Force tactile sensor, manipulator and robot

Abstract

The utility model discloses a force tactile sensor, a manipulator and a robot, the force tactile sensor comprises a circuit board, a piezoresistive sensor and a micromotor system pressure sensor, the circuit board is provided with a first board and a second board which are oppositely arranged along a first direction, and the first direction is the thickness direction of the circuit board; the piezoresistive sensor is arranged on the first board surface and is used for sensing the action range of normal acting force borne by the circuit board; and the micro-motor system pressure sensor is arranged on the second board surface and is used for detecting the magnitude and the position of the normal acting force borne by the circuit board. According to the application, comprehensive force tactile perception is realized by combining sensors of different principles, the magnitude and position of the normal acting force can be obtained, the contour of an object applying the normal acting force externally can be perceived, the perception precision is higher, and the anti-interference capability is strong.

Description

Technical Field

[0001] This utility model relates to the field of sensors, and in particular to a force-tactile sensor, a robotic arm, and a robot. Background Technology

[0002] Force and tactile sensors (such as capacitive sensors and microelectromechanical system pressure sensors) are key sensing elements that play an important role in robotics, human-computer interaction, education and research, medical equipment, and wearable devices. For example, robots can use force and tactile sensors to perceive physical contact with the outside world.

[0003] However, most force-tactile sensors on the market have limited functionality and cannot comprehensively and accurately measure external force. Therefore, it is necessary to design a force-tactile sensor with composite sensing capabilities. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a force-tactile sensor, a robotic arm, and a robot, which can not only detect the magnitude and location of the force but also perceive the outline of the external object exerting the force, thereby achieving accurate force measurement.

[0005] In a first aspect, embodiments of this application provide a force-tactile sensor, including a circuit board, a piezoresistive sensor, and a microelectromechanical system (MEMS) pressure sensor. The circuit board has a first surface and a second surface disposed opposite each other along a first direction, wherein the first direction is the thickness direction of the circuit board; the piezoresistive sensor is disposed on the first surface and is used to sense the range of the normal force acting on the circuit board; the MEMS pressure sensor is disposed on the second surface and is used to detect the magnitude and position of the normal force acting on the circuit board.

[0006] In some embodiments, the first plate surface includes a plurality of alternating conductive areas and a plurality of insulating areas; the piezoresistive sensor includes a diaphragm and a plurality of piezoresistive elements disposed on the diaphragm, wherein the normal projection portion of each piezoresistive element covers two adjacent conductive areas, wherein the normal projection refers to the projection along the first direction onto the first plate surface; when the normal force is applied to the piezoresistive element, the two conductive areas covered by the normal projection portion of the piezoresistive element are respectively electrically connected to the piezoresistive element.

[0007] In some embodiments, the edge of the diaphragm is bonded to the first plate surface, and a plurality of the piezoresistive elements are arranged in an array.

[0008] In some embodiments, the micro-motor system pressure sensor includes a first sensor, a second sensor, a third sensor, and a fourth sensor, and the circuit board is rectangular; wherein the first sensor and the second sensor are symmetrical about the perpendicular bisector of the long side of the circuit board, the third sensor and the fourth sensor are symmetrical about the perpendicular bisector of the long side of the circuit board, the second sensor and the third sensor are symmetrical about the perpendicular bisector of the short side of the circuit board, and the first sensor and the fourth sensor are symmetrical about the perpendicular bisector of the short side of the circuit board.

[0009] In some embodiments, the number of micro-motor system pressure sensors is multiple, and the multiple micro-motor system pressure sensors are arranged at circumferential intervals along the circuit board.

[0010] In some embodiments, the force sensor further includes a temperature sensor disposed on the second plate surface, the temperature sensor being used to detect ambient temperature or object temperature.

[0011] In some embodiments, the force sensor further includes a soft rubber component covering the piezoresistive sensor. The soft rubber component has a force-receiving surface and a limiting step. A first gap is provided between the force-receiving surface and the piezoresistive component, and the limiting step abuts against the diaphragm.

[0012] In some embodiments, the force sensor further includes a housing, the housing including a top plate and a surrounding plate, the top plate and the surrounding plate together forming a receiving cavity, the top plate having a through hole communicating with the receiving cavity; the circuit board being disposed in the receiving cavity and abutting against the housing, the soft rubber component passing through the through hole, wherein the limiting step abutting against the top plate and located within the receiving cavity, and the force-bearing surface protruding from the through hole and located outside the receiving cavity.

