A capacitive tactile handle based on multi-sensory system and its manufacturing method

Abstract

The present invention is a capacitive tactile handle based on a multi-sensory system and a manufacturing method thereof, comprising a cylindrical handle body, a capacitive array flexible pressure sensor wrapped on the outer surface of the handle body, a slit is provided on the outer surface of the handle body along the length direction of the handle body, and the area inside the handle body around the slit is partially hollowed out, the slit is connected to the internal hollowed-out area, and is used to place a connecting line fixed on the flexible pressure sensor; a tension pressure sensor for detecting the force along the vertical direction of the handle when a human hand grasps is installed at the top of the handle body, and an inertial measurement unit IMU is installed in the internal hollowed-out area of ​​the handle body. The tactile handle is equipped with three sensors, which can not only sense the force state of different areas of the palm in real time when grasping, but also dynamically update the hand movement state, thereby sensing the operator's intention in all directions.

Description

Technical Field

[0001] The present invention relates to the fields of pressure detection, medical rehabilitation and human-machine collaboration, and in particular to a capacitive tactile handle based on a multi-sensory system and a manufacturing method thereof. Background Art

[0002] The rapid development of intelligent robot technology has led to its gradual application in other fields besides traditional industry and manufacturing, and the application scenarios of human-machine collaboration are becoming more and more extensive. For people with accurate tactile perception and a complete tactile feedback system, studying their tactile system of grasping will be an important supplement and improvement to the perception of intention in human-machine interaction. At present, the main carrier of grasping is a six-dimensional force sensor, but it is expensive, generally costing several thousand or tens of thousands of yuan, and the grasping posture and related information obtained are lacking. Therefore, there is an urgent need for a simple, low-cost, high-precision device to perceive the grasping posture and movement trend of the human hand, and fully demonstrate the intention of the operator in human-machine collaboration.

[0003] The patent application publication number CN 110531863 A proposes a flexible tactile glove based on the supercapacitor sensing principle, which uses the array capacitor principle to sense the pressure distribution of the entire palm and fingers. The tactile glove needs to be worn by the operator, which is not convenient; the glove has no fixed carrier, and it is easy to damage the capacitor unit due to improper wearing and operation during use; a single product cannot adapt well to users with different hand sizes, and thus cannot fit perfectly with all areas of the palm, and it is easy to have problems such as lack of collected data and loss. Summary of the invention

[0004] In view of the shortcomings of the prior art, the problem to be solved by the present invention is to provide a capacitive tactile handle based on a multi-sensory system. The surface of the tactile handle is wrapped with a capacitive flexible pressure sensor, which adopts the principle of array capacitance and is equipped with a tension pressure sensor and an inertial measurement unit (IMU). When grasping, it can not only sense the force state of different areas of the palm in real time, but also dynamically update the hand movement state, thereby fully sensing the operator's intention.

[0005] The technical solution of the present invention to solve the technical problem is:

[0006] A capacitive tactile handle based on a multi-sensory system, comprising a cylindrical handle body and a capacitive array flexible pressure sensor wrapped on the outer surface of the handle body, characterized in that a slit is provided on the outer surface of the handle body along the length direction of the handle body, and a portion of the inner region of the handle body around the slit is hollowed out, the slit is connected to the inner hollowed-out region, and is used to place a connecting line fixed on the flexible pressure sensor; a tension and pressure sensor for detecting the force along the vertical direction of the handle when a human hand grasps it is installed at the top of the handle body, an inertial measurement unit IMU is installed in the inner hollowed-out region of the handle body, and the inertial measurement unit IMU is used to detect and reflect in real time the motion state of the handle body during the operator grasping the tactile handle, and the angular velocity and acceleration in three-dimensional space;

[0007] The tension and pressure sensor, inertial measurement unit IMU, and flexible pressure sensor are all connected to the signal acquisition device, and are connected to the host computer through a wireless transmission device to complete communication.

