Integrated multi-mode tactile perception dexterous finger and robot

Abstract

The invention relates to an integrated multi-mode tactile perception dexterous finger and a robot, and belongs to the technical field of robot sensing. Comprising a flexible printed circuit which comprises a Wheatstone bridge circuit, a switch chip, a microcontroller, a rigid sensing unit and a flexible triboelectric sensing unit electrode; the rigid sensing unit comprises a temperature and pressure sensing chip; the Wheatstone bridge circuit is connected with the switch chip, and the switch chip is connected with the microcontroller; the microcontroller is respectively connected with the sensing chip and the flexible friction electric sensing unit electrode; the dexterous finger shell comprises a first shell and a second shell; the first shell and the second shell are connected to form a containing cavity, and the flexible printed circuit is arranged in the containing cavity. And the flexible friction electric sensing unit friction layers are arranged on the surfaces of the first shell and the second shell and are connected with the rigid sensing units and the flexible friction electric sensing unit electrodes. The multi-mode touch sensing device has a multi-mode sensing function, can recognize various touch modes, adopts an integrated mode, and enhances reliability and sensing precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot sensing technology, in particular to an integrated multi-modal tactile sensing dexterous finger and robot. BACKGROUND

[0002] Tactile sensing is the core function of a dexterous hand for autonomous operation and complex grasping tasks. As a multi-finger, multi-degree-of-freedom end effector, the demand for tactile sensing of the dexterous hand is increasing with the development of robot technology. Tactile sensors, as the direct interaction medium between the dexterous hand and the target object, can provide key information such as the material type, pressure, and temperature of the contact position, laying the foundation for multi-finger coordinated operation. In the fields of industrial assembly, medical assistance, and human-computer interaction, accurate tactile sensing is of great significance for the fine operation of the dexterous hand.

[0003] However, existing tactile sensor technology has many shortcomings in the application of robot dexterous fingers. Traditional sensors are often limited to a single or a small number of modalities, and can only detect single parameters such as force or temperature. For example, force sensors based on strain gauges or capacitive principles can detect the size of the contact force, while temperature sensors based on thermistors can sense temperature changes. These sensors cannot simultaneously detect multi-parameter information such as three-dimensional force, temperature, material type, roughness, or slip state, making it difficult to meet the complex sensing needs of robots in dynamic and variable environments. In addition, existing sensors often use surface mounting methods, which are not only susceptible to external factors such as wear, humidity, and dust, resulting in low repeatability and reliability, but also increase the volume and complexity of the system due to the need for external signal processing circuits. Long signal paths can easily cause noise and crosstalk, further reducing sensing accuracy and limiting the motion flexibility and compact design of the finger.

[0004] Although related research attempts to improve sensing capability by increasing the number of sensors or optimizing the layout, these methods still do not solve the problem of multi-modal sensing and integrated integration. SUMMARY

[0005] To this end, the technical problem to be solved by the present application is to overcome the single function, narrow sensing range, limited integration method, and low sensing reliability of existing tactile sensors.

[0006] In a first aspect, to solve the above technical problems, the present application provides an integrated multi-modal tactile sensing dexterous finger, comprising: The flexible printed circuit comprises a Wheatstone bridge circuit, a switch chip, a microcontroller, a rigid sensing unit and a flexible triboelectric sensing unit electrode; the rigid sensing unit comprises a sensing chip; the Wheatstone bridge circuit is connected with the switch chip, and the switch chip is connected with the microcontroller; the microcontroller is connected with the sensing chip and the flexible triboelectric sensing unit electrode respectively; The dexterous finger shell comprises a first shell and a second shell; the first shell and the second shell are connected to form a containing cavity, and the flexible printed circuit is arranged in the containing cavity; a first notch is arranged on the first shell, and a second notch is arranged on the second shell, and the first notch and the second notch form an opening; The flexible triboelectric sensing unit friction layer is arranged on the outer surface of the first shell and the second shell; the flexible triboelectric sensing unit friction layer is connected with the rigid sensing unit and the flexible triboelectric sensing unit electrode through the opening.

[0007] In an embodiment of the present application, the rigid sensing unit further comprises a flexible force transmission layer and an encapsulation shell; the flexible force transmission layer is provided with a flexible force transmission cylinder on the side facing the encapsulation shell, the surface of the encapsulation shell facing the flexible force transmission layer is provided with a central through hole, and the flexible force transmission cylinder passes through the central through hole and is connected with the sensing chip.

[0008] In an embodiment of the present application, the side of the encapsulation shell away from the flexible force transmission layer is bottomless and connected with the flexible printed circuit board to form a cavity, and the sensing chip is arranged in the cavity.

[0009] In an embodiment of the present application, the flexible force transmission layer is connected with the flexible triboelectric sensing unit friction layer.

[0010] In an embodiment of the present application, the sensing chip comprises a temperature-sensitive resistance strip, a plurality of pressure-sensitive resistance strips, a plurality of straight-bridge type thin films and a plurality of chip electrodes; the pressure-sensitive resistance strips are arranged above the straight-bridge type thin films.

