Three-dimensional force sensor

Abstract

The embodiment of the invention relates to the technical field of medical instruments, and discloses a three-dimensional force sensor which comprises a square beam elastic body, a circuit board, a first sensing unit, a second sensing unit and a third sensing unit. Through the design of the induction strain gauges and the compensation strain gauges which are arranged on the opposite surfaces and the matched Wheatstone full-bridge circuits, collaborative perception of force components in the same direction is realized, so that effective stress strain information can be amplified, and meanwhile, errors caused by non-uniform distribution of edge stress are counteracted. By utilizing the characteristics of strain isolation and symmetry along the central axis of four orthogonal surfaces of the square beam elastomer and a Wheatstone full-bridge differential measurement mode, any force can be decomposed into non-interfering three-dimensional vectors for independent measurement, interference factors such as force, temperature and electromagnetism of non-sensitive components are removed, and the force detection precision is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a three-dimensional force sensor. Background Technology

[0002] With the rapid development of medical devices, surgical robots have become an important tool in the field of surgery. They have broken the spatial limitations of traditional surgery, allowing surgeons to perform precise operations away from the operating table, and have thus been widely used in clinical practice.

[0003] However, while surgical robots offer convenience, they also have significant drawbacks. Because surgeons cannot directly contact the surgical instruments and lack crucial force sensing capabilities, they are prone to errors. Therefore, force sensors can be integrated into the ends of the surgical instruments on the surgical robot to collect the forces applied during surgery and provide feedback to the surgeon, enabling precise control of the force and improving accuracy.

[0004] In related technologies, fiber Bragg grating sensors can be integrated into the end effectors of surgical robots. This method transmits analog optical signals through optical fibers and then converts the analog optical signals into digital signals to acquire the force intensity during surgery. However, analog optical signals are easily affected by factors such as temperature fluctuations in the surgical environment and the tightness of the fiber optic connector, resulting in poor stability and severely impacting the accuracy of the acquired force. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention provide a three-dimensional force sensor that can improve the accuracy of three-dimensional force detection results.

[0006] The first aspect of this application provides a three-dimensional force sensor, including: a square beam elastic body (101) circuit board (102), a first sensing unit (103), a second sensing unit (104), and a third sensing unit (105). The first sensing unit (103) includes a first strain gauge group (1032) and a first compensation strain gauge group (1031). The first sensing unit (103) is used to acquire the strain signal of the square beam elastic body (101) in the X-axis direction. The second sensing unit (104) includes a second strain gauge group (1042) and a second compensation strain gauge group (1041). The second sensing unit (104) is used to acquire the strain signal of the square beam elastic body (101) in the Y-axis direction. The third sensing unit (105) includes a third strain gauge group (1051) and a third compensation strain gauge group (1052). The third sensing unit (105) is used to acquire the strain signal of the square beam elastic body (101) in the Z-axis direction. The first compensation strain gauge group (1031) and the second compensation strain gauge group (1041) form a four-sided enclosure of the square beam elastic body (101) at the first position, the first sensing strain gauge group (1032) and the second sensing strain gauge group (1042) form a four-sided enclosure of the square beam elastic body (101) at the second position, and the third sensing strain gauge group (1051) and the third compensation strain gauge group (1052) form a four-sided enclosure of the square beam elastic body (101) at the third position. The circuit board (102) is electrically connected to the first sensing unit (103), the second sensing unit (104) and the third sensing unit (105) respectively to construct three Wheatstone full-bridge circuits. One of the Wheatstone full-bridge circuits is used to convert one of the strain signals into a voltage signal and output it.

[0007] In some embodiments of this application, the first sensing strain gauge group (1032) is composed of two first sensing strain gauges, and the first compensation strain gauge group (1031) is composed of two first compensation strain gauges. The two first compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the first position along the first direction, and the two first sensing strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the second position along the first direction. The second strain gauge group (1042) consists of two second strain gauges, and the second compensation strain gauge group (1041) consists of two second compensation strain gauges. The two second compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the first position along the second direction. The two second strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the second position along the second direction. The first direction and the second direction are orthogonal. The third inductive strain gauge group (1051) consists of two third inductive strain gauges, and the third compensation strain gauge group (1052) consists of two third compensation strain gauges. The two third inductive strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the third position along a third direction, and the two third compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the third position along a fourth direction. The third direction and the fourth direction are orthogonal to each other.

[0008] In some embodiments of this application, the three-dimensional force sensor (100) further includes a sensor lead (1000), which is electrically connected to the circuit board (102) and the control module respectively, so as to transmit the voltage signal to the control module, so that the control module determines the force intensity of the square beam elastic body (101) according to the voltage signal.

[0009] In some embodiments of this application, the three-dimensional force sensor (100) further includes a first fixing component (1101), which is disposed on the side of the square beam elastic body (101) near the surgical robot connection end (201). The first fixing component (1101) is provided with a first square hole (1102) and a sensor lead fixing hole (1103). The square beam elastic body (101) passes through the first square hole (1102) and is fixedly connected to the first fixing component (1101); The sensor lead (1000) passes through the sensor lead fixing hole (1103) and is fixedly connected to the first fixing component (1101).

[0010] In some embodiments of this application, the three-dimensional force sensor (100) further includes a second fixing component (1201), the outer diameter of the first fixing component (1101) is smaller than the outer diameter of the second fixing component (1201), the second fixing component (1201) is disposed on the side of the first fixing component (1101) away from the surgical robot connection end (201), the second fixing component (1201) is provided with a second square hole (1202) and a sensor lead groove (1203), and the first fixing component (1101) and the second fixing component (1201) constitute a fixing assembly; The square beam elastic body (101) passes through the first square hole (1102) and the second square hole (1202) and is fixedly connected to the fixing component. The sensor lead (1000) is placed in the sensor lead groove (1203) and passes through the fixing hole of the sensor lead (1000) and is fixedly connected to the fixing component.

[0011] In some embodiments of this application, a sensor lead (1000) mating surface extends from the side of the second fixing component (1201) near the surgical robot connection end (201), and the sensor lead (1000) is fixedly connected to the mating surface of the sensor lead (1000).

