Vacuum Comprehensive Mechanical Performance Verification Device for Space Robotic Arm Strut

Abstract

This invention discloses a vacuum comprehensive mechanical performance verification device for a space robotic arm, belonging to the technical field of ground verification equipment for space products. The verification device comprises three components: a tensile and compressive mechanical performance and fatigue verification section, a bending mechanical performance and fatigue verification section, and a torsional mechanical performance and fatigue verification section. The verification device uses a counterweight as the load, and a winch and steel cable control the loading and unloading of the counterweight load. The tensile and compressive and torsional verification sections employ the lever principle to amplify the counterweight load to the required level. All components selected for the verification device meet the requirements for use in a vacuum environment. This invention has advantages such as small footprint, wide range of test parameters, simple structure, high reliability, and applicability to vacuum environments. By adjusting the counterweight load mass, it is suitable for verifying arm parameters with tensile and compressive loads up to 3000N, bending loads up to 800N·m (related to arm length), and torsional loads up to 600N·m.

Description

Technical Field

[0001] This invention relates to the field of ground verification equipment for space products, and in particular to a vacuum comprehensive mechanical performance verification device for a space robotic arm. Background Technology

[0002] Space robotic arms typically have one or more slender arms to perform tasks at remote locations. During operation, the working end of the robotic arm is subjected to loads and impacts. These forces are amplified through the slender arms, generating a significant torque at the fixed end of the robotic arm. Therefore, the mechanical properties of the arms are subject to high requirements and need to be verified through testing based on usage conditions.

[0003] The mechanical properties of the boom that need to be verified mainly include structural strength and fatigue strength. The structural strength of the boom includes tensile, compressive, bending, and torsional properties, while the fatigue strength of the boom is the fatigue strength against the aforementioned loads. Moreover, the boom operates in a vacuum environment, so the verification process must be as consistent as possible with the working environment, that is, the verification of the boom's mechanical properties must be carried out in a vacuum environment.

[0004] Existing general-purpose testing equipment is mostly limited to verifying a single performance characteristic and cannot be used in a vacuum environment. Therefore, there is a need for a dedicated testing device that is suitable for existing boom dimensions and interface parameters, can be used in a vacuum environment, and can perform verification of all mechanical properties. Summary of the Invention

[0005] The present invention aims to solve the technical problems in the prior art by providing a device for verifying the comprehensive mechanical performance of a space robotic arm in vacuum.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A vacuum comprehensive mechanical performance verification device for a space robotic arm includes, from bottom to top: an arm, an interface flange, a tension / compression point, a tension / compression lever, and a torsion lever; a torsion fork is provided on the outer side of the tension / compression point; a fixed rotation axis is provided on the tension / compression lever near the tension / compression point; the tension / compression lever rotates around the fixed rotation axis to apply a force to the tension / compression point; the torsion lever can apply a torque to the torsion fork;

[0008] The top of the boom is connected to the bottom surface of the interface flange; the tension / compression point and the torsion fork are connected to the top surface of the interface flange;

[0009] The tension / compression lever is connected to a rigid bracket via a fixed rotating shaft;

[0010] The two ends of the tension lever are respectively connected to two first steel cables. The direction of the first steel cables is perpendicular to the direction of gravity and downward. The two first steel cables pass through the winch and are connected to their respective counterweight loads.

[0011] The torsion lever is connected to the rigid support via the fixed rotation axis, and its direction is orthogonal to the tension lever. Two second steel cables are connected to each end of the torsion lever, and the direction of the second steel cables is perpendicular to the plane where the arm and the torsion lever are located. The two second steel cables are 180° rotationally symmetrical with respect to the fixed rotation axis. The two second steel cables pass through the fixed pulley and the winch respectively and are connected to their respective counterweight loads. The two second steel cables connected to both ends of the torsion lever are both horizontal.

[0012] In the above technical solution, the bottom end of the arm is connected to a rigid support.

[0013] In the above technical solution, the connection point of the two second steel cables is the same distance from the fixed rotation axis.

[0014] In the above technical solution, the two second steel cables are connected to the torsion lever in a horizontal direction by the fixed pulley.

[0015] In the above technical solution, the winch can be used in a vacuum environment.

[0016] The present invention has the following beneficial effects:

[0017] The robotic arm lever vacuum comprehensive mechanical performance verification device of the present invention has the ability to verify three types of mechanical properties and their fatigue properties, specifically including: 1. tensile and compressive mechanical properties and their fatigue properties; 2. bending mechanical properties and their fatigue properties; 3. torsional mechanical properties and their fatigue properties.

