Multi-dimensional force sensor and processing method

Abstract

The invention is suitable for the technical field of sensors, and provides a multi-dimensional force sensor which comprises an outer body frame, an inner bearing platform, a strain beam and a strain gauge. A containing hole is formed in the outer body frame, and the containing hole penetrates through the first face and the second face, opposite to each other, of the outer body frame. The inner bearing platform is arranged in the containing hole, and a gap is kept between the inner bearing platform and the containing hole. The strain beam is at least partially arranged in the interval and connected between the outer body frame and the inner bearing platform, and the side edge of the strain beam extends along a straight line. The number of the strain beams is three, each strain beam is provided with at least one patch plane, and no less than six strain gauges are pasted in each patch plane. Through the arrangement, the strain gauges arranged on the same strain beam are concentrated on the same patch plane, so that the convenience and the efficiency of pasting the strain gauges are improved. And meanwhile, the strain gauges are arranged in a concentrated manner, so that the convenience of lead welding is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sensors, and in particular relates to a multi-dimensional force sensor and a processing method thereof. Background Art

[0002] A multi-dimensional force sensor is a sensor that can measure forces and torques in multiple directions at the same time. This type of sensor is widely used in robots, material testing, and machine servo control. Taking a six-dimensional force sensor as an example, referring to the Cartesian coordinate system, a six-dimensional force sensor can detect three forces (Fx, Fy, Fz) and three torques (Mx, My, Mz).

[0003] There are multiple measuring beams inside the six-dimensional force sensor, each of which includes four walls: upper, lower, left, and right. The upper wall is opposite to the lower wall, and the left wall is opposite to the right wall. Usually, strain gauges are attached to the upper, lower, left, and right walls of the measuring beam. The deformation of the measuring beam is sensed by each strain gauge, and the strain on the measuring beam is converted into an electrical signal output.

[0004] In order to realize multi-channel detection, the force sensor in the related technology needs to be mounted with strain gauges on the four walls respectively, and the position of the force sensor needs to be adjusted constantly to complete the mounting. At the same time, the strain gauge located on the side has the problem of inconvenient lead welding. Therefore, the existing force sensor has the problems of low mounting efficiency and inconvenient lead welding. Summary of the invention

[0005] In view of this, the present invention provides a multi-dimensional force sensor and a processing method to solve the problems of low patch efficiency and inconvenient lead welding.

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

[0007] A multi-dimensional force sensor comprises: an outer frame, an installation hole is provided inside, the installation hole passes through a first surface and a second surface of the outer frame, and the first surface and the second surface are opposite to each other; an internal support platform is arranged in the installation hole, the outer frame surrounds the outer side of the internal support platform, and there is a gap between the outer frame and the internal support platform; a strain beam is arranged in the gap and connected between the outer frame and the internal support platform, and the side edge of the strain beam extends along a straight line; three strain beams are arranged, and each of the strain beams has at least one patch plane; a strain gauge is used to detect the strain of the strain beam, and each of the patch planes is respectively provided with the strain gauge, and there are always no less than six strain gauges; wherein, in the three patch planes; two strain gauges are respectively provided in each patch plane; or one strain gauge is respectively provided in two patch planes, and four strain gauges are provided in one patch plane; or three strain gauges are provided in one patch plane, two strain gauges are provided in one patch plane, and one strain gauge is provided in one patch plane.

[0008] The embodiment of the present invention further provides a processing method for processing the above-mentioned multi-dimensional force sensor, the processing method comprising:

[0009] 1) Selecting an outer frame, an inner support platform and a strain beam, setting the inner support platform in the mounting hole of the outer frame, and providing a gap between the outer frame and the inner support platform;

[0010] 2) Setting a strain beam in the interval and connecting between the outer frame and the inner support platform; three strain beams are provided, and the patch plane of each strain beam is oriented in the same direction as one of the first surface or the second surface;

[0011] 3) Clean each patch plane, and then attach strain gauges to the patch planes, each patch plane is attached with a strain gauge, and the total number of strain gauges attached to the three patch planes is not less than six; wherein the attached strain gauges are independent of each other; or the strain gauges are connected as a whole; or at least one strain gauge is independent, and at least two strain gauges are connected as a whole;

[0012] 4) Arranging a circuit board, wherein the circuit board is arranged coplanarly with each of the strain gauges, or is spaced a preset distance from the plane where each of the strain gauges is located, and fixing the circuit board on the outer frame and / or the internal support platform;

[0013] 5) Place the patch plane on any one of the strain beams upward, and then solder the leads of each strain gauge one by one, so that each strain gauge on the current patch plane is electrically connected to the circuit board through the leads;

[0014] 6) Adjust the position of the multi-dimensional force sensor, and repeatedly perform the welding operation in step 5, so that all the strain gauges on each strain beam are electrically connected to the circuit board through leads, thereby completing the processing of the multi-dimensional force sensor.

[0015] A multi-dimensional force sensor and processing method provided by an embodiment of the present invention, the multi-dimensional force sensor includes an outer body frame, an internal support platform, a strain beam and a strain gauge. A receiving hole is provided inside the outer body frame, and the receiving hole passes through the first and second surfaces opposite to each other of the outer body frame. The internal support platform is arranged in the receiving hole, and a gap is maintained between the internal support platform. The strain beam is at least partially arranged in the gap and connected between the outer body frame and the internal support platform, and the side edge of the strain beam extends in a straight line. There are three strain beams, and each strain beam has at least one patch plane, and strain gauges are respectively attached to each patch plane, and there are always no less than six. In this way, the strain gauges arranged on the same strain beam are concentrated on the same patch plane, thereby improving the convenience and efficiency of attaching each strain gauge. At the same time, the centralized arrangement of each strain gauge is also conducive to improving the convenience of lead welding. The processing method can quickly realize the processing of the multi-dimensional force sensor, which is conducive to improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a structure in which a first body, a second body and a strain beam are connected according to an embodiment of the present invention;