[0011] In an embodiment of the present application, the Wheatstone bridge circuit comprises a plurality of decoupling capacitors, a first operational amplifier and a second operational amplifier; the first operational amplifier is connected with the second operational amplifier; and the second operational amplifier is connected with at least one decoupling capacitor.

[0012] In an embodiment of the present application, the flexible printed circuit further comprises an external communication interface, one end of the external communication interface is connected with the microcontroller; and the external communication interface is arranged outside the dexterous finger shell.

[0013] In an embodiment of the present application, one end of the dexterous finger shell is provided with a bearing seat groove for bearing installation.

[0014] In one embodiment of the present application, the material of the flexible triboelectric sensing unit friction layer is a composite material of high electronegativity polytetrafluoroethylene powder and a polydimethylsiloxane solution.

[0015] In a second aspect, to solve the above technical problems, the present application provides a robot comprising the integrated multi-modal tactile perception dexterous finger described above.

[0016] The above technical solutions of the present application have the following beneficial effects compared with the prior art: (1) The integrated multi-modal tactile perception dexterous finger and robot described in the present application realizes accurate detection of multiple physical quantities such as temperature, pressure, and triboelectric charge by fusing rigid sensing units and flexible triboelectric sensing units, expands the application range, and improves the flexibility of operation. This rigid-flexible coupling design effectively overcomes the shortcomings of traditional flexible force sensors in consistency and stability. At the same time, the flexible triboelectric sensing unit on the surface of the finger can overcome the limitations of rigid sensors and achieve accurate identification of multiple tactile modalities.

[0017] (2) The integrated design of the sensing chip, flexible triboelectric sensing unit friction layer, and electrode in the present application not only makes the sensor structure more compact, but also ensures high sensitivity and accuracy. In addition, the design of the flexible printed circuit board integrates the switching chip, microcontroller, and Wheatstone bridge circuit. The mutual connection of these key components provides strong signal processing capability. The connection of the microcontroller with multiple sensing chips and flexible triboelectric sensing unit electrodes ensures accurate acquisition, amplification, and conversion of signals.

[0018] (3) The sensing chip and flexible triboelectric sensing unit electrode are both integrated in the flexible printed circuit board in the present application. Such modular design not only facilitates the upgrading of the system, but also eliminates external circuits. The flexible triboelectric sensing unit friction layer is located on the outer surface of the dexterous finger shell. This layout optimizes the interaction capability of the sensor with the external environment. The accommodating cavity formed by the first shell and the second shell provides internal space for the flexible printed circuit board. This design saves external space and facilitates the integration of the overall structure. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the content of the present application easier to be clearly understood, the following further describes the present application in detail according to specific embodiments of the present application and in conjunction with the accompanying drawings, in which: Figure 1 The structure diagram of a kind of integrated multi-modal tactile perception dexterous finger in preferred embodiment of the present application; Figure 2 The explosion schematic view of a kind of integrated multi-modal tactile perception dexterous finger in preferred embodiment of the present application; Figure 3 Structure diagram of rigid-flexible coupling multi-modal sensor in preferred embodiment of the present application; Figure 4 Structure diagram of silicon-based MEMS sensing unit in preferred embodiment of the present application; Figure 5 Structure diagram of silicon-based MEMS temperature and pressure sensing chip in preferred embodiment of the present application; Figure 6 Structure diagram of flexible triboelectric sensing unit in preferred embodiment of the present application; Figure 7 Partial structure diagram of FPC integrated circuit in preferred embodiment of the present application.

[0020] Explanation of reference signs in the drawings: 1, external communication interface; 2, bearing seat groove; 3, dexterous finger shell; 31, first shell; 32, second shell; 4, FPC integrated circuit; 5, flexible triboelectric sensing unit rubbing layer; 6, flexible triboelectric sensing unit electrode; 7, rigid sensing unit; 8, flexible force transmission layer; 9, packaging shell; 10, sensing chip; 11, flexible force transmission cylinder; 12, central through hole; 13, temperature-sensitive resistance strip; 14, pressure-sensitive resistance strip; 15, straight-bridge type thin film; 16, solder pad. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application. Embodiment one

[0022] Referring to Figures 1 to 2 the drawings, the embodiment of the present application provides an integrated multi-modal tactile perception dexterous finger, which comprises: a flexible printed circuit including a Wheatstone bridge circuit, a switch chip, a microcontroller, a rigid sensing unit 7 and a flexible triboelectric sensing unit electrode 6; the rigid sensing unit 7 includes a sensing chip 10; the Wheatstone bridge circuit is connected with the switch chip, and the switch chip is connected with the microcontroller; the microcontroller is connected with the sensing chip 10 and the flexible triboelectric sensing unit electrode 6 respectively; a dexterous finger shell 3 including a first shell 31 and a second shell 32; the first shell 31 and the second shell 32 are connected to form a containing cavity, and the flexible printed circuit is built-in in the containing cavity; a first gap is provided on the first shell 31, and a second gap is provided on the second shell 32, and the first gap and the second gap form an opening; a flexible triboelectric sensing unit rubbing layer 5 provided on the outer surface of the first shell 31 and the second shell 32; the flexible triboelectric sensing unit rubbing layer 5 is connected with the rigid sensing unit 7 and the flexible triboelectric sensing unit electrode 6 through the opening.