[0012] In some embodiments of this application, the three-dimensional force sensor (100) further includes a surgical instrument connector (1303) and a transmission cable (1306), the transmission cable (1306) being used to control the surgical instruments connected to the surgical instrument connector (1303) of the square beam elastomer (101); The first fixing component (1101) is also provided with a first transmission wire guide hole (1301), the second fixing component (1201) is also provided with a transmission wire through hole (1302), and the surgical instrument connecting seat (1303) is provided with a second transmission wire guide hole (1304) and a third triangular hole (1305). The square beam elastic body (101) is fixedly connected to the surgical instrument connector (1303) through the third triangular hole (1305); The transmission cord (1306) passes through the second transmission cord guide hole (1304) and is fixedly connected to the surgical instrument connector (1303); The end of the transmission cord (1306) away from the surgical instrument connector (1303) passes through the first transmission cord guide hole (1301) and the transmission cord through hole (1302), forming a sliding constraint with the fixing component. The transmission cord (1306) moves along the axial direction of the transmission cord (1306) and is limited in the radial direction perpendicular to the axial direction.

[0013] In some embodiments of this application, the diameter of the transmission wire through hole (1302) is larger than the diameter of the first transmission wire guide hole (1301) or the second transmission wire guide hole (1304).

[0014] In some embodiments of this application, the second fixing component (1201) includes a first sub-fixing component (1401) and a second sub-fixing component (1402), wherein the outer diameter of the second sub-fixing component (1402) is larger than the outer diameter of the first sub-fixing component (1401).

[0015] In some embodiments of this application, the three-dimensional force sensor (100) further includes an instrument axis (1501) for connecting to the surgical robot; The instrument shaft (1501) has a through inner hole. The first fixing component (1101) and the first sub-fixing component (1401) are both placed in the inner hole. The second sub-fixing component (1402) is placed outside the inner hole. The outer diameter of the first fixing component (1101) and the outer diameter of the first sub-fixing component (1401) are adapted to the size of the inner hole. The outer diameter of the second sub-fixing component (1402) is adapted to the outer diameter of the instrument shaft (1501).

[0016] The three-dimensional force sensor 100 provided in this embodiment can form a four-sided enclosure of the square beam elastic body 101 by the first strain gauge group 1032 included in the first sensing unit 103 and the second strain gauge group 1042 included in the second sensing unit 104, and the first sensing unit 103... The first compensation strain gauge group 1031 and the second compensation strain gauge group 1041 of the second sensing unit 104 constitute a four-sided enclosure of the square beam elastic body 101. The third sensing unit 105, consisting of a third sensing strain gauge group 1051 and a third compensation strain gauge group 1052, also constitutes a four-sided enclosure of the square beam elastic body 101. This allows for the coordinated sensing of force components in the same direction through strain gauges positioned on opposite surfaces, thereby amplifying the effective stress-strain signal and offsetting errors caused by uneven edge stress distribution. Furthermore, by utilizing the strain isolation of the four orthogonal surfaces of the square beam elastic body 101, its symmetry along the central axis, and the Wheatstone full-bridge potential distribution characteristics, any force can be decomposed into three independent signals that do not interfere with each other, ensuring that the strain on each surface does not interfere with each other and greatly improving the accuracy of force detection.

[0017] Furthermore, circuit board 102 can be electrically connected to the three sensing units mentioned above to construct three parallel Wheatstone full-bridge circuits. Utilizing the potential amplification and balancing characteristics of the Wheatstone full-bridge circuit, the force and strain signals of the square beam elastic body 101 in the XYZ directions of the Cartesian coordinate system can be accurately captured, achieving effective detection of force in three dimensions and improving the accuracy of the force detection results. Simultaneously, each sensing unit includes a compensation strain gauge group. The compensation strain gauge group can generate resistance shifts with changes in ambient temperature, thereby offsetting the interference of temperature and ambient electromagnetic field changes on the force detection results. Combined with the full-bridge differential measurement method formed by the compensation gauges, this further offsets the systematic errors caused by such interference, improving the accuracy of the force detection results. In addition, the differential measurement method based on the full-bridge structure can resist signal fluctuations that may be caused by the excitation of force instruments. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application; Figure 2 A schematic diagram of a region on a square beam elastic body provided in an embodiment of this application; Figure 3 A schematic diagram of a circuit board structure provided in an embodiment of this application; Figure 4 A schematic diagram of a Wheatstone full-bridge circuit provided in this application embodiment; Figure 5 A schematic diagram of a Wheatstone full-bridge circuit provided in this application embodiment; Figure 6A This is a schematic diagram of the structure of a sensing unit provided in an embodiment of this application; Figure 6B This is a schematic diagram of the structure of a sensing unit provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a three-dimensional force detection system provided in an embodiment of this application; Figure 8 A schematic diagram of a voltage signal provided in an embodiment of this application; Figure 9 A schematic diagram of a voltage signal provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of a sensor lead provided in an embodiment of this application; Figure 11 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application; Figure 12 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application; Figure 13 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application; Figure 14 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application; Figure 15 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention.

[0020] This specification contains numerous specific technical details. However, it should be understood that embodiments of the invention can be implemented without these specific technical details. Such detailed descriptions should not be construed as limiting, and the scope of protection of the invention is defined only by the claims. Elsewhere, well-known structures, circuits, and other details have not been shown in detail to avoid misleading the public about the essential points of the invention.

[0021] In this specification, the accompanying drawings illustrate schematic diagrams of several embodiments of the present invention. However, the drawings are merely illustrative, and it should be understood that other embodiments or combinations may be used, and changes in mechanical structure, physical composition, electrical aspects, and procedures may be made without departing from the spirit and scope of the present invention.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Spatial relative terms, such as “below,” “lower,” “above,” “upper,” etc., are used for ease of explanation to describe the relationship between one element or feature illustrated in the figures and another element or feature. It should be understood that spatial relative terms are intended to cover different orientations of the device in use or operation other than those depicted in the figures. For example, if the device in the figures is flipped over, then an element described as “below” other elements or features will become “above” other elements or features. Thus, the exemplary term “below” can cover both above and below orientations. The device may be oriented in other ways (e.g., rotated 90° or otherwise), and the spatial relative descriptive terms used herein shall be interpreted accordingly.

[0023] As used herein, “several,” the singular form “one,” and “the” are intended to include the plural form as well, unless the context otherwise indicates. It should be further understood that the terms “comprising” and / or “including” specify the presence of a feature, step, operation, element, and / or component without excluding the presence of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0024] The term "object" generally refers to a component or a group of components. Throughout the specification and claims, the terms "object," "component," "part," "part," and "piece" are used interchangeably.

