Multi-attitude-based three-dimensional force sensor decoupling device and method

Abstract

The invention provides a three-dimensional force sensor decoupling device based on multiple postures. The three-dimensional force sensor decoupling device comprises an industrial robot, a laser tracker, a three-dimensional force sensor, a fixing device, a hanging rope seat, a hanging rope rotating shaft, a hanging rope, a weight and a reflection target ball. The fixing device is of a flat plate supporting structure and is installed at one end of a mechanical arm of the industrial robot. The three-dimensional force sensor is fixedly mounted on the fixing device through a positioning pin; the rope hanging seat is fixedly mounted in the middle of the three-dimensional force sensor through a bolt; one end of the sling rotating shaft is arranged in the middle of the sling seat, and the other end is connected with the weight through the sling; the four reflection target balls are fixedly mounted at the four end point positions of the fixing device; the laser tracker is installed on one side of the industrial robot. Meanwhile, the invention also provides a method based on the device, and the method does not need to use a special multi-dimensional force loading platform, thereby reducing the decoupling cost of the three-dimensional force sensor. And meanwhile, the three-dimensional force sensor can be decoupled in a large component assembling field.

Description

Technical Field

[0001] The present invention belongs to the technical field of three-dimensional force sensor decoupling, and in particular relates to a three-dimensional force sensor internal coupling parameter calculation scheme based on multi-posture for large-scale component digital assembly sites, and further relates to a three-dimensional force sensor decoupling device and method based on multi-posture. Background Art

[0002] The output voltage value U of each channel of the ideal three-dimensional force sensor i Depends only on the force F applied in that direction i The size of the force in the other directions is independent of the force in the other directions. However, due to the influence of the patch process, machining level, strain gauge lateral coefficient, etc., almost every force acting on the sensor will affect the output signal of the sensor in other directions. This is inter-dimensional coupling. Inter-dimensional coupling is an important factor affecting the measurement accuracy of three-dimensional force sensors. In order to improve the measurement accuracy of force, it is very important to decouple the three-dimensional force sensor to eliminate inter-dimensional coupling.

[0003] At present, the decoupling of 3D force sensors requires the use of a dedicated multi-dimensional force loading platform, and the accuracy of the force loaded in each dimension of the 3D force sensor will directly affect the decoupling accuracy of the 3D force sensor. However, the conditions for multi-dimensional force loading are often not available at the digital assembly site of large components, and the accuracy of the loaded force is heavily dependent on the accuracy of the multi-dimensional force loading platform.

[0004] In order to be able to perform three-dimensional force sensor decoupling at the digital assembly site of large components, while being able to reduce the cost of three-dimensional force sensor decoupling as much as possible and improve the accuracy of three-dimensional force sensor decoupling, it has become an urgent problem to be solved. Summary of the invention

[0005] Technical solution: In order to solve the technical problem that the traditional three-dimensional force sensor decoupling method relies on a special loading platform and has low decoupling accuracy, the present invention utilizes common equipment and instruments at the digital assembly site of large components such as industrial robots and laser trackers to provide a three-dimensional force sensor decoupling device based on multi-posture, which specifically includes an industrial robot, a laser tracker, a three-dimensional force sensor, a holding device, a lanyard seat, a lanyard shaft, a lanyard, a weight, and a reflective target ball; the holding device is a flat support structure, which is installed at one end of the mechanical arm of the industrial robot; the three-dimensional force sensor is fixedly installed on the holding device through a locating pin; the lanyard seat is fixedly installed in the middle position of the three-dimensional force sensor by bolts; one end of the lanyard shaft is set in the middle of the lanyard seat, and the other end is connected to the weight through a lanyard; four reflective target balls are provided and fixedly installed at the four end positions of the holding device; the laser tracker is installed on one side of the industrial robot.

