Multi-dimensional force sensor and force control robot

Abstract

The utility model belongs to the technical field of robots, and discloses a multi-dimensional force sensor and a force control robot. The sensor comprises a shell and a module group, a containing cavity is formed in the shell, the module group is arranged in the containing cavity, the module group comprises an elastic element, a detection bridge and a circuit board, the circuit board is used for converting electric signals of the detection bridge into digital signals, and the detection bridge and the circuit board are both connected with the elastic element. And the module group can be integrally disassembled and assembled and integrally interchanged. According to the utility model, a modular structure can be formed, so that the structural complexity of the multi-dimensional force sensor is reduced, the interchangeability is ensured, the overall maintainability is improved, and the cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, and in particular to multidimensional force sensors and force-controlled robots. Background Technology

[0002] A multidimensional force sensor is a sensor capable of simultaneously measuring force and torque components in two or more directions. In a Cartesian coordinate system, force and torque can each be decomposed into three components; therefore, the most complete form of multidimensional force sensor is a six-dimensional force / torque sensor, which can simultaneously measure three force components and three torque components.

[0003] Force-controlled robots use multi-dimensional force sensors to sense and control the robot's forces in real time, enabling them to dynamically adjust the applied forces based on factors such as the shape, position, and resistance of the object during operation. This avoids damage to the workpiece and ensures the accuracy and stability of the operation.

[0004] However, current multidimensional force sensors have complex structures and poor interchangeability, resulting in poor overall maintainability and increased maintenance costs. Utility Model Content

[0005] The purpose of this invention is to provide a multi-dimensional force sensor and a force-controlled robot, which realizes a modular structure, thereby reducing the structural complexity of the multi-dimensional force sensor, ensuring interchangeability, improving overall maintainability and reducing costs.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Multidimensional force sensors, including:

[0008] A housing, wherein the housing has an internal cavity;

[0009] The module assembly is located within the receiving cavity. The module assembly includes an elastic element, a detection bridge, and a circuit board. The circuit board is used to convert the electrical signal of the detection bridge into a digital signal. Both the detection bridge and the circuit board are connected to the elastic element. The module assembly can be disassembled and interchanged as a single unit.

[0010] As an alternative solution for a multidimensional force sensor, the housing includes an outer shell and a base. The elastic element is provided with a first connecting part and a second connecting part. The elastic element is detachably connected to the base through the first connecting part, and the elastic element is connected to the outer shell through the second connecting part.

[0011] As an alternative solution for a multidimensional force sensor, the first connecting part is a connecting block located near the center of the elastic element. The connecting block has multiple first connecting holes, and fasteners pass through the first connecting holes to connect with the base.

[0012] As an alternative to a multidimensional force sensor, the second connection portion is located near the edge of the elastic element, and a plurality of second connection holes are provided on the second connection portion along the circumferential direction, through which fasteners are connected to the housing.

[0013] As an alternative solution for a multidimensional force sensor, a sealing ring is sandwiched between the base and the housing, and the base and the housing clamp the sealing ring.

[0014] As an alternative solution for a multidimensional force sensor, the elastic element includes a main body, a housing fitted onto the main body, and the inner wall of the housing adhering to the outer wall of the main body.

[0015] As an alternative solution for a multidimensional force sensor, the detection bridge is provided with multiple first mounting holes, and a first connector can pass through the first mounting holes to connect with the elastic element.

[0016] As an alternative solution for a multidimensional force sensor, the circuit board is provided with a second mounting hole, the circuit board is opposite to and spaced apart from the detection bridge, and the second connector can pass through the second mounting hole to connect with the first connector or to the elastic element.

[0017] As an alternative solution for a multidimensional force sensor, the elastic element is provided with multiple strain beams, and the detection bridge includes multiple sets of strain gauges attached to the strain beams.

[0018] A force-controlled robot, including the multi-dimensional force sensor described in any of the above schemes, wherein the multi-dimensional force sensor is disposed at the end of the robotic arm.

[0019] Beneficial effects:

[0020] In the first aspect of this invention, the housing encapsulates the module assembly within it, providing positioning and protection for the internal structure. The elastic element serves as the force transmission medium for the sensor; when an external force is applied to the sensor, the elastic element deforms. The detection bridge converts the micro-strain of the elastic element into multiple electrical signals. The circuit board converts the electrical signals from the detection bridge into digital signals. This allows the multi-dimensional force sensor to convert physical force / torque into electrical signals, and then into digital multi-dimensional force. The module assembly can be directly used as the smallest assembly unit, either disassembled from the housing as a single unit or installed as a single unit inside the housing, thus forming a modular structure. This reduces the structural complexity of the sensor, allowing for direct replacement of modules when needed, ensuring interchangeability, improving sensor maintainability, and reducing costs.