[0023] The embodiment of the present application provides an integrated multi-modal tactile perception dexterous finger. Through integration of a sensing chip in a rigid sensing unit and a flexible triboelectric sensing unit friction layer and an electrode, the whole sensor structure is more compact, while good sensitivity and accuracy are ensured. In addition, the design of the flexible printed circuit includes a switching chip, a microcontroller and a Wheatstone bridge circuit, and these components are connected to each other to provide strong signal processing capability for the dexterous finger. The connection of the microcontroller with the sensing chip and the flexible triboelectric sensing unit electrode realizes accurate acquisition, amplification and conversion of signals. The sensing chip and the flexible triboelectric sensing unit electrode are both integrated in the flexible printed circuit, and such a design not only eliminates external circuits, but also facilitates daily maintenance work. The flexible triboelectric sensing unit friction layer is arranged on the outer surface of the dexterous finger shell, and such a layout enables the sensor to better interact with the external environment. The accommodating cavity formed by the first shell and the second shell provides built-in space for the flexible printed circuit, and such a design saves external space and facilitates integration of the overall structure. The embodiment of the present application integrates key components in the dexterous finger shell, reduces the influence of the external environment on the performance of the sensor, and thus improves the stability and reliability during use. Such a design is suitable for various complex application scenarios and can meet the demand for high-precision and high-reliability sensors.

[0024] Specifically, the components of the dexterous finger include a rigid-flexible coupling multi-modal sensor, a flexible printed integrated circuit (FPC integrated circuit 4) and a dexterous finger shell 3. As shown in Figure 3 The rigid-flexible coupling multi-modal sensor includes a rigid sensing unit 7 and a flexible triboelectric sensing unit. The dexterous finger shell 3 includes a first shell 31 and a second shell 32, and the FPC integrated circuit 4 is provided with an external communication interface 1 and related electronic components. In order to improve the flexibility and maintainability of the dexterous finger, all components are designed to be detachable. Such a design not only facilitates daily maintenance of functional modules, but also facilitates future technical upgrading and component replacement, thereby prolonging the service life of the dexterous finger and improving its adaptability.

[0025] The embodiment of the present application can realize detection of various physical quantities such as temperature, pressure and triboelectric charge by combining the rigid sensing unit and the flexible triboelectric sensing unit, thereby expanding the application range and enhancing the flexibility. The design of the rigid-flexible coupling multi-modal sensor overcomes the shortcomings of poor consistency and stability of the flexible force sensor. The flexible triboelectric sensing unit can break through the limitations of the rigid sensor and realize recognition of various tactile modalities.

[0026] Specifically, refer to Figure 3As shown, the FPC integrated circuit 4 includes a plurality of rigid sensing units 7, each of which is internally integrated with a sensing chip 10. Taking a dual-chip layout as an example, two identical rigid sensing units can be used, which are respectively installed at the palm and fingertip positions of the dexterous finger. Such a layout can achieve differentiated perception of mechanics and temperature. In addition, such a dual-chip design of the palm and the fingertip can adapt to various application scenarios such as touch, pinch, and click, effectively overcoming the deficiencies of flexible force sensors in consistency and stability, thereby improving the performance and reliability of the sensor.

[0027] Further, in the embodiment of the present application, the rigid sensing unit 7 is preferably a silicon-based MEMS sensing unit 7. Correspondingly, the sensing chip 10 is preferably a silicon-based MEMS temperature and pressure sensing chip 10.

[0028] Further, referring to Figure 4 As shown, the core components of the silicon-based MEMS sensing unit 7 include a flexible force transmission layer 8, an encapsulation shell 9, and a silicon-based MEMS temperature and pressure sensing chip 10. Among them, the flexible force transmission layer 8 is provided with a flexible force transmission cylinder 11 on one side, and the surface of the encapsulation shell 9 is provided with a central through hole 12. The flexible force transmission layer 8 is preferably a rectangular thin layer structure, the flexible force transmission cylinder 11 is arranged on the side facing the encapsulation shell 9 and accurately matches the central through hole 12, and its function is to effectively transmit the force applied from the outside to the silicon-based MEMS temperature and pressure sensing chip 10. The structure of the encapsulation shell 9 adopts a hollow rectangle, one side facing the flexible force transmission layer 8 has a bottom, the central through hole 12 is arranged on this surface, and the other side is bottomless and fixed on the circuit board where the FPC integrated circuit 4 is located, forming a cavity capable of accommodating the silicon-based MEMS temperature and pressure sensing chip 10. The height of the cavity is not less than the height of the silicon-based MEMS temperature and pressure sensing chip 10, so as to ensure that the chip is fully protected. The central through hole 12 is coaxial with the central hole of the silicon-based MEMS temperature and pressure sensing chip 10, so that the flexible force transmission cylinder 11 can directly contact the silicon-based MEMS temperature and pressure sensing chip 10 through the central through hole 12, thereby realizing effective force transmission. In addition, the flexible force transmission layer 8 is in contact with the flexible triboelectric sensing unit friction layer 5.