[0006] As an improvement, it also includes two positioning pins, each of which is independently provided. The positioning pin one fixes the three-dimensional force sensor on the holding device, and the positioning pin two fixes the rope seat on the three-dimensional force sensor.

[0007] At the same time, the present invention also provides a method for decoupling a three-dimensional force sensor based on multi-posture, which is a decoupling method based on the above-mentioned three-dimensional force sensor decoupling device based on multi-posture, and the specific steps include:

[0008] Step 1: First, use a holding device to connect the three-dimensional force sensor to the end of the industrial robot arm, hang a weight, and use a laser tracker to measure the posture of the three-dimensional force sensor relative to the horizontal coordinate system;

[0009] Step 2: Calculate the force components of each dimension of the three-dimensional force sensor based on the mass of the weight and the spatial posture of the three-dimensional force sensor, and record the voltage values ​​output by each dimension of the three-dimensional force sensor;

[0010] Step 3: First, drive the industrial robot to adjust the spatial posture of the three-dimensional force sensor; then the laser tracker measures the spatial posture of the three-dimensional force sensor; finally, calculate the component of the force applied to each dimension of the three-dimensional force sensor, and record the voltage value output by each dimension of the three-dimensional force sensor at this time;

[0011] Step 4: Repeat step 3 n-1 times, and build a coupling parameter solution model for the three-dimensional force sensor according to the magnitude of the force loaded in each dimension of the three-dimensional force sensor under n spatial postures and the voltage value output in each dimension, and use the least squares method to calculate the coupling parameters of the three-dimensional force sensor, where n is an integer not less than 4.

[0012] As an improvement, step one specifically includes the following contents:

[0013] ① A holding device designed to fix the three-dimensional force sensor on the end of the robot. The holding device has four reflective target ball mounting holes. After the reflective target ball is installed, its coordinates in the local coordinate system of the holding device are and Use positioning pins to position the three-dimensional force sensor and the holding device, ensuring that the local coordinate system of the holding device is parallel to the coordinate system of the three-dimensional force sensor;

[0014] ② Design a suspension mechanism for hanging weights so that when the three-dimensional force sensor is adjusted, the straight line where the weight hanging rope is located can always intersect with the Z axis of the three-dimensional force sensor;

[0015] ③ Adjust the laser tracker to a horizontal level and measure the coordinates of the four reflective target balls on the holding device in the horizontal coordinate system. and

[0016] ④ According to the coordinate system conversion principle, the coordinates of the reflective target ball in the local coordinate system of the holding device and the coordinates in the horizontal coordinate system satisfy the following relationship, see formula 1:

[0017]

[0018] where i = {1, 2, 3, 4}, is the attitude matrix of the holding device relative to the horizontal coordinate system is the position vector of the holding device relative to the horizontal coordinate system, and the attitude matrix of the holding device relative to the horizontal coordinate system is calculated using the singular value decomposition method.

[0019] As an improvement, step 2 specifically includes the following contents:

[0020] ① Assuming the mass of the weight to be loaded is m, and the acceleration of gravity is g, then the vector representation of the external force loaded on the three-dimensional force sensor (3) in the horizontal coordinate system Os-xyz is: According to the coordinate system transformation principle, The vector in the holding device coordinate system Og-xyz is expressed as F g , see formula 2

[0021]

[0022] ② The three-dimensional force sensor coordinate system is parallel to the holding device coordinate system Og-xyz, and F s The vector in the three-dimensional force sensor coordinate system is also expressed as F g , let F g =[F x ,F y ,F z ] T , then F x 、F y and F z That is, the force components loaded in three dimensions by the three-dimensional force sensor;

[0023] ③ Assume that the voltage output of the three-dimensional force sensor in three dimensions during loading is U = [U x ,U y ,U z ] T .