[0008] The present invention also protects a method for manufacturing a capacitive tactile handle based on a multi-sensory system, the steps of the method are:

[0009] (1) Preparation of electrode layer

[0010] The pure cotton twill cloth is cut into pieces of suitable size and ironed flat, and then placed and fixed on the screen printing table. The customized screen printing plate is placed on the twill cloth and separated from the twill cloth by a height of 1.5-2.5 cm. A graphene conductive silver paste with a silver content of 60% is poured on the screen printing plate, and a scraper is used to scrape until the conductive silver paste covers the entire pattern. This step is repeated 2-3 times, and the screen printing plate is lifted, and the printed cloth piece is removed and placed in an industrial oven until the conductive silver paste becomes dry and taken out; the conductive performance is measured with a multimeter, and the resistance value of a single electrode is 3-3.2 ohms, and the difference in the resistance value of any two electrodes does not exceed 0.2 ohms; and the upper and lower electrode layers are obtained respectively;

[0011] (2) Sensor wiring

[0012] Select one end of all parallel electrodes of the upper and lower electrode layers, cut the pure cotton twill cloth to a suitable length along the gap between adjacent electrodes, fix the electrodes and wires by pressing with copper sheets, and insulate the joints;

[0013] (3) Handle packaging

[0014] The electrodes of the upper and lower electrode layers are placed vertically to each other, and polyurethane sponge is used as the intermediate dielectric layer 10; the external packaging shielding layer 8 uses a vinyl acetate copolymer single-sided sponge tape, and a dust-free cloth is used as a buffer layer 12, and then the whole is wrapped on the printed cylindrical handle body 13, and the circuit part is concentrated along the gap of the handle body in the hollowed-out area inside the handle body, and the inertial measurement device IMU3 is placed at the lower position inside the handle body 13; a tension and pressure sensor is installed on the top of the handle body 13;

[0015] (4) Sensor calibration

[0016] The packaged handle is calibrated using a tactile sensor calibration experiment platform. The sensor unit is continuously loaded in the range of 0-60N by automatic pressurization. More than ten sensor units at different positions are randomly selected on the sensor for pressure loading experiments. The corresponding loading experiment numerical points of the sensor units at these more than ten different positions are fitted to ensure that the consistency characteristics of the capacitor unit composed of the upper and lower electrode layers are good.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. A gap is left on the outside of the handle, which is connected to the internal hollow area. It is used to place the connecting wire fixed on the flexible pressure sensor, which ensures the airtightness and continuity of the external flexible pressure sensor package to the greatest extent. The gap is very small, and the external sensor can be wrapped end to end to achieve tightness and continuity. All the wires are placed inside and led out from the bottom, which does not affect the grip, and meets the operator's needs for arbitrary grip from different angles and directions.

[0019] 2. The electrode layer of the flexible sensor is printed with graphene conductive silver paste with a silver content of 60% as the printing material, which has lower resistance. It is printed on pure cotton twill by screen printing, so that the width of each electrode and the gap between two electrodes can be guaranteed, the gap between the capacitor units is smaller, the capacitor units are more densely distributed, the resolution is improved, and the accuracy of the sensor is improved overall. The graphene conductive silver paste is printed on pure cotton twill, which is light overall, and because the silver paste is permeable, the electrode is not easy to fall off, the structure is stable, and the flexibility and service life of the sensor are improved.

[0020] 3. The flexible sensor is wrapped on the outer surface of the cylindrical handle, which is convenient for human grasping and suitable for operators with different grasping habits and grasping methods (such as left-hand grasping and right-hand grasping); when grasping, the contact between the entire palm surface and the outer side of the tactile handle is more complete. Because it is wrapped on the outside of the cylinder, the contact between the hand joints and the handle is more complete when grasping, which is better than other flat flexible sensors when pressed by hand, and can fully collect the overall grasping information of the entire hand and the force distribution between various parts of the palm.

[0021] 4. In the manufacturing method of the present invention, in terms of the production of the electrode layer, the electrode layer of the flexible tactile sensor is produced by screen printing. The 28 electrodes are evenly distributed, ensuring the width of the electrode and the gap between two adjacent electrodes. The capacitor units are dense and uniform, thereby improving the accuracy of the sensor. Secondly, the printing material uses graphene conductive silver paste with a silver content of 60%, which has a small resistance and effectively improves the conductivity. Finally, the base of the electrode layer uses pure cotton twill, which is light overall and low in cost. Since pure cotton fiber fabrics are permeable, the electrode adhesion is better and the structure is stable, which improves the flexibility and service life of the sensor.

