WO2022027929A1 - Mechanical flexible mechanism capable of achieving functions of uniaxial, biaxial and triaxial force detection - Google Patents

Abstract

A mechanical flexible mechanism capable of achieving the functions of uniaxial, biaxial and triaxial force detection, comprising a base body (1), a uniaxial force detection flexible mechanism, a biaxial force detection flexible mechanism, a triaxial force detection flexible mechanism and a plurality of displacement detection devices; the uniaxial force detection flexible mechanism, the biaxial force detection flexible mechanism and the triaxial force detection flexible mechanism each are provided with a tool holder (6) and a tool (7); according to different requirements, the corresponding force detection flexible mechanism and the corresponding displacement detection device are mounted on the base body (1), and detection is performed; and the displacement detection device is provided at a detection end of the corresponding force detection flexible mechanism.

Description

A Mechanically Flexible Mechanism That Can Realize Uniaxial, Biaxial and Triaxial Force Detection Functions technical field

The invention relates to the technical field of ultra-precision machining, in particular to a mechanically flexible mechanism capable of realizing single-axis, double-axis and three-axis force detection functions.

Background technique

With the development of ultra-precision technology, the complexity of optical three-dimensional free surfaces in special fields is getting higher and higher, and the demand for high-performance manufacturing of microstructures is increasing day by day.

Cutting force is an important indicator reflecting the cutting state, and real-time detection of cutting force has been widely used to identify or monitor the dynamic behavior of the cutting process and the condition of cutting tools. There are three main applications:

(1) Characterize, model, and optimize the cutting process; understand metal cutting mechanisms, such as the effect of cutting variables on cutting forces, and then enable process planners to determine optimal cutting conditions, such as cutting speed and feed rate.

(2) Monitor the condition of cutting tools, such as tool deflection and breakage; predict real-time tool wear and tool failure; analyze tool and machine tool stress; verify that dimensions, surface position errors, and surface finish meet their geometric tolerances.

(3) Detect the chattering of vibration and the stability of the cutting process, and provide useful information that can be used in the mechanical design of tools, machine tools and their spindle bearings.

The cutting force is detected in real time and adjusted in time to achieve the effect of controlling the cutting force, which can achieve higher machining accuracy. In recent years, several techniques for fabricating microstructures and grooves using diamond tools have been developed. However, most of them can only achieve the required nano/micron-level precision under strict environmental conditions and very complex control systems, or using ultra-high-precision kinematics. This is mainly because conventional cutting sets the depth of cut through its feed mechanism, so the accuracy of the part produced is directly dependent on the precision involved in making the machine. One solution to this constant is to implement a constant force cutting process, the main purpose of which is to control the cutting force applied to the workpiece to be constant in order to form microscale structures with constant depth of cut. At present, by controlling the normal cutting force to be constant, it has been achieved to machine grooves of constant depth on inclined planes and curved surfaces.

The current 3D force detection methods include a 3D force detection method based on a flexible tactile sensor array, a 3D force detection method based on electromagnetic induction, and a capacitive 3D force detection method. At the same time, the three-dimensional force detection accuracy of the above methods is generally not high, while the ultra-precision machining has the characteristics of ultra-low cutting force, and there is also an irreconcilable contradiction.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a mechanically flexible mechanism capable of realizing uniaxial, biaxial and triaxial force detection functions. The displacement detection device detects the displacement change of the flexible mechanism in one, two and three directions, and converts the displacement change and size into the force change and size through the linear relationship between force and displacement, and realizes uniaxial, biaxial and Three-axis force detection function.

The object of the present invention is achieved in this way:

A mechanically flexible mechanism capable of realizing the function of uniaxial force detection, comprising:

The base body is used to be fixed on the detection platform, and is equipped with a single-force detection flexible mechanism and a displacement detection device;

The uniaxial force detection flexible mechanism includes a force block A, the two sides of the force block A are symmetrically arranged with a fixed block A through a first flexible hinge, and one end of the force block A is the detection end;

The displacement detection devices all include a displacement mounting seat fixed on the base body and a displacement sensor, the displacement sensor is arranged at the detection end of the uniaxial force detection flexible mechanism, and is used to detect the displacement amount and the force condition of the detection end;

The tool holder is used to install the tool and is fixed on the force block A.

Preferably, the detection end is fixed with a sleeve, which is sleeved on the outer side of the displacement mounting seat and wraps the displacement sensor to prevent the probe of the displacement sensor from being exposed to the air.

Preferably, the first flexible hinge is a straight circular flexible hinge, and the straight circular flexible hinge includes a rectangular block, and two sets of semicircular holes are opened mirror-symmetrically on two side walls of the rectangular block.

Preferably, the mounting surface of the base body is an XY plane, the width direction is the X-axis direction, and the height direction is the Y-axis direction. Directional displacement detection device;

When the uniaxial force detection flexible mechanism is used to detect the force in the Z-axis direction, the force-bearing block A is connected to the fixed block A through two rows of first flexible hinges arranged symmetrically, and is distributed along the X-axis direction, wherein the first The axis of the semicircular hole of the flexible hinge is arranged along the Y-axis direction; the Z-direction displacement detection device faces the back of the force-bearing block A.