[0018] The vacuum comprehensive mechanical performance verification device for space robotic arms of the present invention has advantages such as small size, large range of test parameters, simple structure, high reliability, and applicability in vacuum environments. By adjusting the counterweight load mass, it is suitable for verifying arm parameters within tensile and compressive loads of up to 3000N, bending loads of up to 800N·m (related to arm length), and torsional loads of up to 600N·m. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a schematic diagram of the connection of the space robotic arm's vacuum integrated mechanical performance verification device of the present invention.

[0021] Figure 2This is a schematic diagram of the vacuum integrated mechanical performance verification device for the space robotic arm of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure for verifying the tensile and compressive mechanical properties of the space robotic arm's boom in vacuum.

[0023] Figure 4 This is a schematic diagram of the structure for verifying the bending mechanical performance of the space robotic arm boom in the vacuum integrated mechanical performance verification device of the present invention.

[0024] Figure 5 This is a schematic diagram of the structure for verifying the torsional mechanical performance of the arm of the space robotic arm in the vacuum integrated mechanical performance verification device of the present invention.

[0025] The reference numerals in the figure are:

[0026] 1-Arm; 2-Interface flange; 3-Torsion fork; 4-Point of application of tension and compression; 5-Torsion lever;

[0027] 6-Torsion lever; 7-Fixed pulley; 8-Windlass; 91-First steel cable; 92-Second steel cable;

[0028] 10 - Counterweight load; 11 - Fixed rotating shaft. Detailed Implementation

[0029] The inventive concept of this invention is as follows: The space robotic arm boom vacuum comprehensive mechanical performance verification device of this invention mainly includes three parts: tensile and compressive mechanical performance and fatigue verification part, bending mechanical performance and fatigue verification part, and torsional mechanical performance and fatigue verification part.

[0030] The space robotic arm vacuum comprehensive mechanical performance verification device of the present invention uses a counterweight as a load, and uses a winch and steel cable to control the loading and unloading of the counterweight load. The tension, compression and torsion verification parts adopt the lever principle to amplify the counterweight load to the required level.

[0031] The components selected for the space robotic arm boom vacuum comprehensive mechanical performance verification device of the present invention all meet the requirements for use in a vacuum environment.

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] like Figure 1 and 2 As shown, the space robotic arm vacuum comprehensive mechanical performance verification device of the present invention includes: an arm to be verified 1, an interface flange 2, a tension / compression lever 5, a tension / compression application point 4, a torsion lever 6, a torsion fork 3, a fixed pulley 7, a winch 8, a first steel cable 91, a second steel cable 92, and a counterweight load 10.

[0034] The bottom end of the boom 1 to be verified is connected to a rigid support, and the top end is connected to the bottom surface of the interface flange 2. The tension and compression application point 4 and the torsion fork 3 are connected to the top surface of the interface flange 2.

[0035] The tension lever 5 is connected to the rigid support via a fixed rotating shaft 11. Two first steel cables 91 are connected to both ends of the tension lever 5. The direction of the first steel cables 91 is perpendicular downward along the direction of gravity. The two first steel cables 91 pass through the winch 8 and are connected to their respective counterweight loads 10.

[0036] The torsion lever 6 is connected to the rigid support via a fixed rotating shaft 11, its direction orthogonal to the tension lever 5, arranged in a cross shape to prevent interference. Two second steel cables 92 are connected to each end of the torsion lever 6. The direction of the second steel cables 92 is perpendicular to the plane containing the arm 1 and the torsion lever 6; one second steel cable 92 is perpendicular to the plane on one side, and the other is perpendicular to the plane on the other side. The connection point of the two second steel cables 92 is equidistant from the fixed rotating shaft 11, and the two second steel cables 92 are 180° rotationally symmetrical relative to the fixed rotating shaft 11. A fixed pulley 7 ensures the second steel cables 92 remain horizontal, and the two second steel cables 92 pass through the fixed pulley 7 and the winch 8 respectively, connecting to their respective counterweight loads 10.

[0037] The bending verification section does not require the introduction of levers for amplification. The second steel cable 92 is directly connected to the side of the interface flange 2. The second steel cable 92 is horizontal, and its extension line passes through the axis of the boom 1. The second steel cable 92 is kept horizontal by the fixed pulley 7. The second steel cable 92 passes through the fixed pulley 7 and the winch 8 and is connected to the counterweight load 10.