[0022] The manufacturing method of the present invention is mainly to improve the electrode layer. The electrode layer is made by printing the conductive silver paste on the pure cotton twill cloth. Since the pure cotton twill cloth has the characteristics of looseness and porosity, the conductive silver paste can penetrate into the gaps of the cloth, and after drying, it forms a whole with the pure cotton twill cloth. The conductive effect of each electrode is not affected (the resistance value is not large), and the electrode layer is not easy to be damaged during use (friction will be generated), and each electrode will not break after bending or even folding at a large angle. The present invention changes the conventional use of colloidal materials as a substrate. In terms of the selection of the substrate, the use of pure cotton twill cloth is determined by evaluating the effect after a large number of experiments. For cloth with fine texture and thin thickness (about 1mm), the silver paste is not easy to penetrate, and the electrode will still break during use; for cloth with large pores, rough surface, and relatively thick thickness (about 3mm), the silver paste will be unevenly distributed, and the resistance value of each electrode cannot be guaranteed. The present invention overcomes the problems that the gap between electrodes cannot be guaranteed, the precision is insufficient, the conductive tape is prone to wrinkles when wrapping the sensor, and the flexibility is poor. When the electrical signal is led out, the wire is placed on the outer surface of the handle, and the array sensor cannot wrap the entire handle, resulting in the failure to collect grip data when grasping a part of the handle, which limits the operator's gripping direction and gripping posture.

[0023] 5. The tactile handle of the present invention is equipped with a tension and pressure sensor and an inertial measurement unit (IMU) to form a multi-sensing system. The flexible array sensor and tension and pressure sensor on the outer surface of the handle body are mainly responsible for detecting the operator's control intention and guiding the robot movement. The IMU provides real-time feedback on the current motion state of the machine, including speed, acceleration and position information, to provide feedback for the operator and the machine. The tension and pressure sensor and inertial IMU are relatively cheap, averaging only a few hundred yuan, which can significantly reduce the cost of the handle and can more comprehensively and fully perceive the operator's intention, making up for the defect of a single perception source of traditional tactile sensing devices. The data collected by the host computer is processed, expanding from the grasping posture of the human hand to the posture intention of the entire arm. It is a tactile sensor of a multi-sensing system.

[0024] 6. The tactile handle has a simple manufacturing process and low cost. It is suitable for people with different hand sizes and has promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the control structure of an embodiment of a capacitive tactile handle based on a multi-sensory system of the present invention.

[0026] Figure 2 It is a schematic diagram of the overall structure of an embodiment of a capacitive tactile handle based on a multi-sensory system of the present invention.

[0027] Figure 3 The figure is a schematic diagram of the structure of a capacitive array flexible pressure sensor according to an embodiment of the present invention.

[0028] Figure 4 The figure is a schematic diagram of the structure of an upper electrode plate according to an embodiment of the present invention.

[0029] Figure 5 The figure is a schematic diagram of the structure of the lower electrode plate according to an embodiment of the present invention.

[0030] Figure 6 This is a pressure distribution diagram of a human hand tightly grasping a tactile handle according to an embodiment of the present invention.

[0031] Figure 7 It is a performance curve diagram of a single capacitor of a tactile sensor according to an embodiment of the present invention.

[0032] Figure 8 It is a consistency curve diagram of a tactile sensing capacitor unit according to an embodiment of the present invention.

[0033] In the figure: 1. Tensile pressure sensor; 2. Capacitive array flexible pressure sensor; 3. Inertial measurement unit IMU; 4. Signal acquisition device; 5. Wireless transmission device; 6. Host computer; 7. Tactile handle and machine connection device; 8. External packaging shielding layer; 9. Upper electrode layer; 10. Dielectric layer; 11. Lower electrode layer; 12. Buffer layer; 13. Handle body; 14. Strip electrode. DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention are given below. The specific embodiments are only used to further illustrate the present invention in detail and do not limit the protection scope of the present application.

[0035] The present invention provides a capacitive tactile handle based on a multi-sensory system (hereinafter referred to as a tactile handle, see Figure 2), including a handle body 13, a tension and pressure sensor 1, a capacitor array flexible pressure sensor 2, an inertial measurement device 3, a signal acquisition device 4, a wireless transmission device 5, and a host computer 6; the capacitor array flexible pressure sensor 2 is wrapped on the outer surface of the handle body 13, and the tension and pressure sensor 1 and the inertial measurement device 3 are respectively fixed on the upper end and the inside of the handle body 13; the entire tactile handle (i.e., the capacitor array flexible pressure sensor, the tension and pressure sensor 1 and the inertial measurement device IMU3) is connected to the signal acquisition device 4, and data communication is completed with the host computer 6 through the wireless transmission device 5, the data is transmitted to the host computer 6, and the image of the distribution of the human hand gripping pressure is obtained in real time through the display of the host computer 6.

