Two-rotation and one-movement parallel posture adjusting mechanism

Abstract

The mechanism comprises a fixed platform and a movable platform, the fixed platform comprises a horizontal mounting part and a vertical mounting part, and a first driving branch chain, a second driving branch chain and a third driving branch chain are connected between the movable platform and the horizontal mounting part in parallel; a first constraint branch chain and a second constraint branch chain are connected in parallel between the movable platform and the vertical mounting part; each of the first driving branch chain and the second driving branch chain comprises a first spherical hinge, a first upper rod, a first lower rod and a first hooke hinge, the third driving branch chain comprises a second spherical hinge, a second upper rod, a second lower rod and a hinge, and each of the first constraint branch chain and the second constraint branch chain comprises a third spherical hinge, a connecting rod and a second hooke hinge which are connected in sequence. The mechanism can realize attitude adjustment of three degrees of freedom of yawing, longitudinal swinging and longitudinal moving of the movable platform, is long in service life, high in stability and accuracy, high in bearing capacity, capable of adapting to complex environments, applied to occasions of heavy-load eccentric attitude adjustment and the like, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the field of robots, and in particular relates to a two-rotation-one-shift parallel attitude adjustment mechanism for heavy-load eccentric attitude adjustment. Background Art

[0002] In many heavy-load posture adjustment situations of large equipment, it is often required to have the ability to adjust posture with two rotational and one translational degrees of freedom. Compared with the series mechanism, the parallel mechanism has the advantages of high load capacity, high rigidity, and good dynamic performance. The parallel mechanism with few degrees of freedom only retains the degrees of freedom required by the task space, and has the advantages of low cost and easy control. Therefore, it is suitable for heavy-load posture adjustment occasions.

[0003] The Chinese patent document CN114888777A discloses a two-rotation one-shift parallel robot, which includes a moving platform, a fixed platform, a simple branch chain 1, a simple branch chain 2 and a simple branch chain 3. The mechanism has the least number of rotation pairs and can easily meet the requirements of high speed and high precision. However, the mechanism has poor load-bearing capacity and weak rigidity.

[0004] Chinese patent document CN106181967A discloses a symmetrical two-rotation-one-shift parallel mechanism with multiple continuous rotation axes and unaccompanied motion. The joints of the mechanism are mainly composed of revolute pairs, with a completely symmetrical structure, good isotropy, low manufacturing cost and easy maintenance. However, the mechanism has poor load-bearing capacity and weak rigidity.

[0005] Chinese patent document CN113664809A discloses a new type of UP type two-rotation one-shift parallel mechanism with circular arc guide rails. The mechanism consists of three simple branches and has a small number of rotation pairs. It can be used for five-axis hybrid processing machine tools, with fast response speed, excellent performance, simple structure, and easy processing and manufacturing. However, the mechanism has poor load-bearing capacity and weak rigidity.

[0006] Currently, there are few reports on two-rotation-one-translation parallel attitude adjustment mechanisms suitable for large loads and large eccentricities. This mechanism requires a compact structure, high rigidity and strong load-bearing capacity. Summary of the invention

[0007] The purpose of the present invention is to provide a two-rotation and one-shift parallel attitude adjustment mechanism with strong load-bearing capacity. The mechanism has a long service life, high stability and precision, strong load-bearing capacity, can adapt to complex environments, and is used in occasions such as heavy-load eccentric attitude adjustment, and has good application prospects.

[0008] The technical solution adopted by the present invention to solve the above technical problems is: a two-rotation-one-shift parallel posture adjustment mechanism, comprising a fixed platform and a moving platform, the fixed platform comprising a horizontal mounting portion and a vertical mounting portion, a first driving branch chain, a second driving branch chain and a third driving branch chain are connected in parallel between the moving platform and the horizontal mounting portion, and a first restraining branch chain and a second restraining branch chain are connected in parallel between the moving platform and the vertical mounting portion;