[0017] Figure 2 is a partial structural schematic diagram of a multi-dimensional force sensor provided by an embodiment of the present invention;

[0018] Figure 3 is a schematic diagram of the six detection channels on the force sensor;

[0019] Figure 4 This is the principle diagram of the Wheatstone bridge;

[0020] Figure 5 is a schematic diagram of a distribution method of strain gauges provided in an embodiment of the present invention;

[0021] Figure 6 is a schematic diagram of another distribution mode of strain gauges provided in an embodiment of the present invention;

[0022] Figure 7 is a schematic diagram of another distribution mode of strain gauges provided in an embodiment of the present invention;

[0023] Figure 8 is a schematic diagram of another distribution mode of strain gauges provided in an embodiment of the present invention;

[0024] Fig. 9 is a schematic diagram of another distribution mode of strain gauges provided in an embodiment of the present invention;

[0025] Fig.10 is a schematic diagram of another distribution mode of strain gauges provided in an embodiment of the present invention;

[0026] Fig.11 It is a schematic diagram of the positions of strain gauges of the multi-dimensional force sensor provided by an embodiment of the present invention in the first single-sided patch mode;

[0027] Fig.12 Schematic diagram of the bridges of each channel of the multi-dimensional force sensor provided by an embodiment of the present invention in the first single-sided patch mode;

[0028] Fig.13 1 is a schematic diagram of the positions of strain gauges of the multi-dimensional force sensor provided by an embodiment of the present invention in the second single-sided patch mode;

[0029] Fig.14 It is a schematic diagram of the bridges of each channel of the multi-dimensional force sensor provided by an embodiment of the present invention in the second single-sided patch mode.

[0030] Description of reference numerals:

[0031] 1. Multi-dimensional force sensor; 11. External frame; 110. Accommodating hole; 111. First surface; 12. Internal support platform; 13. Strain beam; 131. Patch plane; 14. Strain gauge; 140. Inclined strain gauge; 141. Base; 142. Strain unit; P(Q), symmetry axis. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] The various specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction, for example, different embodiments and technical solutions can be formed by combining different specific technical features. In order to avoid unnecessary repetition, various possible combinations of the specific technical features in the present invention will not be described separately.

[0034] In the following description, the terms "first\second\..." are only used to distinguish different objects, and do not mean that the objects have the same or related points. It should be understood that the directions "above", "below", "outside" and "inside" are all directions in normal use, and the directions "left" and "right" refer to the left and right directions shown in the corresponding schematic diagrams, which may or may not be the left and right directions in normal use.

[0035] It should be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element. "Multiple" means greater than or equal to two.

[0036] like Figure 1 and Figure 2 As shown, a multi-dimensional force sensor 1 provided by an embodiment of the present invention can be mainly used to simultaneously measure forces and torques in multiple directions, specifically a force sensor that can simultaneously measure force and torque components in more than two directions. In a Cartesian coordinate system, force and torque can each be decomposed into three components. Therefore, the most complete form of multi-dimensional force is a six-dimensional force / torque sensor, that is, a sensor that can simultaneously measure three force components (Fx, Fy, Fz) and three torque components (Mx, My, Mz).

[0037] like Figure 1 and Figure 2 As shown, the multi-dimensional force sensor 1 includes an outer frame 11, an inner support platform 12, a strain beam 13 and a strain gauge 14. A receiving hole 110 is provided inside the outer frame 11, and the inner support platform 12 is arranged in the receiving hole 110 and is spaced apart from the inner support platform 12. The strain beam 13 is connected between the outer frame 11 and the inner support platform 12, so that the outer frame 11 and the inner support platform 12 are connected as a whole. The strain gauge 14 is used to be attached to the strain beam 13 so as to detect the deformation of the strain beam 13.

[0038] Specifically, the shape of the receiving hole 110 can be any one of a circular, elliptical or polygonal shape, as long as it meets the spacing setting of the internal support platform 12. Of course, the shape of the receiving hole 110 can also match the contour shape of the internal support platform 12.

[0039] The receiving hole 110 passes through the first surface 111 and the second surface of the outer frame 11 , and the first surface 111 and the second surface are two opposite surfaces. That is, the receiving hole 110 is a straight hole that passes through the outer frame 11 in the thickness direction.

[0040] The internal support platform 12 is arranged in the receiving hole 110, and a gap is maintained between the internal support platform 12. The strain beam 13 is arranged in the gap, and the side edge of the strain beam 13 extends in a straight line, forming a straight beam structure, which is easy to manufacture. The opposite ends of the strain beam 13 are respectively connected between the outer frame 11 and the internal support platform 12. In this way, the outer frame 11 and the internal support platform 12 are connected as a whole through the strain beam 13.

[0041] Between the connected outer body frame 11 and the internal support 12, the side of the internal support 12 facing the same direction as the first side 111 can be kept flush with or not flush with the first side 111. Similarly, the other side of the internal support 12 facing the same direction as the second side can be kept flush with or not flush with the first side 111. Usually, the two opposite sides of the internal support 12 are kept flush with the first side 111 and the second side, respectively, to improve the consistency of the product shape.

[0042] Usually, the outer frame 11 is a fixed end, which is used to connect with the supporting components. The internal support platform 12 is a loading end, which is used to connect with the object to be detected, so as to sense the force carried by the object to be detected, and finally manifested in elastic deformation of the strain beam 13. Of course, the outer frame 11 can also be set as a loading end, and the internal support platform 12 can be set as a fixed end. The setting is flexible and can meet different usage requirements. When the internal support platform 12 is set as the loading end, the strain gauge 14 is usually close to the connection between the strain beam 13 and the internal support platform 12. When the outer frame 11 is set as the loading end, the strain gauge 14 is usually close to the connection between the strain beam 13 and the outer frame 11. In this way, because the connection is the part where the deformation is larger, the strain gauge 14 is set here to improve the sensitivity of the detection.