A mechanically flexible mechanism capable of realizing a dual-axis detection function is characterized in that, comprising:

The base body is used to be fixed on the detection platform, and is equipped with a biaxial force detection flexible mechanism and a displacement detection device;

The flexible mechanism for biaxial force detection includes a force-bearing block B, two sides of the force-bearing block B are symmetrically arranged with connecting blocks B through a second flexible hinge, and fixed blocks are symmetrically arranged on both sides of the connecting block B through a third flexible hinge B, one end of the connection block B and the force block B is the detection end;

The two displacement detection devices both include a displacement mounting seat fixed on the base body and a displacement sensor, the displacement sensor is arranged at the detection end of the biaxial force detection flexible mechanism, and is used to detect the displacement amount and the force condition of the detection end;

The tool holder is used to install the tool and is fixed on the force block B.

Preferably, the second flexible hinge and the third flexible hinge are both straight circular flexible hinges, the straight circular flexible hinge includes a rectangular block, and two sets of semicircular holes are mirror-symmetrically opened on two side walls of the rectangular block.

Preferably, when the biaxial force detection flexible mechanism is used to detect the force in the X/Z axis direction, the force receiving block B is connected to the connecting block B through two rows of second flexible hinges arranged symmetrically, and is distributed along the X axis direction , wherein the axis of the semicircular hole of the second flexible hinge is arranged along the Y-axis direction; the Z-direction displacement detection device is installed in the main installation hole and faces the back of the force-bearing block B;

The connecting block B, the third flexible hinge and the fixing block B are distributed along the Y-axis direction, wherein the axis of the semicircular hole of the third flexible hinge is arranged along the Z-axis direction; the base body on one side of the connecting block B is provided with an X-direction displacement detection device.

A mechanically flexible mechanism capable of realizing three-axis detection function is characterized in that, comprising:

The base body is used to be fixed on the detection platform, and three detection flexible mechanisms and displacement detection devices are installed;

The three-axis force detection flexible mechanism includes a force-bearing block C. The adjacent two sides of the force-bearing block C are respectively provided with connecting blocks C through a fifth flexible hinge, and the two connecting blocks C are connected to the same fixed block C through a fourth flexible hinge. , one end of the two connecting blocks C and the force-bearing block C is the detection end;

The three displacement detection devices all include a displacement mounting seat and a displacement sensor fixed on the base body, and the displacement sensor is arranged at the detection end of the three-axis force detection flexible mechanism, and is used to detect the displacement amount and the force condition of the detection end;

The tool holder is used to install the tool and is fixed on the force block C.

Preferably, the fourth flexible hinge is a straight circular flexible hinge, and the straight circular flexible hinge includes a rectangular block, and two sets of semicircular holes are opened mirror-symmetrically on two side walls of the rectangular block;

The fifth flexible hinge is a prism, and each surface of the upper and lower ends of the fifth flexible hinge is respectively provided with an arc surface, and a plurality of arc surfaces intersect to form a connecting part with a small middle and large ends.

Preferably, when the three-axis force detection flexible mechanism is used to detect the force in the X/Y/Z axis direction, the fifth flexible hinge is arranged along the X/Y axis direction, and can realize the movement of the force receiving block C in the Z axis direction , the Z-direction displacement detection device is installed in the main installation hole and faces the back of the force block C;

The connecting block C is connected to the fixing block C through two rows of fourth flexible hinges, the fourth flexible hinges are arranged along the X/Y axis direction, and the axis of the semicircular hole is arranged along the Z axis direction, and the two connecting blocks C are on one side. The X-direction displacement detection device and the Y-direction displacement detection device are respectively arranged on the base of the .

Compared with the prior art, the present invention has outstanding and beneficial technical effects as follows:

(1) The present invention can carry a tool and has a small size, and can be used for machining large-sized workpieces in combination with the displacement mechanism.

(2) The present invention provides uniaxial, biaxial and triaxial force detection flexible mechanisms, which can respectively realize uniaxial, biaxial and triaxial force detection functions, are easy to install and disassemble, and can be respectively applied to different processing occasions.

(3) The flexible mechanism for biaxial and triaxial force detection provided by the present invention has a decoupling effect, and can accurately obtain the force change and magnitude in this direction by detecting the displacement change and magnitude in one direction.

(4) The system of the present invention has high sensitivity, the single-axis force detection flexible mechanism can identify the minimum Z-direction 3mN cutting force; the dual-axis force detection flexible mechanism can identify the X-direction 2mN cutting force, and the Z-direction 2mN cutting force; three axis The force detection flexible mechanism can identify the minimum cutting force of 2mN in the X direction, 3mN in the Y direction, and 2mN in the Z direction.

Description of drawings

FIG. 1 is a schematic diagram of the structure of a substrate in the present invention, wherein (a) is a schematic diagram of the front structure of the substrate; (b) is a schematic diagram of the reverse structure of the substrate.

FIG. 2 is a schematic diagram of a mechanically flexible mechanism for realizing a uniaxial force detection function in the present invention.

FIG. 3 is a schematic diagram of a flexible mechanism for uniaxial force detection in the present invention.