[0009] The first driving branch chain and the second driving branch chain have the same structure, both of which include a first ball joint, a first upper rod, a first lower rod and a first Hooke's hinge connected in sequence, the first upper rod and the first lower rod are connected through a first moving pair, the top end of the first upper rod is connected to the first ball joint, the first ball joint is connected to the bottom of the moving platform, the bottom end of the first lower rod is connected to the first Hooke's hinge, and the first Hooke's hinge is connected to the horizontal mounting portion; the third driving branch chain includes a second ball joint, a second upper rod, a second lower rod and a hinge connected in sequence, the second upper rod and the second lower rod are connected through a second moving pair, the top end of the second upper rod is connected to the second ball joint, the second ball joint is connected to the bottom of the moving platform, the bottom end of the second lower rod is connected to the hinge, and the hinge is connected to the horizontal mounting portion;

[0010] The first constraint branch chain and the second constraint branch chain have the same structure, and both include a third ball joint, a connecting rod and a second Hooke's joint connected in sequence, the two ends of the connecting rod are respectively connected to the third ball joint and the second Hooke's joint, the third ball joint is connected to the side of the moving platform, and the second Hooke's joint is connected to the vertical mounting portion;

[0011] The first axes of the two first Hooke's joints are respectively arranged along the Y direction and are parallel to each other, the first axis of the first Hooke's joint of the first drive branch is collinear with the axis of the hinge, the second axes of the two first Hooke's joints are respectively arranged along the X direction and are parallel to each other, the first axes of the two second Hooke's joints are respectively arranged along the Z direction and are parallel to each other, and the second axes of the two second Hooke's joints are respectively arranged along the Y direction and are collinear.

[0012] The two-rotation-one-shift parallel attitude adjustment mechanism of the present invention designs three drive branches, namely the first drive branch chain, the second drive branch chain and the third drive branch chain, and adds a moving pair between the upper rod and the lower rod of the three drive branches, thereby realizing the attitude adjustment of the three degrees of freedom of lateral swing, longitudinal swing and longitudinal translation of the moving platform. At the same time, by adding two constraint branches, namely the first constraint branch chain and the second constraint branch chain, the forces on the three drive branches during the lateral and longitudinal swing movements of the mechanism are reduced, thereby improving the overall stability, reliability and service life of the mechanism.

[0013] The two-rotation-one-shift parallel posture adjustment mechanism of the present invention has a long service life, high stability and accuracy, strong load-bearing capacity, can adapt to complex environments, and is applied to occasions such as posture adjustment of heavy-load eccentricity. It has good application prospects, and its advantages are mainly reflected in:

[0014] 1) Long service life: Since the center of mass of the moving platform is relatively high when carrying heavy objects, the three drive branches need to bear a large force during the lateral and longitudinal swinging movements. The two constraint branches designed in the mechanism of the present invention can share part of the force, thereby reducing the burden of the three drive branches and extending the service life of the mechanism;

[0015] 2) High stability and precision: By adding three degrees of freedom, namely, yaw, pitch and longitudinal translation, the mechanism of the present invention can better adjust the posture and position of the moving platform, and can maintain high stability and precision even when the external environment changes or during movement;

[0016] 3) Strong bearing capacity: The addition of two restraint branches not only reduces the force on the three drive branches, but also improves the bearing capacity of the moving platform under dynamic load, especially when there are heavy objects on the moving platform, it can effectively distribute and bear the load;

[0017] 4) Adaptability to complex environments: The mechanism of the present invention can effectively cope with dynamic interference in different directions, ensure the stability and reliability of the moving platform, and adapt to more complex application environments, such as posture adjustment of heavy-load eccentricity.

[0018] The two-turn-one-shift parallel attitude adjustment mechanism of the present invention can be applied to a stable platform of a vehicle-mounted system, such as a stable platform in a military vehicle, engineering machinery, or an unmanned vehicle, especially when it is necessary to deal with an unstable road surface or external interference, the mechanism of the present invention can provide stable load support. The two-turn-one-shift parallel attitude adjustment mechanism of the present invention can also be applied to the military and aerospace fields, and applied to a stable platform of high-precision instruments or equipment, carrying high-quality detectors or monitoring equipment and other precision instruments and equipment.

[0019] Preferably, the plane formed by the center lines of the first constraint branch chain and the second constraint branch chain is parallel to the moving platform and the horizontal mounting part, respectively, and the center lines of the first driving branch chain, the second driving branch chain and the third driving branch chain are respectively perpendicular to the plane formed by the center lines of the first constraint branch chain and the second constraint branch chain.