[0043] The strain beam 13 connected between the outer body frame 11 and the internal support platform 12 can be completely located in the interval, or it can be partially protruding from the first surface 111 and / or the second surface, as long as it can meet the detection requirements. Moreover, the number of strain beams 13 can be set according to the detection requirements of the product, and at least not less than three. In addition, when the number of strain beams 13 is set to be greater than three, it is not necessary to affix strain gauges 14 on all the strain beams 13 that are set, and corresponding settings can be made according to product design requirements. That is, in an embodiment of the present invention, when three strain beams 13 are set, all three strain beams 13 are used to affix strain gauges 14, and when four or more strain beams 13 are set, three of the strain beams 13 can be used for affixing the strain gauges, and the remaining ones do not need to be affixed, and the setting flexibility is better.

[0044] Specifically, the strain gauge 14 is usually made of metal or semiconductor material, has high sensitivity and good elastic properties, and can effectively sense the effects of external forces and torques. A strain gauge 14 is arranged on each strain beam 13, and the number of strain gauges 14 can be set according to the specific detection requirements to be achieved, so that the detection of six measurement channels can be achieved. Specifically, if Figure 3 As shown, according to the Cartesian coordinate system, the six measurement channels are three force components (Fx, Fy, Fz) and three torque components (Mx, My, Mz). The three force components correspond to the forces on the X, Y, and Z axes, respectively. The forces on each axis will cause the strain gauge 14 in the corresponding direction to deform, resulting in a change in resistance. The three torque components correspond to the torque on the X, Y, and Z axes, respectively. The torque will also cause the strain gauge 14 in a specific direction to deform, thereby causing a change in resistance.

[0045] The signal of each measurement channel is detected by the strain gauge 14 attached to the strain beam 13. These strain gauges 14 can sense the resistance change caused by the slight deformation and then convert it into an electrical signal output. Through the signals of these channels, combined with the corresponding mathematical model calculation, the magnitude and direction of the applied force and torque can be determined.

[0046] The "six measurement channels" mentioned above correspond to the six force components of the sensor in three-dimensional space. In this way, the strain gauges 14 on different strain beams 13 are combined according to the detection requirements to form a Wheatstone bridge to detect the change in resistance, and the magnitude of the applied force and torque and the direction of the force are finally determined by obtaining the detection signals on different channels.

[0047] like Figure 2As shown, in the embodiment of the present invention, three strain beams 13 are provided, and the three strain beams 13 are evenly distributed around the circumference of the internal support 12, which at least better ensures the consistency of product detection performance and facilitates installation and use. Of course, in another embodiment, under the premise of meeting the detection requirements, they can also be unevenly distributed.

[0048] like Figure 1 and Figure 2 As shown, each strain beam 13 has at least one patch plane 131. When a patch plane 131 is provided on each strain beam 13, the orientation of each patch plane 131 may be the same as the orientation of the first surface 111 or the second surface, or the orientation of a part of each patch plane 131 may be different. A strain gauge 14 is respectively provided on each patch plane 131. Thus, the force or moment acting on the corresponding strain beam 13 is detected by the strain gauge 14.

[0049] The "corresponding strain beam 13" mentioned above refers to the strain beam 13 to which the strain gauge 14 that currently outputs the detection signal is attached. The principle of the strain gauge 14 outputting the detection signal is as follows: when an external force or torque acts on the strain beam 13, the strain beam 13 will undergo a slight deformation (such as a change in length or cross-sectional area), and this deformation will be transmitted to the strain gauge 14 attached to the strain beam 13. The resistance value of the strain gauge 14 changes with the generation of strain, and this resistance change is converted into a voltage or current signal through a specific circuit. A bridge circuit is constructed inside the sensor, connecting multiple strain gauges 14 together in a specific way to form a Wheatstone bridge (refer to Figure 4 ). When the resistance value of the strain gauge 14 changes, the equilibrium state of the bridge circuit will be broken, thereby generating an output signal proportional to the mechanical quantity. After being amplified, filtered and digitized by the signal processing circuit, this signal can be read and analyzed by a terminal device such as a computer, and the corresponding force condition can be obtained.

[0050] In the embodiment of the present invention, the surface of the strain beam 13 for contacting the strain gauge 14 is called the patch plane 131, that is, the patch plane 131 is set to be a flat surface with a smooth surface, all points are on the same plane, and there are no undulations or curves. Therefore, when the strain gauge 14 is attached, all points on the side of the strain gauge 14 for bonding with the patch plane 131 can basically keep in contact with the patch plane 131, not only the bonding firmness is good, but also when pasting, compared with the curved patch surface, there is no need to press for a long time, and the strain gauge 14 can keep in contact with the patch plane 131 by relying on its own gravity, thereby improving the ease of operation of the patch. In addition, the strain gauge 14 is fully attached to the patch plane 131, and the strain beam 13 can be formed as a whole, so that the deformation of the strain beam 13 can be sensitively detected, thereby improving the sensitivity of detection.

[0051] Furthermore, in the embodiment of the present invention, strain gauges 14 are respectively attached to the three patch planes 131, and the total number of strain gauges 14 attached to the three patch planes 131 is not less than six. In this way, the strain gauges 14 are combined to realize the detection of different channels, and each detection channel can form a different type of Wheatstone bridge (full bridge, half bridge and 1 / 4 bridge) according to the detection requirements, and the setting methods are diverse, which improves the flexibility of the detection function setting of the multi-dimensional force sensor 1 and can meet the use of different detection requirements.

[0052] Specifically, strain gauges 14 are respectively attached on three patch planes, and the total number of attached strain gauges is not less than six, and the distribution method can be: in the three patch planes, two strain gauges 14 are respectively attached in each patch plane; or in the three patch planes, one strain gauge 14 is attached in two patch planes respectively, and four strain gauges are attached in one patch plane; or in the three patch planes, three strain gauges 14 are attached in one patch plane, two strain gauges 14 are attached in one patch plane, and one strain gauge 14 is attached in one patch plane. The specific distribution method can be specifically set according to the maintenance requirements.

