High-precision six-dimensional force sensor calibration device and calibration method

Abstract

The invention relates to the technical field of six-dimensional force sensor calibration, in particular to a high-precision six-dimensional force sensor calibration device and calibration method. The invention provides a high-precision six-dimensional force sensor calibration device which comprises a base, a calibration platform, a cross force application frame, an S-shaped tension sensor and a fixed pulley. The calibration platform is arranged on the base and is used for fixing the six-dimensional force sensor; the center point of the cross force application frame is connected to the six-dimensional force sensor, a plurality of fixed pulleys are arranged on the calibration platform, a plurality of S-shaped tension sensors are arranged on the cross force application frame, and loads are applied to the S-shaped tension sensors or directly applied to the cross force application frame through connection of a weight set and a rope and guidance of the fixed pulleys. Therefore, a single-dimensional force, a single-dimensional torque, a composite force or a composite torque is applied to the six-dimensional force sensor. Accurate loading of the six-dimensional force sensor is achieved, the device is simple in structure and convenient to operate, independent calibration of single-dimensional force / torque can be achieved, and combined loading can also be conducted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of six-dimensional force sensor calibration, and particularly to a high-precision six-dimensional force sensor calibration device and method. BACKGROUND

[0002] A six-dimensional force sensor is a high-precision sensor capable of simultaneously measuring three-directional forces (Fx, Fy, Fz) and three-directional moments (Mx, My, Mz) in a spatial Cartesian coordinate system, and is widely used in the fields of robots, industrial automation, aerospace, etc. Due to the influence of factors such as manufacturing process, installation error and material characteristics, the six-dimensional force sensor must be accurately calibrated before actual use to establish an accurate relationship between its input and output.

[0003] At present, common six-dimensional force sensor calibration devices mainly adopt the methods of weight loading, hydraulic loading or electric cylinder loading. For example, Chinese patent ZL200810020511.4 discloses a jack loading type calibration device, which has the advantage of large loading force, but has problems of unstable loading force and difficult alignment; Chinese patent CN101776506A adopts hydraulic loading, but the system is complex and needs to be repeatedly disassembled, which affects the calibration accuracy; Chinese patent ZL200510050834.4 adopts a hand-operated speed reducer for loading, which is difficult to achieve precise force control; and some devices such as CN101936797 can only load composite force and cannot achieve independent calibration of single-dimensional force / moment, which limits the calibration accuracy and applicability.

[0004] In summary, the six-dimensional force sensor calibration devices in the prior art generally have problems of complex structure, cumbersome operation, inability to achieve independent loading of single-dimensional force / moment, and limited calibration accuracy. Therefore, there is an urgent need for a calibration device and method with reasonable structure, simple operation and high-precision single-dimensional and composite loading. SUMMARY

[0005] The present application aims to provide a high-precision six-dimensional force sensor calibration device and method to solve the technical problems of complex structure, cumbersome operation, inability to achieve independent loading of single-dimensional force / moment, and limited calibration accuracy of the six-dimensional force sensor calibration devices in the prior art.

[0006] In a first aspect, the present application provides a high-precision six-dimensional force sensor calibration device, comprising a base, a calibration platform, a cross force applying frame, an S-shaped tension sensor and a fixed pulley. The calibration platform is arranged on the base and is used to fix the six-dimensional force sensor. The center point of the cross force frame is connected to the six-dimensional force sensor, and the cross force frame is used to transmit load, and the cross force frame is parallel to the calibration platform, so that a spatial Cartesian coordinate system can be preset with the center point of the cross force frame as the origin; A plurality of the fixed pulleys are arranged on the calibration platform, and all the fixed pulleys are arranged around the cross force frame, and the fixed pulleys are used to guide the load-bearing rope to change the force direction, and a plurality of the S-shaped tension sensors are arranged on the cross force frame, and the S-shaped tension sensors correspond to the fixed pulleys one by one, wherein the S-shaped tension sensors are loaded by connecting the rope with the weight set and guiding the rope through the fixed pulleys, or the cross force frame is directly loaded by connecting the rope with the weight set, so as to exert single-dimensional force, single-dimensional torque, compound force or compound torque on the six-dimensional force sensor.

[0007] In an optional embodiment, the first support and the second support are further included; The first support and the second support are arranged on the calibration platform, and the fixed pulleys are arranged on the first support and the second support; The first support is provided with four first supports, which are respectively located at the middle positions of the four side edges of the calibration platform, the S-shaped tension sensors are arranged on the upper sides of the four arms of the cross force frame, and the fixed pulleys on the four first supports are located above the corresponding S-shaped tension sensors, so that the force direction of the rope guided through the fixed pulleys on the first support is parallel to the Z-axis of the preset spatial Cartesian coordinate system; The second support is provided with eight second supports, which are respectively located on the left and right sides of each first support, the S-shaped tension sensors are arranged on the left and right sides of the four arms of the cross force frame, and the fixed pulleys on the eight second supports are located on the same horizontal plane as the corresponding S-shaped tension sensors, so that the force direction of the rope guided through the fixed pulleys on the second support is parallel to the X-axis or Y-axis of the preset spatial Cartesian coordinate system.

[0008] In an optional embodiment, the S-shaped tension sensors arranged on the upper surfaces of the four arms of the cross force frame are symmetrically arranged with respect to the two mutually perpendicular central axes and the center point of the cross force frame; and / or; The S-shaped tension sensors arranged on the left and right sides of the four arms of the cross force frame are symmetrically arranged with respect to the two mutually perpendicular central axes and the center point of the cross force frame.