[0036] The handle body 13 is a cylindrical handle formed by 3D printing of PLA material, with a cylindrical diameter of 46mm, which is suitable for operators with most hand shapes to grasp. A 2mm gap is opened on the edge of the outer surface, and part of the internal area is hollowed out. The gap is connected to the internal hollowed-out area and is used to place the connecting wire fixed on the capacitor array flexible pressure sensor 2; the capacitor array flexible pressure sensor 2 is composed of five layers of planar structures stacked, which are, from the outside to the inside, an external packaging shielding layer 8, an upper electrode layer 9, a dielectric layer 10, a lower electrode layer 11 and a buffer layer 12: the upper electrode layer 9 and the lower electrode layer 11 have A and B respectively The electrodes are parallel and spaced apart in strips, wherein the upper and lower electrode layers are customized with appropriate silk-screen printing plates according to size requirements, and the electrode layers are prepared by silk-screen printing. The width of each electrode and the interval between adjacent electrodes are guaranteed. The electrode width of the upper electrode layer is 4mm, and the interval between two adjacent electrodes is 1mm. The electrode width of the lower electrode layer is 4mm, and the interval between two adjacent electrodes is 1.1mm. The handle has a diameter of 46mm, which can achieve complete wrapping. The upper and lower electrode layers are distributed vertically in space to form an array structure, constituting A×B capacitor units. Each electrode Each capacitive unit is a small capacitive sensor; the strip electrode 14 is printed on pure cotton twill cloth using graphene conductive silver paste with a silver content of 60% as raw material. The graphene conductive silver paste has good conductivity. The commonly used silver contents are 40% and 60%. Considering the conductive properties of the silver paste, the silver paste with a silver content of 60% is selected as the printing material. The pure cotton twill cloth has a certain thickness that is conducive to the penetration of the silver paste and has good flexibility. Therefore, it is selected as the base material for printing the electrode. The resistance of each electrode is 3-3.2 ohms. When making it, the twill cloth is flattened on the screen printing table and fixed with tape around it. The screen printing plate is placed The electrodes are placed above the twill cloth and separated from the twill cloth by a height of about 2 cm. The number of printing times is 2-3 times. If the number of printing times is too small, the silver paste will not cover the entire area. If the number of printing times is too large, the excess silver paste may spread and cause a short circuit between two adjacent electrodes. Each electrode is connected to the signal acquisition device 4 through a wire. The specific operation in the connection process is as follows: select one end of the printed electrode, cut a certain length of the edge of the pure cotton twill cloth along the gap between adjacent electrodes, be careful not to damage the electrode, fix the electrode and the wire by pressing with a copper sheet, and insulate the connection to ensure the insulation between adjacent electrodes.

[0037] The external packaging shielding layer 8 is made of EVA sponge tape with a thickness of 0.5mm; the buffer layer is made of dust-free cloth woven from polyester fibers; the dielectric layer 10 is made of polyurethane sponge with good elasticity and strong recovery ability, and has a thickness of 3mm; a tension pressure sensor 1 is installed at the upper end of the handle body 13, which is connected to the signal acquisition device 4 and can detect the force along the vertical direction of the handle when the hand is grasped; the lower end of the handle body 13 is equipped with an inertial measurement device IMU3, which includes three single-axis accelerometers and three single-axis gyroscopes. The accelerometer detects the acceleration of the object in the independent three-axis of the carrier coordinate system. The gyro detects the angular velocity signal of the carrier relative to the navigation coordinate system, measures the angular velocity and acceleration of the object in three-dimensional space, and uses this to calculate the posture of the object, which is connected to the signal acquisition device 4 to detect and reflect the movement state and trend of the handle in the process of the operator grasping the tactile handle in real time, and then the posture of the human arm can be reversed through the human body model. Later, the safe area for the operator to operate the machine can be planned according to the actual operation situation; the upper end of the pull pressure sensor 1 is connected to the tactile handle and the machine connection device 7, which can complete the connection with the end actuator of the working machine;

[0038] The signal acquisition device 4 is a data acquisition card, which mainly includes: a low-pass amplifier module, an AD multi-channel acquisition module, an MCU microcontroller, a DA multi-channel output module and a communication module; the modules involved can be directly implemented using existing technologies, the IMU uses the LPMS-ME1 model, and the tension and pressure sensor can use the HYLY-019 model.