[0024] As an improvement, step three specifically includes the following contents:

[0025] ① Drive the robot, adjust the spatial posture of the three-dimensional force sensor, use the laser tracker to measure the reflective target ball on the holding device, and calculate the posture matrix of the holding device relative to the horizontal coordinate system: Where j indicates that the holding device is in the jth posture;

[0026] ② Calculate the force components loaded by the three-dimensional force sensor in each dimension when the holding device is in the jth posture: and in T represents the transpose of the matrix;

[0027] ③ When the holding device is in the jth posture, the voltage output of each dimension of the three-dimensional force sensor is

[0028] As an improvement, the three-dimensional force sensor coupling parameter solution model in step 4 includes the following contents:

[0029] ① Adjust the spatial posture of the three-dimensional force sensor n-1 times, add the initial posture, and obtain the force components of n groups of three-dimensional sensors And the voltage U output by each dimension of the three-dimensional force sensor j ;

[0030] ②Force load input by 3D force sensor With the output voltage U j A linear relationship is formed, as shown in the following formula 3:

[0031]

[0032] where k lm is the coupling coefficient of the three-dimensional force sensor, l is an integer of 1-3, m is an integer of 1-3, (d x ,d y ,d z ) is the zero drift of the three-dimensional force sensor;

[0033] ③ Order D=[d x ,d y ,d z ] T , then formula (3) can be written in the form of matrix multiplication as shown in formula 4:

[0034] U=K·F g +D (4)

[0035] Let [K,D] T =[X1,X2,X3], [X1,X2,X3] is the coupling parameter of the three-dimensional force sensor, and the formula 5 is obtained.

[0036]

[0037] When the holding device is in the jth posture, the force applied to each dimension of the three-dimensional force sensor is And the output voltage U j The relationship is as follows

[0038]

[0039] ④ Order is the three-dimensional force matrix loaded during decoupling; is the voltage vector in the X direction; is the voltage vector in the Y direction; is the voltage vector in the Z direction, the coupling parameter solution model of the three-dimensional force sensor is expressed as formula 7:

[0040]

[0041] Then, the least squares solutions of X1, X2 and X3 are calculated as Equation 8

[0042]

[0043] and That is, it serves as the coupling parameter of the three-dimensional force sensor.

[0044] Beneficial effects: The device and method proposed by the present invention do not require the use of a dedicated multi-dimensional force loading platform, thereby reducing the cost of decoupling the three-dimensional force sensor; at the same time, it can ensure that the three-dimensional force sensor can be decoupled at the assembly site of large components.

[0045] In addition, the present invention specifically uses a laser tracker to measure the posture of the three-dimensional force sensor relative to the horizontal coordinate system, then calculates the force component values ​​of each dimension of the three-dimensional force sensor, and finally calculates the coupling parameters of the three-dimensional force sensor using the least square method based on multiple groups of force component values ​​of each dimension of the three-dimensional force sensor and the output voltage value. The laser tracker used in this method has extremely high leveling accuracy, which can ensure the accuracy of the force loaded in each dimension of the three-dimensional force sensor, thereby improving the accuracy of the sensor decoupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic flow chart of a three-dimensional force sensor decoupling method based on multi-posture proposed by the present invention.

[0047] Figure 2 This is a schematic diagram of the composition of the multi-posture based three-dimensional force sensor decoupling system proposed in the present invention.

[0048] Figure 3 It is a schematic diagram of the coordination between the three-dimensional force sensor, the fixing device, and the suspension mechanism of the weight.

[0049] In the figure: 1 industrial robot, 2 reflective target ball, 3 three-dimensional force sensor, 4 holding device, 5 hanging rope seat, 6 hanging rope shaft, 7 hanging rope, 8 weight, 9 laser tracker, 10 positioning pin 1, 11 rope threading hole, 12 positioning pin 2, 13 bolt 1, 14 bolt 2. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be described clearly and completely below so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0051] In view of the problem that the traditional three-dimensional force sensor decoupling method relies on a dedicated loading platform and has low decoupling accuracy, the present invention provides a three-dimensional force sensor decoupling method by utilizing common equipment and instruments at large-scale component digital assembly sites, such as industrial robots and laser trackers, to reduce the cost of three-dimensional force sensor decoupling and improve the accuracy of three-dimensional force sensor decoupling.