[0009] In an optional embodiment, the outer end of the S-shaped tension sensor is connected with a hollow screw; One end of the rope is fixed in the center hole of the hollow screw.

[0010] In an optional embodiment, the bottom of the base is provided with a plurality of height-adjustable feet; The feet are used to adjust the levelness of the calibration platform.

[0011] In a second aspect, the application provides a high-precision six-dimensional force sensor calibration method, which is calibrated by using the high-precision six-dimensional force sensor calibration device of any one of the preceding embodiments. The high-precision six-dimensional force sensor calibration method comprises the following steps: Calibration: adjust the calibration platform to a horizontal state; adjust the position of the fixed pulley on the first support so that it is located directly above the corresponding S-shaped tension sensor, so as to ensure the accuracy of the vertical loading direction; adjust the height of the fixed pulley on the second support so that it is at the same horizontal plane as the corresponding S-shaped tension sensor, so as to ensure the accuracy of the horizontal loading direction; Single-dimensional force or single-dimensional torque calibration: connect a plurality of groups of weights to the S-shaped tension sensor or the cross force applying frame respectively, and adjust the mass of the connected groups of weights, so that the resultant force or the resultant torque acting on the cross force applying frame is in a single direction, thereby realizing the loading calibration of the single-dimensional force or single-dimensional torque of the six-dimensional force sensor; Compound force or compound torque calibration: connect a plurality of groups of weights to the S-shaped tension sensor or the cross force applying frame respectively, and adjust the mass of the connected groups of weights, so that the force or torque acting on the cross force applying frame is in multiple directions, thereby realizing the loading calibration of the six-dimensional force sensor in multiple directions. Signal acquisition and processing: during the loading calibration process, the electrical signals output by the six-dimensional force sensor and the S-shaped tension sensor are synchronously acquired, and after the acquired electrical signals are amplified, filtered and isolated by a signal conditioning circuit, they are acquired by a data acquisition card and transmitted to a computer for processing and analysis.

[0012] In an optional embodiment, the step of single-dimensional force calibration comprises Fx positive direction force value calibration: One end of the first rope is connected to the outer end of the first S-shaped tension sensor, and the other end is connected to the first group of weights after passing through the first fixed pulley installed on one of the second supports; One end of the fourth rope is connected to the outer end of the fourth S-shaped tension sensor, and the other end is connected to the fourth group of weights after passing through the fourth fixed pulley installed on the other second support; Adjust the mass of the first and fourth groups of weights so that the force values detected by the first and fourth S-shaped tension sensors are equal.

[0013] In an optional embodiment, the step of single-dimensional force calibration comprises Fz positive direction force value calibration: One end of the ninth rope is connected to the upper end of the ninth S-shaped tension sensor, and the other end is connected to the ninth weight set after passing through the ninth fixed pulley installed on the first first support; One end of the tenth rope is connected to the upper end of the tenth S-shaped tension sensor, and the other end is connected to the tenth weight set after passing through the tenth fixed pulley installed on the second first support; One end of the eleventh rope is connected to the upper end of the eleventh S-shaped tension sensor, and the other end is connected to the eleventh weight set after passing through the tenth fixed pulley installed on the third first support; One end of the twelfth rope is connected to the upper end of the twelfth S-shaped tension sensor, and the other end is connected to the twelfth weight set after passing through the twelfth fixed pulley installed on the fourth first support; Adjust the mass of the ninth weight set, the tenth weight set, the eleventh weight set and the twelfth weight set, so that the force values detected by the ninth S-shaped tension sensor, the tenth S-shaped tension sensor, the eleventh S-shaped tension sensor and the twelfth S-shaped tension sensor are equal; And / or; Step single-dimensional force calibration includes Fz negative direction force value calibration: The thirteenth weight set, the fourteenth weight set, the fifteenth weight set and the sixteenth weight set are directly suspended and connected to the lower side of the four arms of the cross force frame through the thirteenth rope, the fourteenth rope, the fifteenth rope and the sixteenth rope respectively; Adjust the mass of the thirteenth weight set, the fourteenth weight set, the fifteenth weight set and the sixteenth weight set, so that the mass of the thirteenth weight set, the fourteenth weight set, the fifteenth weight set and the sixteenth weight set are equal.

[0014] In an optional embodiment, the step of single-dimensional moment calibration includes Mx positive direction moment calibration: The thirteenth weight set is directly suspended and connected to the lower side of the Y-axis negative direction arm of the cross force frame through the thirteenth rope; One end of the eleventh rope is connected to the upper end of the eleventh S-shaped tension sensor on the upper side of the Y-axis positive direction arm of the cross force frame, and the other end is connected to the eleventh weight set after passing through the tenth fixed pulley installed on a first support; Adjust the mass of the eleventh weight set, so that the force value detected by the eleventh S-shaped tension sensor is equal to the gravity value of the thirteenth weight set.

[0015] In an optional embodiment, the step of single-dimensional moment calibration includes Mz positive direction moment calibration: One end of the first rope is connected to the outer end of the first S-shaped tension sensor, and the other end is connected to the first weight set after passing through the first fixed pulley installed on the X-axis positive direction second support; One end of the fifth rope is connected to the outer end of the fifth S-shaped tension sensor, and the other end is connected to the fifth weight set after passing through the fifth fixed pulley installed on the other second support in the negative direction of the X axis; The mass of the first weight set and the fifth weight set is adjusted so that the force values detected by the first S-shaped tension sensor and the fifth S-shaped tension sensor are equal; and / or; The single-dimensional force moment calibration includes Mz negative direction force moment calibration: One end of the fourth rope is connected to the outer end of the fourth S-shaped tension sensor, and the other end is connected to the fourth weight set after passing through the fourth fixed pulley installed on one second support in the positive direction of the X axis; One end of the eighth rope is connected to the outer end of the eighth S-shaped tension sensor, and the other end is connected to the eighth weight set after passing through the eighth fixed pulley installed on the other second support in the negative direction of the X axis; The mass of the fourth weight set and the eighth weight set is adjusted so that the force values detected by the fourth S-shaped tension sensor and the eighth S-shaped tension sensor are equal.