FIG. 4 is a schematic diagram of a mechanically flexible mechanism capable of realizing a biaxial force detection function in the present invention.

FIG. 5 is a schematic diagram of a flexible mechanism for biaxial force detection in the present invention.

FIG. 6 is a schematic diagram of a mechanically flexible mechanism capable of realizing a triaxial force detection function in the present invention.

FIG. 7 is a schematic diagram of a three-axis force detection flexible mechanism in the present invention.

8 is a schematic diagram of the installation of the three-axis displacement detection device in the present invention, wherein (a) is a schematic diagram of the installation of the X-axis direction displacement sensor; (b) is a schematic diagram of the installation of the Y-axis direction displacement sensor; (c) is the Z-axis direction displacement sensor Installation diagram;

9 is a schematic diagram of the installation structure of the three-axis sleeve in the present invention, wherein (a) is a schematic diagram of the installation of the sleeve in the X-axis direction; (b) is a schematic diagram of the installation of the sleeve in the Y-axis direction; (c) is the installation of the sleeve in the Z-axis direction schematic diagram;

10 is a diagram of the calibration result of the flexible mechanism for uniaxial force detection in the embodiment of the present invention, specifically a change curve of the displacement change in the Z-axis direction detected by the displacement sensor with the dynamic force acting in the Z-axis direction;

Figure 11 is a diagram of the calibration result of the flexible mechanism for biaxial force detection in the embodiment of the present invention, wherein (a) is the change curve of the displacement change in the X-axis direction detected by the displacement sensor with the dynamic force acting in the X-axis direction; (b) is the displacement sensor. The change curve of the detected displacement in the Z-axis direction with the dynamic force acting in the Z-axis direction;

Figure 12 is a diagram of the calibration result of the flexible mechanism for triaxial force detection in the embodiment of the present invention, wherein (a) is the change curve of the displacement change in the X-axis direction detected by the displacement sensor with the dynamic force acting in the X-axis direction; (b) is the displacement sensor. The change curve of the detected displacement in the Y-axis direction with the applied dynamic force in the Y-axis direction; (c) is the change curve of the displacement change in the Z-axis direction detected by the displacement sensor with the applied dynamic force in the Z-axis direction.

The meaning of the symbols in the figure:

1-base body; 2-sleeve; 3-fixed block A; 4-first flexible hinge; 5-forced block A; 6-tool holder; 7-tool;

8-fixed block B; 10-third flexible hinge; 11-connecting block B; 12-second flexible hinge; 13-forced block B;

17-connection block C; 18-fourth flexible hinge; 19-fifth flexible hinge; 20-force block C; 22-fixed block C;

27-Mounting block; 28-Displacement mount; 29-Displacement sensor;

31-X-direction displacement detection device; 32-Y-direction displacement detection device; 33-Z-direction displacement detection device;

41-rectangular block; 42-semi-circular hole; 43-connecting part;

51-main installation hole; 52-first installation hole; 53-second installation hole.

detailed description

Below in conjunction with specific embodiment, the present invention is further described:

A mechanically flexible mechanism capable of realizing uniaxial, biaxial and triaxial force detection functions, comprising:

The base body 1, as shown in Figure 1, is used to be fixed on the detection platform, and can be detached and installed with different force detection flexible mechanisms and displacement detection devices. The force detection flexible mechanisms are divided into uniaxial force detection flexible mechanisms, biaxial For the force detection flexible mechanism and the triaxial force detection flexible mechanism, the corresponding force detection flexible mechanism can be selected and installed on the base body 1 according to the number of axial forces required to be detected. The force detection flexible mechanism mainly includes a force block for installing the tool holder 6, a fixed block installed on the base 1 and a flexible hinge connecting the two. The tool holder 6 is installed with a tool 7, a force block, and a tool holder 6. And the tool 7 is fixedly installed, that is, when the tool 7 is displaced, the force block will also be displaced. The flexible hinge is used to limit the degree of freedom of the force-bearing block and make the force-bearing block move in a desired direction.

In order to better detect the displacement and force changes in multiple axial directions, connecting blocks are also added to the biaxial force detection flexible mechanism and the triaxial force detection flexible mechanism. The connecting blocks are connected to the force block and fixed through different flexible hinges. block, and make it produce a decoupling effect, and more accurately detect the corresponding axial displacement and force change.

For better explanation, the mounting surface of the base body 1 is defined as the XY plane, the width direction is the X-axis direction, the height direction is the Y-axis direction, and the axis direction perpendicular to the mounting surface is defined as the Z-axis direction.

The middle of the mounting surface of the base body 1 is provided with a main mounting hole 51 along the Z-axis direction, the main mounting hole 51 is a through hole, and the main mounting hole 51 is used for mounting the Z-direction displacement detection device 33 . The base body 1 is also provided with a plurality of first mounting holes 52 for mounting the fixing block and a fourth mounting hole for fixing the mounting block 27 . The first mounting holes 52 and the fourth mounting holes are both threaded holes or through holes.