[0021] In a second aspect of this invention, a force-controlled robot based on this multi-dimensional force sensor can improve modularity, thereby enhancing assemblability, interchangeability, and reducing costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the multidimensional force sensor provided in this embodiment of the utility model;

[0023] Figure 2 This is a first exploded view of the multidimensional force sensor provided in this embodiment of the present invention;

[0024] Figure 3 This is a second exploded view of the multidimensional force sensor provided in this embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the elastic element provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the connection between the elastic element and the detection bridge provided in this embodiment of the utility model;

[0027] Figure 6 This is a schematic diagram of the structure of the elastic element, the detection bridge, and the circuit board connection provided in this embodiment of the utility model.

[0028] In the picture:

[0029] 100. Module group; 110. Elastic element; 111. First connecting part; 112. Second connecting part; 113. First connecting hole; 114. Second connecting hole; 115. Main body; 116. Strain beam; 120. Detection bridge; 121. First mounting hole; 122. First connector; 130. Circuit board; 131. Second mounting hole; 132. Second connector;

[0030] 200, outer casing; 300, base; 400, sealing ring; 500, communication board. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0032] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0035] Please see the appendix Figure 1 -Attached Figure 3 The first aspect of this embodiment relates to a multi-dimensional force sensor (hereinafter referred to as "sensor"), which includes a housing and a module assembly 100 fixed on the housing. The housing has an internal cavity, and the module assembly 100 is disposed within the cavity. The module assembly 100 includes an elastic element 110, a detection bridge 120, and a circuit board 130. The circuit board 130 is used to convert the electrical signal of the detection bridge 120 into a digital signal. Both the detection bridge 120 and the circuit board 130 are connected to the elastic element 110. The module assembly 100 can be disassembled and interchanged as a single unit.

[0036] Specifically, the entire sensor has a cylindrical structure, with a housing used to encapsulate the module assembly 100 inside, providing positioning and protection for the internal structure. The housing can be made of metals such as aluminum alloy or stainless steel, or it can be made of polymer materials. Different materials have different properties, and the appropriate material should be selected based on the sensor's operating environment.

[0037] The elastic element 110 serves as the force transmission medium for the sensor. When an external force is applied to the sensor, the elastic element 110 deforms, and this deformation is subsequently captured by the strain gauge and converted into an electrical signal. The material of the elastic element 110 typically possesses good mechanical properties and stability to ensure that the sensor maintains high accuracy and reliability during long-term use. The materials of the elastic element 110 include, but are not limited to, titanium alloys, aluminum alloys, alloy structural steel, and stainless steel.

[0038] The sensing bridge 120 can convert the micro-strain of the elastic element 110 into multiple sets of electrical signals. Typically, the sensing bridge 120 can be a Wheatstone bridge, which can convert small strains into significant voltage outputs.

[0039] Circuit board 130 integrates an operational amplifier and an ADC conversion unit. Circuit board 130 is electrically connected to the detection bridge 120 and includes signal processing circuitry to convert the electrical signals from the detection bridge 120 into digital signals. The data can be transmitted to the back-end microprocessor unit for further calculation to obtain force and torque values ​​in various dimensions. This enables the multidimensional force sensor to convert physical force / torque into electrical signals, and then into digital multidimensional force.

[0040] In this embodiment, the module group 100 as a whole can be directly used as the smallest unit of assembly. It can be disassembled from the inside of the housing in an integrated form or installed in the inside of the housing in an integrated form, thereby forming a modular structure, reducing the structural complexity of the sensor. When it is necessary to replace the module group 100, it can be directly replaced, thereby ensuring the interchangeability of the module group 100, improving the maintainability of the sensor and reducing costs.

[0041] Please see the appendix Figure 1 -Attached Figure 4 Optionally, the housing includes an outer shell 200 and a base 300. The elastic element 110 is provided with a first connecting part 111 and a second connecting part 112. The elastic element 110 is detachably connected to the base 300 through the first connecting part 111 and connected to the outer shell 200 through the second connecting part 112.

[0042] In this embodiment, the outer shell 200 is a sleeve, the base 300 is a flange, and the elastic element 110 is connected to the base 300 by a detachable connection method such as threaded connection or snap-fit ​​through the first connecting part 111. At the same time, the elastic element 110 can also be connected to the outer shell 200 by a detachable connection method such as threaded connection or snap-fit ​​through the second connecting part 112.

[0043] The detachable connection method facilitates the assembly and disassembly of the elastic element 110 with the housing 200 and the base 300.

