A multi-platform composite series-parallel closed-loop motion mechanism

Abstract

The present invention discloses a multi-platform composite series-parallel closed-loop motion mechanism, which includes 3 motion platforms, 9 telescopic motion chains, 12 Hooke joints and 6 spherical joints. The mechanism has multiple levels of motion platforms, which can carry multiple levels of optical devices or other devices, reduce space in a series optical system that requires it, and achieve control for each level; this composite series-parallel motion mechanism is formed by closing and connecting in series a 6-UPS and a 3-UPU type (this part is located inside the mechanism as a whole), and is an inner full-rank or redundant inner closed-loop series-parallel platform, where any one of the 3 platforms is a static platform, and the other two are a 6-degree-of-freedom moving platform and a 3-degree-of-freedom moving platform. This multi-platform composite series-parallel closed-loop motion mechanism adopts a structural form of two levels of motion platforms, realizes the integration of series and parallel in the overall structure, combines the advantages of both series mechanisms and parallel mechanisms, has a larger motion stroke range, higher precision, is structurally compact, and has a small volume, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of compound motion platforms, and particularly relates to a multi-platform composite series-parallel closed-loop motion mechanism. Background Art

[0002] In an optical system, most of the components of the optical path are more than two in number, and in the actual operation process, it is often necessary to manually install and disassemble components to achieve the adjustment of the optical path. Considering that under the condition that the optical system is not easily disassembled, when affected by gravity, temperature, air pressure, vibration, etc., it is necessary to arrange multiple multi-degree-of-freedom motion platforms to adjust the positions and postures of components to achieve the adjustment and calibration tasks of the components of the optical imaging system. At present, most of them adopt the stewart parallel platform based on six degrees of freedom (in the form of six telescopic struts) and the macro-micro motion mechanism of series platform + parallel platform as the main component adjustment mechanism alone. For high-precision multi-stage optical systems, the existing mechanisms fail to meet the requirements of multi-adjustment and small volume of the optical system. Summary of the Invention

[0003] Aiming at the problems existing in the above-mentioned prior art, the invention provides a multi-platform composite series-parallel closed-loop motion mechanism. The motion platform realizes the adjustment task in the optical system through structural design and control method, and has the characteristics of macro-micro regulation, strong space adaptability, no coupling, stable static balance, etc. The invention combines the advantages of parallel mechanisms and series mechanisms, and provides new ideas and methods for composite series-parallel mechanisms.

[0004] To achieve the above object, the invention adopts the following technical solutions:

[0005] A multi-platform composite series-parallel closed-loop motion mechanism, including a first motion platform, a second motion platform, and a third motion platform, 9 telescopic motion chains, 12 Hooke joints, and 6 spherical joints. The second platform is between the first platform and the third platform. The first platform is connected to the first telescopic motion chain through a Hooke joint, the first platform is connected to the second telescopic motion chain through a Hooke joint, the first platform is connected to the third telescopic motion chain through a Hooke joint, the first platform is connected to the seventh telescopic motion chain through a Hooke joint, the first platform is connected to the eighth telescopic motion chain through a Hooke joint, the first platform is connected to the ninth telescopic motion chain through a Hooke joint. The first telescopic motion chain is connected to the second platform through a Hooke joint, the second telescopic motion chain is connected to the second platform through a Hooke joint, the third telescopic motion chain is connected to the second platform through a Hooke joint. The second platform is connected to the fourth telescopic motion chain through a Hooke joint, the second platform is connected to the fifth telescopic motion chain through a Hooke joint, the second platform is connected to the sixth telescopic motion chain through a Hooke joint. The fourth telescopic motion chain is connected to the third platform through a spherical joint, the fifth telescopic motion chain is connected to the third platform through a spherical joint, the sixth telescopic motion chain is connected to the third platform through a spherical joint, the seventh telescopic motion chain is connected to the third platform through a spherical joint, the eighth telescopic motion chain is connected to the third platform through a spherical joint, and the ninth telescopic motion chain is connected to the third platform through a spherical joint;

[0006] The second platform and the third platform are connected in a 3-UPS manner, and are connected in a 3-UPU type parallel connection with the first platform. The connection between the first platform and the third platform is a 3-UPS connection. Its working state is:

[0007] (1) When the first platform is fixed: The second platform and the third platform are the motion platforms. The connection between the second platform and the first platform is a 3-UPU type parallel platform. When the second platform is stationary, the second platform and the first platform are regarded as one body, and the connection between the third platform and the first platform is a 6-UPS type parallel platform;

[0008] (2) When the second platform is fixed: The first platform and the third platform are the motion platforms. The connection between the first platform and the second platform is a 3-UPU type parallel platform. When the first platform is stationary, the first platform and the second platform are regarded as one body, and the connection between the second platform and the third platform is a 6-UPS type parallel platform;