As shown in FIG. 8, the displacement detection device is divided into an X-direction displacement detection device 31, a Y-direction displacement detection device 32 and a Z-direction displacement detection device 33, which respectively detect the X-direction axial force, the Y-direction axial force and the Z-direction axial force. axial force. Each displacement detection device includes a displacement mounting seat 28 and a displacement sensor 29 fixed on the base body 1 , the displacement mounting seat 28 includes a hollow seat body, one end of the seat body is provided with a mounting ring, and the mounting ring is provided with a first Three mounting holes, and are fixed on the corresponding base body 1 or the mounting block 27 by screws. The displacement sensor 29 is mounted on the other end of the seat body, and the displacement sensor 29 is preferably a capacitive displacement sensor. According to the detection needs, the corresponding displacement sensor 29 is arranged at the detection end of the corresponding force detection flexible mechanism to detect the displacement and force change generated at the detection end when the tool 7 is subjected to force. The linear relationship converts the detected displacement change and size into the force change and size to realize the function of force detection.

As shown in FIG. 9 , the detection end is fixed with a sleeve 2 , which is sleeved on the outside of the displacement mounting seat 28 and wraps the displacement sensor 29 to prevent the probe of the displacement sensor 29 from being exposed to the air.

As shown in FIG. 8( a ), it is the X-direction displacement detection device 31 , the displacement mounting seat 28 is fixed on the left or right side of the base 1 through the mounting block 27 , for the convenience of installation, one end of the mounting block 27 is The mounting portion protrudes and is fixed on the fourth mounting hole on the left or right side of the base 1 by screws.

As shown in FIG. 8( b ), it is a Y-direction displacement detecting device 32 , and the displacement mounting seat 28 is fixed on the fourth mounting hole on the upper end or the lower end of the base 1 through the mounting block 27 .

As shown in FIG. 8( c ), it is the Z-direction displacement detecting device 33 , and the mounting ring of the displacement mounting seat 28 is directly fixed on the base 1 by screws. Specifically, a main installation hole 51 along the Z-axis direction is opened in the middle of the installation surface of the base body 1 , the main installation hole 51 is a through hole, the seat body passes through the main installation hole 51 , and the displacement sensor 29 is arranged in the The mounting surface of the base body 1.

The following is a detailed introduction to the force detection flexible mechanism:

【Uniaxial force detection flexible mechanism】

The uniaxial force detection flexible mechanism, as shown in Figure 2-3, includes a force block A5, the force block A5 is a U-shaped block, and a tool holder 6 and a tool 7 are arranged in the middle, and the two sides of the first flexible The hinge 4 is symmetrically provided with a fixing block A3. The fixing block A3 is provided with a second installation hole 53 and is fixed in the first installation hole 52 of the base 1 by a fastener. The fastener is preferably a screw, and is screwed into the first mounting hole 52 . One end of the force-bearing block A5 is the detection end. The uniaxial force detection flexible mechanism is distributed in a straight line.

The first flexible hinge 4 is a straight circular flexible hinge. The straight circular flexible hinge includes a rectangular block 41 . Two sets of semicircular holes 42 are symmetrically opened on two side walls of the rectangular block 41 in mirror images. Specifically, two sets of semi-circular holes 42 are respectively provided at both ends of the rectangular block 41 , and the ends are used to connect the force-bearing block A5 and the fixed block A3 , and each set of semi-circular holes 42 includes two mirror-symmetrical sets on both sides of the rectangular block 41 . semicircular hole in the wall. Preferably, the straight circular flexible hinge is integrally provided with the force receiving block A5 and the fixing block A3.

In this embodiment, when the straight circular flexible hinge is set, the side surface where the semicircular hole is located is always perpendicular to the detected axial force direction. which is:

In the first case, when the uniaxial force detection flexible mechanism is used to detect the force in the Z-axis direction, the force-bearing block A5 is connected to the fixed block A3 through two rows of first flexible hinges 4 symmetrically arranged, and the whole is along the X-axis. Direction distribution, wherein the axis of the semi-circular hole 42 of the first flexible hinge 4 is arranged along the Y-axis direction, that is, the side where the semi-circular hole is located is perpendicular to the detected force in the Z-axis direction. The Z-direction displacement detection device 33 is installed in the main installation hole 51 and faces the back of the force-receiving block A5. As shown in FIG. 9( c ), the back of the force-receiving block A5 is provided with a sleeve 2 .

When the tool 7 is subjected to a force in the Z-axis direction, the force-receiving block A5 will generate a Z-direction displacement, and the corresponding displacement can be detected at the detection end. When the tool is stressed, the movement of the force block A5 along the X, Y directions, and the rotation along the X, Y, and Z axes will be constrained by the flexible structure itself.

In order to verify that the displacement change in the Z-axis direction detected by the displacement sensor of the uniaxial force detection flexible mechanism has a linear relationship with the dynamic force change in the Z-axis direction, the linear coefficient is obtained, and the minimum resolution is measured, and the force detection calibration experiment is carried out. The calibration method is to input different dynamic forces along the Z axis, detect the output displacement change of the displacement sensor in the Z axis direction, and obtain the change curve of the displacement change in the Z axis direction detected by the displacement sensor with the dynamic force acting in the Z axis direction.

