Tactile sensing device based on micro electro mechanical system and robot

Abstract

The invention provides a touch sensing device based on a micro electro mechanical system and a robot, and the touch sensing device comprises a housing which is provided with a recessed part; the circuit board is arranged in the concave part of the shell, and the shape of the circuit board is matched with that of the concave part; the plurality of MEMS pressure sensors are arrayed on the circuit board; and the flexible material is filled in the concave part and the pressure sensing hole of the MEMS pressure sensor, and covers the circuit board and the MEMS pressure sensor. According to the touch sensing device based on the micro electro mechanical system and the robot provided by the invention, precise response can be made to fine change of force.

Description

Technical Field

[0001] The present invention relates to the field of sensing, and particularly to a tactile sensing device and a robot based on a microelectromechanical system. Background Art

[0002] Touch is one of the important perception means for humans to interact with the external environment. It shows extremely high application value in many fields, such as robotics, virtual reality (VR), and medical devices. Especially in robotics, the tactile perception ability is crucial for robots to perform precise grasping and operating tasks in complex environments. Through tactile sensors, the dexterous hands of robots can achieve stable grasping and fine operation of different objects, such as adjusting the grasping force according to the roughness and softness of the object surface. In the medical field, tactile sensors are also applied to rehabilitation devices to design more personalized rehabilitation training programs by monitoring the pressure changes of patients' contact, thereby improving the treatment effect.

[0003] However, the current tactile sensor technology on the market still faces several challenges. For example, although piezoelectric tactile sensors perform well in dynamic response, they are difficult to sense static forces, which limits their use in some applications. And piezoresistive and capacitive tactile sensors constructed with discrete components, although the technology is relatively mature and widely used, their integration degree is low, and coupled with the limitations in sensitivity and resolution, they cannot accurately respond to subtle changes in force. Therefore, there is room for improvement. Summary of the Invention

[0004] The purpose of the present invention is to provide a tactile sensing device and a robot based on a microelectromechanical system, which can accurately respond to subtle changes in force.

[0005] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0006] The present invention provides a tactile sensing device based on a microelectromechanical system, including:

[0007] A housing, on which a recessed portion is formed;

[0008] A circuit board, the circuit board is installed in the recessed portion of the housing, and the shape of the circuit board matches that of the recessed portion;

[0009] A plurality of MEMS pressure sensors, arrayed on the circuit board; and

[0010] A flexible material, filling the recessed portion, the pressure sensing holes of the MEMS pressure sensors, and covering the circuit board and the MEMS pressure sensors.

[0011] In an embodiment of the present invention, it further includes:

[0012] A signal aggregation unit, installed on the circuit board and electrically connected to the output end of the MEMS pressure sensor, for aggregating the output signals of all the MEMS pressure sensors; and

[0013] An interface unit, installed on the circuit board and electrically connected to the output end of the signal aggregation unit, for receiving the output signals.

[0014] In an embodiment of the present invention, the interface unit at least includes a data interface and a power interface. The data interface is electrically connected to an external data line, the power interface is electrically connected to an external power supply line, and the data interface is used to transmit the received output signals to the external data line.

[0015] In an embodiment of the present invention, the aperture of the pressure sensing hole of the MEMS pressure sensor is greater than or equal to 0.5 mm.

[0016] In an embodiment of the present invention, the distance between two adjacent MEMS pressure sensors is in the range of 3 mm to 12 mm.

[0017] In an embodiment of the present invention, the flexible material protrudes or is flush with one side of the housing.

[0018] In an embodiment of the present invention, the flexible material is a flexible silicone material.

[0019] In an embodiment of the present invention, the sensing area formed by multiple MEMS pressure sensors covers the stress area on one side of the housing.

[0020] In an embodiment of the present invention, when pressure is applied to the sensing area, the output pressure data p of a certain point sensed by the tactile sensing device on the sensing area mn , is expressed as: Where X mn represents the coordinates of a certain point in the sensing area, N represents the number of MEMS pressure sensors, λ i represents the sensed pressure data of the i-th MEMS pressure sensor, represents the initial pressure data of the i-th MEMS pressure sensor, represents the Gaussian kernel function, represents the coordinates of the MEMS pressure sensor, represents the distance between a certain point in the sensing area and the i-th MEMS pressure sensor.

[0021] The present invention also provides a robot, including the tactile sensing device based on the microelectromechanical system.

[0022] As described above, the present invention provides a tactile sensing device and a robot based on microelectromechanical systems, which can accurately detect minute pressure changes and provide fine pressure distribution data; are applicable to a variety of measurement occasions from slight contact to large pressure; use off-the-shelf MEMS pressure sensors, with low cost and easy availability of raw materials; enable the traditional MEMS pressure sensors to have the ability to measure physical contact pressure through transformation; can provide detailed pressure distribution data in a two-dimensional space and are applicable to the application of multi-point pressure monitoring.