[0053] In the embodiment of the present invention, the strain gauges 14 to be attached to each strain beam 13 are centrally arranged on the same attachment plane 131, so that when attaching the strain gauges 14, there is no need to frequently adjust the position of the multi-dimensional force sensor 1, the attachment convenience is good, and the efficiency of the attachment is improved. At the same time, all the strain gauges 14 can also be wire-welded in the same state without major position adjustment, thereby improving the convenience of wire welding.

[0054] A multi-dimensional force sensor 1 provided in an embodiment of the present invention comprises an outer frame 11, an inner support platform 12, a strain beam 13 and a strain gauge 14. A receiving hole 110 is provided inside the outer frame 11, and the receiving hole 110 passes through a first surface 111 and a second surface of the outer frame 11, and the first surface 111 and the second surface are opposite to each other. The inner support platform 12 is arranged in the receiving hole 110, and a gap is maintained between the inner support platform 12. The strain beam 13 is at least partially arranged in the gap, and is connected between the outer frame 11 and the inner support platform 12, and the side edge of the strain beam 13 extends in a straight line. Three strain beams 13 are arranged, and each strain beam 13 has at least one patch plane 131, and strain gauges 14 are respectively attached to each patch plane 131, and there are always no less than six. In this arrangement, the strain gauges 14 arranged on the same strain beam 13 are concentrated on the same patch plane 131, thereby improving the convenience and efficiency of attaching each strain gauge 14. Moreover, each surface in contact with the strain gauge 14 is a plane, which reduces the difficulty of attaching each strain gauge 14 and helps to keep each strain gauge 14 firmly attached. At the same time, each strain gauge 14 on each strain beam 13 is concentrated on the same patch plane 131, which also helps to improve the convenience of lead welding.

[0055] In the embodiment of the present invention, the principle of realizing the detection of six channels through three strain beams 13 is: referring to the Cartesian coordinate system, combined with the decomposition of force, each strain beam 13 can be used to sense the components on the three axes of X, Y, and Z, thereby forming three force components (Fx, Fy, Fz) and three torque components (Mx, My, Mz). Combined with the combination of strain gauges 14 on different strain beams 13 to form a Wheatstone bridge, the corresponding detection signal can be output to achieve the purpose of detection.

[0056] like Figure 4 As shown, the Wheatstone bridge is a circuit device composed of four resistors, which is used to measure the resistance of one of the resistors, provided that the resistance of the other three resistors is known. The basic principle is to determine the value of the unknown resistor by comparing the voltage difference between two circuit branches. When the bridge is in a balanced state, the voltage difference between the two relative joints is zero, at which time the resistance of the unknown resistor can be inferred from the three known resistance values. In the Wheatstone bridge, each resistor (or strain gauge 14) is usually called a bridge arm, so there are four bridge arms.

[0057] In specific applications, the main types of Wheatstone bridges include full bridge, half bridge and quarter bridge. In the full bridge configuration, strain gauges 14 are used in all four bridge arms, and each strain gauge 14 produces the same amplitude of resistance change for the same strain, but the change direction is opposite; in the half bridge configuration, only two bridge arms use strain gauges 14, and the other two are fixed resistors; in the quarter bridge configuration, only one bridge arm uses strain gauges 14, and the other three are fixed resistors. Among the three different types of bridges, the principles of strain detection of full bridge, half bridge and quarter bridge are different in their sensitivity to strain and measurement accuracy. The full bridge configuration provides the highest sensitivity and accuracy, while the quarter bridge configuration provides the lowest sensitivity and accuracy. Therefore, the type of bridge to be combined can be selected according to the actual use requirements, so as to meet different detection requirements and have good setting flexibility.

[0058] The strain gauge 14 is usually fixed on the strain beam 13 by pasting, and in order to achieve multi-channel detection, the strain gauge 14 needs to be pasted on the four wall surfaces of each strain beam 13, so that the position of the strain beam 13 or the direction of the patch needs to be adjusted continuously during patching, resulting in cumbersome patching steps and inconvenience, affecting the efficiency of the patch and the operability of the lead welding, and increasing the difficulty of manufacturing the multi-dimensional force sensor 1. Therefore, in the embodiment of the present invention, by concentrating the strain gauges 14 that need to be pasted on each strain beam 13 on the same patch plane 131, not only can multi-channel detection be achieved, but also there is no need to frequently adjust the patch position, so that the convenience and efficiency of the patch are improved, and at the same time, the convenience of lead welding is also improved.

[0059] Specifically, the arrangement position and quantity of each strain gauge 14 can be selected according to the needs of detection, so that it can be used to detect forces in three different directions and moments in three different directions. In this way, a plurality of strain gauges 14 are arranged on each strain beam 13, and the strain gauges 14 at corresponding positions can be selected for combination, thereby realizing a multi-channel detection function. The above "can be used to detect forces in three different directions and moments in three different directions" means that the position and quantity of the strain gauges 14 can be set according to the needs of detection, so as to meet the performance of being able to detect forces in three different directions and moments in three different directions. Not every strain gauge 14 can detect six channels, and in the actual detection process, it is not necessary for each strain gauge 14 to detect six channels at the same time. That is, the multi-dimensional force sensor 1 can have the performance of being able to detect forces in three different directions and moments in three different directions by integrating multiple strain gauges 14 and combining the distribution at different positions, thereby improving the detection function and having good practicality.