Each dynamic force input along the Z axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.819.6 49 98]mN, and the displacement change obtained in turn is D=[16.4548 32.9052 81.9898 164.5213 ]nm, see the table below:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	16.4548	32.9052	81.9898	164.5213

To sum up, the linear fitting result of displacement change to dynamic force change is D=1.6785*F-0.0533. As shown in Figure 10, the displacement change in the Z-axis direction detected by the displacement sensor has a linear proportional relationship with the dynamic force change along the Z-axis direction. The minimum recognized displacement change is 4 nm, and the minimum recognized force in the Z-axis direction is 2.41 mN.

In addition, in the first case of this embodiment, by changing the position of the base body 1 so that the detection direction of the uniaxial force detection flexible mechanism corresponds to the direction of the force to be detected, axial force detection in any direction can be satisfied.

If the position of the base body 1 is not changed, there are the following ways to detect other axial forces:

In the second case, when the uniaxial force detection flexible mechanism is used to detect the force in the X-axis direction, the force-bearing block A5 is connected to the fixed block A3 through two rows of first flexible hinges 4 symmetrically arranged, and the whole is along the Y-axis. The axis of the semicircular hole 42 of the first flexible hinge 4 is arranged along the Z-axis direction; the X-direction displacement detection device 31 is installed on the base 1 at the left/right end of the force-receiving block A5 (not shown in the figure). out).

In the third case, when the uniaxial force detection flexible mechanism is used to detect the force in the Y-axis direction, the force-bearing block A5 is connected to the fixed block A3 through two rows of first flexible hinges 4 symmetrically arranged, and the whole is along the X-axis. The axis of the semicircular hole 42 of the first flexible hinge 4 is arranged along the Z-axis direction; the Y-direction displacement detection device 32 is installed on the base 1 of the upper/lower end of the force-receiving block A5 (not shown in the figure). out).

【Flexible Mechanism for Biaxial Force Detection】

The biaxial force detection flexible mechanism, as shown in Figure 4-5, includes a force block B13, the force block B13 is a U-shaped block, and a tool holder 6 and a tool 7 are arranged in the middle, and the two sides of the force block B13 A connecting block B11 is symmetrically arranged through the second flexible hinge 12 , and fixing blocks B8 are symmetrically arranged on both sides of the connecting block B11 through the third flexible hinge 10 . The component is fixed in the first mounting hole 52 of the base 1 . The second flexible hinge 12 and the third flexible hinge 10 are straight circular flexible hinges. One ends of the connecting block B11 and the force receiving block B13 are both detection ends. As shown in FIG. 9( c ), a sleeve 2 is provided on the back of the force receiving block A5 ; as shown in FIG. 9( a ), a sleeve 2 is provided on the outer side of the connecting block B11 . The dual-axis force detection flexible mechanism adopts a symmetrical flexible design concept and has a dual-axis decoupling effect.

In the first case, as shown in Figure 4-5, when the biaxial force detection flexible mechanism is used to detect the force in the X/Z axis direction, the biaxial force detection flexible mechanism is in an H-shaped distribution, and the force block B13 is connected to the connecting block B11 through two rows of second flexible hinges 12 arranged symmetrically, and is distributed along the X-axis direction, wherein the axis of the semicircular hole 42 of the second flexible hinge 12 is arranged along the Y-axis direction, that is, the side where the semicircular hole is located The force perpendicular to the detected Z-axis direction. The Z-direction displacement detection device 33 is installed in the main installation hole 51 and faces the back surface of the force receiving block B13.

The connecting block B11, the third flexible hinge 10 and the fixing block B8 are distributed along the Y-axis direction, and are perpendicular to the part formed by the force-bearing block B13, the second flexible hinge 12 and the connecting block B11, wherein the third flexible hinge 10 is The axis of the semi-circular hole 42 is set along the Z-axis direction, that is, the side surface where the semi-circular hole is located is perpendicular to the detected force in the X-axis direction. An X-direction displacement detection device 31 is provided on the base body 1 on one side of the connecting block B11. Of course, the X-direction displacement detection device 31 can also be provided on the base body 1 on one side of the other connection block B11 to make the measurement more accurate.

When the tool 7 is subjected to forces in the X and Z directions, the force receiving block B13 will generate displacements in the X and Z directions, and the corresponding displacement can be detected at the corresponding detection end. When the tool is under force, the movement of the force end along the Y direction and the rotation along the X, Y, and Z axes will be constrained by the flexible structure itself.

In order to verify that the displacement changes in the X and Z axis directions detected by the displacement sensor of the biaxial force detection flexible mechanism are linearly related to the dynamic force changes in the X and Z axis directions respectively, the linear coefficient of the corresponding axis is obtained, and the corresponding axis is measured. The minimum resolution, the force detection calibration experiment was carried out. The calibration method is to input different dynamic forces along the X and Z axes respectively, and detect the output displacement change of the corresponding axial displacement sensor.