[0009] (3) When the third platform is fixed: The first platform and the second platform are the motion platforms. The connection between the first platform and the second platform is a 3-UPU type parallel platform. When the first platform or the second platform is stationary, the first platform and the second platform are regarded as one body, and the second platform or the first platform is a 6-UPS type parallel platform;

[0010] When the 6-UPS type parallel platform reaches the coupling position or multiple analytical positions, by adjusting the 3-UPU type parallel platform, the initial position of the 6-UPS type parallel platform is changed, thereby changing the initial length and azimuth state of the telescopic kinematic chain, and further achieving the purpose of the unique solution of the 6-UPS type parallel platform. And when the moving platform has a sufficiently large movement stroke of the telescopic kinematic chain, the movement stroke of the platform is gradually accumulated and enlarged.

[0011] Furthermore, the 3-UPU configuration chain is replaced with other chain configurations n-XXX to form a full-rank configuration connecting the two platforms, constituting a series connection of a 6-degree-of-freedom moving platform and a moving platform with other degrees of freedom. Among them, n is the number of chains, and XXX is the form of the chain connected by kinematic pairs between the platforms; when applied to multi-stage series-parallel mechanisms, the rule for connecting the platforms through telescopic kinematic chains is: the sequential connection method between the platforms is: full-rank configuration parallel connection - 3-UPS parallel connection - full-rank configuration parallel connection - 3-UPS parallel connection..., repeating in a cycle, where the full-rank configuration is 4-UPU or 6-UPS or 2-RPU-2-UPS; the mutual connection method between other platforms and the first platform is all 3-UPS.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The motion mechanism of the present invention adopts a structural form of series connection of 3-UPU and 3-UPS parallel platforms. It has the advantage of a large actuation range of the series mechanism in terms of the motion stroke, and the platforms are connected in parallel with each other, with a compact structure, small volume, high stability, and the characteristics of high precision of the parallel mechanism.

[0014] 2. The motion mechanism of the present invention has multi-stage moving platforms, which can carry multi-stage optical devices or other devices, and can reduce space in an optical system that requires series-connected devices and achieve control for each stage.

[0015] 3. The platform of this motion mechanism has various fixed situations, and a certain fixed mode can be selected according to the actual situation.

[0016] 4. When the platform of the motion mechanism of the present invention reaches the coupling position or multiple analytical positions of 6-UPS, the initial position of the 6-UPS parallel platform can be changed by adjusting the 3-UPU parallel platform, thereby changing the initial length and azimuth state of the kinematic chain, and further achieving the purpose of the unique solution of the 6-UPS parallel platform. And when the moving platform has a sufficiently large movement stroke of the kinematic chain, the movement stroke of the platform can be gradually accumulated and enlarged.

[0017] 5. This motion mechanism realizes the motion system adjustment mechanism through structural design and control methods, with strong space adaptability, no coupling, and stable static balance. Brief Description of the Drawings

[0018] Figure 1 This is a three-dimensional view of a multi-platform composite series-parallel closed-loop motion mechanism of the present invention. Among them, 1 is the first platform, 2 is the Hooke's joint, 3 is the second platform, 4 is the telescopic motion chain, 5 is the spherical joint, and 6 is the third platform;

[0019] Figure 2 This is a schematic diagram of the multi-stage series-parallel connection of the multi-platform composite series-parallel closed-loop motion mechanism of the present invention. Detailed Embodiment

[0020] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] See Figure 1 , the multi-platform composite series-parallel closed-loop motion mechanism of the present invention includes 3 motion platforms, namely the first platform 1, the second platform 3, and the third platform 6; 9 telescopic motion chains 4, namely the first telescopic motion chain 4-1, the second telescopic motion chain 4-2, the third telescopic motion chain 4-3, the fourth telescopic motion chain 4-4, the fifth telescopic motion chain 4-5, the sixth telescopic motion chain 4-6, the seventh telescopic motion chain 4-7, the eighth telescopic motion chain 4-8, and the ninth telescopic motion chain 4-9; 12 Hooke's joints 2; and 6 spherical joints 5.