[0038] The robotic arm boom vacuum comprehensive mechanical performance verification device of the present invention uses a winch 8 that can be used in a vacuum environment, and uses vacuum grease in the lubrication process to ensure that the boom 1 will not be contaminated in a vacuum environment. This verification device can test the tensile, compressive, bending, torsional and fatigue mechanical properties of the boom 1 separately. During the test, the boom 1 does not need to be repeatedly disassembled or the working conditions changed. A single test can verify whether all mechanical properties meet the technical requirements.

[0039] The robotic arm lever vacuum comprehensive mechanical performance verification device of the present invention has the ability to verify three types of mechanical properties and their fatigue properties, specifically including: 1. tensile and compressive mechanical properties and their fatigue properties; 2. bending mechanical properties and their fatigue properties; 3. torsional mechanical properties and their fatigue properties.

[0040] The space robotic arm boom vacuum comprehensive mechanical performance verification device of the present invention relies on the counterweight load to apply force, the force is amplified by the lever, the interface flange 2 transmits the force to the boom 1 structure, and the winch 8 controls the application and unloading of the force and can verify the fatigue performance of the boom 1.

[0041] The working process of the robotic arm vacuum comprehensive mechanical performance verification device of the present invention will be described in detail below.

[0042] like Figure 1 As shown, this invention comprises three independent verification devices that can apply four types of loads—tension, compression, bending, and torsion—to the boom 1 to verify its mechanical properties. Furthermore, the fatigue performance of the boom 1 is verified through periodic loading and unloading operations.

[0043] One end of the robotic arm 1 to be verified is fixedly connected to a rigid support, and the other end is connected to the interface flange 2 of the verification device. All three independent verification devices complete the verification test by applying a load to the interface flange 2.

[0044] 1. Verification of tensile and compressive mechanical properties

[0045] The verification method for the tensile and compressive properties of the robotic arm lever 1 is as follows: Figure 3 As shown.

[0046] A fixed fulcrum is connected to a rigid structure, and tension and compression levers are connected to the fixed fulcrum via rotating shafts. Tension and compression application points are designed at a certain distance from the fixed fulcrum, with the force application points located on the axis of arm 1 and connected to interface flange 2. The two ends of the tension and compression levers 5 are connected to counterweight loads 10 via first steel cables 91. The rotation of winch 8 drives the first steel cables 91 to rise and fall, allowing for separate control of the loading and unloading of the two types of counterweight loads 10. The two loads can generate tensile and compressive forces on arm 1 at the force application points, respectively. The magnitude of the force is determined by the mass of the counterweight load 10, the lever length, the fixed fulcrum, and the position of the force application point. Generally, tensile and compressive loads within 3000N can be achieved without special structural reinforcement.

[0047] In the initial state, the two winches 8 lift the counterweights 10 at both ends, and the boom 1 is not subjected to tension or compression. Controlling the left winch 8 lowers the left counterweight 10, which, after being amplified by a lever, generates pressure on the boom 1 at the point of force application. Controlling the right winch 8 lowers the right counterweight 10, which, after being amplified by a lever, generates tension on the boom 1 at the point of force application. The winches 8 can also achieve periodic control of the counterweights 10 to verify the tensile and compressive fatigue performance of the boom 1.

[0048] 2. Verification of bending mechanical properties

[0049] The verification method for the bending mechanical properties of the robotic arm lever 1 is as follows: Figure 4 As shown.

[0050] The bending force of the robotic arm 1 acts directly on the interface flange 2, with its direction perpendicular to the axis of arm 1. A fixed pulley 7, connected to a rigid structure, is used to change the direction of the force. One end of the second steel cable 92 is connected to the side of the interface flange 2, and the other end passes through a winch 8 and connects to the counterweight load 10. The rotation of the winch 8 drives the second steel cable 92 to rise and fall, controlling the loading and unloading of the force. The force can generate a bending moment at the fixed end of arm 1, the magnitude of which is determined by both the mass of the counterweight load 10 and the length of arm 1. Generally, the bending load can be within 800 N·m, depending on the specific length of arm 1.

[0051] In the initial state, the winch 8 lifts the counterweight load 10, at which point the boom 1 is not subjected to bending moment. Controlling the rotation of the winch 8 lowers the counterweight load 10, causing a bending moment at the fixed end of the boom 1. The winch 8 can also achieve periodic control of the counterweight load 10 to verify the bending fatigue performance of the boom 1.