[0016] Compared with the prior art, the high-precision six-dimensional force sensor calibration device and calibration method provided by the application have the following technical advantages: The high-precision six-dimensional force sensor calibration device provided by the application comprises a base, a calibration platform, a cross force frame, S-shaped tension sensors and fixed pulleys. The calibration platform is arranged on the base and is used for fixing the six-dimensional force sensor. The center point of the cross force frame is connected to the six-dimensional force sensor, and the cross force frame is used for transmitting load. The cross force frame is parallel to the calibration platform, so that a spatial Cartesian coordinate system can be preset with the center point of the cross force frame as the origin. A plurality of fixed pulleys are arranged on the calibration platform, and all the fixed pulleys are arranged around the cross force frame. The fixed pulleys are used for guiding the load-bearing ropes to change the force direction. A plurality of S-shaped tension sensors are arranged on the cross force frame, and the S-shaped tension sensors correspond to the fixed pulleys one by one. The S-shaped tension sensors are loaded by the load of the weight set guided by the fixed pulleys or the load of the weight set connected to the ropes directly loaded on the cross force frame, so as to exert single-dimensional force, single-dimensional force moment, compound force or compound force moment on the six-dimensional force sensor.

[0017] The high-precision S-shaped tension sensor is combined with the weight set and the fixed pulley to realize accurate loading of the six-dimensional force sensor. The device has a simple structure and is convenient to operate. The device can realize independent calibration of single-dimensional force / force moment and can also perform compound loading. The device effectively overcomes the problems of unstable loading and inability to load single-dimensionally in the background technology.

[0018] The high-precision six-dimensional force sensor calibration method provided by the application adopts the high-precision six-dimensional force sensor calibration device, and thus achieves the technical advantages and effects of the high-precision six-dimensional force sensor calibration device, which will not be described in detail here.

[0019] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings required to be used in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 The high-precision six-dimensional force sensor calibration device structure schematic diagram provided by the embodiment of the present application; Figure 2 The Fx positive direction force value calibration schematic diagram provided by the embodiment of the present application; Figure 3 The Fz positive direction force value calibration schematic diagram provided by the embodiment of the present application; Figure 4 The Fz negative direction force value calibration schematic diagram provided by the embodiment of the present application; Figure 5 The Mx positive direction torque calibration schematic diagram provided by the embodiment of the present application; Figure 6 The Mz positive direction torque calibration schematic diagram provided by the embodiment of the present application; Figure 7 The Mz negative direction torque calibration schematic diagram provided by the embodiment of the present application; Figure 8 The calibration platform, six-dimensional force sensor and cross force frame installation schematic diagram provided by the embodiment of the present application; Figure 9 The cross force frame and S-type tension sensor installation schematic diagram provided by the embodiment of the present application; Figure 10 The second bracket and fixed pulley structure schematic diagram provided by the embodiment of the present application; Figure 11 The relative installation position diagram of the six-dimensional force sensor, cross force frame, S-type tension sensor and hollow screw provided by the embodiment of the present application.

[0022] Icon: 1-base; 2-calibration platform; 3-six-dimensional force sensor; 4-cross force frame; 5-S type tension sensor; 6-first support; 7-second support; 8-fixed pulley; 9-anchorage; 10-hollow screw; 1001-first rope; 501-first S type tension sensor; 801-first fixed pulley; 2001-first weight set; 1004-fourth rope; 504-fourth S type tension sensor; 804-fourth fixed pulley; 2004-fourth weight set; 1009-ninth rope; 509-ninth S type tension sensor; 809-ninth fixed pulley; 2009-ninth weight set; 1010-tenth rope; 510-tenth S type tension sensor; 810-tenth fixed pulley; 2010-tenth weight set; 1011-eleventh rope; 511-eleventh S type tension sensor; 811-tenth fixed pulley; 2011-eleventh weight set; 1012-twelfth rope; 512-twelfth S type tension sensor; 812-twelfth fixed pulley; 2012-twelfth weight set; 2013-thirteenth weight set; 2014-fourteenth weight set; 2015-fifteenth weight set; 2016-sixteenth weight set; 1013-thirteenth rope; 1014-fourteenth rope; 1015-fifteenth rope; 1016-sixteenth rope; 1005-fifth rope; 505-fifth S type tension sensor; 805-fifth fixed pulley; 2005-fifth weight set; 1008-eighth rope; 508-eighth S type tension sensor; 808-eighth fixed pulley; 2008-eighth weight set. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present application.

[0024] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that the person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0027] The present application will be further described in detail below by specific examples and in conjunction with the accompanying drawings.

[0028] The specific structure is shown in Figures 1 to 11 .