[0022] The second platform 3 is between the first platform 1 and the third platform 6; the first platform 1 is connected to the first extensible kinematic chain 4-1 through a Hooke's joint 2, the first platform 1 is connected to the second extensible kinematic chain 4-2 through a Hooke's joint 2, the first platform 1 is connected to the third extensible kinematic chain 4-3 through a Hooke's joint 2, the first platform 1 is connected to the seventh extensible kinematic chain 4-7 through a Hooke's joint 2, the first platform 1 is connected to the eighth extensible kinematic chain 4-8 through a Hooke's joint 2, the first platform 1 is connected to the ninth extensible kinematic chain 4-9 through a Hooke's joint 2, the first extensible kinematic chain 4-1 is connected to the second platform 3 through a Hooke's joint 2, the second extensible kinematic chain 4-2 is connected to the second platform 3 through a Hooke's joint 2, the third extensible kinematic chain 4-3 is connected to the second platform 3 through a Hooke's joint 2, the second platform 3 is connected to the fourth extensible kinematic chain 4-4 through a Hooke's joint 2, the second platform 3 is connected to the fifth extensible kinematic chain 4-5 through a Hooke's joint 2, the second platform 3 is connected to the sixth extensible kinematic chain 4-6 through a Hooke's joint 2, the fourth extensible kinematic chain 4-4 is connected to the third platform 6 through a spherical joint 5, the fifth extensible kinematic chain 4-5 is connected to the third platform 6 through a spherical joint 5, the sixth extensible kinematic chain 4-6 is connected to the third platform 6 through a spherical joint 5, the seventh extensible kinematic chain 4-7 is connected to the third platform 6 through a spherical joint 5, the eighth extensible kinematic chain 4-8 is connected to the third platform 6 through a spherical joint 5, and the ninth extensible kinematic chain 4-9 is connected to the third platform 6 through a spherical joint 5.

[0023] The first platform 3 and the third platform 6 are connected in a 3-UPS manner, and are connected in a 3-UPU type parallel connection with the first platform 1. The connection between the first platform 1 and the third platform 6 is a 3-UPS connection. Among them, the connection method is represented by n-XXX, where n represents the number of kinematic chains connecting between the platforms, and XXX represents the kinematic chain connection type. U represents a Hooke's joint, P represents a prismatic joint, S represents a spherical joint, and R represents a revolute joint. Its working conditions are as follows:

[0024] (1) The first platform 1 is fixed: The second platform 3 and the third platform 6 are moving platforms. The second platform 3 and the first platform 1 form a 3-UPU type parallel platform. When the second platform 3 is stationary, the third platform 6 and the first platform 1 form a 6-UPS type parallel platform.

[0025] (2) The second platform 3 is fixed: The first platform 1 and the third platform 6 are moving platforms. The first platform 1 and the second platform 3 form a 3-UPU type parallel platform. When the first platform 1 is stationary, the second platform 3 and the third platform 6 form a 6-UPS type parallel platform.

[0026] (3) Fixing of the third platform 6: The first platform 1 and the second platform 3 are moving platforms. There is a 3-UPU type parallel platform between the first platform 1 and the second platform 3. When the first platform 1 or the second platform 3 is stationary, the second platform 3 or the first platform 1 is a 6-UPS type parallel platform.

[0027] At this time, the third platform 6 is connected in a 6-UPS connection. When reaching the coupling position or various resolution positions, the 3-UPU parallel platform can be adjusted, that is, the second platform 3 or the first platform 1 is adjusted, to change the 6-UPS parallel platform, that is, the initial position of the third platform 6, so as to change the initial length and azimuth state of the telescopic moving chain, and further achieve the purpose of the unique solution of the 6-UPS parallel platform. And when the moving platform has a sufficiently large moving stroke in the telescopic moving chain, the moving stroke of the platform can be gradually accumulated and expanded.

[0028] The multi-platform composite series-parallel closed-loop motion mechanism of the present invention can also replace the 3-UPU configuration chain with other chain configurations to form a series connection of a 6-degree-of-freedom moving platform and other degree-of-freedom moving platforms. The other chain configurations include chain configurations formed by changing the number of chains n and the chain forms of the kinematic pairs used for connecting between platforms, such as full-rank type connections such as 2-RPU-2-UPS, 4-UPU, etc. When applied to a multi-stage series-parallel mechanism, see Figure 2 .. The chain rules between platforms should follow: Represent each series-parallel platform by A, B, C, D, E... The sequential connection method between platforms is a full-rank configuration parallel connection method (between platforms A and B, defined as a 0-level series connection) - 3-UPS parallel connection (between platforms B and C, a 1-level series-parallel connection) - full-rank configuration parallel connection method (between C and D, a 2-level series-parallel connection) - 3-UPS parallel connection (between D and E, a 3-level parallel connection)..., repeating in a cycle, where the full-rank configuration satisfies all connection methods for determining the moving platform: n-XXX, for example, it can be 4-UPU or 6-UPS or 2-RPU-2-UPS, etc. It should be noted here that the number of chains n changes with the type XXX of the chain connection to ensure a full-rank connection between two platforms; the mutual connection methods between other platforms B, C, D, E and platform A are all 3-UPS.