[0020] Preferably, the center line of the first constraint branch chain and the center line of the first drive branch chain are perpendicular to each other and intersect at one point, and the center line of the second constraint branch chain and the center line of the third drive branch chain are perpendicular to each other and intersect at one point.

[0021] Preferably, the first movable pair and the second movable pair are both driven by hydraulic pressure or electric cylinder.

[0022] Preferably, the cross-section of the moving platform is an equilateral triangle, the first drive branch chain, the second drive branch chain and the third drive branch chain are respectively connected and arranged at the bottom of the three corners of the moving platform, and the first constraint branch chain and the second constraint branch chain are respectively connected and arranged on the sides of the two corners of the moving platform.

[0023] Compared with the prior art, the present invention has the following advantages: the two-turn-one-shift parallel attitude adjustment mechanism of the present invention designs three drive branches, namely the first drive branch chain, the second drive branch chain and the third drive branch chain, and adds a moving pair between the upper rod and the lower rod of the three drive branches, thereby realizing the attitude adjustment of the three degrees of freedom of the moving platform, namely the lateral swing, longitudinal swing and longitudinal translation. At the same time, by adding the two constraint branches, namely the first constraint branch chain and the second constraint branch chain, the forces on the three drive branches during the lateral and longitudinal swing movements of the mechanism are reduced, so as to improve the overall stability, reliability and service life of the mechanism. The two-turn-one-shift parallel attitude adjustment mechanism of the present invention has a long service life, high stability and precision, strong load-bearing capacity, can adapt to complex environments, and is applied to occasions such as posture adjustment of heavy-load eccentricity, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The appearance of the two-rotation-one-shift parallel posture adjustment mechanism in the embodiment is shown in FIG. Figure 1 ;

[0025] Figure 2 The appearance of the two-rotation-one-shift parallel posture adjustment mechanism in the embodiment is shown in FIG. Figure 2 ;

[0026] Figure 3 is a schematic diagram of the appearance of the first driving branch chain in the embodiment;

[0027] Figure 4 is a schematic diagram of the appearance of the third drive branch chain in the embodiment;

[0028] Figure 5 is a schematic diagram of the appearance of the first constraint branch in the embodiment;

[0029] The specific reference numerals in the figure are as follows:

[0030] 100-moving platform, 400-fixed platform, 410-horizontal mounting part, 420-vertical mounting part;

[0031] 210 - first drive branch chain, 220 - second drive branch chain, 230 - third drive branch chain;

[0032] 211 - first ball joint, 212 - first upper rod, 213 - first lower rod, 241 - first Hooke's joint, 215 - first axis of the first Hooke's joint, 216 - second axis of the first Hooke's joint;

[0033] 231 - second ball joint, 232 - second upper rod, 233 - second lower rod, 234 - hinge;

[0034] 310-first constraint branch chain, 320-second constraint branch chain;

[0035] 311 - second Hooke's joint, 312 - connecting rod, 313 - third spherical joint, 314 - first axis of the second Hooke's joint, 315 - second axis of the second Hooke's joint. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings. The X direction, Y direction, and Z direction described in the present invention refer to the X direction, Y direction, and Z direction in three-dimensional coordinates, respectively. Figure 1 As shown in the lower left corner of the figure. Components or structures not limited in the present invention all adopt conventional technical means in the art.

[0037] Embodiment: A two-turn and one-shift parallel posture adjustment mechanism, such as Figure 1 and Figure 2 As shown, it includes a fixed platform 400 and a moving platform 100, and the fixed platform 400 includes a horizontal mounting portion 410 and a vertical mounting portion 420. In this embodiment, the longitudinal section of the fixed platform 400 is L-shaped, and the cross-section of the moving platform 100 is an equilateral triangle. The first drive branch chain 210, the second drive branch chain 220 and the third drive branch chain 230 are connected in parallel between the moving platform 100 and the horizontal mounting portion 410, and the first constraint branch chain 310 and the second constraint branch chain 320 are connected in parallel between the moving platform 100 and the vertical mounting portion 420. Specifically, the first drive branch chain 210, the second drive branch chain 220 and the third drive branch chain 230 are respectively connected to the bottom of the three corners of the moving platform 100, and the first constraint branch chain 310 and the second constraint branch chain 320 are respectively connected to the sides of the two corners of the moving platform 100.