[0060] In some embodiments, the distribution of the strain gauge 14 can be set to include any of the following according to different design methods:

[0061] In the first distribution mode, in a patch plane 131 on which a strain gauge 14 is attached, the strain gauge 14 is located at the side of the patch plane 131 or on the symmetry axis in the width direction of the patch plane 131. Specifically, Figure 5 As shown, the strain gauge 14 is set on the side of the patch plane 131, which is usually used to detect the forces in the Fx and Fy directions and the torque in the Mz direction. Alternatively, the strain gauge 14 is set on the symmetry axis in the width direction of the patch plane 131, which is usually used to detect the torque in the Mx and My directions and the force in the Fz direction. In this way, it can be adjusted according to the detection needs, and the setting flexibility is good. Combined with the strain gauges 14 set on other patch planes 131, a Wheatstone bridge can be formed, and the detection sensitivity is good.

[0062] The “axis of symmetry in the width direction of the patch plane 131 ” mentioned above means that the patch plane 131 is usually set as a quadrilateral with unequal length and width and regular shape. Therefore, it has an axis of symmetry in the width direction, which is called the axis of symmetry in the width direction of the patch plane 131 .

[0063] The second distribution mode is that in the patch plane 131 with two strain gauges 14, the two strain gauges 14 are usually used to detect the forces in the Fx and Fy directions and the moments in the Mz direction. They are located at two opposite sides of the patch plane 131, or are located side by side on the same side, or one strain gauge 14 is located at the side of the patch plane 131, and the symmetry axis of the other strain gauge 14 is collinear with the symmetry axis in the width direction of the patch plane 131. Specifically, as Figure 6 As shown, the two strain gauges 14 are respectively located on two opposite sides of the patch plane 131, or the two strain gauges 14 are located side by side on the same side. These two types are usually used to detect the forces in the Fx and Fy directions and the moments in the Mz direction. Alternatively, one of the two strain gauges 14 is set on the side of the patch plane 131, and the axis of symmetry of the other strain gauge 14 is collinear with the axis of symmetry in the width direction of the patch plane 131. In this arrangement, the strain gauge 14 located on the side is usually used to detect the forces in the Fx and Fy directions and the moments in the Mz direction, and the strain gauge 14 whose axis of symmetry is collinear with the axis of symmetry in the width direction of the patch plane 131 is usually used to detect the moments in the Mx and My directions and the forces in the Fz direction. In this way, the detection functions that can be realized are further increased, and they can be adjusted according to the detection needs, and the setting flexibility is good. Combined with the strain gauges 14 set on other patch planes 131, it can constitute a Wheatstone 1 / 4 bridge circuit with good detection sensitivity.

[0064] In the third distribution mode, in the patch plane 131 where three strain gauges 14 are mounted, each strain gauge 14 is at least distributed in a T-shape, or an L-shape, or is arranged at intervals on the same straight line. Specifically, Figure 7As shown, when the distribution becomes T-type or L-type, both types can be used to detect the forces in the Fx and Fy directions and the torque in the Mz direction, as well as the torque in the Mx and My directions and the force in the Fz direction. That is, it has the detection requirements of six channels and the setting is ingenious. When the intervals are set on the same straight line, when they are distributed along the length direction of the patch plane 131 and located on the side of the patch plane 131, they are usually used to detect the forces in the Fx and Fy directions and the torque in the Mz direction. When the strain gauge 14 whose own axis of symmetry is colinear with the axis of symmetry in the width direction of the patch plane 131 is usually used to detect the torque in the Mx and My directions and the force in the Fz direction. When it is distributed along the width direction of the patch plane 131 and close to the connection between the strain gauge and the internal support 12, it is usually used to detect the forces in the Fx, Fy and Fz directions. The combination of each strain gauge 14 can form a Wheatstone half-bridge or 1 / 4 bridge circuit, which has good detection sensitivity.

[0065] In the fourth distribution mode, in the patch plane 131 where four strain gauges 14 are mounted, the strain gauges 14 are distributed in a T-shape, or are arranged at intervals on the same straight line, or are distributed in a quadrilateral. Figure 8 As shown, when forming a T-shaped or spaced shape arranged on the same straight line, the same shape has basically the same detection performance as the third distribution method, which will not be described in detail here. When distributed in a quadrilateral, there are two strain gauges 14 on the two opposite sides of the patch plane 131. This distribution direction is usually used to detect the forces in the Fx and Fy directions and the torque in the Mz direction. The combination of each strain gauge 14 can form a Wheatstone half-bridge or 1 / 4 bridge circuit, which has good detection sensitivity.

[0066] The fifth distribution mode is that in a patch plane 131 on which at least five strain gauges 14 are attached, as shown in FIG. Figure 2 and 9 As shown, each strain gauge 14 is distributed in a T-shape, L-shape, I-shape, quadrilateral, or spaced on the same straight line. In an arrangement with at least five strain gauges 14, as the number of strain gauges 14 increases, when forming a T-shape, L-shape, I-shape, quadrilateral, or spaced on the same straight line, the number of strain gauges 14 used as a whole in each shape increases, and the number of achievable detection channels increases. At the same time, the number of strain gauges 14 that can be combined in each detection channel also increases, which not only improves the comprehensiveness of the detection performance, but also improves the sensitivity of the detection by combining multiple strain gauges 14 in the same channel.

[0067] It should be explained that the strain gauges 14 are usually selected to detect a certain channel according to their sensitivity to force, so as to improve the sensitivity and accuracy of the detection. For example, when the forces in the Fx and Fy directions and the moments in the Mz direction are applied to the strain beams 13, the sides of the strain beams 13 are the maximum deformation parts, so the strain gauges 14 arranged on the sides of the patch plane 131 are mainly used to detect the forces in the Fx and Fy directions and the moments in the Mz direction. When the moments in the Mx and My directions and the forces in the Fz direction are applied to the strain beams 13, the deformation at the axis of the strain beams 13 is the largest, so the strain gauges 14 arranged on the symmetry axis in the width direction of the patch plane 131 are mainly used to detect the moments in the Mx and My directions and the forces in the Fz direction. Of course, it can be understood that when the force or moment is applied to the same strain beam 13, the strain gauges 14 at various positions on it can basically detect the deformation of the strain beam 13, but there is a difference in the strength of the detection signal. Considering the detection accuracy, the strain gauge 14 that generates a stronger signal is usually selected for the detection of the corresponding channel. Therefore, there are strain gauges 14 arranged at different positions in the same patch plane 131 for the detection of different channels.