[0025] The terms “instrument,” “surgical instrument,” and “surgical device” are used herein to describe medical devices configured for insertion into a patient and for performing surgical or diagnostic procedures, including end-effectors. End-effectors can be surgical tools associated with one or more surgical tasks, such as forceps, needle holders, scissors, bipolar cauterizers, tissue stabilizers or retractors, clamp applicators, anastomosis devices, imaging devices (e.g., endoscopes or ultrasound probes), and the like. Some instruments used in embodiments of the invention further provide articulated supports (sometimes referred to as “wrists”) for the surgical tool, allowing the position and orientation of the end-effector to be manipulated relative to the instrument axis with one or more mechanical degrees of freedom. Further, many end-effectors include functional mechanical degrees of freedom, such as jaws that open or close or a knife that translates along a path. Instruments may also contain permanent or updatable stored information (e.g., on a PCBA board within the instrument). Accordingly, one-way or two-way communication between the instrument and one or more components may be provided in embodiments of this application.

[0026] Finally, the terms “or” and “and / or” as used herein should be interpreted inclusively, meaning either one or any combination thereof. Therefore, “A, B, or C” or “A, B, and / or C” means any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C. Exceptions to this definition will only occur when the combination of elements, functions, steps, or actions is inherently mutually exclusive in some way.

[0027] In related technologies, fiber Bragg grating sensors can be integrated into the end effectors of surgical robots. This method transmits analog optical signals through optical fibers and then converts the analog optical signals into digital signals to acquire the force intensity during surgery. However, analog optical signals are easily affected by factors such as temperature fluctuations in the surgical environment and the tightness of the fiber optic connector, resulting in poor stability and severely impacting the accuracy of the acquired force.

[0028] To address the aforementioned technical problems, this application provides a three-dimensional force sensor. This three-dimensional force sensor, based on the strain gauge principle, is a sensing device capable of real-time and independent acquisition of force signals in three mutually orthogonal directions (i.e., the X, Y, and Z directions in a Cartesian coordinate system). One end of the three-dimensional force sensor can be connected to surgical instruments, and the other end can be connected to a surgical robot. It can detect the forces between surgical instruments and human tissue during surgical procedures in real time, and transmit the feedback to the surgeon via the surgical robot, thereby assisting the surgeon in achieving precise control of the operating force, and thus improving the accuracy and safety of the surgical procedure.

[0029] In this embodiment, the three-dimensional force sensor is specifically as follows: Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0030] like Figure 1 As shown, the three-dimensional force sensor 100 may include a square beam elastic body 101, a circuit board 102, and three sensing units: a first sensing unit 103, a second sensing unit 104, and a third sensing unit 105. The square beam elastic body 101 is a beam-shaped elastic structure with a square cross-section and is the core mechanical sensing carrier of the three-dimensional force sensor 100. It is typically made of a metal material (such as aluminum alloy, titanium alloy, or stainless steel) with stable elastic modulus and excellent fatigue resistance. The square beam elastic body 101 can serve as the mounting base for the three sensing units. When subjected to forces in three mutually orthogonal directions in three-dimensional space, the corresponding area will generate a small elastic strain proportional to the magnitude of the force, providing accurate mechanical signal input for the three sensing units.

[0031] The three sensing units described above can be fixedly connected to the square beam elastic body 101, and the connection method is not limited to welding, bonding, etc. Each sensing unit includes a group of inductive strain gauges and a group of compensating strain gauges. The group of inductive strain gauges can capture the strain generated by the square beam elastic body 101 under force in the corresponding direction and convert it into a change in resistance according to the metal strain effect. The group of compensating strain gauges can respond to changes in ambient temperature and offset the non-stress-induced shift in the resistance of the inductive strain gauge group caused by temperature changes, thus avoiding detection errors caused by non-stress factors.

[0032] Specifically, the first sensing unit 103 may include a first compensated strain gauge group 1031 and a first sensing strain gauge group 1032, and the first sensing unit 103 is used to acquire strain signals in the X-axis direction of the square beam elastic body 101. The second sensing unit 104 may include a second compensated strain gauge group 1041 and a second sensing strain gauge group 1042, and the second sensing unit 104 is used to acquire strain signals in the Y-axis direction of the square beam elastic body 101. The third sensing unit 105 may include a third sensing strain gauge group 1051 and a third compensated strain gauge group 1052, and the third sensing unit 105 is used to acquire strain signals in the Z-axis direction of the square beam elastic body 101.

[0033] The first compensating strain gauge group 1031 and the second compensating strain gauge group 1041 can be disposed at the first position and form a four-sided enclosure of the square beam elastic body 101 at the first position. The first sensing strain gauge group 1032 and the second sensing strain gauge group 1042 can be disposed at the second position and form a four-sided enclosure of the square beam elastic body 101 at the second position. The third sensing strain gauge group 1051 and the third compensating strain gauge group 1052 can be disposed at the third position and form a four-sided enclosure of the square beam elastic body 101 at the third position.

[0034] It is important to note that the material, size, strain coefficient, packaging, and lead material of the strain gauge array in each of the first, second, and third positions can be flexibly adjusted according to the requirements of the actual application scenario. For example, for scenarios requiring high detection accuracy, an Evan alloy strain gauge array with a high strain coefficient and low temperature coefficient can be selected. Furthermore, in high-temperature operating environments, strain gauge arrays with high-temperature resistant packaging and lead materials can be chosen.

[0035] In some embodiments of this application, the location of each sensing unit can be set based on the principles of cantilever beam mechanics and strain distribution, as detailed below. Figure 2 As shown, Figure 2 This is a schematic diagram of a region on a square beam elastic body provided in an embodiment of this application.

[0036] like Figure 2As shown, one end of the square beam elastic body 101 is the surgical robot connection end 201, and the other end is the surgical instrument connection end 202. The area near the surgical robot connection end 201 is the micro-strain region 203, which is the region where the square beam elastic body 101 deforms the least under stress. The first position where the first compensation strain gauge group 1031 and the second compensation strain gauge group 1041 are located can be set within the micro-strain region 203. To the right of the micro-strain region 203 is the root high-strain region 204, which is the region near the surgical instrument connection end 202 where the deformation is greater under stress. The second position where the first sensing strain gauge group 1032 and the second sensing strain gauge group 1042 are located can be set within the root high-strain region 204. The area near the surgical instrument connection end 202 is the end high-strain region 205, that is, the region where the square beam elastic body 101 deforms the most under stress. The third position where the third sensing strain gauge group 1051 and the third compensation strain gauge group 1052 are located can be set within the end high-strain region 205.

[0037] The circuit board 102, also known as the flexible bridge board, can be electrically connected to the three sensing units mentioned above to construct three Wheatstone full-bridge circuits. Each Wheatstone full-bridge circuit can convert the strain signal collected by the corresponding sensing unit into a voltage signal proportional to the force on the square beam elastic body 101 and output it.