Each dynamic force input along the X axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.8, 19.6 49 98]mN, and the displacement change obtained in turn is D=[20.5384 36.7723 90.4907 187.8377 ]nm, see the table below:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	20.5384	36.7723	90.4907	187.8377

To sum up, the linear fitting result of displacement change to dynamic force change is D=1.9045*F-0.0784. The change curve of the displacement change in the X-axis direction detected by the displacement sensor with the dynamic force acting in the X-axis direction is obtained. Linear proportional relationship, the minimum recognized displacement change is 4nm, then the minimum recognized force in the X-axis direction is 2.14mN.

Each dynamic force input along the Z axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.8 19.6 49 98]mN, and the displacement change obtained in turn is D=[24.4040 49.0593 118.7180 239.9147] nm, see the table below for details:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	24.4040	49.0593	118.7180	239.9147

To sum up, the linear fitting result of displacement change to dynamic force change is D=2.4382*F+0.4990. The change curve of the displacement change in the Z-axis direction detected by the displacement sensor with the dynamic force acting in the Z-axis direction is obtained. Linear proportional relationship, the minimum recognized displacement change is 4nm, and the minimum recognized force in the Z-axis direction is 1.44mN.

In addition, in the first case of this embodiment, by changing the position of the base body 1 so that the detection direction of the biaxial force detection flexible mechanism corresponds to the direction of the force to be detected, the detection of the Y/Z axis direction and the X/Y axis direction can be satisfied. Axial force detection.

If the position of the base body 1 is not changed, there are the following ways to detect other axial forces:

In the second case, when the biaxial force detection flexible mechanism is used to detect the force in the Y/Z axis direction, it is only necessary to rotate the first structure by 90 degrees to install, that is, the biaxial force detection flexible mechanism is in the shape of an I-shape. The force-bearing block B13 is connected to the connecting block B11 through two rows of second flexible hinges 12 arranged symmetrically, and is distributed along the Y-axis direction, wherein the axis of the semicircular hole 42 of the second flexible hinge 12 is along the X-axis direction Set, that is, the side where the semicircular hole is located is always perpendicular to the detected force in the Z-axis direction. The Z-direction displacement detection device 33 is installed in the main installation hole 51 and faces the back surface of the force receiving block B13.

The connecting block B11, the third flexible hinge 10 and the fixing block B8 are distributed in the X-axis direction, wherein the axis of the semi-circular hole 42 of the third flexible hinge 10 is arranged along the Z-axis direction, that is, the side of the semi-circular hole is always perpendicular to the detection. The force in the Y-axis direction. A Y-direction displacement detection device 32 is provided on the base body 1 on the side of the connection block B11.

In the third case, when the dual-axis force detection flexible mechanism is used to detect the force in the X/Y axis direction, it is only necessary to set the axis of the semicircular hole 42 of the second flexible hinge 12 in the first structure along the Z axis direction. That is, the force-bearing block B13 is connected to the connecting block B11 through two rows of second flexible hinges 12 arranged symmetrically, and is distributed along the X-axis direction, wherein the axis of the semicircular hole 42 of the second flexible hinge 12 is along the Z-axis direction Set, that is, the force on the side where the semicircular hole is located is perpendicular to the detected Y-axis direction. The upper/lower end of the force receiving block B13 is provided with a Y-direction displacement detection device 32 .

The connecting block B11, the third flexible hinge 10 and the fixing block B8 are distributed along the Y-axis direction, wherein the axis of the semi-circular hole 42 of the third flexible hinge 10 is arranged along the Z-axis direction, that is, the side of the semi-circular hole is always perpendicular to the detection The force in the X-axis direction. The base body 1 on the side of the connection block B11 is provided with an X-direction displacement detection device 31 .

【Triaxial Force Detection Flexible Mechanism】

The three-axis force detection flexible mechanism, as shown in Figures 6-7, includes a force-bearing block C20, and two adjacent sides of the force-bearing block C20 are respectively provided with connecting blocks C17 through fifth flexible hinges 19. The fifth flexible The hinge 19 is a prismatic flexible hinge. The prismatic flexible hinge is a prism, and each surface of the upper and lower ends is respectively provided with an arc surface. After the multiple arc surfaces intersect, a connecting portion 43 with a small middle and large ends is formed. In this embodiment, four prismatic flexible hinges are arranged between each force receiving block C20 and the connecting block C17, and the four corners are distributed. The two connection blocks C17 are connected to the same fixed block C22 through a fourth flexible hinge 18, and the fourth flexible hinge 18 is a straight circular flexible hinge. The fixing block C22 is provided with a second installation hole 53 and is fixed in the first installation hole 52 of the base 1 by a fastener. One end of the two connecting blocks C17 and the force receiving block C20 are both detection ends. The three-axis force detection flexible mechanism is distributed in a mouth shape. The three-axis force detection flexible mechanism adopts a symmetrical flexible design concept and has a three-axis decoupling effect.

Specifically, when the three-axis force detection flexible mechanism is used to detect the force in the X/Y/Z axis direction, the fifth flexible hinge 19 is arranged along the X/Y axis direction, and can realize the Z axis direction of the force receiving block C20 Moving, the Z-direction displacement detection device 33 is installed in the main installation hole 51 and faces the back of the force receiving block C20.