[0068] It can be understood that each strain gauge 14 can be regarded as a point, so the strain gauge 14 has its own symmetry axis. Therefore, it can be understood that the symmetry axis of the strain gauge 14 itself is set to be collinear with the symmetry axis of the patch plane 131 in the width direction.

[0069] In some embodiments, Fig.10 As shown, in the patch plane 131 with at least two strain gauges 14, each strain gauge 14 is arranged in parallel along the length direction of the patch plane 131, and the symmetry axis P of each strain gauge 14 is collinear with the symmetry axis Q in the width direction of the patch plane 131. In this way, a plurality of strain gauges 14 are arranged at intervals on the symmetry axis Q in the width direction of the patch plane 131, thereby meeting the performance of being able to detect the moment in the Mx and My directions and the force in the Fz direction, and the sensitivity and accuracy of the detection can be improved by combining the detection of a plurality of strain gauges 14.

[0070] In some embodiments, Fig.11As shown, among the strain gauges 14 arranged in parallel, at least one inclined strain gauge 140 is included, and the angle between the symmetry axis P of the inclined strain gauge 140 and the symmetry axis Q in the width direction of the patch plane 131 is between 0-75 degrees. In this way, the inclined strain gauge 140 can more sensitively detect deformation that is substantially the same as its inclined direction. By adjusting the inclined direction and arrangement position of the inclined strain gauge 140, it can be used for multi-channel detection, thereby improving the flexibility of detection. Specifically, the inclined strain gauge 140 can not only be used for the detection of torque in the Mx or My direction and force in the Fz direction, but also, due to the inclined setting, the distance from the side of the corresponding strain beam 13 is relatively close, so it also has the detection performance of force in the Fx or Fy direction and torque in the Mz direction. Therefore, it can be combined to form a corresponding Wheatstone bridge according to the detection requirements, with ingenious design and good flexibility.

[0071] Specifically, for ease of understanding, Fig.10 As shown, the symmetry axis P of the tilted strain gauge 140 and the symmetry axis Q in the width direction of the patch plane 131. The angle between the symmetry axis P and the symmetry axis Q is set between 0-75 degrees. Optionally, the angle between the two can be 15 degrees, or 45 degrees, or 60 degrees, or 75 degrees, and of course, it can also be any other value within the range of 0-75 degrees. Different angles correspond to different detection sensitivities under each channel, so the tilt angle of the tilted strain gauge 140 can be set according to the requirements of the detection channel, and the setting flexibility is good.

[0072] In some embodiments, Fig.10 As shown, two inclined strain gauges 140 are symmetrically arranged relative to the symmetry axis Q in the width direction of the patch plane 131. In this way, at least one inclined strain gauge 140 is arranged on both sides of the symmetry axis Q. Moreover, each inclined strain gauge 140 on both sides is inclined in two different directions, so that deformations in different directions can be detected respectively. In this way, with the mutual complementation of the detection functions of each inclined strain gauge 140 on both sides, deformations occurring on the two sides in the same detection direction as the inclined strain gauge 140 can basically be detected, further improving the sensitivity and accuracy of the detection.

[0073] In some embodiments, Fig.12 As shown, the strain gauge 14 includes a substrate 141 and a strain unit 142, and the strain unit 142 is solidified on one side of the substrate 141; wherein, in the patch plane 131 where at least two strain gauges 14 are attached, each strain unit 142 is independent of each other, and each substrate 141 is not connected. In this arrangement, each strain gauge 14 is a single independent part, so that when attached, the attached position can be adjusted according to different detection requirements, and the arrangement flexibility is good, which can meet different arrangement requirements.

[0074] Specifically, the strain unit 142 is used to change with the deformation of the strain beam 13, and then generate a corresponding detection signal. The strain unit 142 is usually made of a thin wire made of a material such as constantan, nickel-chromium alloy, etc., and then wound into a grid or spiral shape so that it can effectively sense the deformation when subjected to force. The strain unit 142 can be fixedly connected to the surface of the substrate 141 by an adhesive, and the shape of the strain unit 142 supported by the substrate 141 remains basically stable.

[0075] The substrate 141 is usually made of a thin sheet of polyimide material, which has good insulation performance and the ability to transmit strain. In some special applications, ceramic materials are also used as the substrate 141 to provide higher stability and high temperature resistance.

[0076] In some embodiments, Figure 1 As shown, the strain gauge 14 includes a substrate 141 and a strain unit 142, and the strain unit 142 is solidified on one side of the substrate 141; wherein, in the patch plane 131 where at least two strain gauges 14 are attached, each strain unit 142 is independent and fixed on the same substrate 141. In this arrangement, each strain unit 142 is combined with the same substrate 141 to form an integrated strain gauge 14, so that by performing an operation of fixing the substrate 141 on the strain beam 13 once, multiple strain units 142 can be attached. That is, at least multiple strain units 142 can be attached at one time, without having to be attached one by one, saving the attachment steps of the strain gauge 14, thereby improving the attachment efficiency of the strain gauge 14. Furthermore, the position and firmness of each strain unit 142 fixed on the base 141 have been completed in advance, so when pasting and fixing on the strain beam 13, it is only necessary to ensure the accuracy of the pasting position of the base 141 to achieve accurate pasting of each strain unit 142. At the same time, the consistency of pasting of each strain unit 142 can be ensured, so that each strain unit 142 has a more sensitive detection performance, thereby improving the sensitivity and accuracy of detection of each strain unit 142 pasted on the strain beam 13.