[0038] The circuit board 102 is as follows: Figure 3 As shown, Figure 3 This is a schematic diagram of a circuit board structure provided in an embodiment of this application.

[0039] like Figure 3 As shown, the circuit board 102 may include XY axis bridge pads 1021, Z axis bridge pads 1022, wire network 1023 and output pads 1024. The XY axis bridge pads 1021 include X-axis bridge pads and Y-axis bridge pads.

[0040] The X-axis bridge pad is the circuit connection interface on the circuit board 102 corresponding to the first sensing unit 103. It is precisely aligned in space with the lead soldering area of ​​the first sensing unit 103 so as to electrically connect with the first sensing unit 103 through the X-axis bridge pad, thereby constructing a Wheatstone full-bridge circuit corresponding to the X-axis direction. This Wheatstone full-bridge circuit is used to convert the strain signal collected by the first sensing unit 103 into a voltage signal and output it.

[0041] The Y-axis bridge pad is the circuit connection interface on the circuit board 102 corresponding to the second sensing unit 104. It is precisely aligned in space with the lead soldering area of ​​the second sensing unit 104 so as to electrically connect with the second sensing unit 104 through the Y-axis bridge pad, thereby constructing a Wheatstone full-bridge circuit in the Y-axis direction. This Wheatstone full-bridge circuit is used to convert the strain signal collected by the second sensing unit 104 into a voltage signal and output it.

[0042] The structural diagrams of the two Wheatstone full-bridge circuits mentioned above are as follows: Figure 4 As shown, Figure 4 This is a schematic diagram of a Wheatstone full-bridge circuit provided in an embodiment of this application.

[0043] like Figure 4 As shown, the first inductive strain gauge group 1032 corresponds to resistors R1 and R2, and the first compensation strain gauge group 1031 corresponds to resistors R3 and R4, forming a Wheatstone full-bridge circuit in the X-axis direction. The second inductive strain gauge group 1042 corresponds to resistors R1 and R2, and the second compensation strain gauge group 1041 corresponds to resistors R3 and R4, forming a Wheatstone full-bridge circuit in the Y-axis direction.

[0044] The induced voltages corresponding to the two Wheatstone full-bridge circuits mentioned above are respectively , That is, measuring the voltage at the circuit port. , and the input voltage of the full-bridge circuit Strain gauge sensitivity coefficient Poisson's ratio of square beam metal materials Mean strain The relationship between them is:

[0045]

[0046] Z-axis bridge pad 1022 is the circuit connection interface on the circuit board 102 corresponding to the third sensing unit 105. It is precisely aligned in space with the lead soldering area of ​​the third sensing unit 105 so as to electrically connect with the third sensing unit 105 through the Z-axis bridge pad, thereby constructing a Wheatstone full-bridge circuit in the Z-axis direction. This Wheatstone full-bridge circuit is used to convert the strain signal collected by the third sensing unit 105 into a voltage signal and output it.

[0047] The structural diagram of the Wheatstone full-bridge circuit corresponding to the Z-axis direction is as follows: Figure 5 As shown, Figure 5 This is a schematic diagram of a Wheatstone full-bridge circuit provided in an embodiment of this application.

[0048] The third inductive strain gauge group 1051 corresponds to resistors R1 and R3, and the third compensation strain gauge group 1052 corresponds to resistors R2 and R4, forming a Wheatstone full-bridge circuit in the Z-axis direction.

[0049] The induced voltage of the Wheatstone full-bridge circuit in the Z-axis direction mentioned above. That is, measuring the voltage at the circuit port. , and the input voltage of the full-bridge circuit Strain gauge sensitivity coefficient Mean strain The relationship between them is:

[0050] The Wheatstone full-bridge circuits corresponding to the XYZ directions form a parallel structure. The wire network 1023 is the integrated circuit trace inside the circuit board 102, serving as the signal transmission channel between the pads. The output pad 1024 is the output interface component of the circuit board 102, used to transmit the voltage signal output by the parallel Wheatstone full-bridge circuits in the XYZ directions to the outside.

[0051] Therefore, the three-dimensional force sensor 100 provided in this embodiment can form a four-sided enclosure of the square beam elastic body 101 by the first strain gauge group 1032 included in the first sensing unit 103 and the second strain gauge group 1042 included in the second sensing unit 104, and through the first sensing unit 103 The first compensation strain gauge group 1031 and the second compensation strain gauge group 1041 of the second sensing unit 104 constitute a four-sided enclosure of the square beam elastic body 101. The third sensing unit 105, consisting of a third sensing strain gauge group 1051 and a third compensation strain gauge group 1052, also constitutes a four-sided enclosure of the square beam elastic body 101. This allows for the coordinated sensing of force components in the same direction through strain gauges positioned in the central region of opposite surfaces. This amplifies the strain signal of the effective force component while offsetting errors caused by uneven stress distribution at the edges. Furthermore, by utilizing the strain isolation of the four orthogonal surfaces of the square beam elastic body 101, its symmetry along the central axis, and the Wheatstone full-bridge potential variation law, any force can be decomposed into three independent signals that do not interfere with each other, greatly improving the accuracy of force detection.

[0052] Furthermore, circuit board 102 can be electrically connected to the three sensing units mentioned above to construct three parallel Wheatstone full-bridge circuits. Utilizing the potential amplification and balancing characteristics of the Wheatstone full-bridge circuit, the force and strain signals of the square beam elastic body 101 in the XYZ directions of the Cartesian coordinate system can be accurately captured, achieving effective detection of force in three dimensions and improving the accuracy of the force detection results. Simultaneously, each sensing unit includes a compensation strain gauge group. The compensation strain gauge group can generate resistance shifts with changes in ambient temperature, thereby offsetting the interference of temperature and ambient electromagnetic field changes on the force detection results. Combined with the full-bridge differential measurement method formed by the compensation gauges, this further offsets the systematic errors caused by such interference, improving the accuracy of the force detection results. In addition, the differential measurement method based on the full-bridge structure can resist signal fluctuations that may be caused by the excitation of force instruments.

[0053] In some embodiments of this application, the layout of strain gauge groups in each sensing unit can be flexibly set according to actual force detection needs, so that the strain-sensitive direction of each group of sensing units is accurately matched with the corresponding detection direction, ensuring that it only responds to the force strain in the corresponding orthogonal direction, while weakening signal interference in other directions, thus meeting the personalized directional needs of three-dimensional force detection in different scenarios.

[0054] For example, the aforementioned three sensing units are specifically as follows: Figure 6A as well as Figure 6B As shown, Figure 6A Figure 6B These are all schematic diagrams of a sensing unit provided in the embodiments of this application.