[0039] The wireless transmission device 5 is a Bluetooth module and / or a wireless transmission module, and is connected to the signal acquisition device 4 and the host computer 6 .

[0040] The working principle and workflow of the present invention are as follows: during the movement of the operator grasping the handle, the capacitance unit of the capacitor array flexible pressure sensor wrapped on the outer surface of the handle body is subjected to the external pressure to produce a capacitance change, thereby causing a change in the voltage across the series resistor; the pull pressure sensor at the upper end of the handle is subjected to the force, causing the resistance inside the pull pressure sensor to change, and the electrical signal changes accordingly; the inertial measurement unit IMU produces position and speed changes with the movement of the handle, and generates corresponding electrical signals with the help of the built-in acceleration sensor and gyroscope; the three are connected to a data acquisition card, and the collected data is transmitted to the host computer in real time through a wireless transmission device. The host computer collects the change value of the electrical signal, and after data processing (the data collected by the acquisition card used is in the form of hexadecimal data, which is then converted to decimal by the host computer, and then the data is grouped and stored according to the acquisition frequency, and finally visualized to obtain an image), it can display the pressure distribution image of the human hand grasping in different postures, the force change curve of the pull pressure sensor, and the linear acceleration and rotation angular rate from three directions measured by the IMU, and the posture, speed and displacement information of the tactile handle can be obtained by solving the host computer.

[0041] Figure 6 This is the pressure distribution of a human hand when it is tightly grasping a tactile handle. The left half of the figure is the four-finger area, which is clearly distinguished. The right half is the thumb and thenar area, and the lower middle half is the hypothenar area. The blank area sandwiched between the three areas is the center area of ​​the palm. Accurate detection of the center area of ​​the palm and the four-finger area is of great help in locating the feature area, realizing grasping in different directions, and improving the accuracy of subsequent intelligent algorithm learning. This shows that the handle prepared in the present application has higher detection accuracy and better effect.

[0042] Figure 7 The loading pressure and capacitance reading show a positive proportional relationship within a certain range, indicating that the sensor has good mechanical repeatability performance. When the loading force is relatively small (0-10N), the image linearity is improved to a certain extent. Figure 8 Ten capacitor units at different positions were randomly selected on the capacitive flexible array sensor for pressure loading experiments, and the pressure loading experimental data of the capacitor units at these 10 different positions were fitted. The fitting curve is shown in Figure 8 The black line in the figure shows that the curve tends to be stable, the gaps between the curves in the image are smaller, and the consistency characteristics of the tactile sensor capacitor unit are relatively good.

