Multi-dimensional force detection device with air-floating steering structure

Abstract

The application relates to the technical field of multi-dimensional force detection, in particular to a multi-dimensional force detection device with air floating steering structures. The multi-dimensional force detection device with air floating steering structures comprises a rack, a plurality of air floating steering structures and a plurality of weight force applying structures are arranged on the rack, a plurality of the weight force applying structures apply force to a calibrated multi-dimensional force sensor through a plurality of the air floating steering structures, the plurality of the air floating steering structures and the plurality of the weight force applying structures are one-to-one corresponding, and the air floating steering structure is used for converting the gravity of the weight force applying structure into force in different directions. The application has the following effects: the horizontal force generated after the gravity of the weight is passed through the air floating steering structure can be guaranteed to be equivalent to the gravity of the weight, friction error is reduced, calibration accuracy is improved, and the device can load and calibrate the multi-dimensional force sensor in multiple directions.

Description

Technical Field

[0001] This application relates to the technical field of multidimensional force detection, and in particular to a multidimensional force detection device with an air-bearing steering structure. Background Technology

[0002] A multidimensional force sensor is a precision device that can simultaneously measure three force components (Fx, Fy, Fz) and three torque components (Mx, My, Mz), and is widely used in fields such as robotics, aerospace, precision machining, and biomechanics.

[0003] The detection accuracy of multi-component force sensors directly affects the quality and performance of related products. Therefore, developing high-precision and reliable multi-component calibration devices has important practical significance and application value.

[0004] In the past, hydraulic loading was commonly used to calibrate multi-component force sensors. This involved using a hydraulic system to generate stable pressure and applying force to the sensor via a hydraulic cylinder. However, the friction and gaps in the mechanical structure could introduce significant measurement errors, affecting the accuracy of the calibration. Utility Model Content

[0005] To improve the calibration accuracy of multi-component force sensors, this application provides a multi-dimensional force detection device with an air-bearing steering structure.

[0006] This application provides a multi-dimensional force detection device with an air-bearing steering structure, which adopts the following technical solution: it includes a frame, on which multiple air-bearing steering structures and multiple weight-applying structures are arranged. The multiple weight-applying structures apply force to the calibrated multi-dimensional force sensor through the multiple air-bearing steering structures. The multiple air-bearing steering structures and the multiple weight-applying structures correspond one-to-one. The air-bearing steering structure is used to convert the gravity of the weight-applying structure into force in different directions.

[0007] By adopting the above technical solution, since the friction coefficient of air is extremely low and can be ignored, it can be ensured that the horizontal force generated by the weight of the weight after passing through the air buoyancy deflection structure remains equal to the weight of the weight. Multiple weight force-applying structures apply force to the calibrated multidimensional force sensor through multiple air buoyancy deflection structures, reducing friction error, improving calibration accuracy, and enabling the device to perform multi-directional force loading and calibration of the multidimensional force sensor.

[0008] Preferably, the frame is further provided with a movable beam and a force-applying workpiece. The movable beam and the force-applying workpiece are respectively used to fix the two ends of the calibrated multidimensional force sensor. The movable beam is slidably connected to the frame in the vertical direction. The multiple weight force-applying structures apply force to the force-applying workpiece through multiple air-bearing steering structures.

[0009] Preferably, the plurality of air-bearing steering structures are horizontal force air-bearing steering structures and Z-force air-bearing steering structures, wherein there are four sets of Z-force air-bearing steering structures, which are arranged above the workpiece applying the force. One end of each Z-force air-bearing steering structure is connected to the workpiece applying the force, and the other end is connected to the weight-applying structure. Below the connection between the workpiece applying the force and each Z-force air-bearing steering structure, a weight-applying structure is also suspended to form a force couple. A reverser is also provided on the frame. The top of the reverser is pressed against the workpiece applying the force, and the weight-applying structure is suspended at the bottom of the reverser.

[0010] The existing torque loading method applies a force F at the position of the force center line L of the off-center sensor and calculates the torque component according to the formula T=L×F. However, in reality, in addition to generating torque on the sensor, a portion of the force F at the force center line L is decomposed into an axial force. The magnitude of this decomposition is related to L, and the actual generated torque needs to be calculated based on the structural dimensions of the sensor under test and L, which increases the measurement error. By adopting the above technical solution, a couple loading method is used, applying forces F1 and F2 at symmetrical positions on the left and right sides of the force center line L of the off-center sensor. F1 and F2 have the same magnitude but opposite directions. When F1=F2, the loading of the axial force is eliminated, generating a couple that applies Mx and My to the calibrated multidimensional force sensor. Meanwhile, the weight force-applying structure at the bottom of the inverter generates a vertically downward force Fz on the calibrated multidimensional force sensor through the inverter.