[0029] The embodiment provides a high-precision six-dimensional force sensor calibration device, which comprises a base 1, a calibration platform 2, a cross force frame 4, an S-shaped tension sensor 5 and a fixed pulley 8; the calibration platform 2 is arranged on the base 1 and is used for fixing the six-dimensional force sensor 3; the center point of the cross force frame 4 is connected to the six-dimensional force sensor 3, and the cross force frame 4 is used for transmitting load, and the cross force frame 4 is parallel to the calibration platform 2, so that a spatial Cartesian coordinate system can be preset with the center point of the cross force frame 4 as the origin; a plurality of fixed pulleys 8 are arranged on the calibration platform 2, and all the fixed pulleys 8 are arranged around the cross force frame 4, the fixed pulley 8 is used for guiding the load-bearing rope to change the force direction, a plurality of S-shaped tension sensors 5 are arranged on the cross force frame 4, and the S-shaped tension sensor 5 corresponds to the fixed pulley 8 one by one, wherein the load is applied to the S-shaped tension sensor 5 by connecting the rope through the weight group and guiding through the fixed pulley 8 or the load is directly applied to the cross force frame 4 by connecting the rope through the weight group, so that the single-dimensional force, single-dimensional moment, compound force or compound moment is applied to the six-dimensional force sensor 3.

[0030] In this embodiment, the calibration platform 2 is fixed on the base 1, and is used to install and fix the six-dimensional force sensor 3 to be calibrated. The center of the cross force frame 4 is connected with the loading end of the six-dimensional force sensor 3, and is used to transmit the load. The cross force frame 4 is arranged in parallel with the calibration platform 2, and a spatial Cartesian coordinate system is established with the center of the cross force frame 4 as the origin. The axes of the four arms of the cross force frame 4 are relative to the center point, and the axes form the X axis and the Y axis. The vertical line through the center point is the Z axis. A plurality of fixed pulleys 8 are arranged around the cross force frame 4 on the calibration platform 2, and are used to guide the load-bearing ropes to change the force direction. A plurality of S-shaped tension sensors 5 are installed on the cross force frame 4, and are used to accurately measure the applied force value in real time. The S-shaped tension sensors 5 correspond to the fixed pulleys 8 one by one. The ropes are connected through the weight sets, and are guided through the fixed pulleys 8. The S-shaped tension sensors 5 can be loaded, or the cross force frame 4 can be directly loaded, so as to realize accurate calibration of the single-dimensional force, single-dimensional torque, compound force or compound torque of the six-dimensional force sensor 3. Through the weight sets and the fixed pulleys 8, and in combination with the high-precision S-shaped tension sensors 5, the accurate loading of the six-dimensional force sensor 3 is realized. The device has simple structure and convenient operation. The independent calibration of the single-dimensional force / torque can be realized, and the compound loading can also be realized. The problems of unstable loading and inability to load single-dimensionally existing in the background art are effectively overcome.

[0031] In the optional technical solution of this embodiment, the first support 6 and the second support 7 are further included. The first support 6 and the second support 7 are both arranged on the calibration platform 2, and the fixed pulleys 8 are arranged on the first support 6 and the second support 7. The first support 6 is provided with four first supports, and is located at the middle positions of the four side edges of the calibration platform 2. The S-shaped tension sensors 5 are arranged on the upper sides of the four arms of the cross force frame 4, and the fixed pulleys 8 on the four first supports 6 are all located above the corresponding S-shaped tension sensors 5. In this way, the ropes are guided through the fixed pulleys 8 on the first support 6, so that the force direction of the ropes to the six-dimensional force sensor 3 is parallel to the Z axis of the preset spatial Cartesian coordinate system. The second support 7 is provided with eight second supports, and is located on the left and right sides of each first support 6. The S-shaped tension sensors 5 are arranged on the left and right sides of the four arms of the cross force frame 4, and the fixed pulleys 8 on the eight second supports 7 are all located on the same horizontal plane as the corresponding S-shaped tension sensors 5. In this way, the ropes are guided through the fixed pulleys 8 on the second support 7, so that the force direction of the ropes to the six-dimensional force sensor 3 is parallel to the X axis or the Y axis of the preset spatial Cartesian coordinate system.

[0032] In the embodiment, the calibration device further comprises a first support 6 and a second support 7. The first support 6 and the second support 7 are arranged on the calibration platform 2, and each is provided with a fixed pulley 8. The first support 6 is provided with four, which are respectively located at the middle positions of the four side edges of the calibration platform 2. The upper sides of the four arms of the cross force frame 4 are each provided with an S-shaped tension sensor 5, and the fixed pulleys 8 on the four first supports 6 are located directly above the corresponding S-shaped tension sensors 5, so that the ropes are guided through the fixed pulleys 8 on the first supports 6, and the force direction of the six-dimensional force sensor 3 is parallel to the Z axis. The second support 7 is provided with eight, which are respectively located on the left and right sides of each first support 6. The left and right sides of the four arms of the cross force frame 4 are each provided with an S-shaped tension sensor 5, and the fixed pulleys 8 on the eight second supports 7 are located on the same horizontal plane as the corresponding S-shaped tension sensors 5, so that the ropes are guided through the fixed pulleys 8 on the second supports 7, and the force direction of the six-dimensional force sensor 3 is parallel to the X axis or the Y axis. Through the reasonable arrangement of the first support 6 and the second support 7, the accurate application of the forces in the X, Y and Z directions is realized, the accuracy and consistency of the loading direction are ensured, and structural support for improving the calibration accuracy is provided.

[0033] In the optional technical solution of the embodiment, the S-shaped tension sensors 5 arranged on the upper surfaces of the four arms of the cross force frame 4 are symmetrically arranged relative to the two mutually perpendicular central axes and the center point of the cross force frame 4; and / or the S-shaped tension sensors 5 arranged on the left and right sides of the four arms of the cross force frame 4 are symmetrically arranged relative to the two mutually perpendicular central axes and the center point of the cross force frame 4.