[0055] like Figure 6A As shown, the first sensing strain gauge group 1032 can be composed of two first sensing strain gauges, and the first compensation strain gauge group 1031 can be composed of two first compensation strain gauges. The two first compensation strain gauges can be respectively disposed on two opposite surfaces of the square beam elastic body 101 at the first position along the first direction. The two first sensing strain gauges can be respectively disposed on two opposite surfaces of the square beam elastic body 101 at the second position along the first direction. In this embodiment, the first direction can be set as the X-axis direction.

[0056] The second strain gauge group 1042 can be composed of two second strain gauges, and the second compensation strain gauge group 1041 can be composed of two second compensation strain gauges. The two second compensation strain gauges can be respectively disposed on two opposite surfaces of the square beam elastic body 101 at the first position along the second direction. The two second strain gauges can be respectively disposed on two opposite surfaces of the square beam elastic body 101 at the second position along the second direction. The first direction and the second direction are orthogonal. In the embodiment of this application, the first direction can be set as the Y-axis direction.

[0057] like Figure 6BAs shown, the third inductive strain gauge group 1051 can be composed of two third inductive strain gauges, and the third compensation strain gauge group 1052 can be composed of two third compensation strain gauges. The two third inductive strain gauges can be respectively arranged on two opposite surfaces of the square beam elastic body 101 at the third position along a third direction, and the two third compensation strain gauges can be respectively arranged on two opposite surfaces of the square beam elastic body 101 at the third position along a fourth direction. The third direction and the fourth direction are orthogonal. In this embodiment, the third direction can be set as the Y-axis direction, and the fourth direction can be set as the X-axis direction.

[0058] Strain gauges placed on two opposite surfaces can synchronously acquire strain signals from both surfaces under the action of force in the same direction. This allows for differential measurement of the opposite surfaces. Specifically, under the action of force in the same direction, the two opposite surfaces will generate synchronous tensile / compressive strain signals. Differential calculations can be performed on the acquired strain signals from both surfaces under the action of force in the same direction. Through differential calculations, the effective strain signals can be superimposed and amplified, making the changes in strain signals corresponding to weak forces more significant. Differential calculations can also cancel out the interference errors caused by non-inductive force components, temperature changes, and magnetic field fluctuations on the two opposite surfaces, achieving coordinated sensing of forces in the same direction and improving the accuracy of force detection.

[0059] By forming a four-sided enclosure of the square beam elastic body 101 with the first strain gauge group 1032 and the second strain gauge group 1042, and by forming a four-sided enclosure of the square beam elastic body 101 with the first compensation strain gauge group 1031 and the second compensation strain gauge group 1041, and by forming a four-sided enclosure of the square beam elastic body 101 with the third strain gauge group 1051 and the third compensation strain gauge group 1052, the strain isolation characteristics of the four orthogonal surfaces of the square beam elastic body 101 and the potential change law of the Wheatstone full bridge can be utilized to decompose any force into three independent signals that do not interfere with each other. By using the difference between the physical structure and the electrical signal, the signal coupling of forces in different directions is avoided, which greatly improves the accuracy of force detection in each of the three directions XYZ.

[0060] The compensation strain gauge group in this embodiment can simultaneously acquire interference signals such as temperature drift, environmental vibration, and torsional interference. For each of the three directions XYZ, the effective signal can be amplified and the systematic errors caused by temperature drift, environmental vibration, and torsional interference can be offset by differential calculation between the strain signal acquired by the corresponding inductive strain gauge group and the interference signal acquired by the compensation strain gauge group, thereby further improving the accuracy of force detection in each of the three directions XYZ.

[0061] In addition, the strain gauges on the surface of the square beam elastic body 101 are symmetrically aligned along the center line of the surface, which ensures that the spatial orientation of the strain gauges is consistent with the stress response.

[0062] In some embodiments of this application, the control host 705 operated by the doctor may integrate a control module. This control module can determine the force intensity in the corresponding direction based on the voltage signals output by the Wheatstone full-bridge circuit in the aforementioned three directions and feed it back to the doctor, thereby assisting the doctor in achieving precise control of the operating force and thus improving the accuracy and safety of the surgical operation.

[0063] Therefore, in order to achieve effective transmission of voltage signals between the circuit board 102 and the control module, the three-dimensional force sensor 100 may also include sensor leads 1000, which are electrically connected to the circuit board 102 and the control module respectively, so as to transmit the voltage signal output by the Wheatstone full-bridge circuit to the control module, so that the control module can determine the force intensity of the square beam elastic body 101 according to the voltage signal.

[0064] In some embodiments of this application, the three-dimensional force sensor 100 can form a three-dimensional force detection system with the surgical robot and the control host 705 operated by the doctor, as detailed below. Figure 7 As shown, Figure 7 This is a structural schematic diagram of a three-dimensional force detection system provided in an embodiment of this application.

[0065] like Figure 7 As shown, the control module can be integrated into the control host 705. Based on the voltage signals output from the Wheatstone full-bridge circuits in the three directions, the control module can determine the force intensity in the corresponding direction and provide feedback to the doctor. The strain measurement module 701 can be integrated into the surgical robot. The strain measurement module 701 includes a monitoring unit 702, a signal conditioning unit 703, and an analog-to-digital converter 704. The monitoring unit 702 monitors the health status of the sensing unit by sampling the voltage across the resistor Rs. The signal conditioning unit 703 can amplify and filter the signal output from the sensing unit. The analog-to-digital converter 704 can convert the analog signals output from the monitoring unit 702 and the signal conditioning unit 703 into digital signals and communicate with the control host 705 using protocols such as UART and IIC.

[0066] Continue to use Figure 7 In some embodiments of this application, experiments can also be used to verify whether the actual voltage output matches the theoretical voltage output. For example, strain gauge resistance. The resistance can be set to 1.2 kΩ, the strain gauge sensitivity coefficient k is 2, and the Poisson's ratio is... The value is 0.3, the sampling resistor Rs is set to 10Ω, and the voltage... +5V The initial value is 0V, corresponding to the input voltage Vi of the sensing unit. Theoretical output voltage , , as follows:

[0067] V V V

[0068] A normal stress load of 0~9N can be applied to the square beam elastic body 101 along the XYZ axes, and the strain level generated by the square beam elastic body 101 ranges from 0~102με. The XY axis voltage signals acquired after gain conditioning by the signal conditioning unit 703 are as follows: Figure 8 As shown, the Z-axis voltage signal is as follows: Figure 9 As shown. Figure 8 This is a schematic diagram of a voltage signal provided in an embodiment of this application. Figure 9 This is a schematic diagram of a voltage signal provided in an embodiment of this application.