[0043] Embodiment 1, the tactile handle can sense the operator's operating intention and realize human-computer interaction. The handle body 13 is a cylindrical handle formed by 3D printing of PLA material. The cylindrical diameter is 46mm, which is suitable for operators with most hand shapes to grasp. A 2mm gap is opened on the edge of the outer surface, and part of the internal area is hollowed out. The gap is connected to the hollowed-out area and is used to place the connecting wire fixed on the capacitor array flexible pressure sensor 2; the capacitor array flexible pressure sensor 2 is composed of five layers of planar structure stacked, which are respectively an external packaging shielding layer 8, an upper electrode layer 9, a dielectric layer 10, a lower electrode layer 11 and a buffer layer 12 from the outside to the inside: the upper electrode layer 9 and the lower electrode layer 11 have 28 and 28 strip-shaped parallel electrodes with a certain interval, respectively, wherein the upper and lower electrode layers are 28 and 28 respectively. The electrodes are spaced apart. The lower electrode layer is customized with a suitable silk screen according to the size requirements, and the preparation of the electrode layer is completed by silk screen printing. The electrode width of the upper electrode layer is 4mm, and the spacing between two adjacent electrodes is 1mm. The electrode width of the lower electrode layer is 4mm, and the spacing between two adjacent electrodes is 1.1mm; the upper and lower electrode layers are distributed vertically in space to form an array structure, constituting 28×28 capacitor units, and each capacitor unit is a small capacitor sensor; the strip electrode 14 is printed on pure cotton twill (thickness 0.2mm) using graphene conductive silver paste with a silver content of 60% as the material, and the resistance of each electrode is 3-3.2 ohms; each electrode is connected to the signal acquisition device 4 through a wire; the connection The specific operation in the connection process is as follows: select one end of the printed electrode, cut the edge of the pure cotton twill cloth to a length of about 1-2 cm along the gap between adjacent electrodes, be careful not to damage the electrode, use copper sheets to press the electrode and the wire to fix it, and insulate the connection, such as wrapping the outer surface of the copper sheet with insulating tape to ensure the insulation between adjacent electrodes; ensure the insulation between adjacent electrodes; the external packaging shielding layer 8 uses EVA sponge tape with a thickness of 0.5 mm; the buffer layer uses dust-free cloth woven from polyester fibers; the dielectric layer 10 uses polyurethane sponge with a thickness of 3 mm; the upper end of the handle body 13 is equipped with a tension and pressure sensor 1, and the lower end of the handle body 13 is equipped with an inertial measurement unit IMU3, It includes three single-axis accelerometers and three single-axis gyroscopes. The accelerometers detect the acceleration signals of the object in the independent three axes of the carrier coordinate system, while the gyroscopes detect the angular velocity signals of the carrier relative to the navigation coordinate system. The two sensors are connected to the signal acquisition device 4, and the collected data are transmitted to the host computer in real time through the wireless transmission device. The host computer collects the change value of the electrical signal. After data processing, it can display the pressure distribution image of the human hand grasping in different postures, the force change curve of the tension and pressure sensor, and the linear acceleration and rotational angular rate from three directions measured by the IMU; the upper end of the tension and pressure sensor 1 is connected to the tactile handle and the machine connection device 7, which can be connected to the end of the machine actuator (such as the end of the robotic arm).

[0044] When the operator uses the tactile handle to work, the capacitive flexible array sensor wrapped around the outside of the handle body can detect the pressure distribution image of the human hand grasping in different postures, and can distinguish the grasping posture of the human hand through image processing. The pull pressure sensor can detect the force change trend along the vertical direction of the handle. The IMU measures the linear acceleration and rotation angular rate of the handle from three directions. The posture, speed and displacement of the handle can be obtained through calculation, and then the posture of the human arm can be reversed through the human body model. Later, the safe area for the operator to operate the machine can be planned according to the actual operation situation; the comprehensive grasping posture of the human hand, the force change in the vertical direction of the handle, and the posture and movement trend of the human arm can fully perceive the operator's intention information, and then efficiently, accurately and safely complete the mechanical operations in different scenarios, and improve the level of human-computer interaction.

[0045] Embodiment 2, the tactile handle can help patients with hand diseases to perform rehabilitation training and recovery assessment. The handle body 13 is a cylindrical handle formed by 3D printing of PLA material. The cylindrical diameter is 46mm, which is suitable for operators with most hand shapes to grasp. A 2mm gap is opened on the edge of the outer surface, and part of the internal area is hollowed out. The gap is connected to the hollowed-out area and is used to place the connecting wire fixed on the capacitor array flexible pressure sensor 2; the capacitor array flexible pressure sensor 2 is composed of five layers of planar structure stacked, which are respectively an external encapsulation shielding layer 8, an upper electrode layer 9, a dielectric layer 10, a lower electrode layer 11 and a buffer layer 12 from the outside to the inside: the upper electrode layer 9 and the lower electrode layer 11 have 28 and 28 strips parallel and with a certain interval respectively. Electrode, wherein the upper and lower electrode layers are customized with suitable silk screen printing plates according to size requirements, and the preparation of the electrode layer is completed by silk screen printing. The electrode width of the upper electrode layer is 4mm, and the spacing between two adjacent electrodes is 1mm. The electrode width of the lower electrode layer is 4mm, and the spacing between two adjacent electrodes is 1.1mm. The upper and lower electrode layers are distributed vertically in space to form an array structure, constituting 28×28 capacitor units, each of which is a small capacitor sensor. The strip electrode 14 is printed on pure cotton twill (pure cotton twill specifications: C40X40130X702 / 1) using graphene conductive silver paste with a silver content of 60% as a material, and the resistance of each electrode is 3-3.2 ohms; ; Each electrode is connected to the signal acquisition device 4 through a wire; the specific operations in the connection process are: select one end of the printed electrode, cut the edge of the pure cotton twill cloth to a length of 1.5 cm along the gap between adjacent electrodes, be careful not to damage the electrode, use copper sheets to press the electrode and the wire to fix it, and insulate the connection to ensure the insulation between adjacent electrodes; ensure the insulation between adjacent electrodes; the external packaging shielding layer 8 uses EVA sponge tape with a thickness of 0.5 mm; the buffer layer uses dust-free cloth woven from polyester fibers; the dielectric layer 10 uses polyurethane sponge with a thickness of 3 mm; the upper end of the handle body 13 is equipped with a tension pressure sensor 1, and the lower end of the handle body 13 is equipped with an inertia The measuring device IMU3 includes three single-axis accelerometers and three single-axis gyroscopes. The accelerometers detect the acceleration signals of the object in the independent three axes of the carrier coordinate system, while the gyroscopes detect the angular velocity signals of the carrier relative to the navigation coordinate system. The three sensors are connected to the signal acquisition device 4, and the collected data are transmitted to the host computer in real time through the wireless transmission device. The host computer collects the change value of the electrical signal. After data processing, it can display the pressure distribution image of the hand grasping in different postures, the force change curve of the tension pressure sensor, and the linear acceleration and rotational angular rate from three directions measured by the IMU; the upper end of the tension pressure sensor 1 is connected to the tactile handle and the machine connection device 7, which can be connected to a movable mechanism.