[0023] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic diagram of a tactile sensing device based on microelectromechanical systems in an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of a circuit board and other electronic components in an embodiment of the present invention;

[0027] Figure 3 It is a distribution diagram of initial pressure data of an induction area without external pressure applied in an embodiment of the present invention;

[0028] Figure 4 It is a distribution diagram of output pressure data of an induction area with external pressure applied in an embodiment of the present invention.

[0029] In the figure: 10, housing; 11, recessed part;

[0030] 20, circuit board;

[0031] 30, MEMS pressure sensor;

[0032] 40, signal aggregation unit;

[0033] 50, interface unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0035] Please refer to Figure 1 , the present invention discloses a tactile sensing device based on a microelectromechanical system. The tactile sensing device can be applied to devices such as robots and medical devices to accurately respond to subtle changes in force. The tactile sensing device may include a housing 10, a circuit board 20, a MEMS pressure sensor 30, a signal aggregation unit 40, an interface unit 50, etc.

[0036] Please refer to Figure 1 , in some embodiments, the housing 10 can be an external protective shell or support structure of the tactile sensing device, and its structure can be customized according to different application requirements. For example, if the tactile sensing device is installed on the finger of a robot, in order to enable the robot finger to grasp and feel objects more naturally and precisely, the housing 10 can be designed in a shape similar to a real finger. This can not only improve the flexibility of the robotic finger but also enhance its tactile perception ability, making it closer to the tactile experience of a human hand. Another example is in the medical field, such as a rehabilitation device used to monitor the muscle or joint pressure during a patient's recovery process. The housing 10 can be designed to fit the shape of a specific part of the human body to ensure that the sensor can accurately capture the force changes generated during the patient's movement, thereby providing personalized medical evaluation and rehabilitation guidance.

[0037] Please refer to Figure 1 , in some embodiments, a recess 11 can be formed on the housing 10 for mounting the circuit board 20. The circuit board 20 can be installed in the recess 11, and the shape of the circuit board 20 matches the shape of the recess 11 to ensure the stability and compactness of the installation. The recess 11 can be of any shape, and the specific shape depends on the outer shape of the circuit board 20 and the installation requirements.

[0038] In some embodiments, the circuit board 20 can be conveniently installed and removed in the recess 11 by a detachable connection method (such as a buckle, screw, etc.). The shape of the circuit board 20 matches the shape of the recess 11, and the circuit board 20 can be tightly embedded in the recess 11, reducing unnecessary gaps and improving the stability and compactness of the installation. For example, if the recess 11 is rectangular, then the circuit board 20 should also be rectangular to ensure a perfect fit between the two.

[0039] Please refer to Figure 1 and Figure 2, in some embodiments, multiple MEMS pressure sensors 30 can be arranged on the circuit board 20 according to a certain layout to form a two-dimensional sensor array. The sensing area formed by the sensor array can cover the force-bearing area on one side of the housing 10. The array design can improve the spatial resolution of the tactile sensing device, enabling it to more accurately sense forces at different positions. The circuit board 20 provides a platform for supporting and connecting multiple MEMS pressure sensors 30, ensuring the electrical connection and signal transmission of the MEMS pressure sensors 30.

[0040] Please refer to Figure 1 and Figure 2 , in some embodiments, the pressure sensing holes of the MEMS pressure sensors 30 should have a relatively large aperture (diameter greater than or equal to 0.5 mm) to expose the internal sensing device as much as possible. The pressure sensing hole refers to a small hole on the MEMS pressure sensor 30 for transmitting the externally applied pressure to the internal sensitive element. A larger aperture allows the internal sensing device of the sensor to come into contact with the externally applied pressure more fully, improving the sensitivity of the sensor. Through the larger aperture, it is ensured that the internal sensing device can more directly sense the changes in the external environment, thereby improving the accuracy and reliability of the measurement.

[0041] Please refer to Figure 1 and Figure 2 , in some embodiments, to ensure a wide force measurement range, the MEMS pressure sensors 30 should have a pressure measurement range of at least 120 KPa, so as to ensure that the MEMS pressure sensors 30 can accurately measure the pressure in different application scenarios (such as grasping objects of different hardness and weights).

[0042] Please refer to Figure 1 and Figure 2 , in some embodiments, the distance between two adjacent MEMS pressure sensors 30 should be between 3 mm and 12 mm. The setting of the spacing is to balance the density of the MEMS pressure sensors 30 and the feasibility of wiring. A spacing within the range of 3 mm to 12 mm can ensure that the sensor array operates at a sufficiently high spatial resolution, while avoiding complex wiring and manufacturing difficulties caused by too small a spacing. Too large a spacing will reduce the spatial resolution of the sensor array, possibly resulting in the sensor being unable to accurately sense the pressure changes in some areas.