[0069] Depend on Figure 8 It can be seen that the X-axis and Y-axis output signals of the sensing unit have a linear relationship with the applied load, and the decoupling error is about 1.9%.

[0070] Depend on Figure 9 It can be seen that the output signals of the sensor's Z-axis and Y-axis have a linear relationship with the applied load. Therefore, it can be determined that the above-mentioned three-dimensional force sensor 100 can identify three-dimensional force vector loading.

[0071] Continue to use Figure 7 In this embodiment, the health status of the sensing unit can also be monitored. The resistance of the strain gauges in the sensor unit is... This can be achieved by comparing the above sampling resistors. voltage at both ends With initial value To determine if there is a short circuit in the sensing unit, if and If the deviation between them is large, there may be a short circuit in the sensing unit.

[0072] initial value The following formula can be used to determine it:

[0073] The sensor lead 1000 described above is as follows: Figure 10 , Figure 10 This is a schematic diagram of the structure of a sensor lead provided in an embodiment of this application.

[0074] like Figure 10 As shown, the sensor lead 1000 may include a first mating pad 1001, a wire 1002, and a second mating pad 1003. The first mating pad 1001 is electrically connected to the output pad 1024 on the circuit board 102, and the second mating pad 1003 is electrically connected to the control module. Each wire 1002 is composed of a thin wire portion and a thick wire portion in a one-to-one correspondence. By precisely matching the width / length of the thin wire portion and the thick wire portion, the DC resistance balance of the input / output ports of the aforementioned three Wheatstone full-bridge circuits can be achieved, ensuring that the excitation voltage distribution of each Wheatstone full-bridge circuit is uniform and the signal transmission characteristics are consistent, laying the circuit foundation for the consistency and accuracy of three-dimensional force detection.

[0075] In some embodiments of this application, in order to enhance the structural stability of the square beam elastic body 101 and to provide orderly constraint on the sensor lead 1000, the three-dimensional force sensor 100 further includes a first fixing component 1101, as detailed below. Figure 11 As shown, Figure 11 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0076] like Figure 11 As shown, the first fixing component 1101 is disposed on the side of the square beam elastic body 101 near the surgical robot connection end 201. The first fixing component 1101 is provided with a first square hole 1102 and a sensor lead fixing hole 1103. The square beam elastic body 101 passes through the first square hole 1102 and is fixedly connected to the first fixing component 1101. The sensor lead 1000 passes through the sensor lead fixing hole 1103 and is fixedly connected to the first fixing component 1101.

[0077] The fixed connection methods in the embodiments of this application are not limited to threaded connection, welding, interference fit, pin connection, riveting connection, snap connection, etc.

[0078] In some embodiments of this application, in order to further improve the structural stability of the square beam elastic body 101, and to avoid the sensor lead 1000 from contacting the square beam elastic body 101, which would cause the square beam elastic body 101 to generate additional strain and thus cause inaccurate force detection results, the three-dimensional force sensor 100 also includes a second fixing component, as detailed below. Figure 12 As shown, Figure 12 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0079] like Figure 12As shown, the second fixing component 1201 is disposed on the side of the first fixing component 1101 away from the surgical robot connection end 201. The first fixing component 1101 and the second fixing component 1201 can constitute a fixing assembly. The outer diameter of the first fixing component 1101 is smaller than the outer diameter of the second fixing component 1201, which can form a stepped structure. The second fixing component 1201 is provided with a second square hole 1202 and a sensor lead groove 1203. The square beam elastic body 101 can pass through the first square hole 1102 and the second square hole 1202 and be fixedly connected to the fixing assembly, further improving the structural stability of the square beam elastic body 101. The sensor lead 1000 can be placed in the sensor lead groove 1203 and pass through the sensor lead fixing hole 1103 and be fixedly connected to the fixing assembly.

[0080] It can be seen that the second fixing component 1201, with its larger outer diameter design, can lift the sensor lead 1000 upward and maintain it at a preset height, so that a reliable physical isolation space is formed between the sensor lead 1000 and the square beam elastic body 101. Structurally, this avoids the possibility of the sensor lead 1000 drooping due to its own weight, vibration, or assembly deviation directly contacting the square beam elastic body 101, thereby effectively avoiding the situation where the square beam elastic body 101 generates additional strain, leading to inaccurate force detection results.

[0081] In some embodiments of this application, to further improve the structural stability of the sensor lead 1000, a sensor lead contact surface can be extended from the side of the second fixing component 1201 near the surgical robot connection end 201, and the sensor lead 1000 can be fixedly connected to the sensor lead contact surface. The sensor lead contact surface is a plane adapted to the shape of the sensor lead 1000, and the height of the sensor contact surface is level with the height of the surface formed by the aforementioned sensor lead groove, ensuring that the sensor lead 1000 can naturally and tightly fit against the sensor lead contact surface. By fixing the sensor lead 1000 to the sensor lead contact surface, the possibility of the sensor lead 1000 directly contacting the square beam elastic body 101 due to its own weight sagging, vibration, or assembly deviation can be further avoided, thus improving the structural stability of the sensor lead 1000.

[0082] In some embodiments of this application, in order to achieve reliable assembly and operation control of surgical instruments, the three-dimensional force sensor 100 may further include a surgical instrument connector 1303 and a transmission cable 1306. One end of the transmission cable 1305 can be connected to the surgical instrument connected to the surgical instrument connector 1303, and the other end can extend to the operating end held by the doctor. When the doctor pulls, releases, or finely adjusts the tension of the transmission cable at the operating end, the transmission cable can transmit the operating force to the surgical instrument to control the surgical instrument connected to the surgical instrument connector 1303 of the square beam elastic body 101 to complete clamping, rotating, telescopic and other actions.

[0083] Specifically as follows: Figure 13 As shown, Figure 13 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0084] like Figure 13 As shown, the first fixing component 1101 is also provided with a first transmission wire guide hole 1301, the second fixing component 1201 is also provided with a transmission wire through hole 1302, and the surgical instrument connecting seat 1303 is provided with a second transmission wire guide hole 1304 and a third triangular hole 1305.

[0085] The square beam elastic body 101 is fixedly connected to the surgical instrument connector 1303 through a third rectangular hole 1305. The transmission cable 1306 passes through the second transmission cable guide hole 1304 and is fixedly connected to the surgical instrument connector 1303. One end of the transmission cable 1306 away from the surgical instrument connector 1303 can pass through the first transmission cable guide hole 1301 and the transmission cable through hole 1302, forming a sliding constraint with the first fixed component 1101. The transmission cable 1306 can move along the axial direction of the transmission cable and is limited in the radial direction perpendicular to the axial direction.