[0034] In the embodiment, the S-shaped tension sensors 5 arranged on the upper surfaces of the four arms of the cross force frame 4 and the S-shaped tension sensors 5 arranged on the left and right sides of the four arms are symmetrically arranged relative to the two mutually perpendicular central axes and the center point of the cross force frame 4. The symmetrically arranged S-shaped tension sensors 5 make the load application more balanced, effectively reduce the measurement error caused by asymmetric force, and further improve the calibration accuracy and reliability.

[0035] In the optional technical solution of the embodiment, the outer end of the S-shaped tension sensor 5 is connected with a hollow screw 10; one end of the rope is fixed in the center hole of the hollow screw 10.

[0036] In the embodiment, the outer end of the S-shaped tension sensor 5 is connected with a hollow screw 10, and one end of the rope is fixed in the center hole of the hollow screw 10. The structure of the hollow screw 10 is convenient for fixing and dismounting the rope, the connection is reliable, the rope slipping is effectively prevented, and the continuity and stability of force transmission are ensured.

[0037] In the optional technical solution of the embodiment, the bottom of the base 1 is provided with a plurality of height-adjustable feet 9; the feet 9 are used to adjust the levelness of the calibration platform 2.

[0038] In this embodiment, the bottom of the base 1 is provided with a plurality of height-adjustable feet 9 for adjusting the levelness of the calibration platform 2. By adjusting the feet 9, the calibration platform 2 can be quickly and accurately adjusted to a horizontal state, which lays a foundation for accurately establishing a spatial coordinate system and ensuring the accuracy of the loading direction.

[0039] Specifically, the cross force applying frame 4 is a cross-symmetric structure with its center coinciding with the center of the six-axis force sensor 3; a plurality of threaded holes are formed on the four arms of the cross force applying frame 4 for mounting S-type tension sensors 5; the spatial positions of the threaded holes and the mounted S-type tension sensors 5 are symmetrically arranged with respect to the two perpendicular central axes and the center point of the cross force applying frame 4. The number of S-type tension sensors 5 is twelve, which are respectively mounted on the twelve symmetrically distributed threaded holes of the cross force applying frame 4 through screws; one end of the rope is fixed in the center hole of the hollow screw 10. The first support 6 is four long supports, which are respectively vertically mounted on the middle parts of the four sides of the calibration platform 2; the second support 7 is eight short supports, which are symmetrically installed in pairs on both sides of each long support; the fixed pulley 8 is installed at a predetermined position on the long support and the short support, and its installation height and orientation are adjusted so that the force direction of the rope on the six-axis force sensor 3 is parallel to the X-axis, Y-axis or Z-axis of the preset spatial Cartesian coordinate system.

[0040] The high-precision six-axis force sensor calibration method provided in this embodiment is calibrated by using the high-precision six-axis force sensor calibration device described above, and thus the technical advantages and effects achieved by the high-precision six-axis force sensor calibration method include those achieved by the high-precision six-axis force sensor calibration device, which will not be repeated here.

[0041] The high-precision six-dimensional force sensor calibration method comprises the following steps: a calibration step: adjusting the calibration platform 2 to a horizontal state; adjusting the position of the fixed pulley 8 on the first support 6 to be located directly above the corresponding S-shaped tension sensor 5 to ensure the accuracy of the vertical, i.e. Z-direction, loading direction; adjusting the height of the fixed pulley 8 on the second support 7 to be at the same horizontal plane as the corresponding S-shaped tension sensor 5 to ensure the accuracy of the horizontal, i.e. X-direction and Y-direction, loading direction. A single-dimensional force or single-dimensional torque calibration step: connecting a plurality of groups of weights to specific positions of the S-shaped tension sensor 5 or the cross force applying frame 4, respectively, and adjusting the mass of the connected weight group to make the resultant force or resultant torque acting on the cross force applying frame 4 in a single direction, thereby realizing the accurate loading calibration of the single-dimensional force or single-dimensional torque of the six-dimensional force sensor 3. A compound force or compound torque calibration step: connecting a plurality of groups of weights to different force points of a plurality of different S-shaped tension sensors 5 or cross force applying frames 4, respectively, and adjusting the mass of the weight group to realize the application of force components or torque components in multiple directions to the six-dimensional force sensor 3 for compound loading calibration. A signal acquisition and processing step: during the loading calibration process, the electrical signals output by the six-dimensional force sensor 3 and the S-shaped tension sensor 5 are synchronously acquired, amplified, filtered and isolated by a signal conditioning circuit, and then acquired by a data acquisition card and transmitted to a computer for processing and analysis, and finally the calibration matrix and performance parameters are obtained. The method has clear steps, simple operation, accurate loading direction ensured by calibration, comprehensive evaluation of sensor performance by single-dimensional and compound loading, and high-precision and high-efficiency calibration process realized by combining signal processing technology.

[0042] Specifically, the four ground anchors 9 at the bottom of the base 1 are adjusted using a wrench, the upper surface of the calibration platform 2 is adjusted to a horizontal state, and a level can be used for measurement; the positions of the fixed pulleys 8 in the middle of all four first supports 6 are adjusted, and the top of the plummet is aligned with the screw hole center of the S-shaped tension sensor 5 below according to the positioning rope measurement to ensure the accuracy and consistency of the Fz loading direction; the heights of the fixed pulleys 8 on the eight second supports 7 are adjusted to be at the same horizontal line as the centers of the eight horizontal S-shaped tension sensors 5 by a height gauge; the hollow screw 10 with a center hole is connected to the outer end threaded hole of the S-shaped tension sensor 5, and one end of the rope is fixed in the center hole of the hollow screw 10.