[0044] Furthermore, the first connecting part 111 is a connecting block located near the center of the elastic element 110. The connecting block is provided with a plurality of first connecting holes 113, and the fastener passes through the first connecting holes 113 to connect with the base 300.

[0045] Specifically, the elastic element 110 is disc-shaped, and a connecting block is provided at the center of the elastic element 110. The connecting block can be a cube structure, and multiple first connecting holes 113 are provided in the thickness direction of the elastic element 110. In this embodiment, the first connecting holes 113 are respectively provided near the four apex corners of the connecting block. The fastener can be a threaded fastener, which is screwed onto the base 300 through the first connecting holes 113.

[0046] Furthermore, the second connecting portion 112 is disposed near the edge of the elastic element 110, and a plurality of second connecting holes 114 are provided on the second connecting portion 112 along the circumferential direction, through which fasteners pass and connect to the housing 200.

[0047] Specifically, a second connecting portion 112 is formed on the outer periphery of the elastic element 110 near its edge. The second connecting portion 112 and the first connecting portion 111 can be an integral structure or a separate structure connected by other connection methods. Multiple second connecting holes 114 are formed on the second connecting portion 112, through which threaded fasteners pass and are screwed to the outer casing 200. Of course, the fasteners can also be rivets or other snap-fit ​​components; the specific type can be selected based on the usage scenario, connection strength, and ease of assembly and disassembly.

[0048] Optionally, a sealing ring 400 is sandwiched between the base 300 and the outer shell 200, and the sealing ring 400 is clamped between the base 300 and the outer shell 200.

[0049] Since both the base 300 and the outer shell 200 are connected to the elastic element 110, any gap between them would allow external impurities such as dust to enter the cavity, affecting the performance of internal components and reducing the sensor's detection accuracy. In this embodiment, a sealing ring 400 is sandwiched between the base 300 and the outer shell 200. After installation, the gap between the base 300 and the outer shell 200 is less than the thickness of the sealing ring 400 in its free state, ensuring a tight seal and achieving a sealing effect.

[0050] Optionally, the elastic element 110 includes a main body 115, a housing 200 sleeved on the main body 115, and the inner wall of the housing 200 is attached to the outer wall of the main body 115.

[0051] The main body 115 and the outer shell 200 form a hole-shaft fit, that is, when the outer shell 200 and the main body 115 are assembled, the radial positioning of the outer shell 200 relative to the elastic element 110 is achieved directly through the fit between the inner wall of the outer shell 200 and the outer wall of the main body 115.

[0052] Optionally, the elastic element 110 is provided with multiple strain beams 116, and the detection bridge 120 includes multiple sets of strain gauges attached to the strain beams 116.

[0053] Specifically, one end of the strain beam 116 is connected to the first connecting part 111, and the other end is connected to the second connecting part 112. The width of the strain beam 116 is free on both sides to provide space for deformation of the strain beam 116, and also to allow the elastic element 110 to form a hollow structure, reducing weight. In this embodiment, four strain beams 116 are provided, that is, one is provided every 90° in the circumferential direction of the first connecting part 111. In other embodiments, the number of strain beams 116 can be set as needed, for example, 3, 6 or 8, etc. The deformation of the strain beam 116 is usually very small, on the order of 0.01 mm or less.

[0054] The strain gauges are bonded to the strain beam 116 by an adhesive process. Combined with the wiring arrangement of the bridge plate, multiple strain gauges at different positions form multiple sets of detection bridges 120 to detect deformation in different dimensions, thereby measuring the micro-strain on the strain beam 116 caused by external force. The micro-strain is the ratio of the deformation to the original size of the initial structure.

[0055] Please see the appendix Figure 1 -Attached Figure 3 and appendix Figure 5 Optionally, the detection bridge 120 is provided with a plurality of first mounting holes 121, and the first connector 122 can pass through the first mounting holes 121 to connect with the elastic element 110.

[0056] Specifically, the main body of the detection bridge 120 is provided with a plurality of first mounting holes 121. The first connector 122 passes through the first mounting holes 121 and can be connected to the elastic element 110. The specific connection method can be screw connection or riveting. In this embodiment, in order to improve the efficiency of assembly and disassembly, the first connector 122 is threadedly connected to the elastic element 110.

[0057] Please see the appendix Figure 1 -Attached Figure 3 and appendix Figure 6 Furthermore, the circuit board 130 is provided with a second mounting hole 131. The circuit board 130 and the detection bridge 120 are opposite to each other and spaced apart. The second connector 132 can pass through the second mounting hole 131 to connect with the first connector 122 or to the elastic element 110.