[0052] 3. Verification of torsional mechanical properties

[0053] The verification method for the torsional mechanical properties of the robotic arm lever 1 is as follows: Figure 5 As shown.

[0054] A fixed rotating shaft 11 is connected to a rigid structure, and a torsion lever 6 is connected to the fixed rotating shaft 11. The plug end of the torsion fork 3 extends into the corresponding hole in the torsion lever 6, and the other end is connected to the interface flange 2. A fixed pulley 7 is connected to the rigid structure to change the direction of the force. The two ends of the torsion lever 6 are connected to the counterweight load 10 via a second steel cable 92. The winch 8 rotates, driving the second steel cable 92 to rise and fall, thus controlling the loading and unloading of the counterweight load 10. The load can generate torque on the arm 1 at the torsion fork 3, and the magnitude of the torque is determined by the mass of the counterweight load 10, the lever length, and the plug spacing of the torsion fork 3. Generally, a torsion load of less than 600 N·m can be achieved without special structural reinforcement.

[0055] To prevent the boom 1 from generating bending moment while being subjected to torque, thus avoiding a combined bending and torsion phenomenon, the torque loading method is designed as a couple loading method. That is, equal and opposite forces are applied to both ends of the torsion lever 6, so that the boom 1 is in a pure torsion state and does not generate bending moment.

[0056] In the initial state, the two winches 8 lift the counterweights 10 at both ends, and the boom 1 is not subjected to torque. After the test begins, the winches 8 on both sides are controlled to lower the counterweights 10 on both sides simultaneously. After being amplified by levers, torque is generated on the boom 1 at the torsion fork 3. The winches 8 can also achieve periodic control of the counterweights 10 to verify the torsional fatigue performance of the boom 1.

[0057] The robotic arm lever vacuum comprehensive mechanical performance verification device of the present invention has the ability to verify three types of mechanical properties and their fatigue properties, specifically including: 1. tensile and compressive mechanical properties and their fatigue properties; 2. bending mechanical properties and their fatigue properties; 3. torsional mechanical properties and their fatigue properties.

[0058] The vacuum comprehensive mechanical performance verification device for space robotic arms of the present invention has advantages such as small size, large range of test parameters, simple structure, high reliability, and applicability in vacuum environments. By adjusting the counterweight load mass, it is suitable for verifying arm parameters within tensile and compressive loads of up to 3000N, bending loads of up to 800N·m (related to arm length), and torsional loads of up to 600N·m.

[0059] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A device for verifying the comprehensive mechanical performance of a space robotic arm in vacuum, characterized in that, From bottom to top, it includes: arm (1), interface flange (2), tension and pressure application point (4), tension and pressure lever (5), and torsion lever (6); a torsion fork (3) is provided on the outside of the tension and pressure application point (4); a fixed rotating shaft (11) is provided on the tension and pressure application point (4) near the tension and pressure application point (4); the tension and pressure lever (5) rotates around the fixed rotating shaft (11) to apply force to the tension and pressure application point (4); the torsion lever (6) can apply torque to the torsion fork (3); The top end of the arm (1) is connected to the bottom surface of the interface flange (2); the tension and compression application point (4) and the torsion fork (3) are connected to the top surface of the interface flange (2); The tension lever (5) is connected to the rigid bracket via a fixed rotating shaft (11); The two ends of the tension lever (5) are respectively connected to two first steel cables (91). The direction of the first steel cables (91) is vertically downward along the direction of gravity. The two first steel cables (91) pass through the winch (8) and are connected to their respective counterweight loads (10). The torsion lever (6) is connected to the rigid support via the fixed rotating shaft (11), and its direction is orthogonal to the tension lever (5); two second steel cables (92) are connected to both ends of the torsion lever (6), and the direction of the second steel cables (92) is perpendicular to the plane where the arm (1) and the torsion lever (6) are located; the two second steel cables (92) are 180° rotationally symmetrical with respect to the fixed rotating shaft (11); the two second steel cables (92) pass through the fixed pulley (7) and the winch (8) respectively and are connected to their respective counterweight loads (10); the two second steel cables (92) connected to both ends of the torsion lever (6) are both in the horizontal direction; The bottom end of the boom (1) is connected to a rigid support; The connection point of the two second steel cables (92) is at the same distance from the fixed rotating axis (11); The two second steel cables (92) are connected to the torsion lever (6) in a horizontal direction by the fixed pulley (7).

2. The space robotic arm boom vacuum comprehensive mechanical performance verification device according to claim 1, characterized in that, The winch (8) can be used in a vacuum environment.

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