[0029] Further, referring to Figure 5 As shown, the silicon-based MEMS temperature and pressure sensing chip 10 includes a temperature-sensitive resistance strip 13, a plurality of pressure-sensitive resistance strips 14, a plurality of straight-bridge type thin films 15, a plurality of chip electrodes, and other devices, wherein the pressure-sensitive resistance strips 14 are arranged above the straight-bridge type thin films 15. The silicon-based MEMS temperature and pressure sensing chip 10 is electrically connected to the FPC integrated circuit 4 through metal pins, and the surface thereof is provided with a plurality of solder pads 16 for detecting the resistance change of the temperature-sensitive resistance strip 13 and the resistance change of the pressure-sensitive resistance strip 14 (in Figure 5In the middle, S1 to S4 represent the resistance of the pressure-sensitive resistor strip 14). For example, the silicon-based MEMS temperature and pressure sensing chip 10 is provided with 10 pads 16, of which 2 pads 16 are used to detect the resistance change of the temperature-sensitive resistor strip 13, and 8 pads 16 are used to detect the resistance change of the pressure-sensitive resistor strip 14. The silicon-based MEMS temperature and pressure sensing chip 10 is uniformly distributed in a circular manner on the side away from the FPC integrated circuit board, and the temperature-sensitive resistor strip 13 and the hollow straight bridge type film 15 are arranged. Each straight bridge type film 15 is provided with two pressure-sensitive resistor strips 14. The structure of the hollow straight bridge type film 15 can sensitively capture slight deformation, and the resistance values of the pressure-sensitive resistor strips 14 and the temperature-sensitive resistor strip 13 accurately change with the pressure and temperature changes of the fingers. By analyzing the initial resistance value and the change value, the load and temperature information can be accurately obtained. In addition, the size of the silicon-based MEMS temperature and pressure sensing chip 10 can be set to 2mm x 2mm. The number of straight bridge type films 15 can be 4, and the number of pressure-sensitive resistor strips can be 8 (2x4).

[0030] Specifically, referring to FIG. 1, Figure 6 As shown in FIG. 1, the flexible triboelectric sensor unit includes a flexible triboelectric sensor unit rubbing layer 5 and a plurality of flexible triboelectric sensor unit electrodes 6. The flexible triboelectric sensor unit rubbing layer 5 is prepared by using a composite material of high electronegativity polytetrafluoroethylene (PTFE) powder and polydimethylsiloxane (PDMS) solution, and is fixed on the upper surface of the dexterous finger shell 3 by a potting process. The selection of such a composite material not only ensures that the rubbing layer has excellent triboelectric properties, but also endows it with good flexibility and durability, enabling it to adapt to various touch and pressure changes. Therefore, the flexible triboelectric sensor unit rubbing layer 5 on the surface of the finger can overcome the functional limitations of traditional rigid sensors and achieve accurate recognition of multiple haptic modalities.

[0031] Further, the rigid sensor unit 7 and the flexible triboelectric sensor unit electrode 6 are designed in a laminated integrated manner and are integrated in the FPC integrated circuit 4. Through the FPC integrated circuit 4, the resistance signal and the triboelectric signal are collected cooperatively to complete multi-modal tactile perception.

[0032] Further, the working principle of the flexible triboelectric sensor unit is as follows: through the triboelectric effect and the electrostatic induction principle, when the finger contacts with external objects, the flexible triboelectric sensor unit rubbing layer 5 generates a triboelectric signal, which is captured by the flexible triboelectric sensor unit electrode 6 on the FPC integrated circuit 4. The high electronegativity of the rubbing layer enables it to generate significant triboelectric signals when it comes into contact with various materials, supporting multi-modal perception functions.

[0033] Specifically, the FPC integrated circuit 4 includes an external communication interface 1, a switch chip, a microcontroller, a Wheatstone bridge circuit and related electronic components. Among them, the external communication interface 1 is used to realize signal transmission and power supply, one end of which is connected with the microcontroller, and the other end is connected with the external device; the switch chip is used to control the selection of the signal path, realizing the switching of different sensor signals; the microcontroller is used to process and analyze the collected signals, and transmit data through the external communication interface 1; the Wheatstone bridge circuit is used to convert the resistance change of the sensor into a voltage signal, which is convenient for subsequent processing.

[0034] In the embodiment of the application, the external communication interface 1 is preferably of 7pin x 0.5mm specification. The FPC integrated circuit 4 cooperates with the electrodes of the silicon-based MEMS sensor chip 10 and the flexible triboelectric sensing unit electrode 6 to realize the recognition of multiple tactile modalities. The switch chip is preferably MAX4617EUE, which has low on-resistance and fast switching capability to ensure the efficiency and real-time performance of signal transmission, and low power consumption and high stability to ensure reliable operation in complex environments. The microcontroller is preferably PIC16F1825, which has rich peripheral interfaces and powerful processing capability, can efficiently perform complex signal processing tasks, and has low power consumption design and friendly development environment to further improve the overall performance and development efficiency of the dexterous finger.