[0029] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-platform composite series-parallel closed-loop motion mechanism, characterized in that: It includes a first platform (1), a second platform (3) and a third platform (6), 9 telescopic kinematic chains (4), 12 Hooke's joints (2) and 6 spherical joints (5); the second platform (3) is between the first platform (1) and the third platform (6); the first platform (1) is connected to the first telescopic kinematic chain (4-1) through a Hooke's joint (2), the first platform (1) is connected to the second telescopic kinematic chain (4-2) through a Hooke's joint (2), the first platform (1) is connected to the third telescopic kinematic chain (4-3) through a Hooke's joint (2), the first platform (1) is connected to the seventh telescopic kinematic chain (4-7) through a Hooke's joint (2), the first platform (1) is connected to the eighth telescopic kinematic chain (4-8) through a Hooke's joint (2), the first platform (1) is connected to the ninth telescopic kinematic chain (4-9) through a Hooke's joint (2), the first telescopic kinematic chain (4-1) is connected to the second platform (3) through a Hooke's joint (2), the second telescopic kinematic chain (4-2) is connected to the second platform (3) through a Hooke's joint (2), the third telescopic kinematic chain (4-3) is connected to the second platform (3) through a Hooke's joint (2), the second platform (3) is connected to the fourth telescopic kinematic chain (4-4) through a Hooke's joint (2), the second platform (3) is connected to the fifth telescopic kinematic chain (4-5) through a Hooke's joint (2), the second platform (3) is connected to the sixth telescopic kinematic chain (4-6) through a Hooke's joint (2), the fourth telescopic kinematic chain (4-4) is connected to the third platform (6) through a spherical joint (5), the fifth telescopic kinematic chain (4-5) is connected to the third platform (6) through a spherical joint (5), the sixth telescopic kinematic chain (4-6) is connected to the third platform (6) through a spherical joint (5), the seventh telescopic kinematic chain (4-7) is connected to the third platform (6) through a spherical joint (5), the eighth telescopic kinematic chain (4-8) is connected to the third platform (6) through a spherical joint (5), and the ninth telescopic kinematic chain (4-9) is connected to the third platform (6) through a spherical joint (5); The second platform (3) and the third platform (6) are in a 3-UPS connection and are connected in parallel with the first platform (1) of the 3-UPU type. The connection between the first platform (1) and the third platform (6) is a 3-UPS connection; its working state is: (1) The first platform (1) is fixed: the second platform (3) and the third platform (6) are moving platforms. The second platform (3) and the first platform (1) form a 3-UPU type parallel platform. When the second platform (3) is stationary, the second platform (3) and the first platform (1) are regarded as one body, and the third platform (6) and the first platform (1) form a 6-UPS type parallel platform; (2) The second platform (3) is fixed: The first platform (1) and the third platform (6) are moving platforms. Between the first platform (1) and the second platform (3) is a 3-UPU type parallel platform. When the first platform (1) is stationary, the first platform (1) and the second platform (3) are regarded as one body, and between the second platform (3) and the third platform (6) is a 6-UPS type parallel platform; (3) The third platform (6) is fixed: The first platform (1) and the second platform (3) are moving platforms. Between the first platform (1) and the second platform (3) is a 3-UPU type parallel platform. When the first platform (1) or the second platform (3) is stationary, the first platform (1) and the second platform (3) are regarded as one body, and the second platform (3) or the first platform (1) is a 6-UPS type parallel platform; In the case where the 6-UPS type parallel platform reaches the coupling position or multiple analytical positions, by adjusting the 3-UPU type parallel platform, the initial position of the 6-UPS type parallel platform is changed, thereby changing the initial length and azimuth state of the telescopic moving chain, and further achieving the purpose of the unique solution of the 6-UPS type parallel platform. And when the moving platform has a sufficiently large moving stroke of the telescopic moving chain, the moving stroke of the platform is gradually accumulated and expanded.

2. The multi-platform composite series-parallel closed-loop motion mechanism according to claim 1, characterized in that: Replace the 3-UPU configuration chain with other chain configurations n-XXX to form a full-rank configuration connecting the two platforms, and form a series connection of a 6-degree-of-freedom moving platform and a moving platform with other degrees of freedom. Among them, n is the number of chains, and XXX is the form of the chain connected by kinematic pairs between the platforms; when applied to a multi-stage series-parallel mechanism, the rule for connecting the platforms through telescopic moving chains is: The connection method between the platforms in sequence is: cyclic full-rank configuration parallel connection - 3-UPS parallel connection - full-rank configuration parallel connection - 3-UPS parallel connection, where the full-rank configuration is 4-UPU or 6-UPS or 2-RPU-2-UPS; the mutual connection method between other platforms and the first platform is all 3-UPS.

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