth rotation pair R6 is always perpendicular to the axis of the seventh rotation pair R7; the instantaneous rotation axis of the fifth connecting rod 5 coincides with the rotation axis of the sixth rotation pair R6; the light beam 8 emitted by the light beam emitter 7 coincides with the axis of the sixth rotation pair R6; the light beam 8 coincides with the instantaneous rotation axis of the fifth connecting rod 5, and the direction of the light beam 8 changes in space with the movement of the mechanism.

[0031] The first rotating pair R1, the fifth rotating pair R5, the sixth rotating pair R6, the seventh rotating pair R7 and the fourth rotating pair R4 form a 5R spherical loop, and the structure parameters of the 5R spherical loop are selected to not limit the rotation angle of the first rotating pair R1 and the fourth rotating pair R4 in the spherical 4R mechanism loop formed by the first rotating pair R1, the second connecting rod 2, the second rotating pair R2, the fifth connecting rod 5, the third rotating pair R3, the sixth connecting rod 6 and the fourth rotating pair R4, that is, in the mechanism structure shown in the figure, the relationship between the rotating pair and the rotation angle and the rotation range in the spherical mechanism loop formed by the first rotating pair R1, the second rotating pair R2, the third rotating pair R3 and the fourth rotating pair R4 are the same as those in the spherical mechanism formed by only the first rotating pair R1, the second connecting rod 2, the second rotating pair R2, the fifth connecting rod 5, the third rotating pair R3, the sixth connecting rod 6 and the fourth rotating pair R4. Figure 1

[0032] In the three-dimensional modeling software, a three-dimensional model is established according to the content described in the application, a point is selected on the axis of the sixth rotating pair R6, and the trajectory of the point is tracked, so that the trajectory formed by the instantaneous rotation axis of the fifth connecting rod 5 in the spherical 4R mechanism formed by the first rotating pair R1, the second connecting rod 2, the second rotating pair R2, the fifth connecting rod 5, the third rotating pair R3, the sixth connecting rod 6 and the fourth rotating pair R4 in space can be obtained.

[0033] The parallel mechanism for drawing the instantaneous rotation axis of the connecting rod of the instantaneous spherical 4R mechanism can be used to study the change of the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism, and solves the problem that the instantaneous rotation axis of the connecting rod of the spherical 4R mechanism needs to be drawn through software programming at present, and the process is complex and not easy to intuitively represent the relationship between the mechanism position and the instantaneous rotation axis.

[0034] The above is only a preferred embodiment of the application and is not used to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.​

Claims

1. A device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism, characterized in that, The application relates to a kind of 5R spherical linkage mechanisms, comprising fixed platform and movable platform, two motion branches are arranged between the fixed platform and the movable platform, the fixed platform is provided with first rotary pair, fourth rotary pair, the first rotary pair is provided with rotary motor, the motion branch includes first branch and second branch; The first branch includes second connecting rod, the second connecting rod is connected with movable platform by fifth rotary pair, the second branch includes fourth connecting rod and sixth connecting rod, one end of the sixth connecting rod is provided with rotary pair, the sixth connecting rod is connected with the fourth connecting rod by seventh rotary pair, the fourth connecting rod is connected with the movable platform by sixth rotary pair, the second connecting rod is connected with fifth connecting rod by second rotary pair, the sixth connecting rod is connected with the fifth connecting rod by third rotary pair, one end of the movable platform is fixedly connected with light beam emitter.

2. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 1, characterized in that, The rotary axis of the fifth rotary pair is perpendicular to the rotary axis of the first rotary pair and the second rotary pair.

3. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 2, characterized in that, The rotary axis of the seventh rotary pair is perpendicular to the rotary axis of the third rotary pair and the fourth rotary pair.

4. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 3, characterized in that, The rotary axis of the first rotary pair, the second rotary pair, the third rotary pair, the fourth rotary pair, the fifth rotary pair, the sixth rotary pair, the seventh rotary pair, and the coordinate system O point are all through the coordinate system O point.

5. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 4, characterized in that, The sixth rotary pair axis and the fifth rotary pair axis are always perpendicular.

6. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 5, characterized in that, The sixth rotary pair axis and the seventh rotary pair axis are always perpendicular.

7. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 6, characterized in that, The instantaneous rotary axis of the fifth connecting rod coincides with the rotary axis of the sixth rotary pair.

8. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 7, characterized in that, The light beam emitter emits light beam, the light ray of the light beam coincides with the axis of the sixth rotary pair.

9. The device for visualizing the instantaneous rotation axis trajectory of a spherical 4R mechanism link according to claim 8, characterized in that, The light ray of the light beam coincides with the instantaneous rotary axis of the fifth connecting rod, and the direction of the light beam changes in space with the movement of the mechanism.

10. The device for visualizing the instantaneous rotation axis trajectory of the links of a spherical 4R mechanism according to claim 9, characterized in that, The first rotary pair, the fifth rotary pair, the sixth rotary pair, the seventh rotary pair and the fourth rotary pair form 5R spherical loop, and the structural parameters of the 5R spherical loop do not limit the rotation angle of the first rotary pair and the fourth rotary pair in the spherical 4R mechanism loop composed of the first rotary pair, the second connecting rod, the second rotary pair, the fifth connecting rod, the third rotary pair, the sixth connecting rod and the fourth rotary pair.

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