[0013] Secondly, embodiments of this application provide a robotic arm, including the aforementioned force-tactile sensor and a robotic arm body, wherein the force-tactile sensor is connected to the robotic arm body via the micro-motor system pressure sensor.

[0014] Thirdly, embodiments of this application provide a robot, including the aforementioned manipulator and a control unit, wherein the control unit is used to control the movement of the manipulator. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0016] Figure 1This is a perspective view of a force-tactile sensor according to one embodiment of this application;

[0017] Figure 2 yes Figure 1 Rear view;

[0018] Figure 3 yes Figure 2 A schematic diagram showing the result after cutting along the straight line PP;

[0019] Figure 4 yes Figure 1 Exploded view;

[0020] Figure 5 yes Figure 4 Exploded view of the middle section of the structure;

[0021] Figure 6 This is a schematic diagram of the assembly of the piezoresistive sensor and the circuit board;

[0022] In the diagram: 1. Force sensor; 2. Circuit board; 3. Piezoresistive sensor; 4. Micro-motor system pressure sensor; 5. Temperature sensor; 6. Housing; 7. Soft rubber component;

[0023] 201. First plate surface; 202. Second plate surface; 21. Conductive area;

[0024] 31. Diaphragm; 32. Piezoresistive element;

[0025] 61. Roof panel; 62. Enclosure panel;

[0026] 601, receiving cavity; 621, connecting hole; 611, through hole;

[0027] 71. Force-bearing surface; 72. Limiting step. Detailed Implementation

[0028] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "vertical," "horizontal," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, 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. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0030] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] like Figure 1-3 As shown, one embodiment of this application provides a force-tactile sensor 1, including a circuit board 2, a piezoresistive sensor 3, and a micro-electro-mechanical system (MEMS) pressure sensor 4. The circuit board 2 has a first plate surface 201 and a second plate surface 202 disposed opposite each other along a first direction Z. The piezoresistive sensor 3 is disposed on the first plate surface 201, and the MEMS pressure sensor 4 is disposed on the second plate surface 202. The piezoresistive sensor 3 is used to sense the range of the normal force acting on the circuit board 2, and the micro-electro-mechanical system pressure sensor 4 is used to detect the magnitude and position of the normal force acting on the circuit board 2.

[0032] Thus, by employing the force tactile sensor 1 of this application, not only can the magnitude and location of the normal force be obtained through the MEMS pressure sensor 4, but the range of action of the normal force applied to the circuit board 2 by the piezoresistive sensor 3 can also be sensed to perceive the outline of the object to which the normal force is applied. This results in higher sensing accuracy and stronger anti-interference capability. The piezoresistive sensor and the MEMS pressure sensor are arranged on both sides of the circuit board, enabling effective force transmission and accurate sensing.

[0033] It should be noted that the first direction mentioned above refers to the thickness direction of circuit board 2. Circuit board 2 is provided with several electrical components for detection, such as resistors, capacitors, or other components. The specific electrical components are selected and arranged according to the designed detection circuit. In this embodiment, in order to reduce the interference of the electrical components on the piezoresistive sensor 3 located on the first board surface 201, the electrical components are arranged on the second board surface 202 as much as possible.

[0034] Understandably, the shape of circuit board 2 can be designed as needed and is not limited to the shape shown in the accompanying drawings. For example, it can be a rectangle or a square, or a circle or other shapes. In this embodiment, the shape of circuit board 2 is a convex shape formed by two squares of different sizes.

[0035] In some embodiments, as Figure 4-6 As shown, the first plate surface 201 includes a plurality of alternating conductive areas 21 and a plurality of insulating areas. The piezoresistive sensor 3 includes a diaphragm 31 and a plurality of piezoresistive elements 32 disposed on the diaphragm 31. The normal projection portion of each piezoresistive element 32 covers two adjacent conductive areas 21, wherein the normal projection refers to the projection along the first direction on the first plate surface 201; when a normal force is applied to the piezoresistive element 32, the two conductive areas 21 covered by the normal projection portion of the piezoresistive element 32 are electrically connected to the piezoresistive element 32.

[0036] Please combine Figure 5 and Figure 6 When a normal force is applied to at least one piezoresistive element 32, the compressed piezoresistive element 32 will move along the first direction Z. Two adjacent conductive areas 21 located directly below the compressed piezoresistive element 32 will be electrically connected to it, thus forming a circuit under the action of the compressed piezoresistive element 32. The resistance at the piezoresistive element 32 will change, thereby achieving the purpose of detection. By utilizing the resistance change caused by multiple piezoresistive elements 32 being compressed, the range of action of the normal force applied to the circuit board 2 along the first direction can be sensed, thereby realizing the contour perception of the object to which the normal force is applied.