[0086] In some embodiments of this application, to avoid the transmission of additional force to the square beam elastic body 101 during the pulling, releasing, or fine-tuning of the tension of the transmission wire rope 1306, which would cause additional strain in the square beam elastic body 101 and affect the accuracy of the force detection results, the diameter of the transmission wire rope through hole 1302 can be set to be larger than the diameter of the first transmission wire rope guide hole 1301 or the second transmission wire rope guide hole 1304. This allows for independent space for the transmission wire rope to pass through and move, ensuring that the transmission wire rope 1306 always maintains a safe distance from the hole wall and the sensor lead wire 1000. This ensures that the strain of the square beam elastic body 101 is not affected by the transmission wire rope and is only caused by the force of the surgical instrument, thus improving the accuracy of the force detection results.

[0087] In some embodiments of this application, the second fixing component 1201 may include a first sub-fixing component 1401 and a second sub-fixing component 1402, as detailed below. Figure 14As shown, Figure 14 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0088] like Figure 14 As shown, the second fixing component 1201 may include a first sub-fixing component 1401 and a second sub-fixing component 1402. The outer diameter of the second sub-fixing component 1402 may be set to be larger than the outer diameter of the first sub-fixing component 1401. The axial constraint is achieved through the size difference, so as to form a limiting fit with the instrument shaft 1501 in the future, restricting the overall displacement of the second fixing component 1201 along the axial direction and preventing axial movement during the pulling of the transmission wire rope, etc.

[0089] In some embodiments of this application, the three-dimensional force sensor 100 may also be provided with a mechanical interface to connect with the surgical robot, ensuring the accurate transmission of the surgical robot's control commands to the surgical instruments. Details are as follows: Figure 15 As shown, Figure 15 This is a schematic diagram of the structure of a three-dimensional force sensor provided in an embodiment of this application.

[0090] like Figure 15 As shown, the three-dimensional force sensor 100 may further include an instrument shaft 1501, which is used to connect to the surgical robot. The instrument shaft 1501 may have a through inner hole, in which the first fixing component 1101 and the first sub-fixing component 1401 are placed, and the second sub-fixing component 1402 is placed outside the inner hole. The outer diameters of the first fixing component 1101 and the first sub-fixing component 1401 are adapted to the size of the inner hole, and the outer diameter of the second sub-fixing component 1402 is adapted to the outer diameter of the instrument shaft 1501. Through axial constraint, the displacement of the second fixing component 1201 as a whole along the axial direction can be restricted, preventing axial movement during transmission cable pulling and other processes.

[0091] In this embodiment, the material of the instrument shaft 1501 is not limited to stainless steel, titanium alloy, cobalt-chromium alloy, etc., and the connection method between the instrument shaft 1501 and the surgical robot is not limited to flange rigid connection, quick-change interface connection, conical surface mating connection, threaded connection, etc.

[0092] In the embodiments of this application, the strain gauge material can be Evan alloy with high resistivity, and the substrate can be high-temperature resistant polyester film PET or polyimide PI.

[0093] In this embodiment, the three-dimensional force sensor 100 can capture the force and strain signals of the square beam elastic body 101 in the XYZ directions in the Cartesian coordinate system. The control module can then process these signals to obtain the forces acting in the XYZ directions. Furthermore, these three forces can be synthesized based on vector operation rules to provide data support for the subsequent manipulation of surgical instruments. The specific formula for the aforementioned force synthesis calculation is as follows: in, The vector sum of forces acting in the X, Y, and Z directions, also known as the resultant force. The force is in the X direction. The force is in the Y direction. The force is acting in the Z direction.

[0094] The scalar values ​​and specific formulas for the forces acting in the X, Y, and Z directions are as follows:

[0095] in, The scalar sum of forces acting in the X, Y, and Z directions, also known as the magnitude of the resultant force. The force is in the X direction. The force is in the Y direction. The force is acting in the Z direction.

[0096] combined efforts The angles between the forces acting on the forces in the X, Y, and Z directions are respectively calculated using the following formulas:

[0097] in, Force in the X direction With combined force The included angle.

[0098]

[0099] in, Represents the force in the Y direction With combined force The included angle.

[0100]

[0101] in, Indicates the force in the Z direction With combined force The included angle.

[0102] Therefore, the three-dimensional force sensor 100 provided in this embodiment can form a four-sided enclosure of the square beam elastic body 101 by the first strain gauge group 1032 included in the first sensing unit 103 and the second strain gauge group 1042 included in the second sensing unit 104, and through the first sensing unit 103 The first compensation strain gauge group 1031 and the second compensation strain gauge group 1041 of the second sensing unit 104 constitute a four-sided enclosure of the square beam elastic body 101. The third sensing unit 105, consisting of a third sensing strain gauge group 1051 and a third compensation strain gauge group 1052, also constitutes a four-sided enclosure of the square beam elastic body 101. This allows for the coordinated sensing of force components in the same direction through strain gauges positioned on opposite surfaces, thereby amplifying the effective stress-strain signal and offsetting errors caused by uneven edge stress distribution. Furthermore, by utilizing the strain isolation of the four orthogonal surfaces of the square beam elastic body 101, its symmetry along the central axis, and the Wheatstone full-bridge potential distribution characteristics, any force can be decomposed into three independent signals that do not interfere with each other, ensuring that the strain on each surface does not interfere with each other and greatly improving the accuracy of force detection.