[0035] Further, as shown in Figure 7 In the Wheatstone bridge circuit, power is supplied through VCC, and the reference point of the circuit is formed through grounding (GND). In order to ensure the stability of the power supply and reduce noise, a plurality of decoupling capacitors (such as C1, C2, C3, and C4), a first operational amplifier and a second operational amplifier are included in the circuit. The first operational amplifier is connected with the second operational amplifier; the second operational amplifier is connected with at least one decoupling capacitor (such as C3). In the embodiment of the application, the first operational amplifier is preferably OP07, and the second operational amplifier is preferably AD620.

[0036] Further, the output of the operational amplifier OP07 is connected to the ground through the resistor R7, forming a voltage follower configuration, thereby providing a stable reference voltage for the operational amplifier AD620. The operational amplifier AD620 is configured as a differential amplifier for amplifying the sensing unit signal selected by the analog switch. In addition, the power supply pins of all operational amplifiers are connected to the circuit power supply to ensure their normal work.

[0037] Further, a plurality of resistors (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11) are also included in the circuit for functions such as voltage division, current limiting, biasing, and decoupling, to ensure the stability of the circuit and the accuracy of the signal. Among them, resistors R1 and R2 are connected to form a voltage dividing circuit for outputting a specified stable voltage; resistors R6 and R7 also form a voltage dividing circuit, also for outputting a specified stable voltage. Resistors R8, R9, R10, and R11 are used for subsequent signal conditioning. Specifically, resistors R8, R10, and R11 are connected in series as reference resistors for adjusting the input voltage of operational amplifier AD620; while resistor R9 is used to adjust the amplification factor of operational amplifier AD620. The ultimate goal of these adjustments is to make the output voltage of AD620 after amplification fall within the acceptable range of the single-chip microcomputer.

[0038] For Figure 7 , it should be noted that wires marked with the same symbol in the figure indicate that they are connected to each other. For example, Figure 7 , the wire marked "R8 1" on the left side of resistor R11, and the wire marked "R8 1" below resistor R8, indicate that resistor R11 is connected to resistor R8. For another example, the MAX4617EUE switch chip is marked with C1, C2, C3 (not indicating capacitor symbols here), and the PIC16F1825 microcontroller is also marked with C1, C2, C3, indicating that the corresponding marks are connected to each other. The purpose of this marking method is to simplify the circuit diagram and reduce visual complexity, making the connection relationship of the circuit clearer and more explicit.

[0039] The above Wheatstone bridge circuit is designed to accurately control the analog switch through the microcontroller, select and amplify different input signals, and then output the processed signals to the microcontroller for further analysis and processing. This structure not only improves the flexibility of signal processing, but also enhances the overall stability and reliability.

[0040] Specifically, referring to Figure 7 , the working principle of FPC integrated circuit 4 is described with 2 identical rigid sensing units 7, i.e. dual-chip layout, as an example. The specific principle is as follows: the X0-X7 pins of the switch chip are connected to the resistors S1-S8 of the silicon-based MEMS sensor chip 10 respectively. The A, B, C control pins of the switch chip are connected to the RC0, RC1, RC2 pins of the microcontroller to realize control of the switch chip. It should be noted that Figure 5As shown, each silicon-based MEMS sensor chip 10 contains resistors S1 to S4. To more clearly distinguish the resistors on the two sensor chips, the resistors S1 to S4 on the second silicon-based MEMS sensor chip are labeled as S5 to S8, respectively. This labeling method helps avoid confusion when describing and analyzing the circuit, ensuring that each resistor can be accurately identified and referenced. The microcontroller selects the signal input channel (X0-X7) of any one of the resistors S1-S8 by controlling the level state of the A, B, C pins of the switch chip. The selected resistor signal is sent to the designed Wheatstone bridge circuit through the common output X of the switch chip, and after bridge processing, the resistance change is converted into a voltage difference, and the final output signal is connected to the RC3 pin of the microcontroller. Through signal operation amplification, the pressure resistance information change of the 8 straight bridge arrays can generate three-dimensional force information. Further, the FPC integrated circuit 4 part extends to the outside of the finger, leaving only 7 pins with a pitch of 0.5 mm, which are VCC, GND, RA0, RA1, RA3, RX, and TX. Among them, VCC and GND are used for power supply; RA0, RA1, and RA3 pins are used for programming the PIC16F1825 microcontroller through the ICSP interface; RX and TX pins are used for serial communication with the outside world. In addition, the flexible triboelectric sensor unit electrode 6 is directly connected to the RA2 pin of the microcontroller. When the flexible triboelectric sensor unit rubbing layer 5 (i.e. the surface of the dexterous finger) comes into contact with an object, the triboelectric signal generated is transmitted to the single-chip microcomputer through the electrode for processing and real-time output of the triboelectric signal.