[0037] It is understandable that the piezoresistive sensor 3 senses the contour of an object by having contact points between the arrayed piezoresistive elements 32 and the external environment. Specifically, the number of piezoresistive elements 32 subjected to external force determines whether contact has occurred and measures the magnitude of the external force, while the position and relative displacement of the piezoresistive elements 32 subjected to external force determine the contour of the object.

[0038] In some embodiments, as Figure 5 and Figure 6 As shown, multiple piezoresistive elements 32 are arranged in an m×n array on the diaphragm 31 at equal intervals, and two adjacent conductive regions 21 are arranged below each piezoresistive element 32. When a normal force is applied to the multiple piezoresistive elements 32, the contour of the object to which the normal force is applied can be obtained based on the position of the multiple piezoresistive elements 32 under pressure, thus realizing the contour perception of the object.

[0039] It should be understood that the diaphragm 31 and the first plate surface 201 can be connected by adhesive bonding or other methods, and the specific connection method can be set as needed. In this embodiment, the edge of the diaphragm 31 is connected to the first plate surface 201 by adhesive bonding, which helps to improve the assembly efficiency between the piezoresistive sensor 3 and the circuit board 2.

[0040] In some embodiments, as Figure 2 and Figure 3As shown, at least one MEMS pressure sensor 4 is provided at each of the opposite ends of the circuit board 2 along a direction perpendicular to the first direction Z. That is, as Figure 2 As shown, the direction perpendicular to the first direction Z refers to along... Figure 2 As shown in the diagram, in either direction X or direction Y, the circuit board 2 has at least one MEMS pressure sensor 4 at each end of both directions X and / or Y. The MEMS pressure sensors 4 at both ends of directions X and / or Y can be on the same straight line or not, depending on the requirements. In this way, the applied normal force is distributed among multiple MEMS pressure sensors 4 using the circuit board 2. By combining the force distribution across multiple MEMS pressure sensors 4, the location of the force point on the circuit board 2 and the magnitude of the force can be analyzed. Furthermore, using multiple MEMS pressure sensors 4 for joint detection improves detection accuracy and reduces the influence of the external environment on the external force applied to the circuit board 2, thus enhancing detection precision.

[0041] It should be understood that if there are multiple MEMS pressure sensors 4, the multiple MEMS pressure sensors 4 are arranged circumferentially along the circuit board 2. The distance between the multiple MEMS pressure sensors 4 and the object to which the force tactile sensor 1 is to be installed should be as equal as possible, so as to ensure that the multiple MEMS pressure sensors 4 can be pressed simultaneously when a normal force is applied to the circuit board 2, so that the multiple MEMS pressure sensors 4 can perform detection together, which is beneficial to improving the detection results.

[0042] In some embodiments, as Figure 2 As shown, the circuit board 2 is rectangular in shape. The MEMS pressure sensor 4 includes a first sensor 41, a second sensor 42, a third sensor 43, and a fourth sensor 44. The first sensor 41 and the second sensor 42 are symmetrical about the perpendicular bisector P1 of the long side of the circuit board 2. The third sensor 43 and the fourth sensor 44 are symmetrical about the perpendicular bisector P1 of the long side of the circuit board 2. The second sensor 42 and the third sensor 43 are symmetrical about the perpendicular bisector P2 of the short side of the circuit board 2. The first sensor 41 and the fourth sensor 44 are symmetrical about the perpendicular bisector P2 of the short side of the circuit board 2.

[0043] In this embodiment, four MEMS pressure sensors 4 are located at the four corners of the second surface 202 of the circuit board 2. This increases the detection range and enables more accurate sensing of the normal force applied to the circuit board 2. For ease of understanding of the force sensor 1 in this application, Figure 2 The MEMS pressure sensor 4 shown in the figure is used as an example, but this does not mean that the number of MEMS pressure sensors 4 can only be the four shown in the figure. They can be any number, as long as they can detect the external pressure force.

[0044] When in use, the coordinate positions of the first sensor 41, the second sensor 42, the third sensor 43 and the fourth sensor 44 can be obtained in advance after calibration, which are (X1,Y1), (X2,Y2), (X3,Y3) and (X4,Y4) respectively.