The connecting block C17 is connected to the fixing block C22 through two rows of fourth flexible hinges 18. The fourth flexible hinges 18 are arranged along the X/Y axis direction, and the axis of the semicircular hole 42 thereof is arranged along the Z axis direction. An X-direction displacement detecting device 31 and a Y-direction displacement detecting device 32 are respectively provided on the base body 1 on the side of the block C17.

When the tool 7 is subjected to forces in the X, Y, and Z directions, the force-receiving end will generate displacements in the X, Y, and Z directions, and the corresponding displacement can be detected at the corresponding detection end. When the tool is under force, the rotation of the force end along the X, Y, and Z axes will be constrained by the flexible structure itself.

In order to verify that the displacement changes in the X, Y, and Z axis directions detected by the displacement sensor of the three-axis force detection flexible mechanism are linearly related to the dynamic force changes in the X, Y, and Z axis directions respectively, the linear coefficient of the corresponding axis is obtained, and the measured The minimum resolution of the corresponding axis, and the force detection calibration experiment is carried out. The calibration method is to input different dynamic forces along the X, Y and Z axes respectively, and detect the output displacement change of the corresponding axial displacement sensor.

Each dynamic force input along the X axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.8 19.6 49 98]mN, and the displacement change obtained in turn is D=[22.6215 43.1873 106.9158 211.8564] nm, see the table below for details:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	22.6215	43.1873	106.9158	211.8564

To sum up, the linear fitting result of displacement change to dynamic force change is D=2.1481*F+1.4134. The change curve of the displacement change in the X-axis direction detected by the displacement sensor with the dynamic force acting in the X-axis direction is obtained. As shown in Figure 12(a), the displacement change in the X-axis direction detected by the displacement sensor and the dynamic force acting in the Z-axis direction are the same. Linear proportional relationship, the minimum recognized displacement change is 4nm, and the minimum recognized force in the X-axis direction is 1.20mN.

Each dynamic force input along the Y-axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.8 19.6 49 98]mN, and the displacement change obtained in turn is D=[17.8263 34.2783 85.6922 171.3872] nm, see the table below for details:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	17.8263	34.2783	85.6922	171.3872

To sum up, the linear fitting result of displacement change to dynamic force change is D=1.7438*F+0.3930. The change curve of the displacement change in the Y-axis direction detected by the displacement sensor with the dynamic force acting in the Y-axis direction is obtained. Linear proportional relationship, the minimum recognized displacement change is 4nm, and the minimum recognized force in the Y-axis direction is 2.07mN.

Each dynamic force input along the Z axis is applied multiple times, and the results are similar and averaged. The applied dynamic force vector is F=[9.8 19.6 49 98]mN, and the displacement change obtained in turn is D=[22.6239 45.2457 113.1090 226.2183] nm, see the table below for details:

Reference value (unit)	Test 1	Test 2	Test 3	Test 4
Input value F(mN)	9.8	19.6	49	98
Detection average value D(nm)	22.6239	45.2457	113.1090	226.2183

To sum up, the linear fitting result of displacement change to dynamic force change is D=2.3083*F+0.0021. The change curve of the displacement change in the Z-axis direction detected by the displacement sensor (29) with the dynamic force acting in the Z-axis direction is obtained. As shown in Figure 12(c), the displacement change in the Z-axis direction detected by the displacement sensor and the dynamic force along the Z-axis direction The force change is in a linear proportional relationship. The minimum recognized displacement change is 4 nm, and the minimum recognized force in the Z-axis direction is 1.73 mN.

The above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore: all equivalent changes made according to the structure, shape and principle of the present invention shall be covered by the protection of the present invention. within the range.

Claims (10)

1. A mechanically flexible mechanism capable of realizing a uniaxial force detection function is characterized in that, comprising:

   The base body (1) is used to be fixed on the detection platform, and is equipped with a single-force detection flexible mechanism and a displacement detection device;

   The uniaxial force detection flexible mechanism includes a force-bearing block A(5), and fixed blocks A(3) are symmetrically arranged on both sides of the force-bearing block A(5) through a first flexible hinge (4). One end of (5) is the detection end;

   Displacement detection devices, each comprising a displacement mounting seat (28) fixed on a base body (1) and a displacement sensor (29), the displacement sensor (29) being arranged at the detection end of the uniaxial force detection flexible mechanism for detecting and detecting The displacement and the force of the end;

   The tool holder (6) is used to install the tool (7) and is fixed on the force-bearing block A (5).
2. The mechanically flexible mechanism capable of realizing a uniaxial force detection function according to claim 1, wherein a sleeve (2) is fixed on the detection end, and the sleeve (2) is sleeved on the displacement mounting seat (28) and wrap the displacement sensor (29) to prevent the probe of the displacement sensor (29) from being exposed to the air.
3. The mechanical flexible mechanism capable of realizing a uniaxial force detection function according to claim 1, wherein the first flexible hinge (4) is a straight circular flexible hinge, and the straight circular flexible hinge includes a rectangular block (41), two sets of semicircular holes (42) are formed on the two side walls of the rectangular block (41) in mirror image symmetry.
4. A mechanically flexible mechanism capable of realizing a uniaxial force detection function according to claim 1, 2 or 3, wherein the mounting surface of the base body (1) is an XY plane, the width direction is the X axis direction, the height The direction is the Y-axis direction, and a main installation hole (51) along the Z-axis direction is opened in the middle of the installation surface, and the Z-direction displacement detection device (33) is installed in the main installation hole (51);