[0077] In some embodiments, Figure 1 As shown, the strain gauge 14 includes a substrate 141 and a strain unit 142, and the strain unit 142 is solidified on one side of the substrate 141; wherein, in the patch plane 131 on which at least three strain gauges 14 are attached, at least one strain unit 142 is fixed on one substrate 141 alone, and at least two strain units 142 are fixed on another substrate 141 together. This arrangement constitutes a combination of a single strain gauge 14 and an integrated strain gauge 14, which has the advantages of both types and can also improve the flexibility of the arrangement of each strain gauge 14.

[0078] In some embodiments, Figure 1As shown, the outline shape of the base 141 is set to be rectangular or T-shaped. In this way, when the shape of the base 141 at least satisfies the arrangement of each group of strain units 142. The base 141 of this shape can also be used to preliminarily know the position and shape type of each strain unit 142 when it is necessary to arrange each strain unit 142 into a rectangle or T shape according to the shape of the base 141 itself. At this time, the shape of the base 141 plays a role in guiding the arrangement, which improves the accuracy of the position of each strain unit 142 when arranging and the convenience of arrangement.

[0079] In order to facilitate understanding of the detection principle of the multi-dimensional force sensor 1 provided in the embodiment of the present invention, an example is given by attaching a plurality of strain gauges 14 to each strain beam 13. Fig.11 As shown, eight strain gauges 14 are arranged on each strain beam 13, and are distributed in a T-shaped manner. In this distribution mode, due to the design of the three strain beams 13, the structure cannot be decoupled, and the strain gauges 14 used to detect the six channels are mixed together. There are many schemes for selecting the corresponding strain gauges 14 for each channel to form a Wheatstone bridge, which can be randomly matched. There is no F before decoupling. X 、F Y 、F Z 、M X 、M Y and M Z It is necessary to combine the corresponding analysis method and then analyze and process the detection signals of each channel through software decoupling to obtain the corresponding detection signals.

[0080] The bridge composed of each channel is as follows Fig.12 As shown, under this configuration, each detection channel can also constitute a full bridge, so that the multi-dimensional force sensor 1 has a higher detection sensitivity and can better meet the detection requirements.

[0081] In another embodiment, Fig.13 As shown, eight strain gauges 14 are arranged on each strain beam 13, and are distributed in a T-shaped manner. In this distribution mode, due to the design of the three strain beams 13, the structure cannot be decoupled, and the strain gauges 14 used to detect the six channels are mixed together. There are many schemes for selecting the corresponding strain gauges 14 for each channel to form a Wheatstone bridge, which can be randomly matched. There is no F before decoupling. X 、F Y 、F Z 、M X 、M Y and M Z It is necessary to combine the corresponding analysis method and then analyze and process the detection signals of each channel through software decoupling to obtain the corresponding detection signals.

[0082] The bridge composed of each channel is as follows Fig.14 As shown, under this configuration, each detection channel can also constitute a full bridge, so that the multi-dimensional force sensor 1 has a higher detection sensitivity and can better meet the detection requirements.

[0083] The embodiment of the present invention further provides a processing method for processing the multi-dimensional force sensor 1 described in any of the above embodiments. The processing method comprises:

[0084] 1) Select the outer frame 11, the inner support 12 and the strain beam 13, and set the inner support 12 in the receiving hole 110 of the outer frame 11, and make a gap between the outer frame 11 and the inner support 12. The position where the inner support 12 is set in the receiving hole 110 can be circumferential, and the interval size of each position can be kept equal, or it can be unequal.

[0085] 2) The strain beam 13 is arranged in the interval and connected between the outer frame 11 and the inner support 12. Three strain beams 13 are arranged, and the patch plane 131 of each strain beam 13 is oriented in the same direction as the first surface 111 or the second surface. In this way, the patch plane 131 is not blocked by other parts, which is conducive to the arrangement of the strain gauge 14.

[0086] 3) Clean each patch plane 131 to make sure that there is no dust, oil or other impurities on each patch plane 131. Then, a strain gauge 14 is attached to the patch plane 131, which can be fixed by glue-like adhesives, or the silicon strain gauge 14 is fixed by a glass micro-melting process. The specific patch method is to attach a strain gauge 14 to each patch plane 131, and the total number of strain gauges 14 attached to the three patch planes 131 is not less than six. Among them, the attached strain gauges 14 are independent of each other; or the strain gauges 14 are connected as a whole; or at least one strain gauge 14 is independent, and at least two strain gauges 14 are connected as a whole. That is, the attached strain gauges 14 can be completely independent parts, or they can be integrated strain gauges 14 in which the strain gauges 14 are connected as a whole, or they can be a combination of independent strain gauges 14 and integrated strain gauges 14. They can be selected according to specific patch requirements, and the patch has good flexibility.

[0087] 4) Arrange the circuit board. The arranged circuit board can be arranged coplanarly with each strain gauge 14, or separated from the plane where each strain gauge 14 is located by a preset distance, and the distance is not greater than 10 mm. The circuit board is fixed on the outer frame 11 and / or the internal support 12 so that the position of the circuit board can be kept stable.

[0088] 5) Place the patch plane 131 on any strain beam 13 upward, and then perform wire welding on each strain gauge 14 one by one. The welding method can be manual welding or self-welding using a wire welding machine. After each strain gauge 14 on the current patch plane 131 is electrically connected to the circuit board through the lead wires, the welding of all strain gauges 14 on the current strain beam 13 is completed. Specifically, each strain gauge 14 has two independent pads, and each pad is electrically connected to the corresponding welding position on the circuit board through the lead wire to realize the transmission of the detection signal.

[0089] 6) Repeat the welding operation of step 5 so that all strain gauges 14 on each strain beam 13 are electrically connected to the circuit board through leads, thereby completing the processing of the multi-dimensional force sensor 1.