[0011] Preferably, the horizontal force air buoyancy steering structure is provided in eight sets. One end of the horizontal force air buoyancy steering structure is connected to the force-applying workpiece, and the other end of the horizontal force air buoyancy steering structure is connected to the weight force-applying structure. Among them, four sets of horizontal force air buoyancy steering structures cooperate with four sets of weight force-applying structures to apply horizontal force to the force-applying workpiece along the X-axis and Y-axis coordinates, respectively. The other four sets of horizontal force air buoyancy steering structures generate a pair of force couples to apply force to the force-applying workpiece.

[0012] Similarly, by adopting the above technical solution, two sets of weight force-applying structures and two sets of corresponding horizontal force air-float steering structures are used to apply the gravity of weights of equal mass and opposite direction to the force-applying workpieces with equal lever arms, generating a pair of force couples to apply Mz to the calibrated multidimensional force sensor; while the other four sets of weight force-applying structures and corresponding horizontal force air-float steering structures generate forces Fx and Fy in the direction of water flow to the calibrated multidimensional force sensor through the force-applying workpieces.

[0013] Preferably, the horizontal force air buoyancy steering structure includes an air buoyancy bearing assembly and a flexible connector. The flexible connector bypasses the air buoyancy bearing assembly, and one end of the flexible connector is connected to the weight force application structure, while the other end of the flexible connector is connected to the force application workpiece.

[0014] Since the basic force source is the gravity of the weights, and the direction of the force is vertically downward, by adopting the above technical solution, the gravity of the weights is converted into a horizontal force. The flexible connector can withstand extremely large loads and has very high flexibility, eliminating the mutual interference between the various standard components.

[0015] Preferably, the Z-axis force air buoyancy steering structure includes an air buoyancy bearing assembly, a flexible connector, and a balance weight. One end of the flexible connector is connected to the force-applying workpiece, and the other end of the flexible connector is connected to the balance weight after bypassing the air buoyancy bearing assembly. The end of the balance weight away from the air buoyancy bearing assembly is connected to the weight force-applying structure.

[0016] By adopting the above technical solution, four equal-mass balancing weights change the direction of force through the air bearing assembly, causing the balancing weights to exert their own weight on the force-applying structure.

[0017] Preferably, the air bearing assembly includes a base, two air bearing blocks, two air bearing bushings, and a pulley. The base is mounted on the frame. The air bearing blocks, air bearing bushings, and pulleys are coaxially mounted on the base, with the two air bearing blocks and two air bearing bushings symmetrically located on both sides of the pulley, allowing the pulley and the base to be rotatably connected. The flexible connector passes around the pulley.

[0018] By adopting the above technical solution, the air-bearing bushing utilizes the principle of air buoyancy to enable the pulley to rotate with almost no friction. It has an internal air passage, through which compressed air is introduced to form an air film. The pulley is used to change the direction of the flexible connector to reduce friction with the flexible connector.

[0019] Preferably, the weight force-applying structure includes multiple weights of different weights suspended and connected together, a weight tray, and a driving component. The weight tray is located directly below the weights, and the driving component is used to drive the weight tray to slide back and forth in the vertical direction to carry multiple weights one by one.

[0020] By adopting the above technical solution, the position of the weight tray is controlled to realize the loading and unloading of weights, thus meeting the range requirements of different weights.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. The force direction is changed based on air flotation technology. Since the friction coefficient of air is extremely low and negligible, the force generated by the weight of the weight after passing through the force reversal component is equal to the weight of the weight, thus improving the calibration accuracy. 2. The device applies force in the X, Y, and Z directions by using weights, and has the ability to calibrate force values ​​in the X, Y, and Z directions, as well as the ability to calibrate torque in the X, Y, and Z directions clockwise and counterclockwise. 3. By using two sets of weight force application structures and two corresponding horizontal force air buoyancy steering structures, the gravity of weights with equal mass and opposite direction is applied to the force application workpiece with equal lever arms, generating a pair of force couples, and applying Mz, Mx and My to the calibrated multidimensional force sensor. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a partial structural diagram of this application; Figure 3 This is a partial structural diagram of this application; Figure 4 This is a partial structural diagram of this application; Figure 5 yes Figure 1 A magnified view of part A in the diagram.