[0052] The main idea of ​​the present invention is to use a laser tracker to measure the posture of a three-dimensional force sensor relative to a horizontal coordinate system, then calculate the force component values ​​loaded in each dimension of the three-dimensional force sensor, and finally use the least squares method to calculate the coupling parameters of the three-dimensional force sensor based on the force component values ​​loaded in each dimension of the three-dimensional force sensor and the output voltage value.

[0053] See Figure 2 and Figure 3 As shown, a three-dimensional force sensor decoupling device based on multi-posture is specifically included, which includes an industrial robot 1, a laser tracker 9, a three-dimensional force sensor 3, a holding device 4, a hanging rope seat 5, a hanging rope shaft 6, a hanging rope 7, a weight 8, and a reflective target sphere 2; the holding device 4 is a flat support structure, which is installed at one end of the mechanical arm of the industrial robot 1; the three-dimensional force sensor 3 is fixedly installed on the holding device 4 through a locating pin; the hanging rope seat 5 is fixedly installed at the middle position of the three-dimensional force sensor 3 through bolts; one end of the hanging rope shaft 6 is arranged in the middle of the hanging rope seat 5, and the other end is connected to the weight 8 through the hanging rope 7; the reflective target sphere 2 is provided with four, which are fixedly installed at the four end positions of the holding device 4; the laser tracker 9 is installed on one side of the industrial robot 1.

[0054] It also includes a positioning pin 10 and a positioning pin 12, both of which are independently provided with two. The positioning pin 10 fixes the three-dimensional force sensor 3 on the holding device 4, and the positioning pin 12 fixes the rope seat 5 on the three-dimensional force sensor 3.

[0055] It also includes a bolt 13 and a bolt 2 14 , both of which are independently provided with two bolts. The bolt 13 fixes the three-dimensional force sensor 3 on the holding device 4 , and the bolt 2 14 fixes the rope seat 5 on the three-dimensional force sensor 3 .

[0056] The rope holder 5 is fixedly mounted on the three-dimensional force sensor 3 .

[0057] The present invention also provides a three-dimensional force sensor decoupling method based on multi-posture of the above device, such as Figure 1-3 As shown, the following steps are included:

[0058] Step 1: First, use the holding device 1 to connect the three-dimensional force sensor 3 to the end of the robot 1 and hang the weight 8, and the laser tracker 9 measures the posture of the three-dimensional force sensor 3 relative to the horizontal coordinate system, as follows:

[0059] ① The holding device 4 is designed to fix the three-dimensional force sensor 3 to the end of the robot 1. The three-dimensional force sensor 3 and the holding device 4 are positioned using a positioning pin 10 and fixed using a bolt 13 to ensure that the local coordinate system of the holding device 4 is parallel to the coordinate system of the three-dimensional force sensor 3. Four reflective target balls 2 are installed on the holding device 4. The coordinates of the reflective target balls in the local coordinate system of the holding device 4 are and

[0060] ② A suspension mechanism is designed for hanging the weight 8, which is composed of a rope seat 5 and a rope shaft 6. The rope seat 5 and the three-dimensional force sensor 3 are positioned using a positioning pin 12 and fixed using a bolt 14, so that the central axis of the rope seat 5 coincides with the Z axis of the three-dimensional force sensor 3. The rope shaft 6 can rotate around the rope seat 5, and the rope shaft 6 has a rope hole 11, through which the rope 7 for hanging the weight 8 can pass.