[0043] In the optional technical solution of the embodiment, the step of single-dimensional force calibration includes Fx positive direction force value calibration: one end of the first rope 1001 is connected to the outer end of the first S-shaped tension sensor 501, and the other end is connected to the first weight set 2001 after passing through the first fixed pulley 801 installed on one second support 7; one end of the fourth rope 1004 is connected to the outer end of the fourth S-shaped tension sensor 504, and the other end is connected to the fourth weight set 2004 after passing through the fourth fixed pulley 804 installed on another second support 7; the masses of the first weight set 2001 and the fourth weight set 2004 are adjusted so that the force values detected by the first S-shaped tension sensor 501 and the fourth S-shaped tension sensor 504 are equal, thereby ensuring that the force acting on the six-dimensional force sensor 3 is a pure +Fx direction force. Through the symmetrical arrangement of the force application points and the real-time force value feedback and adjustment, high-precision single-dimensional force loading is realized, and the errors introduced by factors such as pulley friction are effectively eliminated. Similarly, Fx negative direction, Fy positive direction and Fy negative direction force value calibration can be realized.

[0044] In the optional technical solution of the embodiment, the step of single-dimensional force calibration includes Fz positive direction force value calibration: one end of the ninth rope 1009 is connected to the upper end of the ninth S-shaped tension sensor 509, and the other end is connected to the ninth weight set 2009 after passing through the ninth fixed pulley 809 installed on the first first support 6; one end of the tenth rope 1010 is connected to the upper end of the tenth S-shaped tension sensor 510, and the other end is connected to the tenth weight set 2010 after passing through the tenth fixed pulley 810 installed on the second first support 6; one end of the eleventh rope 1011 is connected to the upper end of the eleventh S-shaped tension sensor 511, and the other end is connected to the eleventh weight set 2011 after passing through the tenth fixed pulley 811 installed on the third first support 6; one end of the twelfth rope 1012 is connected to the upper end of the twelfth S-shaped tension sensor 512, and the other end is connected to the twelfth weight set 2012 after passing through the twelfth fixed pulley 812 installed on the fourth first support 6; the masses of the four weight sets are adjusted so that the force values detected by the four S-shaped tension sensors 5 are equal, thereby ensuring that the force acting on the six-dimensional force sensor 3 is a pure +Fz direction force.

[0045] The step of single-dimensional force calibration includes Fz negative direction force value calibration: the thirteenth weight set 2013, the fourteenth weight set 2014, the fifteenth weight set 2015 and the sixteenth weight set 2016 are directly suspended and connected to the lower side of the four arms of the cross force application frame 4 through the thirteenth rope 1013, the fourteenth rope 1014, the fifteenth rope 1015 and the sixteenth rope 1016; the masses of the four weight sets are adjusted so that they are equal, thereby ensuring that the force acting on the six-dimensional force sensor 3 is a pure -Fz direction force.

[0046] In the embodiment, complete bidirectional calibration capability in the positive and negative directions of the Z-axis is provided. The positive direction uses a pulley combined with an S-shaped sensor, and has high precision; the negative direction uses direct suspension, avoids pulley friction, and is simple to operate and accurate in force value.

[0047] In the optional technical solution of the embodiment, the step of single-dimensional moment calibration includes Mx positive direction moment calibration: the thirteenth weight set 2013 is directly suspended and connected to the lower side of the Y-axis negative direction arm of the cross force frame 4 through the thirteenth rope 1013; one end of the eleventh rope 1011 is connected to the upper end of the eleventh S-shaped tension sensor 511 on the upper side of the Y-axis positive direction arm of the cross force frame 4, and the other end is connected to the eleventh weight set 2011 after passing through the tenth fixed pulley 811 installed on a first support 6; the mass of the eleventh weight set 2011 is adjusted so that the force value detected by the eleventh S-shaped tension sensor 511 is equal to the gravity value of the thirteenth weight set 2013, thereby ensuring that the moment acting on the six-dimensional force sensor 3 is a pure +Mx direction moment. A pair of forces with equal size and opposite directions form a pure moment load, the structure is ingenious, and high-precision independent calibration of the moment component is achieved. Similarly, Mx negative direction, My positive direction, and My negative direction moment calibration can be completed.

[0048] In the optional technical solution of the embodiment, the step of single-dimensional moment calibration includes Mz positive direction moment calibration: one end of the first rope 1001 is connected to the outer end of the first S-shaped tension sensor 501, and the other end is connected to the first weight set 2001 after passing through the first fixed pulley 801 installed on a second support 7 in the X-axis positive direction; one end of the fifth rope 1005 is connected to the outer end of the fifth S-shaped tension sensor 505, and the other end is connected to the fifth weight set 2005 after passing through the fifth fixed pulley 805 installed on another second support 7 in the X-axis negative direction; the masses of the first weight set 2001 and the fifth weight set 2005 are adjusted so that the force values detected by the first S-shaped tension sensor 501 and the fifth S-shaped tension sensor 505 are equal, thereby ensuring that the moment acting on the six-dimensional force sensor 3 is a pure +Mz direction moment.