[0041] In particular, with reference to Figure 1 As shown, the surface shape of the dexterous finger shell 3 is set as an arc structure to better simulate the natural bending shape of the human finger. The flexible triboelectric sensor unit rubbing layer 5 is ingeniously arranged on the outer arc surface, thereby ensuring that the sensor can flexibly interact with the contact surface and achieve efficient triboelectric charge induction. The first shell 31 and the second shell 32 are respectively provided with notches, and when the first shell 31 and the second shell 32 are spliced left and right, the two notches together form an opening, which can expose part of the elements (such as the flexible force transmission layer 8, the flexible triboelectric sensor unit electrode 6, etc.) of the FPC integrated circuit 4. Through the opening, the flexible force transmission layer 8 can be in contact with the flexible triboelectric sensor unit rubbing layer 5.

[0042] Further, the dexterous finger shell 3 is provided with a bearing seat groove 2 at one end for installing a bearing to realize reliable connection of the finger with the mechanical structure. As shown in Figure 2 As shown, the first shell 31 and the second shell 32 are respectively provided with a half structure of the bearing seat groove 2 at the same end, and when the two shells are spliced, a complete bearing seat groove 2 can be formed.

[0043] Specifically, the assembly steps of the dexterous finger components are as follows: first, the silicon-based MEMS sensing unit 7 and related electronic components are integrated on the FPC integrated circuit 4. Then, the FPC integrated circuit 4 is folded and embedded in the dexterous finger shell 3. Figure 2 The state of the FPC integrated circuit 4 before folding is shown, Figure 3 The state of the FPC integrated circuit 4 after folding is shown). During embedding, the flexible force transmission layer 8 and the flexible triboelectric sensing unit electrode 6 are tightly attached to the corresponding notch surfaces of the first shell 31 and the second shell 32 on both sides of the circuit board, and are fixed by special adhesive. In addition, only a section of the 7pinx0.5mm external communication interface 1 extends to the outside of the dexterous finger shell 3 for signal transmission and power supply. The remaining components are completely integrated inside the finger. After assembly, the PTFE / PDMS composite solution is poured into the opening part of the dexterous finger shell 3, and after curing, a stable flexible triboelectric sensing unit rubbing layer 5 is formed, realizing the final packaging of the dexterous finger. In addition, through the bearing seat groove 2, the dexterous finger can realize fast and reliable modular connection with other mechanical structures.

[0044] The embodiment of the present application embeds the sensor and the circuit inside the finger, shielding external interference (such as humidity and dust), improving reliability and wear resistance. The surface has zero occupation, allowing more complex driving structures (such as multi-joint tendon) to be integrated, enhancing dexterity. At the same time, the shorter signal path reduces noise interference and improves data accuracy. The size of the finger is only 2cmx1cmx1.5cm, close to the human finger, and the silicon-based MEMS temperature and pressure sensing chip 10 is only 2mmx2mm, supporting modular adaptation to different platforms.

[0045] Specifically, the dexterous finger described in the embodiment of the present application has the functions of interacting with objects, three-dimensional force detection, temperature detection, proximity detection, material type detection, roughness detection, slip state detection and circuit detection. The working principle of the above functions is as follows: When the dexterous finger interacts with the object: through the rigid-flexible coupling synergy of the silicon-based MEMS temperature and pressure chip 10 and the flexible triboelectric sensing unit, high-precision detection of various physical parameters is realized.

[0046] Three-dimensional force detection principle: The silicon-based MEMS temperature and pressure sensing chip 10 realizes the detection of three-dimensional force (X, Y, Z direction) through its internal straight bridge structure. Each silicon-based MEMS temperature and pressure sensing chip 10 contains four straight bridges, and each straight bridge is integrated with a piezoresistive element. When an external force acts on the dexterous finger, the force is transmitted to the straight bridge through the flexible force transmission layer 8, causing it to deform. The packaging shell 9 can reduce the force on the silicon-based MEMS temperature and pressure sensing chip 10, thereby protecting the fragile silicon-based bridge structure. Under normal load, the piezoresistive straight bridges bend synchronously, and the resistance equivalent shifts. Extracting the center value of the shift can estimate the normal force. When subjected to lateral load, the flexible force transmission layer 8 causes the central column to twist and rotate slightly, and the two piezoresistive bridges on the force application axis generate unequal deformation and resistance shift due to the difference in force; at the same time, the two bridges perpendicular to the axis exhibit consistent morphological changes and equivalent resistance fluctuations. Based on the differential signals generated by the piezoresistive bridges on the force application axis, combined with the consistent signals in the perpendicular direction, the three-dimensional resultant force (normal force and tangential force) is finally calculated and measured. The silicon-based MEMS sensor double chips 10 in the finger pulp and the fingertip have clear division of labor. The finger pulp is suitable for detecting the overall force during grasping, while the fingertip is better at sensing fine pressing or local contact mechanical information. This distributed design improves the comprehensiveness of the dexterous finger's force perception.