[0045] Since the external force applied to circuit board 2 is a normal force perpendicular to circuit board 2, the torques on the surface of circuit board 2 are balanced. That is, the torques in the X and Y directions are balanced, thus the position coordinates of the touch point can be deduced, as follows:

[0046] Let the resultant force Fc = F1 + F2 + F3 + F4, where Fc is the external force, and F1, F2, F3 and F4 are the forces shared by the first sensor 41, the second sensor 42, the third sensor 43 and the fourth sensor 44, respectively. The magnitude of the resultant force Fc is the magnitude of the normal force applied to the circuit board 2.

[0047] Based on moment equilibrium, the position (Xc, Yc) of the resultant force Fc can be calculated as shown below:

[0048] The position of Fc in the direction X is: Xc = (F1*X1 + F2*X2 + F3*X3 + F4*X4) / Fc;

[0049] The position of Fc in the Y direction is: Yc = (F1*Y1 + F2*Y2 + F3*Y3 + F4*Y4) / Fc.

[0050] Thus, by detecting the force through four sensors, the position of the normal force acting on the circuit board 2 and the magnitude of the external force can be determined, thereby realizing the detection of the normal force acting on the force sensor 1.

[0051] In some embodiments, as Figure 2 As shown, the force tactile sensor 1 also includes a temperature sensor 5, which is located on the second plate 202 and is used to detect the ambient temperature or the temperature of an object.

[0052] Temperature sensor 5 is used to sense changes in external temperature, so as to compensate for the temperature drift of MEMS pressure sensor 4 and piezoresistive sensor 3 according to the external temperature. Temperature drift of the sensor refers to the phenomenon that the output value of the sensor may deviate from the actual value when the temperature changes. Adjusting the sensing of the sensor under different temperature conditions can reduce the impact of external temperature changes on force tactile sensor 1, significantly improve the measurement accuracy and stability of the sensor, and ensure the accuracy and reliability of the sensor.

[0053] In some embodiments, the force sensor 1 further includes a soft rubber component 7. The soft rubber component 7 covers the piezoresistive sensor 3, and includes a force-receiving surface 71 and a limiting step 72. A first gap is provided between the force-receiving surface 71 and the piezoresistive component 32, and the limiting step 72 abuts against the diaphragm 31.

[0054] The surface of the piezoresistive sensor 3 is covered with a layer of soft silicone material, which facilitates effective force transmission and accurate sensing. The first gap between the force-bearing surface 71 and the piezoresistive element 32 ensures that there is no preload (i.e., no interaction force) between the force-bearing surface 71 and the piezoresistive sensor 3, avoiding changes in resistance of the piezoresistive sensor 3 when it is not subjected to an externally applied normal force. This enables more sensitive contact and conduction under stress, which is beneficial for accurate force measurement.

[0055] In some embodiments, the force sensor 1 further includes a housing 6, which includes a top plate 61 and a surrounding plate 62. The top plate 61 and the surrounding plate 62 together form a receiving cavity 601. A through hole 611 is provided on the top plate 61, which communicates with the receiving cavity 601. A circuit board 2 is disposed within the receiving cavity 601 and abuts against the housing 6. A soft rubber component 7 passes through the through hole 611. A limiting step 72 abuts against the top plate 61 and is located within the receiving cavity 601. The limiting step 72 abuts against the diaphragm 31 so that the diaphragm 31 does not abut against the housing. At the same time, the limiting step 72 is not connected to the housing to ensure that the soft rubber component 7 is in a free state, so that the external force can be completely transmitted to the piezoresistive sensor 3 and the circuit board 2. The force-bearing surface 71 protrudes from the through hole 611 and is located outside the receiving cavity 601. Specifically, the soft rubber component 7 is enveloped and limited by the housing 6, and the soft rubber component 7 is not connected to the housing 6.

[0056] In some embodiments, please refer again Figure 4 The enclosure 62 has connection holes 621 on both sides, which are used to connect to the object on which the force sensor 1 is to be installed. The connection holes 621 can be complete circular holes or incomplete holes, depending on the requirements. In this embodiment, there are two connection holes 621 on each side of the enclosure 62. Having two connection holes 621 on each side facilitates the stable installation of the force sensor on the object. For example, the force sensor 1 can be installed on the finger of a robotic arm through the connection holes 621 on both sides.

[0057] Understandably, the housing 6 can be manufactured in one piece, such as through injection molding, die casting, or other methods. That is, the top plate 61 and the surrounding plate 62 are integrally connected, which improves the assembly efficiency of the force sensor 1. The housing 6 can be made of plastic or metal, depending on the deformation caused by the force and the range of the external force to be measured. If the deformation caused by the force is small, plastic can be chosen; if the deformation caused by the force is large, metal can be chosen.