[0061] ③ Adjust the laser tracker 9 to a horizontal level and measure the coordinates of the four reflective target balls 2 on the holding device in the horizontal coordinate system Os-xyz. and

[0062] ④ According to the coordinate system conversion principle, the coordinates of the reflective target sphere 2 in the local coordinate system Og-xyz of the holding device 4 and the coordinates in the horizontal coordinate system Os-xyz satisfy the following relationship:

[0063]

[0064] where i = {1, 2, 3, 4}, is the attitude matrix of the holding device relative to the horizontal coordinate system is the position vector of the holding device relative to the horizontal coordinate system, and the attitude matrix of the holding device relative to the horizontal coordinate system Os-xyz is calculated using the singular value decomposition method.

[0065] Step 2: Calculate the force components of the three-dimensional force sensor in each dimension according to the mass m of the weight and the spatial posture of the three-dimensional force sensor, and record the voltage values ​​output by the three-dimensional force sensor in each dimension at the same time, as follows:

[0066] ① Assuming the mass of the weight to be loaded is m, and the acceleration of gravity is g, the vector of the external force loaded on the three-dimensional force sensor 3 in the horizontal coordinate system Os-xyz can be expressed as According to the coordinate system transformation principle, The vector in the holding device coordinate system Og-xyz can be expressed as F g

[0067]

[0068] ② Since the three-dimensional force sensor coordinate system is parallel to the fixture coordinate system Og-xyz, F s The vector in the three-dimensional force sensor coordinate system can also be expressed as F g Let F g =[F x ,F y ,F z ] T , then F x 、F y and F z That is, the force component loaded in each dimension of the three-dimensional force sensor.

[0069] ③ Assume that the voltage output of each dimension of the three-dimensional force sensor during loading is U = [U x ,U y ,U z ] T .

[0070] Step 3: First, drive the robot 1 to adjust the spatial posture of the three-dimensional force sensor 3; then use the laser tracker 9 to measure the spatial posture matrix of the three-dimensional force sensor; finally, calculate the component of the force loaded in each dimension of the three-dimensional force sensor, and record the voltage value output by each dimension of the three-dimensional force sensor at this time, as follows:

[0071] ① Drive the robot 1, adjust the spatial posture of the three-dimensional force sensor 3, and use the laser tracker 9 to measure the reflective target ball 2 on the holding device 4. The posture matrix of the holding device 4 relative to the horizontal coordinate system Os-xyz can be calculated as follows: Wherein j indicates that the holding device is in the jth posture.

[0072] ② It can be calculated that when the holding device 4 is in the jth posture, the force components loaded in each dimension of the three-dimensional force sensor 3 are: and F i z .in

[0073] ③ When the holding device 4 is in the jth posture, the voltage output of each dimension of the three-dimensional force sensor 3 is

[0074] Step 4: Repeat step 3 n-1 times, and calculate the force applied to each dimension of the 3D force sensor in each spatial position. And the voltage U output in each dimension j A coupling parameter calculation model for the three-dimensional force sensor is constructed, and the coupling parameters of the three-dimensional force sensor are calculated using the least squares method.

[0075] ① Adjust the spatial posture of the three-dimensional force sensor 3 n-1 times, and add the initial posture to obtain the force components of n groups of three-dimensional force sensors. And the voltage U output by each dimension of the three-dimensional force sensor j .

[0076] ② A large number of 3D force sensor calibration experiments show that the input force load of the 3D force sensor With the output voltage U j A linear steady-state system is formed, that is, the output voltage of each output channel is obtained by the combined effect of the forces loaded in the three dimensions of X, Y, and Z and the zero-point drift, as shown in formula (3).

[0077]

[0078] where k lm is the coupling coefficient of the three-dimensional force sensor 3, (d x ,d y ,d z ) is the zero drift of the three-dimensional force sensor.

[0079] ③ Order D=[d x ,d y ,d z ] T , then formula (3) can be written in the form of matrix multiplication.