[0038] In this embodiment, the first drive branch chain 210 and the second drive branch chain 220 have the same structure. Figure 3 As shown, they all include a first ball joint 211, a first upper rod 212, a first lower rod 213 and a first Hooke's joint 214 connected in sequence, the first upper rod 212 and the first lower rod 213 are connected by a first moving pair (not shown in the figure), the top end of the first upper rod 212 is connected to the first ball joint 211, the first ball joint 211 is connected to the bottom of the moving platform 100, the bottom end of the first lower rod 213 is connected to the first Hooke's joint 214, and the first Hooke's joint 214 is connected to the horizontal mounting portion 410; as shown Figure 4As shown, the third driving branch chain 230 includes a second ball joint 231, a second upper rod 232, a second lower rod 233 and a hinge 234 connected in sequence, the second upper rod 232 and the second lower rod 233 are connected by a second moving pair (not shown in the figure), the top end of the second upper rod 232 is connected to the second ball joint 231, the second ball joint 231 is connected to the bottom of the moving platform 100, the bottom end of the second lower rod 233 is connected to the hinge 234, and the hinge 234 is connected to the horizontal mounting portion 410; the first constraint branch chain 310 and the second constraint branch chain 320 have the same structure, as shown in FIG. Figure 5 As shown, they all include a third ball joint 313, a connecting rod 312 and a second Hooke's joint 311 connected in sequence, the two ends of the connecting rod 312 are respectively connected to the third ball joint 313 and the second Hooke's joint 311, the third ball joint 313 is connected to the side of the moving platform 100, and the second Hooke's joint 311 is connected to the vertical mounting portion 420. The first moving pair and the second moving pair are both driven by hydraulic or electric cylinders.

[0039] In this embodiment, the first axes of the two first Hooke's hinges 214 (i.e., the center lines of the first axes 215 of the first Hooke's hinges 214) are respectively arranged along the Y direction and are parallel to each other, the first axis of the first Hooke's hinge 214 of the first drive branch chain 210 is collinear with the axis of the hinge 234, the second axes of the two first Hooke's hinges 214 (i.e., the center lines of the second axes 216 of the first Hooke's hinges 214) are respectively arranged along the X direction and are parallel to each other, and the first axes of the two second Hooke's hinges 311 (i.e., the center lines of the first axes 314 of the second Hooke's hinges 311) are respectively arranged along the X direction and are parallel to each other. ) are respectively arranged along the Z direction and are parallel to each other, the second axes of the two second Hooke's joints 311 (i.e., the center lines of the second axes 315 of the second Hooke's joints 311) are respectively arranged along the Y direction and are collinear; the planes formed by the center lines of the first constraint branch 310 and the second constraint branch 320 are respectively parallel to the moving platform 100 and the horizontal mounting portion 410, and the center lines of the first driving branch 210, the second driving branch 220 and the third driving branch 230 are respectively perpendicular to the planes formed by the center lines of the first constraint branch 310 and the second constraint branch 320.

[0040] In this embodiment, the center line of the first constraint branch chain 310 and the center line of the first driving branch chain 210 are perpendicular to each other and intersect at one point, and the center line of the second constraint branch chain 320 and the center line of the third driving branch chain 230 are perpendicular to each other and intersect at one point.

[0041] The above-mentioned two-turn-one-shift parallel attitude adjustment mechanism realizes the attitude adjustment of the three degrees of freedom of yaw, pitch and longitudinal translation of the moving platform 100 by designing the three drive branches of the first drive branch 210, the second drive branch 220 and the third drive branch 230, and reduces the force of the three drive branches during the yaw and pitch movement of the mechanism by adding the two constraint branches of the first constraint branch 310 and the second constraint branch 320, so as to improve the overall stability, reliability and service life of the mechanism. The two-turn-one-shift parallel attitude adjustment mechanism has a long service life, high stability and accuracy, strong load-bearing capacity, can adapt to complex environments, and is applied to occasions such as posture adjustment of heavy-load eccentricity, and has good application prospects.