[0058] In this embodiment, the circuit board 130 can be directly connected to the elastic element 110. For example, the second connector 132 passes through the second mounting hole 131 and is directly screwed onto the elastic element 110. Alternatively, the first connector 122 has a threaded hole that mates with the second connector 132. That is, the circuit board 130 has a second mounting hole 131 at the position corresponding to the first connector 122, and the second connector 132 passes through the second mounting hole 131 and is directly screwed onto the first connector 122. This reduces the length of the second connector 132. The second connector 132 and the first connector 122 can adopt the same structure to reduce the number of parts and reduce processing costs.

[0059] Optionally, a communication board 500 is also provided in the cavity, which is opposite to and spaced apart from the circuit board 130.

[0060] Specifically, the communication board 500, as an important component of the multidimensional force sensor, has one of its main functions: converting the force and torque data measured by the sensor into transmittable signals and transmitting these signals to external devices, such as computers, controllers, or data acquisition systems, via a specific communication protocol. This data transmission is performed in real time, ensuring the accuracy and timeliness of the data.

[0061] The second aspect of this embodiment also relates to a force-controlled robot, which includes a robotic arm and more than one multi-dimensional force sensor, the multi-dimensional force sensor being disposed at the end of the robotic arm.

[0062] Specifically, force-controlled robots use multi-dimensional force sensors to sense the contact force between the robotic arm's end effector and the workpiece. This allows the robot to adjust its movements based on force feedback, achieving precise assembly and preventing damage to the workpiece. Multi-dimensional force sensors help force-controlled robots accurately perceive the force and torque when grasping objects, thereby adjusting the grasping force and posture to ensure stable grasping of objects of different shapes and weights.

[0063] Force-controlled robots based on this multi-dimensional force sensor can improve modularity, thereby enhancing assemblability, interchangeability, and reducing costs.

[0064] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A multidimensional force sensor, characterized in that, include: A housing, wherein the housing has an internal cavity; A module assembly (100) is disposed within the receiving cavity. The module assembly (100) includes an elastic element (110), a detection bridge (120), and a circuit board (130). The circuit board (130) is used to convert the electrical signal of the detection bridge (120) into a digital signal. Both the detection bridge (120) and the circuit board (130) are connected to the elastic element (110). The module assembly (100) can be disassembled and interchanged as a single unit.

2. The multidimensional force sensor according to claim 1, characterized in that, The housing includes an outer shell (200) and a base (300). The elastic element (110) is provided with a first connecting part (111) and a second connecting part (112). The elastic element (110) is detachably connected to the base (300) through the first connecting part (111), and the elastic element (110) is connected to the outer shell (200) through the second connecting part (112).

3. The multidimensional force sensor according to claim 2, characterized in that, The first connecting part (111) is a connecting block located near the center of the elastic element (110). The connecting block has a plurality of first connecting holes (113), and fasteners pass through the first connecting holes (113) to connect with the base (300).

4. The multidimensional force sensor according to claim 2, characterized in that, The second connecting part (112) is disposed near the edge of the elastic element (110), and a plurality of second connecting holes (114) are provided on the second connecting part (112) along the circumferential direction. Fasteners pass through the second connecting holes (114) and are connected to the housing (200).

5. The multidimensional force sensor according to claim 2, characterized in that, A sealing ring (400) is sandwiched between the base (300) and the outer shell (200), and the base (300) and the outer shell (200) clamp the sealing ring (400).

6. The multidimensional force sensor according to claim 2, characterized in that, The elastic element (110) includes a main body (115), and the outer shell (200) is sleeved on the main body (115) with the inner wall of the outer shell (200) fitting against the outer wall of the main body (115).

7. The multidimensional force sensor according to claim 1, characterized in that, The detection bridge (120) is provided with a plurality of first mounting holes (121), and the first connector (122) can pass through the first mounting holes (121) and connect to the elastic element (110).

8. The multidimensional force sensor according to claim 7, characterized in that, The circuit board (130) is provided with a second mounting hole (131). The circuit board (130) and the detection bridge (120) are opposite to each other and spaced apart. The second connector (132) can pass through the second mounting hole (131) to connect with the first connector (122) or to the elastic element (110).

9. The multidimensional force sensor according to any one of claims 1-8, characterized in that, The elastic element (110) is provided with multiple strain beams (116), and the detection bridge (120) includes multiple sets of strain gauges attached to the strain beams (116).

10. A force-controlled robot, characterized in that, It includes a robotic arm and a multidimensional force sensor as described in any one of claims 1-9, wherein the multidimensional force sensor is disposed at the end of the robotic arm.

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