[0023] Explanation of reference numerals in the attached drawings: 110, frame; 111, base; 112, lower column; 113, middle beam; 114, upper column; 115, ball spline; 116, upper beam; 117, moving beam; 118, workpiece applying force; 119, reverser; 120, weight force application structure; 121, weight; 122, weight tray; 123, drive component; 1231, electric cylinder; 1232, servo motor; 131, horizontal force air-bearing steering structure; 132, Z-axis force air-bearing steering structure; 133, flexible connector; 134, balance weight; 140, air-bearing bearing assembly; 141, base; 142, air-bearing stop; 143, air-bearing bushing; 144, pulley. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the accompanying drawings.

[0025] This application discloses a multi-dimensional force detection device with an air-bearing steering structure, which is used to improve the calibration accuracy of multi-component force sensors.

[0026] refer to Figures 1-5 A multi-dimensional force detection device with an air-bearing steering structure includes a frame 110, on which multiple air-bearing steering structures, multiple weight force-applying structures 120, a moving beam 117, and a force-applying workpiece 118 are arranged.

[0027] The frame 110 provides support and installation foundation for the entire device. Specifically, the frame 110 includes a base 111, lower columns 112, a middle beam 113, upper columns 114, ball screws, and an upper beam 116. The base 111 is made of 45# steel forgings, is flat, and has a large area and a certain thickness to ensure stable support. The base 111 is rigidly connected to the middle beam 113 through four lower columns 112, and the middle beam 113 is connected to the upper beam 116 through four upper columns 114. A rigid connection is formed, with two ball screws installed between the middle beam 113 and the upper beam 116 via angular contact bearings for raising and lowering the moving beam 117. The moving beam 117 is located between the middle beam 113 and the upper beam 116. In this embodiment, four pairs of ball splines 115 are used to guide the up and down movement of the moving beam 117 and to withstand the force and torque generated by the weight force-applying structure 120, forming a structure with sufficient strength and rigidity to stably support the operation of the entire detection device.

[0028] Multiple air-bearing steering structures and multiple weight-applying force structures 120 are correspondingly arranged on the frame 110. The weight-applying force structure 120 applies force to the multi-dimensional force sensor being calibrated through the air-bearing steering structure. The moving beam 117 and the force-applying workpiece 118 are used to fix the two ends of the multi-dimensional force sensor being calibrated. First, the two ends of the multi-dimensional force sensor being calibrated are fixed with the upper and lower tooling plates respectively. Then, the positioning holes of the upper tooling plate and the force-applying workpiece 118 are positioned by the positioning pins. Finally, the upper tooling plate and the force-applying workpiece 118 are locked with bolts. After moving to the appropriate position, the lower tooling plate and the moving beam 117 are connected in the same way. Since all forces and torques are applied to the force-applying workpiece 118, when the calibrated multidimensional force sensor is fixed with the moving beam 117 and the force-applying workpiece 118, the applied force and torque positions are also fixed. The error mainly comes from the gap between the positioning pin and the positioning hole, as well as the positional error of the positioning hole of the upper tooling plate and the force-applying workpiece 118. In this embodiment, the positional error of the positioning hole of the upper tooling plate and the force-applying workpiece 118 is controlled to be 0.01mm during processing, the fit clearance between the positioning pin and the positioning hole is controlled to be 0.01mm, and the maximum positioning error is 0.02mm.

[0029] Specifically, the multiple air-bearing steering structures are a horizontal force air-bearing steering structure 131 and a Z-axis force air-bearing steering structure 132. The horizontal force air-bearing steering structure 131 has eight sets, corresponding to eight sets of weight-applying structures 120. One end of the horizontal force air-bearing steering structure 131 is connected to the force-applying workpiece 118, and the other end is connected to the weight-applying structures 120. Four sets of weight-applying structures 120, in conjunction with the four sets of horizontal force air-bearing steering structures 131, apply the gravity of the weight 121 horizontally along the X and Y axes to the force-applying workpiece 118, generating horizontal forces Fx and Fy on the calibrated multidimensional force sensor through the force-applying workpiece 118. The other four sets of weight-applying structures 120, in conjunction with the four sets of horizontal force air-bearing steering structures 131, apply the gravity of weights 121 of equal mass and opposite direction to the force-applying workpiece 118 with equal lever arms, thus applying horizontal forces Fx and Fy to the calibrated multidimensional force sensor. The force sensor applies Mz, generating two pairs of force couples, Mz1 and Mz2. Four sets of Z-axis force air buoyancy steering structures 132 are provided, each corresponding to a weight-applying structure 120. One end of each Z-axis force air buoyancy steering structure 132 is connected to the force-applying workpiece 118, and the other end is connected to the weight-applying structure 120. A weight-applying structure 120 is suspended below the connection point between the force-applying workpiece 118 and each Z-axis force air buoyancy steering structure 132. Similarly, four pairs of force couples are generated, Mx1, Mx2, My1, and My2. Furthermore, a reverser 119 is provided on the frame 110. The top of the reverser 119 presses against the force-applying workpiece 118, and a weight-applying structure 120 is suspended at the bottom of the reverser 119. The force-applying workpiece 118 generates a vertically downward force Fz on the calibrated multidimensional force sensor.