[0049] The step of single-dimensional moment calibration includes Mz negative direction moment calibration: one end of the fourth rope 1004 is connected to the outer end of the fourth S-shaped tension sensor 504, and the other end is connected to the fourth weight set 2004 after passing through the fourth fixed pulley 804 installed on a second support 7 in the X-axis positive direction; one end of the eighth rope 1008 is connected to the outer end of the eighth S-shaped tension sensor 508, and the other end is connected to the eighth weight set 2008 after passing through the eighth fixed pulley 808 installed on another second support 7 in the X-axis negative direction; the masses of the fourth weight set 2004 and the eighth weight set 2008 are adjusted so that the force values detected by the fourth S-shaped tension sensor 504 and the eighth S-shaped tension sensor 508 are equal, thereby ensuring that the moment acting on the six-dimensional force sensor 3 is a pure -Mz direction moment.

[0050] In the embodiment, the positive and negative two directions around the Z axis are realized. Through the symmetrical arrangement of the force point and the balance adjustment of the force value, the pure torque is effectively generated, and the calibration process is accurate and controllable.

[0051] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-precision six-dimensional force sensor calibration device, characterized in that, include: Base (1), calibration platform (2), cross force application frame (4), S-type tension sensor (5) and fixed pulley (8); The calibration platform (2) is set on the base (1) and is used to fix the six-dimensional force sensor (3). The center point of the cross force application frame (4) is connected to the six-dimensional force sensor (3), and the cross force application frame (4) is used to transmit loads. The cross force application frame (4) is parallel to the calibration platform (2) so that a spatial Cartesian coordinate system can be preset with the center point of the cross force application frame (4) as the origin. The calibration platform (2) is provided with a plurality of fixed pulleys (8), and all the fixed pulleys (8) are arranged around the cross force application frame (4). The fixed pulleys (8) are used to guide the load-bearing rope to change the direction of the applied force. The cross force application frame (4) is provided with a plurality of S-shaped tension sensors (5), and the S-shaped tension sensors (5) correspond one-to-one with the fixed pulleys (8). The load is applied to the S-shaped tension sensor (5) by connecting the rope with a weight set and guiding it through the fixed pulleys (8), or the load is applied directly to the cross force application frame (4) by connecting the rope with a weight set, thereby applying a single-dimensional force, a single-dimensional torque, a composite force, or a composite torque to the six-dimensional force sensor (3).

2. The high-precision six-dimensional force sensor calibration device according to claim 1, characterized in that, It also includes a first support (6) and a second support (7); The first bracket (6) and the second bracket (7) are both mounted on the calibration platform (2), and the fixed pulley (8) is mounted on both the first bracket (6) and the second bracket (7). The first support (6) is provided in four parts, and is located in the middle of the four sides of the calibration platform (2). The upper side of the four arms of the cross force application frame (4) is provided with the S-shaped tension sensor (5), and the fixed pulleys (8) on the four first supports (6) are located above the corresponding S-shaped tension sensor (5), so that the rope is guided by the fixed pulleys (8) on the first support (6) to apply force to the six-dimensional force sensor (3) in a direction parallel to the Z-axis of the preset spatial Cartesian coordinate system; The second bracket (7) is provided in eight parts, and is located on the left and right sides of each of the first brackets (6). The S-shaped tension sensor (5) is provided on the left and right sides of the four arms of the cross force application frame (4). The fixed pulleys (8) on the eight second brackets (7) are all located on the same horizontal plane as the corresponding S-shaped tension sensor (5), so that the rope is guided by the fixed pulleys (8) on the second bracket (7) to apply force to the six-dimensional force sensor (3) in a direction parallel to the X-axis or Y-axis of the preset spatial Cartesian coordinate system.

3. The high-precision six-dimensional force sensor calibration device according to claim 2, characterized in that, The S-shaped tension sensors (5) provided on the upper surfaces of the four arms of the cross-shaped force application frame (4) are symmetrically arranged with respect to the two mutually perpendicular central axes and the center point of the cross-shaped force application frame (4); and / or; The S-shaped tension sensors (5) on the left and right sides of the four arms of the cross-shaped force-applying frame (4) are symmetrically arranged with respect to the two mutually perpendicular central axes and center points of the cross-shaped force-applying frame (4).

4. The high-precision six-dimensional force sensor calibration device according to claim 1, characterized in that, The outer end of the S-type tension sensor (5) is connected to a hollow screw (10). One end of the rope is fixed in the central hole of the hollow screw (10).

5. The high-precision six-dimensional force sensor calibration device according to claim 1, characterized in that, The base (1) is provided with multiple height-adjustable feet (9) at its bottom. The foot (9) is used to adjust the levelness of the calibration platform (2).

6. A high-precision six-dimensional force sensor calibration method, characterized in that, The high-precision six-dimensional force sensor calibration device according to any one of claims 1-5 is used for calibration, and the high-precision six-dimensional force sensor calibration method includes the following steps: Calibration: Adjust the calibration platform (2) to a horizontal state; adjust the position of the fixed pulley (8) on the first bracket (6) so that it is directly above the corresponding S-type tension sensor (5) to ensure that the vertical loading direction is accurate; adjust the height of the fixed pulley (8) on the second bracket (7) so that it is on the same horizontal plane as the corresponding S-type tension sensor (5) to ensure that the horizontal loading direction is accurate. Single-dimensional force or single-dimensional torque calibration: Connect multiple sets of weights to the S-type tension sensor (5) or the cross force frame (4) respectively, and adjust the mass of the connected weights so that the resultant force or resultant torque acting on the cross force frame (4) is in a single direction, thereby realizing the single-dimensional force or single-dimensional torque loading calibration of the six-dimensional force sensor (3); Composite force or composite torque calibration: Connect multiple sets of weights to the S-type tension sensor (5) or the cross force frame (4) respectively, and adjust the mass of the connected weights so that the force or torque acting on the cross force frame (4) is multi-directional, so as to apply force components or torque components in multiple directions to the six-dimensional force sensor (3) for composite loading calibration; Signal acquisition and processing: During the loading calibration process, the electrical signals output by the six-dimensional force sensor (3) and the S-type tension sensor (5) are acquired simultaneously. The acquired electrical signals are amplified, filtered and isolated by the signal conditioning circuit, and then acquired by the data acquisition card and transmitted to the computer for processing and analysis.