[0080] U=K·F g +D (4)

[0081] Therefore, [(F g ) T ,1][K,D] T =U T Let [K,D]T =[X1,X2,X3], [X1,X2,X3] is the coupling parameter of the three-dimensional force sensor. Therefore, the following formula is obtained

[0082]

[0083] When the three-dimensional force sensor 4 is in the jth posture, the force applied to each dimension of the three-dimensional force sensor 4 is And the output voltage U j The following relationship exists

[0084]

[0085] ④ Order Then the three-dimensional force sensor coupling parameter solution model can be expressed as

[0086]

[0087] The least squares solutions of X1, X2 and X3 can be calculated as

[0088]

[0089] and That is, it serves as the coupling parameter of the three-dimensional force sensor.

[0090] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A three-dimensional force sensor decoupling device based on multi-posture, characterized in that: The invention comprises an industrial robot (1), a laser tracker (9), a three-dimensional force sensor (3), a holding device (4), a hanging rope seat (5), a hanging rope rotating shaft (6), a hanging rope (7), a weight (8), and a reflective target ball (2); the holding device (4) is a flat support structure, which is installed at one end of the mechanical arm of the industrial robot (1); the three-dimensional force sensor (3) is fixedly installed on the holding device (4) through a positioning pin; the hanging rope seat (5) is fixedly installed at the middle position of the three-dimensional force sensor (3) through a bolt; one end of the hanging rope rotating shaft (6) is arranged in the middle of the hanging rope seat (5), and the other end is connected to the weight (8) through a hanging rope (7); four reflective target balls (2) are arranged and fixedly installed at the four end positions of the holding device (4); and the laser tracker (9) is installed on one side of the industrial robot (1).

2. The multi-posture three-dimensional force sensor decoupling device according to claim 1, characterized in that: It also includes two independently arranged positioning pins, one positioning pin (10) and two positioning pins (12), wherein the one positioning pin (10) fixes the three-dimensional force sensor (3) on the holding device (4), and the two positioning pins (12) fixes the rope holder (5) on the three-dimensional force sensor (3).

3. A three-dimensional force sensor decoupling method based on multi-posture, characterized in that: The decoupling method is performed based on the multi-posture three-dimensional force sensor decoupling device according to claim 1 or 2, and the specific steps include: Step 1: First, a three-dimensional force sensor (3) is connected to the end of the mechanical arm of the industrial robot (1) using a fixing device (4), and a weight (8) is hung, and a laser tracker (9) is used to measure the posture of the three-dimensional force sensor (3) relative to the horizontal coordinate system; Step 2: Calculate the force components of each dimension of the three-dimensional force sensor (3) based on the mass of the weight (8) and the spatial posture of the three-dimensional force sensor (3), and record the voltage values ​​output by each dimension of the three-dimensional force sensor; Step 3: First, the industrial robot (1) is driven to adjust the spatial posture of the three-dimensional force sensor (3); then the laser tracker (9) measures the spatial posture of the three-dimensional force sensor (3); finally, the component of the force applied to each dimension of the three-dimensional force sensor (3) is calculated, and the voltage value output by each dimension of the three-dimensional force sensor is recorded at the same time; Step 4: Repeat step 3 n-1 times, and build a coupling parameter solution model for the three-dimensional force sensor according to the magnitude of the force loaded in each dimension of the three-dimensional force sensor under n spatial postures and the voltage value output in each dimension, and use the least squares method to calculate the coupling parameters of the three-dimensional force sensor, where n is an integer not less than 4.