[0030] The horizontal force air buoyancy steering structure 131 includes an air bearing assembly 140 and a flexible connector 133. The flexible connector 133 bypasses the air bearing assembly 140 and is connected at one end to the weight force application structure 120, while the other end is connected to the force application workpiece 118. The Z-axis force air buoyancy steering structure 132 includes an air bearing assembly 140, a flexible connector 133, and a balance weight 134. One end of the flexible connector 133 is connected to the force application workpiece 118, while the other end bypasses the air bearing assembly 140. The component 140 is connected to the balance weight 134. The end of the balance weight 134 away from the air bearing assembly 140 is connected to the weight force application structure 120. The four balance weights 134 of the same mass change the direction of the force through the air bearing assembly 140, causing the self-weight of the balance weight force application structure 120 to be reduced. In this embodiment, the flexible connector 133 is made of carbon fiber. Since carbon fiber has extremely high tensile strength, which can reach more than 3000MPa, it can withstand extremely large loads and has very high flexibility, eliminating the mutual interference of each standard component.

[0031] The air bearing assembly 140 includes a base 141, two air bearing blocks 142, two air bearing bushings 143, and a pulley 144. The air bearing blocks 142, air bearing bushings 143, and pulley 144 are coaxially arranged on the base 141, with the two air bearing blocks 142 and the two air bearing bushings 143 symmetrically located on both sides of the pulley 144. The base 141 is made of metal and has a certain strength and stability. Its shape is designed according to the installation and use requirements of the air bearing assembly 140. The air bearing blocks 142 are used to limit the axial position of the air bearing bushings 143 and the pulley 144 to ensure their stable operation. They are made of wear-resistant materials and have a finely machined surface. The air bearing bushings 143 utilize the air buoyancy principle to enable the pulley 144 to rotate with almost no friction. They have an internal air passage, which forms an air film by introducing compressed air. The pulley 144 is used to change the direction of the flexible connector 133 to reduce friction with the flexible connector 133.

[0032] Furthermore, the weight-applying structure 120 includes multiple weights 121 suspended and connected by different weights, a weight tray 122, and a driving component 123. The weight tray 122 is positioned directly below the weights 121. The driving component 123 drives the weight tray 122 to slide back and forth vertically, carrying multiple weights 121 one by one. The weights 121 are made of 304 stainless steel with a surface roughness of less than 1.6µm. The maximum permissible error of the weights 121 does not exceed 0.005%. The weights 121 are configured to meet the range requirements of different weights. In this embodiment, the weights 121 are configured to meet the following ranges: Z-axis force range of 500 N, 1000 N, 1500 N, 2000 N, 2500 N, 3000 N, and 5000 N; X-axis and Y-axis force ranges of 200 N, 400 N, 600 N, 800 N, 1000 N, 1200 N, and 2000 N. The five-point calibration of multi-component force sensors with torque ranges of 10 Nm, 20 Nm, 30 Nm, 40 Nm, 50 Nm, 60 Nm, and 100 Nm, respectively, is performed. The five-point calibration refers to the loading of 20%, 40%, 60%, 80%, and 100% of the full-scale force value. The drive unit 123 consists of an electric cylinder 1231 and a servo motor 1232, and adopts an electric displacement control method with a position control accuracy better than 0.02 mm. It can accurately control the position of the weight tray 122 to realize the loading and unloading of the weights 121.

[0033] The implementation principle of the multi-dimensional force detection device with an air-bearing steering structure in this embodiment is as follows: The multi-dimensional force detection device in this embodiment provides a stable support structure through the frame 110. The air-bearing steering structure uses the air bearing assembly 140 to reduce friction and accurately convert the gravity of the weight force application structure 120 into forces in different directions applied to the multi-dimensional force sensor being calibrated. This improves the calibration accuracy of the multi-dimensional force sensor and reduces measurement errors caused by friction, force decomposition, and other problems in traditional calibration methods. The weight force application structure 120 can load weights 121 of different weights according to calibration requirements to achieve multi-component force loading. Compared with the prior art, this represents a significant improvement and enhancement, and can better meet the needs of high-precision calibration of multi-dimensional force sensors in industrial production.