   When the uniaxial force detection flexible mechanism is used to detect the force in the Z-axis direction, the force-receiving block A(5) is connected to the fixed block A(3) through the symmetrically arranged two rows of first flexible hinges (4), and along the X-axis The axis of the semicircular hole (42) of the first flexible hinge (4) is arranged along the Y-axis direction; the Z-direction displacement detection device (33) faces the back of the force-bearing block A (5).
5. A mechanically flexible mechanism capable of realizing biaxial force detection function is characterized in that, comprising:

   The base body (1) is used to be fixed on the detection platform, and is equipped with a biaxial force detection flexible mechanism and a displacement detection device;

   The biaxial force detection flexible mechanism includes a force-receiving block B(13), and connecting blocks B(11) are symmetrically arranged on both sides of the force-receiving block B(13) through a second flexible hinge (12). The two sides of 11) are symmetrically provided with fixed blocks B (8) through the third flexible hinge (10), and one end of the connecting block B (11) and the force receiving block B (13) are both detection ends;

   The two displacement detection devices each include a displacement mounting seat (28) fixed on the base body (1) and a displacement sensor (29), the displacement sensor (29) being arranged at the detection end of the biaxial force detection flexible mechanism, and used for Detect the displacement and force of the detection end;

   The tool holder (6) is used to install the tool (7) and is fixed on the force receiving block B (13).
6. The mechanically flexible mechanism capable of realizing a biaxial force detection function according to claim 5, wherein the second flexible hinge (12) and the third flexible hinge (10) are both straight circular flexible hinges, The straight circular flexible hinge comprises a rectangular block (41), and two sets of semicircular holes (42) are symmetrically opened on two side walls of the rectangular block (41) in mirror images.
7. A mechanically flexible mechanism capable of realizing a biaxial force detection function according to claim 6, wherein when the biaxial force detection flexible mechanism is used to detect the force in the X/Z axis direction, the force receiving block B (13) Connected to the connecting block B (11) through two rows of symmetrically arranged second flexible hinges (12) and distributed along the X-axis direction, wherein the axis of the semicircular hole (42) of the second flexible hinge (12) is along the The Y-axis direction is arranged; the Z-direction displacement detection device (33) is installed in the main installation hole (51) and faces the back of the force-receiving block B (13);

   The connecting block B (11), the third flexible hinge (10) and the fixing block B (8) are distributed along the Y-axis direction, wherein the axis of the semicircular hole (42) of the third flexible hinge (10) is along the Z-axis direction Arrangement; an X-direction displacement detection device (31) is arranged on the base body (1) on one side of the connection block B (11).
8. A mechanically flexible mechanism capable of realizing a triaxial force detection function is characterized in that, comprising:

   The base body (1) is used to be fixed on the detection platform, and is equipped with a three-detection flexible mechanism and a displacement detection device;

   A three-axis force detection flexible mechanism includes a force-bearing block C (20), and two adjacent sides of the force-bearing block C (20) are respectively provided with a connecting block C (17) through a fifth flexible hinge (19). The block C(17) is connected to the same fixed block C(22) through a fourth flexible hinge (18), and one end of the two connecting blocks C(17) and the force-receiving block C(20) are both detection ends;

   The three displacement detection devices each include a displacement mounting seat (28) fixed on the base body (1) and a displacement sensor (29), the displacement sensor (29) being arranged at the detection end of the triaxial force detection flexible mechanism, and used for Detect the displacement and force of the detection end;

   The tool holder (6) is used to install the tool (7) and is fixed on the force receiving block C (20).
9. The mechanical flexible mechanism capable of realizing triaxial force detection function according to claim 8, wherein the fourth flexible hinge (18) is a straight circular flexible hinge, and the straight circular flexible hinge comprises a rectangular block (41), two sets of semicircular holes (42) are opened in mirror symmetry on the two side walls of the rectangular block (41);

   The fifth flexible hinge (19) is a prism, and each surface of the upper and lower ends of the fifth flexible hinge is respectively provided with an arc surface, and a plurality of arc surfaces intersect to form a connecting part (43) with a small middle and large ends.
10. The mechanical flexible mechanism capable of realizing a triaxial force detection function according to claim 9, wherein when the triaxial force detection flexible mechanism is used to detect the force in the X/Y/Z axis direction, the fifth The flexible hinge (19) is arranged along the X/Y axis direction, and can realize the movement of the force receiving block C (20) in the Z axis direction, and the Z direction displacement detection device (33) is installed in the main installation hole (51) and faces the receiving force The back of the force block C(20);

    The connecting block C (17) is connected to the fixing block C (22) through two rows of fourth flexible hinges (18), the fourth flexible hinges (18) are arranged along the X/Y axis direction, and the semicircular hole (42) The axis of ) is arranged along the Z-axis direction, and an X-direction displacement detection device (31) and a Y-direction displacement detection device (32) are respectively provided on the base body (1) on one side of the two connecting blocks C (17).

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