4. The method for decoupling a three-dimensional force sensor based on multi-posture according to claim 3 is characterized in that: step 1 specifically includes the following contents: ① A holding device designed to fix the three-dimensional force sensor on the end of the robot. The holding device has four reflective target ball mounting holes. After the reflective target ball is installed, its coordinates in the local coordinate system of the holding device are and Use positioning pins to position the three-dimensional force sensor and the holding device, ensuring that the local coordinate system of the holding device is parallel to the coordinate system of the three-dimensional force sensor; ② Design a suspension mechanism for hanging weights so that when the three-dimensional force sensor is adjusted, the straight line where the weight hanging rope is located can always intersect with the Z axis of the three-dimensional force sensor; ③ Adjust the laser tracker to a horizontal level and measure the coordinates of the four reflective target balls on the holding device in the horizontal coordinate system. and ④ According to the coordinate system conversion principle, the coordinates of the reflective target ball in the local coordinate system of the holding device and the coordinates in the horizontal coordinate system satisfy the following relationship, see formula 1: where i = {1, 2, 3, 4}, is the attitude matrix of the holding device relative to the horizontal coordinate system, is the position vector of the holding device relative to the horizontal coordinate system, and the attitude matrix of the holding device relative to the horizontal coordinate system is calculated using the singular value decomposition method.

5. The method for decoupling a three-dimensional force sensor based on multiple postures according to claim 3 is characterized in that: step 2 specifically includes the following contents: ① Assuming the mass of the weight to be loaded is m, and the acceleration of gravity is g, then the vector representation of the external force loaded on the three-dimensional force sensor (3) in the horizontal coordinate system Os-xyz is: According to the coordinate system transformation principle, The vector in the holding device coordinate system Og-xyz is expressed as F g , see formula 2 ② The three-dimensional force sensor coordinate system is parallel to the holding device coordinate system Og-xyz, and F s The vector in the three-dimensional force sensor coordinate system is also expressed as F g , let F g =[F x ,F y ,F z ] T , then F x 、F y and F z That is, the force components loaded in three dimensions by the three-dimensional force sensor; ③ Assume that the voltage output of the three-dimensional force sensor in three dimensions during loading is U = [U x ,U y ,U z ] T .

6. The method for decoupling a three-dimensional force sensor based on multiple postures according to claim 3 is characterized in that: step 3 specifically includes the following contents: ① Drive the robot, adjust the spatial posture of the three-dimensional force sensor, use the laser tracker to measure the reflective target ball on the holding device, and calculate the posture matrix of the holding device relative to the horizontal coordinate system: Where j indicates that the holding device is in the jth posture; ② Calculate the force components loaded by the three-dimensional force sensor in each dimension when the holding device is in the jth posture: and in T represents the transpose of the matrix; ③ When the holding device is in the jth posture, the voltage output of each dimension of the three-dimensional force sensor is 7. The method for decoupling a three-dimensional force sensor based on multi-posture according to claim 3 is characterized in that: in step 4, the three-dimensional force sensor coupling parameter solution model, the construction of the model specifically includes the following contents: ① Adjust the spatial posture of the three-dimensional force sensor n-1 times, add the initial posture, and obtain the force components of n groups of three-dimensional sensors And the voltage U output by each dimension of the three-dimensional force sensor j ; ②Force load input by 3D force sensor With the output voltage U j A linear relationship is formed, as shown in the following formula 3: where k lm is the coupling coefficient of the three-dimensional force sensor, l is an integer of 1-3, m is an integer of 1-3, (d x ,d y ,d z ) is the zero drift of the three-dimensional force sensor; ③ Order D=[d x ,d y ,d z ] T , then formula (3) is written in the form of matrix multiplication, see formula 4: U=K·F g +D (Formula 4) Let [K,D] T =[X1,X2,X3], [X1,X2,X3] is the coupling parameter of the three-dimensional force sensor, and the formula is obtained as 5 When the holding device is in the jth posture, the force applied to each dimension of the three-dimensional force sensor is And the output voltage U j The relationship is as follows ④ Order is the three-dimensional force matrix loaded during decoupling; is the voltage vector in the X direction; is the voltage vector in the Y direction; is the voltage vector in the Z direction, the coupling parameter solution model of the three-dimensional force sensor is expressed as formula 7: Then, the least squares solutions of X1, X2 and X3 are calculated as Equation 8 and That is, it serves as the coupling parameter of the three-dimensional force sensor.

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