[0090] The processing method provided in the embodiment of the present invention is that the strain gauges 14 that need to be attached to each strain beam 13 on the multi-dimensional force sensor 1 are attached on the same patch plane 131, so that the patch operation is simple, and there is no need to change the patch position over a large range, which also improves the patch efficiency. At the same time, since the strain gauges 14 on each strain beam 13 are on the same plane, when performing lead welding, at least when welding the strain gauges 14 in the same patch plane 131, there is no need to adjust the welding position over a large range, which is conducive to improving the welding efficiency. In addition, the orientation of the patch plane 131 is the same as the orientation of the first surface 111 or the second surface, so that there is no other parts blocking the welding direction, which also improves the convenience of the welding operation. This processing method can quickly realize the processing of the multi-dimensional force sensor 1, which is conducive to improving production efficiency.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-dimensional force sensor, characterized in that: include: An outer frame, with a mounting hole formed therein, the mounting hole passing through a first surface and a second surface of the outer frame, the first surface and the second surface being opposite to each other; An internal support platform is arranged in the mounting hole, and the external body frame surrounds the outer side of the internal support platform and has a gap between the internal support platform and the external body frame; A strain beam is arranged in the interval and connected between the outer frame and the inner support platform, and the side of the strain beam extends along a straight line; three strain beams are arranged, and each of the strain beams has at least one patch plane; A strain gauge, used to detect the strain of the strain beam, wherein each of the patch planes is provided with the strain gauge, and there are always no less than six of them; Among them, in the three patch planes; Two strain gauges are respectively mounted on each patch plane; or, One strain gauge is attached to each of the two patch planes, and four strain gauges are attached to one patch plane; or, Three strain gauges are attached to one patch plane, two strain gauges are attached to one patch plane, and one strain gauge is attached to another patch plane.

2. The multi-dimensional force sensor according to claim 1, characterized in that: The distribution of the strain gauges includes any one of the following methods: In the patch plane on which one strain gauge is attached, the strain gauge is located at a side of the patch plane or on a symmetry axis in a width direction of the patch plane; or, In the patch plane on which the two strain gauges are mounted, the two strain gauges are located at two opposite sides of the patch plane, or are located side by side on the same side, or one strain gauge is located at a side of the patch plane, and the symmetry axis of the other strain gauge is collinear with the symmetry axis in the width direction of the patch plane; or, In the patch plane where the three strain gauges are mounted, the strain gauges are at least distributed in a T-shape or an L-shape, or are arranged at intervals on the same straight line; or, In the patch plane where the four strain gauges are mounted, the strain gauges are arranged in a T-shape, or are arranged at intervals on the same straight line, or are distributed in a quadrilateral; or, In the patch plane where at least five strain gauges are mounted, the strain gauges are distributed in a T-shape, an L-shape, an I-shape, or a quadrilateral.

3. The multi-dimensional force sensor according to claim 1, characterized in that: In the patch plane on which at least two strain gauges are mounted, the strain gauges are arranged side by side along the length direction of the patch plane, and the symmetry axis of each strain gauge is collinear with the symmetry axis of the width direction of the patch plane.

4. The multi-dimensional force sensor according to claim 3, characterized in that: The strain gauges arranged in parallel include at least one inclined strain gauge, and the angle between the symmetry axis of the inclined strain gauge and the symmetry axis in the width direction of the patch plane is between 0 and 75 degrees.

5. The multi-dimensional force sensor according to claim 4, characterized in that: Two inclined strain gauges are symmetrically arranged relative to the symmetry axis in the width direction of the patch plane.

6. The multi-dimensional force sensor according to claim 1, characterized in that: The strain gauge includes a substrate and a strain unit, and the strain unit is solidified on one side of the substrate; wherein, in the patch plane where at least two strain gauges are attached, the strain units are independent of each other, and the substrates are not connected.

7. The multi-dimensional force sensor according to claim 1, characterized in that: The strain gauge includes a substrate and a strain unit, and the strain unit is solidified on one side of the substrate; wherein, in the patch plane where at least two strain gauges are attached, the strain units are independent of each other and fixed on the same substrate.

8. The multi-dimensional force sensor according to claim 1, characterized in that: The strain gauge includes a substrate and a strain unit, and the strain unit is solidified on one side of the substrate; wherein, in the patch plane where at least three strain gauges are attached, at least one strain unit is individually fixed on one substrate, and at least two strain units are jointly fixed on another substrate.

9. The multi-dimensional force sensor according to claim 7 or 8, characterized in that: The outline shape of the base is set to be rectangular or T-shaped.

10. A processing method for processing a multi-dimensional force sensor as claimed in any one of claims 1 to 9, characterized in that: The processing method comprises: 1) Selecting an outer frame, an inner support platform and a strain beam, setting the inner support platform in the mounting hole of the outer frame, and providing a gap between the outer frame and the inner support platform; 2) Setting a strain beam in the interval and connecting between the outer frame and the inner support platform; three strain beams are provided, and the patch plane of each strain beam is oriented in the same direction as one of the first surface or the second surface; 3) Clean each patch plane, and then attach strain gauges to the patch planes, each patch plane is attached with a strain gauge, and the total number of strain gauges attached to the three patch planes is not less than six; wherein the attached strain gauges are independent of each other; or the strain gauges are connected as a whole; or at least one strain gauge is independent, and at least two strain gauges are connected as a whole; 4) Arranging a circuit board, wherein the circuit board is arranged coplanarly with each of the strain gauges, or is spaced a preset distance from the plane where each of the strain gauges is located, and fixing the circuit board on the outer frame and / or the internal support platform; 5) Place the patch plane on any one of the strain beams upward, and then solder the leads of each strain gauge one by one, so that each strain gauge on the current patch plane is electrically connected to the circuit board through the leads; 6) Repeat the welding operation of step 5 so that all the strain gauges on each strain beam are electrically connected to the circuit board through leads, thereby completing the processing of the multi-dimensional force sensor.

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