[0103] Furthermore, circuit board 102 can be electrically connected to the three sensing units mentioned above to construct three parallel Wheatstone full-bridge circuits. Utilizing the potential amplification and balancing characteristics of the Wheatstone full-bridge circuit, the force and strain signals of the square beam elastic body 101 in the XYZ directions of the Cartesian coordinate system can be accurately captured, achieving effective detection of force in three dimensions and improving the accuracy of the force detection results. Simultaneously, each sensing unit includes a compensation strain gauge group. The compensation strain gauge group can generate resistance shifts with changes in ambient temperature, thereby offsetting the interference of temperature and ambient electromagnetic field changes on the force detection results. Combined with the full-bridge differential measurement method formed by the compensation gauges, this further offsets the systematic errors caused by such interference, improving the accuracy of the force detection results. In addition, the differential measurement method based on the full-bridge structure can resist signal fluctuations that may be caused by the excitation of force instruments.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A three-dimensional force sensor, characterized in that, The three-dimensional force sensor (100) includes a square beam elastomer (101), a circuit board (102), a first sensing unit (103), a second sensing unit (104), and a third sensing unit (105). The first sensing unit (103) includes a first strain gauge group (1032) and a first compensation strain gauge group (1031). The first sensing unit (103) is used to acquire the strain signal of the square beam elastic body (101) in the X-axis direction. The second sensing unit (104) includes a second strain gauge group (1042) and a second compensation strain gauge group (1041). The second sensing unit (104) is used to acquire the strain signal of the square beam elastic body (101) in the Y-axis direction. The third sensing unit (105) includes a third strain gauge group (1051) and a third compensation strain gauge group (1052). The third sensing unit (105) is used to acquire the strain signal of the square beam elastic body (101) in the Z-axis direction. The first compensation strain gauge group (1031) and the second compensation strain gauge group (1041) form a four-sided enclosure of the square beam elastic body (101) at the first position, the first sensing strain gauge group (1032) and the second sensing strain gauge group (1042) form a four-sided enclosure of the square beam elastic body (101) at the second position, and the third sensing strain gauge group (1051) and the third compensation strain gauge group (1052) form a four-sided enclosure of the square beam elastic body (101) at the third position. The circuit board (102) is electrically connected to the first sensing unit (103), the second sensing unit (104) and the third sensing unit (105) respectively to construct three Wheatstone full-bridge circuits. One of the Wheatstone full-bridge circuits is used to convert one of the strain signals into a voltage signal and output it.

2. The three-dimensional force sensor according to claim 1, characterized in that, The first inductive strain gauge group (1032) is composed of two first inductive strain gauges, and the first compensation strain gauge group (1031) is composed of two first compensation strain gauges. The two first compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the first position along the first direction, and the two first inductive strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the second position along the first direction. The second strain gauge group (1042) consists of two second strain gauges, and the second compensation strain gauge group (1041) consists of two second compensation strain gauges. The two second compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the first position along the second direction. The two second strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the second position along the second direction. The first direction and the second direction are orthogonal. The third inductive strain gauge group (1051) consists of two third inductive strain gauges, and the third compensation strain gauge group (1052) consists of two third compensation strain gauges. The two third inductive strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the third position along a third direction, and the two third compensation strain gauges are respectively disposed on two opposite surfaces of the square beam elastic body (101) at the third position along a fourth direction. The third direction and the fourth direction are orthogonal to each other.

3. The three-dimensional force sensor according to claim 1, characterized in that, The three-dimensional force sensor (100) also includes sensor leads (1000), which are electrically connected to the circuit board (102) and the control module respectively, so as to transmit the voltage signal to the control module, so that the control module can determine the force intensity of the square beam elastic body (101) according to the voltage signal.

4. The three-dimensional force sensor according to claim 3, characterized in that, The three-dimensional force sensor (100) also includes a first fixing component (1101), which is disposed on the side of the square beam elastic body (101) near the surgical robot connection end (201). The first fixing component (1101) is provided with a first square hole (1102) and a sensor lead fixing hole (1103). The square beam elastic body (101) passes through the first square hole (1102) and is fixedly connected to the first fixing component (1101); The sensor lead (1000) passes through the sensor lead fixing hole (1103) and is fixedly connected to the first fixing component (1101).

5. The three-dimensional force sensor according to claim 4, characterized in that, The three-dimensional force sensor (100) further includes a second fixing component (1201). The outer diameter of the first fixing component (1101) is smaller than the outer diameter of the second fixing component (1201). The second fixing component (1201) is disposed on the side of the first fixing component (1101) away from the surgical robot connection end (201). The second fixing component (1201) is provided with a second square hole (1202) and a sensor lead groove (1203). The first fixing component (1101) and the second fixing component (1201) constitute a fixing assembly. The square beam elastic body (101) passes through the first square hole (1102) and the second square hole (1202) and is fixedly connected to the fixing component. The sensor lead (1000) is placed in the sensor lead groove (1203) and passes through the fixing hole of the sensor lead (1000) and is fixedly connected to the fixing component.

6. The three-dimensional force sensor according to claim 5, characterized in that, The second fixing component (1201) extends a sensor lead (1000) mating surface on the side near the surgical robot connection end (201), and the sensor lead (1000) is fixedly connected to the sensor lead (1000) mating surface.

7. The three-dimensional force sensor according to claim 5, characterized in that, The three-dimensional force sensor (100) also includes a surgical instrument connector (1303) and a transmission cable (1306), the transmission cable (1306) being used to control the surgical instruments connected to the surgical instrument connector (1303) of the square beam elastomer (101); The first fixing component (1101) is also provided with a first transmission wire guide hole (1301), the second fixing component (1201) is also provided with a transmission wire through hole (1302), and the surgical instrument connecting seat (1303) is provided with a second transmission wire guide hole (1304) and a third triangular hole (1305). The square beam elastic body (101) is fixedly connected to the surgical instrument connector (1303) through the third triangular hole (1305); The transmission cord (1306) passes through the second transmission cord guide hole (1304) and is fixedly connected to the surgical instrument connector (1303); The end of the transmission cord (1306) away from the surgical instrument connector (1303) passes through the first transmission cord guide hole (1301) and the transmission cord through hole (1302), forming a sliding constraint with the fixing component. The transmission cord (1306) moves along the axial direction of the transmission cord (1306) and is limited in the radial direction perpendicular to the axial direction.

8. The three-dimensional force sensor according to claim 7, characterized in that, The diameter of the transmission wire through hole (1302) is larger than the diameter of the first transmission wire guide hole (1301) or the second transmission wire guide hole (1304).

9. The three-dimensional force sensor according to claim 5, characterized in that, The second fixing component (1201) includes a first sub-fixing component (1401) and a second sub-fixing component (1402), wherein the outer diameter of the second sub-fixing component (1402) is larger than the outer diameter of the first sub-fixing component (1401).

10. The three-dimensional force sensor according to claim 9, characterized in that, The three-dimensional force sensor (100) also includes an instrument axis (1501) for connecting to the surgical robot; The instrument shaft (1501) has a through inner hole. The first fixing component (1101) and the first sub-fixing component (1401) are both placed in the inner hole. The second sub-fixing component (1402) is placed outside the inner hole. The outer diameter of the first fixing component (1101) and the outer diameter of the first sub-fixing component (1401) are adapted to the size of the inner hole. The outer diameter of the second sub-fixing component (1402) is adapted to the outer diameter of the instrument shaft (1501).

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