[0058] The force-tactile sensor 1 provided in this application includes a circuit board 2, a piezoresistive sensor 3, and a MEMS pressure sensor 4. The circuit board 2 has a first surface 201 and a second surface 202 disposed opposite each other along a first direction Z. The piezoresistive sensor 3 is disposed on the first surface 201 and is used to sense the range of the normal force acting on the circuit board 2. The MEMS pressure sensor 4 is disposed on the second surface 202 and is used to detect the magnitude and position of the normal force acting on the circuit board 2. The force-tactile sensor 1 of this application achieves comprehensive force-tactile perception by combining sensors based on different principles. It can not only determine the magnitude and position of the normal force but also sense the outline of the object to which the normal force is applied, resulting in higher sensing accuracy and stronger anti-interference capability.

[0059] Another embodiment of this application provides a robotic arm, including the force sensor 1 in the above embodiment. The location of the force sensor 1 can be selected as needed. For example, the force sensor 1 can be located at the finger joints of the robotic arm, or at the palm of the robotic arm, or at other locations, as long as it is a location where force needs to be detected.

[0060] This application also provides a robot, including the robotic arm and control unit described in the above embodiments, wherein the control unit is used to control the movement of the robotic arm.

[0061] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A force-sensitive tactile sensor, characterized in that, include: A circuit board has a first surface and a second surface disposed opposite to each other along a first direction, wherein the first direction is the thickness direction of the circuit board; A piezoresistive sensor is disposed on the first board surface, and the piezoresistive sensor is used to sense the range of the normal force acting on the circuit board; A micro-motor system pressure sensor is disposed on the second plate surface. The micro-motor system pressure sensor is used to detect the magnitude and position of the normal force acting on the circuit board.

2. The force-tactile sensor according to claim 1, characterized in that, The first plate surface includes multiple conductive areas and multiple insulating areas arranged alternately; The piezoresistive sensor includes a diaphragm and a plurality of piezoresistive elements disposed on the diaphragm. The normal projection portion of each piezoresistive element covers two adjacent conductive regions, wherein the normal projection refers to the projection along the first direction onto the first plate surface. When the normal force is applied to the piezoresistive element, the two conductive areas covered by the normal projection portion of the piezoresistive element are electrically connected to the piezoresistive element.

3. The force-tactile sensor according to claim 2, characterized in that, The edge of the diaphragm is bonded to the first plate surface, and multiple piezoresistive elements are arranged in an array.

4. The force-tactile sensor according to claim 1, characterized in that, The micro-motor system pressure sensor includes a first sensor, a second sensor, a third sensor, and a fourth sensor, and the circuit board is rectangular in shape; wherein, The first sensor and the second sensor are symmetrical about the perpendicular bisector of the long side of the circuit board, the third sensor and the fourth sensor are symmetrical about the perpendicular bisector of the long side of the circuit board, the second sensor and the third sensor are symmetrical about the perpendicular bisector of the short side of the circuit board, and the first sensor and the fourth sensor are symmetrical about the perpendicular bisector of the short side of the circuit board.

5. The force-tactile sensor according to claim 1, characterized in that, The micro-motor system pressure sensor is a plurality of such sensors, which are arranged at intervals along the circumference of the circuit board.

6. The force-tactile sensor according to claim 1, characterized in that, Also includes: A temperature sensor is disposed on the second plate surface, and the temperature sensor is used to detect the ambient temperature or the temperature of an object.

7. The force-tactile sensor according to claim 2, characterized in that, Also includes: A soft rubber component is provided to cover the piezoresistive sensor. The soft rubber component has a force-bearing surface and a limiting step. A first gap is provided between the force-bearing surface and the piezoresistive component. The limiting step abuts against the diaphragm.

8. The force-tactile sensor according to claim 7, characterized in that, Also includes: The housing includes a top plate and a surrounding plate, which together form a receiving cavity. A through hole is provided on the top plate, and the through hole communicates with the receiving cavity. The circuit board is disposed in the receiving cavity and abuts against the housing, the soft rubber part passes through the through hole, wherein the limiting step abuts against the top plate and is located in the receiving cavity, and the force-bearing surface protrudes from the through hole and is located outside the receiving cavity.

9. A robotic arm, characterized in that, It includes a force-tactile sensor as described in any one of claims 1-8 and a robotic arm body, wherein the force-tactile sensor is connected to the robotic arm body via the micro-motor system pressure sensor.

10. A robot, characterized in that, It includes the robotic arm as described in claim 9 and a control unit, wherein the control unit is used to control the movement of the robotic arm.

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