[0034] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-dimensional force detection device with an air-bearing steering structure, comprising a frame (110), characterized in that: The frame (110) is provided with multiple air-bearing steering structures and multiple weight-applying structures (120). The multiple weight-applying structures (120) apply force to the calibrated multidimensional force sensor through the multiple air-bearing steering structures. The multiple air-bearing steering structures and the multiple weight-applying structures (120) correspond one-to-one. The air-bearing steering structure is used to convert the gravity of the weight-applying structure (120) into force in different directions.

2. The multi-dimensional force detection device with an air-float steering structure according to claim 1, characterized in that: The frame (110) is also provided with a movable beam (117) and a force-applying workpiece (118). The movable beam (117) and the force-applying workpiece (118) are respectively used to fix the two ends of the calibrated multidimensional force sensor. The movable beam (117) is slidably connected to the frame (110) in the vertical direction. Multiple weight force-applying structures (120) apply force to the force-applying workpiece (118) through multiple air-bearing steering structures.

3. The multi-dimensional force detection device with an air-float steering structure according to claim 2, characterized in that: The multiple air-bearing steering structures are a horizontal force air-bearing steering structure (131) and a Z-force air-bearing steering structure (132). Four sets of the Z-force air-bearing steering structures (132) are provided, positioned above the force-applying workpiece (118). One end of each Z-force air-bearing steering structure (132) is connected to the force-applying workpiece (118), and the other end is connected to the weight. The weight force application structure (120) is connected to the force application workpiece (118) and each of the Z-direction force air buoyancy steering structures (132). A weight force application structure (120) is also suspended below the connection between the force application workpiece (118) and each of the Z-direction force air buoyancy steering structures (132) to form a pair of force couples. A reverser (119) is also provided on the frame (110). The top of the reverser (119) is pressed above the force application workpiece (118), and the weight force application structure (120) is suspended at the bottom of the reverser (119).

4. A multi-dimensional force detection device with an air-float steering structure according to claim 3, characterized in that: The horizontal force air buoyancy steering structure (131) is provided in eight sets. One end of the horizontal force air buoyancy steering structure (131) is connected to the force-applying workpiece (118), and the other end of the horizontal force air buoyancy steering structure (131) is connected to the weight force-applying structure (120). Four sets of the horizontal force air buoyancy steering structure (131) cooperate with four sets of the weight force-applying structure (120) to apply horizontal force to the force-applying workpiece (118) along the X-axis and Y-axis coordinates, respectively. The other four sets of the horizontal force air buoyancy steering structure (131) generate a pair of force couples to apply force to the force-applying workpiece (118).

5. A multi-dimensional force detection device with an air-float steering structure according to claim 4, characterized in that: The horizontal force air-bearing steering structure (131) includes an air-bearing assembly (140) and a flexible connector (133). The flexible connector (133) bypasses the air-bearing assembly (140) and one end of the flexible connector (133) is connected to the weight force-applying structure (120). The other end of the flexible connector (133) is connected to the force-applying workpiece (118).

6. A multi-dimensional force detection device with an air-float steering structure according to claim 5, characterized in that: The Z-axis force air-bearing steering structure (132) includes an air-bearing assembly (140), a flexible connector (133), and a balance weight (134). One end of the flexible connector (133) is connected to the force-applying workpiece (118), and the other end of the flexible connector (133) is connected to the balance weight (134) after bypassing the air-bearing assembly (140). The end of the balance weight (134) away from the air-bearing assembly (140) is connected to the weight force-applying structure (120).

7. A multi-dimensional force detection device with an air-float steering structure according to claim 5 or 6, characterized in that: The air bearing assembly (140) includes a base (141), two air bearing blocks (142), two air bearing bushings (143), and a pulley (144). The base (141) is mounted on the frame (110). The air bearing blocks (142), the air bearing bushings (143), and the pulley (144) are coaxially mounted on the base (141). The two air bearing blocks (142) and the two air bearing bushings (143) are symmetrically located on both sides of the pulley (144) so ​​that the pulley (144) and the base (141) are rotatably connected. The flexible connector (133) passes around the pulley (144).

8. A multi-dimensional force detection device with an air-float steering structure according to claim 7, characterized in that: The weight force application structure (120) includes multiple weights (121) suspended and connected by different weights, a weight tray (122) and a driving member (123). The weight tray (122) is located directly below the weights (121), and the driving member (123) is used to drive the weight tray (122) to slide back and forth in the vertical direction to carry multiple weights (121) one by one.

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