[0043] Please refer to Figure 1 and Figure 2, in some embodiments, a flexible material is filled into the recess 11 on the housing 10 to ensure that the circuit board 20 and the MEMS pressure sensor 30 can be completely wrapped after installation. The flexible material also fills the pressure sensing holes on the MEMS pressure sensor 30, and these holes are used to transmit the externally applied pressure to the internal sensing device of the sensor. The flexible material covers the surfaces of the circuit board 20 and the MEMS pressure sensor 30 to ensure the sealing and protection of the entire device.

[0044] Please refer to Figure 1 and Figure 2 , in some embodiments, a flexible material can be poured into the pressure sensing holes of the MEMS pressure sensor 30, and the air bubbles generated during the molding process of the flexible material can be eliminated, so that the external force can be evenly transmitted to the surface of the MEMS pressure sensor 30. For example, a liquid flexible material can be poured into the pressure sensing holes of the MEMS pressure sensor 30 to ensure that the holes are completely filled. Subsequently, vacuum degassing or other methods are used to remove the air bubbles in the flexible material to prevent the air bubbles from affecting the transmission of force and the accuracy of measurement. By eliminating the air bubbles, it is ensured that the flexible material can evenly transmit the externally applied pressure to the surface of the MEMS pressure sensor 30, improving the reliability and accuracy of measurement. After the above steps are completed, wait for the flexible material to solidify naturally or fix it through specific drying and curing processes. This can ensure the stability and durability of the entire device during use. Among them, the thickness of the poured flexible material can be between 0.5 cm and 1.5 cm, for example, it can be 0.5 cm, 1 cm, 1.5 cm, etc.

[0045] Please refer to Figure 1 and Figure 2 , in some embodiments, the MEMS pressure sensor 30 has pressure sensing holes, and the pressure sensing holes can be used to construct the force transmission path required for stress measurement. Through the pressure sensing holes, the flexible material can form a continuous path, so that the external force can be evenly transmitted to the internal sensing device of the MEMS pressure sensor 30 to achieve accurate pressure measurement.

[0046] Please refer to Figure 1 and Figure 2 , in some embodiments, after the flexible material is filled and covered, its surface should be flush with one side of the recess 11 of the housing 10 or slightly protrude. Doing so can ensure that when the device presses an object, the flexible material can effectively transmit the force to the MEMS pressure sensor 30, rather than having the contact force blocked by the edge of the housing.

[0047] In some embodiments, the flexible material can be selected from various elastic flexible materials that can deform when subjected to an external force and return to their original state after the force is removed, such as flexible silicone materials. Specifically, the flexible material can be Ecoflex or PDMS, etc. Among them, Ecoflex is a semi-high elastic silicone material commonly used in fields such as soft robotics, biomedicine, and wearable devices. PDMS (polydimethylsiloxane) is a commonly used silicone elastomer material with excellent transparency, elasticity, chemical stability, and biocompatibility.

[0048] Please refer to Figure 1 and Figure 2 , in some embodiments, the signal aggregation unit 40 can be installed on the circuit board 20 and electrically connected to the output end of the MEMS pressure sensor 30 for aggregating the output signals of all the MEMS pressure sensors 30. The signal aggregation unit 40 can be a circuit module specifically used for collecting and aggregating the signals of multiple MEMS pressure sensors 30. The signal aggregation unit 40 is connected to the output end of each MEMS pressure sensor 30 through an electrical connection to collect the signals from each sensor. The signal aggregation unit 40 aggregates the output signals of multiple MEMS pressure sensors 30 together for subsequent processing and transmission.

[0049] Please refer to Figure 1 and Figure 2 , in some embodiments, the MEMS pressure sensor 30 can use the I2C interface (Inter-Integrated Circuit) for communication. The signal aggregation unit 40 can be a tca9548a chip. The tca9548a chip is a commonly used I2C bus multiplexer chip that can connect multiple I2C devices (such as MEMS pressure sensors 30) to an I2C bus, thereby reducing the I2C interface requirements.

[0050] Please refer to Figure 1 and Figure 2 , in some embodiments, the interface unit 50 can be installed on the circuit board 20 and electrically connected to the output end of the signal aggregation unit 40 for receiving the output signal. The interface unit 50 can be a circuit module specifically used for receiving and transmitting the aggregated signal. The interface unit 50 receives the aggregated signal from the signal aggregation unit 40 through an electrical connection. The interface unit 50 is responsible for further processing the aggregated signal or transmitting it to an external device.