[0047] Temperature detection principle: The silicon-based MEMS temperature and pressure sensing chip 10 is built-in with a temperature-sensitive resistance strip (i.e. temperature-sensitive resistance strip 13), whose resistance value adjusts with the change of environmental temperature according to thermal effect. When the finger contacts an object, the resistance strip senses the temperature change of the contact area and generates a corresponding electrical signal. This signal, after being processed by the microcontroller, can output real-time temperature data of the contact point. The double-point detection of the finger pulp and the fingertip ensures the spatial coverage and reliability of the temperature information.

[0048] Proximity detection principle: The flexible triboelectric sensing unit friction layer 5 uses high electronegativity PTFE material and works based on single-electrode nano-friction sensitive mechanism. When an object approaches the surface of the finger, even if no direct contact occurs, the electrostatic field coupling between the object and the PTFE will cause a change in the charge distribution, resulting in a weak voltage signal. The electrode layer of the sensor captures this change, and after circuit amplification and filtering processing, a signal inversely proportional to the distance of the object is generated, realizing non-contact proximity detection.

[0049] Material type detection principle: Different materials have different electron cloud states, resulting in different time-domain peak values and shapes of the triboelectric signals generated by the flexible triboelectric sensing unit. When the PTFE material on the surface of the dexterous finger comes into contact with the surface of an object and then separates, it will generate a unique triboelectric signal. By analyzing these signal characteristics, the material type of the object can be distinguished, such as metal, plastic or wood.

[0050] Roughness detection principle: the roughness of the object surface affects the triboelectric signal amplitude of the flexible triboelectric sensing unit. The smaller the roughness, the larger the contact area, the more the charge accumulation, and the higher the signal amplitude. By calibrating the relationship between signal amplitude and roughness, the dexterous finger can quantitatively detect the roughness of the object surface.

[0051] Slip state detection principle: the triboelectric-piezoresistive signal dual-mode co-detection principle is adopted. When the object slips during the grasping process of the dexterous finger, the change of contact force will trigger the high-frequency vibration component in the triboelectric signal, which is manifested as a sharp change in signal amplitude, and the moment of slip event occurrence can be accurately captured. At the same time, the silicon-based MEMS temperature and pressure sensing chip 10 detects the pressure change during the grasping process of the dexterous finger. In the stable grasping stage, the resistance signal fluctuation amplitude collected by the silicon-based MEMS temperature and pressure sensing chip 10 is small; when the slip event occurs, due to the change of friction force, the grasping force will fluctuate greatly, and the resistance signal will show a clear change trend. Under the action of the two signal co-detection modes, when the dexterous finger contacts the object, the flexible triboelectric sensing unit determines the slip event start time window in real time through the surface charge change. If the slip is detected, the dexterous finger will analyze the piezoresistive force signal collected synchronously, and then realize the judgment of the slip state.

[0052] Circuit detection principle: the FPC integrated circuit 4 integrates the electrodes of the rigid sensing unit 7 and the flexible triboelectric sensing unit electrode 6. The circuit is built-in the finger, without external circuit. The core circuit uses MAX4617EUE switch chip, X0-X7 pins are connected to S1-S8, A, B, C pins are controlled by RC0-RC2 of PIC16F1825 microcontroller, select input channel, common output X is connected to Wheatstone bridge circuit, convert resistance change to voltage, output to RC3, generate three-dimensional force information after amplification. The flexible triboelectric sensing unit electrode 6 is connected to the microcontroller RA2, which processes the triboelectric signal when contacting the object. The external communication interface 1 of the FPC integrated circuit 4 has only 7 0.5mm pitch pins (VCC, GND, RA0, RA1, RA3, RX, TX), which supports program burning and serial communication, realizes compact and efficient signal processing.

[0053] Further, the multi-modal tactile sensor of the embodiment of the present application performs well in the practical application of the robot dexterous finger, covering multiple functions such as grasping, identification, navigation and fine operation. In the scene of grasping a water cup, when the dexterous finger contacts the surface of the water cup, the sensor detects the three-dimensional force and temperature state in real time; when the water cup becomes heavy after being filled with water, the dexterous finger identifies the sliding trend through the significant changes of the triboelectric and piezoresistive signals, and automatically adjusts the clamping force to ensure stable grasping. At the same time, the sensor can accurately identify the material of the water cup (such as metal, plastic or ceramic) through the unique triboelectric signal pattern generated by the PTFE when in contact, and distinguish the surface roughness through signal amplitude analysis, which is suitable for sorting tasks of different water cups. In a cluttered environment, the sensor uses the proximity function to detect the distance of the object through electrostatic field coupling, which assists the robot dexterous finger to realize obstacle avoidance and navigation. In addition, when performing fine operations such as assembly or surgical assistance, the sensor provides multi-modal data including three-dimensional force, temperature, material type, which helps the robot to realize accurate force control and environmental perception, significantly improving the operation precision and adaptability.