7. The high-precision six-dimensional force sensor calibration method according to claim 6, characterized in that, The single-dimensional force calibration step includes the calibration of the force value in the positive direction of Fx: One end of the first rope (1001) is connected to the outer end of the first S-shaped tension sensor (501), and the other end is connected to the first weight group (2001) after passing over the first fixed pulley (801) installed on a second bracket (7). One end of the fourth rope (1004) is connected to the outer end of the fourth S-type tension sensor (504), and the other end is connected to the fourth weight group (2004) after passing over the fourth fixed pulley (804) installed on another second bracket (7). Adjust the mass of the first weight group (2001) and the fourth weight group (2004) so ​​that the force values ​​detected by the first S-type tension sensor (501) and the fourth S-type tension sensor (504) are equal.

8. The high-precision six-dimensional force sensor calibration method according to claim 6, characterized in that, The single-dimensional force calibration step includes the calibration of the force value in the positive direction of Fz: One end of the ninth rope (1009) is connected to the upper end of the ninth S-type tension sensor (509), and the other end is connected to the ninth weight group (2009) after passing over the ninth fixed pulley (809) installed on the first first bracket (6). One end of the tenth rope (1010) is connected to the upper end of the tenth S-type tension sensor (510), and the other end is connected to the tenth weight group (2010) after passing over the tenth fixed pulley (810) installed on the second first bracket (6). One end of the eleventh rope (1011) is connected to the upper end of the eleventh S-type tension sensor (511), and the other end is connected to the eleventh fixed pulley (811) installed on the third first bracket (6) and then connected to the eleventh weight group (2011). One end of the twelfth rope (1012) is connected to the upper end of the twelfth S-type tension sensor (512), and the other end is connected to the twelfth weight group (2012) after passing over the twelfth fixed pulley (812) installed on the fourth first bracket (6). Adjust the mass of the ninth weight group (2009), the tenth weight group (2010), the eleventh weight group (2011), and the twelfth weight group (2012) so that the force values ​​detected by the ninth S-type tension sensor (509), the tenth S-type tension sensor (510), the eleventh S-type tension sensor (511), and the twelfth S-type tension sensor (512) are equal; and / or; The single-dimensional force calibration step includes the calibration of the force value in the negative direction of Fz: The thirteenth weight group (2013), the fourteenth weight group (2014), the fifteenth weight group (2015), and the sixteenth weight group (2016) are directly suspended and connected to the lower side of the four arms of the cross force application frame (4) via the thirteenth rope (1013), the fourteenth rope (1014), the fifteenth rope (1015), and the sixteenth rope (1016), respectively. Adjust the masses of the thirteenth weight group (2013), the fourteenth weight group (2014), the fifteenth weight group (2015), and the sixteenth weight group (2016) so that their masses are equal.

9. The high-precision six-dimensional force sensor calibration method according to claim 6, characterized in that, The single-dimensional torque calibration step includes the calibration of the positive direction torque Mx: The thirteenth weight set (2013) is directly suspended and connected to the lower side of the cross force application frame (4) in the negative Y-axis direction via the thirteenth rope (1013); One end of the eleventh rope (1011) is connected to the upper end of the eleventh S-type tension sensor (511) on the upper side of the cross force application frame (4) in the positive direction of the Y axis, and the other end is connected to the eleventh fixed pulley (811) installed on a first bracket (6) and then connected to the eleventh weight group (2011). Adjust the mass of the eleventh weight group (2011) so that the force value detected by the eleventh S-type tension sensor (511) is equal to the gravity value of the thirteenth weight group (2013).

10. The high-precision six-dimensional force sensor calibration method according to claim 6, characterized in that, The single-dimensional torque calibration step includes the calibration of the torque in the positive direction of Mz: One end of the first rope (1001) is connected to the outer end of the first S-shaped tension sensor (501), and the other end is connected to the first weight group (2001) after passing over the first fixed pulley (801) installed on a second bracket (7) in the positive direction of the X-axis. One end of the fifth rope (1005) is connected to the outer end of the fifth S-type tension sensor (505), and the other end is connected to the fifth weight group (2005) after passing over the fifth fixed pulley (805) installed on another second bracket (7) in the negative direction of the X-axis. Adjust the mass of the first weight group (2001) and the fifth weight group (2005) so that the force values ​​detected by the first S-type tension sensor (501) and the fifth S-type tension sensor (505) are equal; and / or; The single-dimensional torque calibration step includes the calibration of the torque in the negative Mz direction: One end of the fourth rope (1004) is connected to the outer end of the fourth S-type tension sensor (504), and the other end is connected to the fourth weight group (2004) after passing over the fourth fixed pulley (804) installed on a second bracket (7) in the positive direction of the X-axis. One end of the eighth rope (1008) is connected to the outer end of the eighth S-type tension sensor (508), and the other end is connected to the eighth weight group (2008) after passing over the eighth fixed pulley (808) installed on another second bracket (7) in the negative direction of the X-axis. Adjust the mass of the fourth weight group (2004) and the eighth weight group (2008) so that the force values ​​detected by the fourth S-type tension sensor (504) and the eighth S-type tension sensor (508) are equal.

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