[0042] The above-mentioned two-rotation and one-shift parallel attitude adjustment mechanism can be applied to the stable platform of vehicle-mounted systems, such as the stable platform in military vehicles, engineering machinery, or unmanned vehicles. In particular, when it is necessary to deal with unstable roads or external interference, the mechanism can provide stable load support; the above-mentioned two-rotation and one-shift parallel attitude adjustment mechanism can also be applied to military and aerospace fields, and used for the stable platform of high-precision instruments or equipment, carrying high-quality detectors or monitoring equipment and other precision instruments and equipment.

Claims

1. A two-rotation and one-shift parallel posture adjustment mechanism, characterized in that: It comprises a fixed platform and a moving platform, wherein the fixed platform comprises a horizontal mounting portion and a vertical mounting portion, a first driving branch chain, a second driving branch chain and a third driving branch chain are connected in parallel between the moving platform and the horizontal mounting portion, and a first restraining branch chain and a second restraining branch chain are connected in parallel between the moving platform and the vertical mounting portion; The first driving branch chain and the second driving branch chain have the same structure, both of which include a first ball joint, a first upper rod, a first lower rod and a first Hooke's hinge connected in sequence, the first upper rod and the first lower rod are connected through a first moving pair, the top end of the first upper rod is connected to the first ball joint, the first ball joint is connected to the bottom of the moving platform, the bottom end of the first lower rod is connected to the first Hooke's hinge, and the first Hooke's hinge is connected to the horizontal mounting portion; the third driving branch chain includes a second ball joint, a second upper rod, a second lower rod and a hinge connected in sequence, the second upper rod and the second lower rod are connected through a second moving pair, the top end of the second upper rod is connected to the second ball joint, the second ball joint is connected to the bottom of the moving platform, the bottom end of the second lower rod is connected to the hinge, and the hinge is connected to the horizontal mounting portion; The first constraint branch chain and the second constraint branch chain have the same structure, and both include a third ball joint, a connecting rod and a second Hooke's joint connected in sequence, the two ends of the connecting rod are respectively connected to the third ball joint and the second Hooke's joint, the third ball joint is connected to the side of the moving platform, and the second Hooke's joint is connected to the vertical mounting portion; The first axes of the two first Hooke's joints are respectively arranged along the Y direction and are parallel to each other, the first axis of the first Hooke's joint of the first drive branch is collinear with the axis of the hinge, the second axes of the two first Hooke's joints are respectively arranged along the X direction and are parallel to each other, the first axes of the two second Hooke's joints are respectively arranged along the Z direction and are parallel to each other, and the second axes of the two second Hooke's joints are respectively arranged along the Y direction and are collinear.

2. The two-rotation-one-shift parallel posture adjustment mechanism according to claim 1, characterized in that: The plane formed by the center lines of the first constraint branch chain and the second constraint branch chain is parallel to the moving platform and the horizontal mounting portion, respectively, and the center lines of the first drive branch chain, the second drive branch chain and the third drive branch chain are perpendicular to the plane formed by the center lines of the first constraint branch chain and the second constraint branch chain, respectively.

3. The two-rotation-one-shift parallel posture adjustment mechanism according to claim 2, characterized in that: The center line of the first constraint branch chain and the center line of the first drive branch chain are perpendicular to each other and intersect at one point, and the center line of the second constraint branch chain and the center line of the third drive branch chain are perpendicular to each other and intersect at one point.

4. The two-rotation-one-shift parallel posture adjustment mechanism according to claim 1, characterized in that: The first movable pair and the second movable pair are both driven by hydraulic pressure or electric cylinder.

5. A two-rotation-one-shift parallel posture adjustment mechanism according to any one of claims 1-4, characterized in that: The cross-section of the moving platform is an equilateral triangle, the first drive branch chain, the second drive branch chain and the third drive branch chain are respectively connected and arranged at the bottom of the three corners of the moving platform, and the first constraint branch chain and the second constraint branch chain are respectively connected and arranged on the sides of the two corners of the moving platform.

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