[0051] In some embodiments, the interface unit 50 includes at least a data interface and a power interface. The data interface is electrically connected to an external data line, and the power interface is electrically connected to an external power supply line. Among them, the data interface can be used to connect to an external data line, and the data interface can be used to transmit the received output signal to an external system through the external data line. The power interface can be used to connect to an external power supply line, and the external system can provide necessary power support to the tactile sensing device through the external power supply line.

[0052] In some embodiments, when an external pressure is applied to the sensing area formed by the MEMS pressure sensor 30, the initial pressure data of each MEMS pressure sensor 30 can be measured first, that is, the initial pressure reading of the MEMS pressure sensor 30 when it is in standby after power-on. After applying the external pressure, the sensed pressure data of each MEMS pressure sensor 30 can be measured. Subsequently, the output pressure data of a certain point on the sensing area can be calculated by an interpolation method.

[0053] In some embodiments, when a pressure is applied to the sensing area, the output pressure data p of a certain point sensed by the tactile sensing device on the sensing area mn , is expressed as: Where X mn represents the coordinates of a certain point in the sensing area, X mn =(x m , y n ); N represents the number of MEMS pressure sensors; λ i represents the sensed pressure data of the i-th MEMS pressure sensor; represents the initial pressure data of the i-th MEMS pressure sensor; represents the coordinates of the MEMS pressure sensor, represents the distance between a certain point in the sensing area and the i-th MEMS pressure sensor; represents the Gaussian kernel function, ε = 1 / D, D represents the distance between two adjacent MEMS pressure sensors, and r represents

[0054] Please refer to Figure 3 and Figure 4 , in some embodiments, when an external pressure is applied to the sensing area, the output pressure data of all points on the sensing area can be represented in the form of a matrix, that is As Figure 3 shown, when no external pressure is applied, the initial pressure data of the sensing area is flat. As Figure 4 shown, after applying the external pressure, the greater the external pressure received by a certain point, the greater the deformation of that point.

[0055] In some embodiments, the present invention also discloses a robot, which can apply the above-mentioned tactile sensing device based on microelectromechanical systems to make precise responses to subtle changes in force.

[0056] It can be seen that in the above solution, it is possible to accurately detect minute pressure changes, provide fine pressure distribution data; be applicable to a variety of measurement occasions from slight contact to large pressure; use off-the-shelf MEMS pressure sensors, with low cost and easy availability of raw materials; by modifying traditional MEMS pressure sensors to enable them to measure physical contact pressure; be able to provide detailed pressure distribution data in a two-dimensional space and be applicable to applications of multi-point pressure monitoring.

[0057] The embodiments of the present invention disclosed above are only used to help explain the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A tactile sensing device based on a micro-electromechanical system, characterized in that: include: a housing having a recessed portion formed thereon; A circuit board, the circuit board is installed in the recessed portion of the housing, and the shape of the circuit board matches the recessed portion; A plurality of MEMS pressure sensors are arrayed on the circuit board; and a flexible material, which fills the recessed portion and the pressure sensing hole of the MEMS pressure sensor and covers the circuit board and the MEMS pressure sensor.

2. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: Also includes: a signal aggregation unit, mounted on the circuit board and electrically connected to the output end of the MEMS pressure sensor, for aggregating the output signals of all the MEMS pressure sensors; as well as The interface unit is installed on the circuit board and is electrically connected to the output end of the signal aggregation unit to receive the output signal.

3. The micro-electromechanical system-based tactile sensing device according to claim 2, characterized in that: The interface unit at least includes a data interface and a power interface, the data interface is electrically connected to an external data line, the power interface is electrically connected to an external power supply line, and the data interface is used to transmit the received output signal to the external data line.

4. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: The diameter of the pressure sensing hole of the MEMS pressure sensor is greater than or equal to 0.5 mm.

5. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: The distance between two adjacent MEMS pressure sensors is in the range of 3 mm to 12 mm.

6. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: The flexible material protrudes or lies flat on one side of the housing.

7. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: The flexible material is a flexible silicone material.

8. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: The sensing area formed by the multiple MEMS pressure sensors covers the force-bearing area on one side of the shell.

9. The micro-electromechanical system-based tactile sensing device according to claim 1, characterized in that: When pressure is applied to the sensing area, the tactile sensing device senses a certain point on the sensing area and outputs pressure data p mn , expressed as: Among them, X mn represents the coordinates of a point in the sensing area, N represents the number of MEMS pressure sensors, and λ i represents the sensing pressure data of the i-th MEMS pressure sensor, represents the initial pressure data of the i-th MEMS pressure sensor, represents the Gaussian kernel function, represents the coordinates of the MEMS pressure sensor, Represents the distance between a certain point in the sensing area and the i-th MEMS pressure sensor.

10. A robot, characterized in that: The invention comprises a micro-electromechanical system-based tactile sensing device as claimed in any one of claims 1 to 9.

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