[0054] The dexterous finger provided by the embodiment of the present application simultaneously detects three-dimensional force, temperature, proximity, material type, roughness and slip state, surpasses the traditional single sensor, and changes from "perceiving a single signal" to "understanding a complex scene", thereby improving the operation precision and environmental adaptability of the dexterous finger. Further, the present application provides a broad prospect for the robot to more accurately understand the environment and human needs. Specifically, the present application can simultaneously detect three-dimensional force, temperature, proximity, material type, roughness and slip state, and breaks through the limitations of the traditional single sensor. In the design, the multi-modal works cooperatively in a rigid-flexible coupling manner: the silicon-based MEMS sensor double-chip at the position of the finger pulp and fingertip is responsible for three-dimensional force and temperature detection, and the flexible triboelectric sensing unit on the surface of the finger is based on the PTFE single electrode structure, and innovatively realizes the perception of material type, roughness and proximity. In addition, through the dual-mode co-detection method of triboelectric signal and piezoresistive signal, the system can accurately identify the slip state and its direction.

[0055] Further, the present application is an integrated embedded sensing finger. The core is to completely embed the sensor and its signal processing circuit inside the dexterous finger, and only connect with the outside through a 7-pin FPC interface, so as to realize a compact and efficient system architecture. In terms of circuit, the combination of MAX4617EUE switch chip and PIC16F1825 microcontroller supports efficient internal processing and output of multi-channel signals, and ensures the real-time and accuracy of the perception data. Embodiment two

[0056] The embodiment provides a robot, which comprises the integrated multi-modal tactile perception dexterous finger provided in the embodiment one.

[0057] Those skilled in the art will appreciate that embodiments of the application can be devised for a method, a system, or a computer program product. Accordingly, the present application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0058] The present application is described in reference to the flowchart illustrations and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0059] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0061] Obviously, the above-described embodiments are only examples and are not intended to limit the present application. Based on the above description, those skilled in the art can make other variations and modifications of the present application without departing from the present application. Neither requiring nor intending to limit the application to the exact forms of these embodiments, the application is therefore intended to cover all modifications and alternatives arising from the followings.

Claims

1. An integrated multimodal tactile sensing dexterous finger, characterized in that: include: A flexible printed circuit comprises a Wheatstone bridge circuit, a switch chip, a microcontroller, a rigid sensing unit, and electrodes of a flexible triboelectric sensing unit; the rigid sensing unit comprises a sensor chip; the Wheatstone bridge circuit is connected to the switch chip, which is connected to the microcontroller; and the microcontroller is respectively connected to the sensor chip and the electrodes of the flexible triboelectric sensing unit. The dexterous finger housing comprises a first housing and a second housing; the first housing and the second housing are connected to form a receiving cavity, and the flexible printed circuit is built into the receiving cavity; the first housing is provided with a first notch, the second housing is provided with a second notch, and the first notch and the second notch form an opening; A flexible triboelectric sensing unit friction layer is provided on the outer surfaces of the first and second housings; The friction layer of the flexible triboelectric sensing unit is connected to the rigid sensing unit and the flexible triboelectric sensing unit electrode through the opening.

2. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: The rigid sensing unit also includes a flexible force transmission layer and an encapsulation shell; the flexible force transmission layer is provided with a flexible force transmission cylinder on the side facing the encapsulation shell, and the surface of the encapsulation shell facing the flexible force transmission layer is provided with a central through hole, and the flexible force transmission cylinder passes through the central through hole to engage with the sensor chip.

3. The integrated multimodal tactile sensing dexterous finger according to claim 2, characterized in that: The side of the packaging shell away from the flexible force transmission layer is bottomless and is connected to the flexible printed circuit board to form a cavity, and the sensor chip is arranged in the cavity.

4. The integrated multimodal tactile sensing dexterous finger according to claim 2, characterized in that: The flexible force transmission layer is connected to the friction layer of the flexible triboelectric sensing unit.

5. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: The sensor chip includes a temperature-sensitive resistor strip, a plurality of pressure-sensitive resistor strips, a plurality of straight-bridge-type films, and a plurality of chip electrodes; the pressure-sensitive resistor strip is arranged above the straight-bridge-type films.

6. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: The Wheatstone bridge circuit includes a plurality of decoupling capacitors, a first operational amplifier and a second operational amplifier; the first operational amplifier is connected to the second operational amplifier; and the second operational amplifier is connected to at least one of the decoupling capacitors.

7. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: The flexible printed circuit further comprises an external communication interface, one end of which is connected to the microcontroller; the external communication interface is arranged outside the housing of the dexterous finger.

8. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: A bearing seat groove is provided at one end of the dexterous finger housing for mounting a bearing.

9. The integrated multimodal tactile sensing dexterous finger according to claim 1, characterized in that: The material of the friction layer of the flexible triboelectric sensing unit is a composite material of highly electronegative polytetrafluoroethylene powder and polydimethylsiloxane solution.

10. A robot, characterized in that: A dexterous finger with integrated multimodal tactile perception comprising any one of claims 1 to 9.

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