[0046] First, multiple groups of data obtained by three sensors under normal human hand grasping can be collected to make a data set. When the patient uses the tactile handle for recovery training, the flexible array sensor wrapped outside the handle body can detect the pressure distribution image of the patient's grasping in different postures, analyze the threshold of pressure in each area, and the tension pressure sensor can detect the force size and change trend along the vertical direction of the handle. The IMU measures the linear acceleration and rotation angular rate of the handle from three directions. Through the solution, the handle's posture, speed and displacement information can be obtained, and then the posture of the human arm can be reversed through the human body model; the pressure distribution image of the human hand grasping, the force size and change trend in the vertical direction of the handle, and the patient's arm posture can be compared with the produced data set in real time through the host computer to develop a reasonable evaluation system. For hand injuries, by detecting the force changes in various areas of the palm and comparing them with the data of normal people, the degree of recovery and the palm area that needs further treatment and strengthening can be judged, which is convenient for purposeful hand grasping training and a reasonable evaluation of the recovery situation.

[0047] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A capacitive tactile handle based on a multi-sensory system, comprising a cylindrical handle body and a capacitive array flexible pressure sensor wrapped on the outer surface of the handle body, characterized in that: A slit is provided on the outer surface of the handle body along the length direction of the handle body, and the area inside the handle body around the slit is partially hollowed out, and the slit is connected to the internal hollowed-out area for placing a connecting line fixed on the flexible pressure sensor; a tension pressure sensor for detecting the force along the vertical direction of the handle when a human hand grasps is installed at the top of the handle body, and an inertial measurement unit IMU is installed in the hollowed-out area inside the handle body, and the inertial measurement unit IMU is used to detect and reflect the movement state of the handle body in the process of the operator grasping the tactile handle in real time, and the angular velocity and acceleration in three-dimensional space; The tension and pressure sensor, inertial measurement unit IMU, and flexible pressure sensor are all connected to the signal acquisition device, and connected to the host computer through a wireless transmission device to complete the communication; The capacitive array flexible pressure sensor can be bent and rolled up at will, and the direction from far away from the handle body to close to the handle body is respectively an external packaging shielding layer, an upper electrode layer, a dielectric layer, a lower electrode layer and a buffer layer: the upper electrode layer and the lower electrode layer respectively have A and B strip-shaped parallel electrodes with a certain interval, and the electrodes are printed on pure cotton twill cloth with a graphene conductive silver paste with a silver content of 40-60%; the thickness of the pure cotton twill cloth is 0.2mm, the resistance value of a single electrode is 3-3.2 ohms, and the difference in resistance value between any two electrodes does not exceed 0.2 ohms; In the pressure distribution of the human hand when tightly grasping the tactile handle, the four fingers can be clearly distinguished. Accurate detection of the central area of ​​the palm and the four-finger area is used to locate the characteristic area and realize grasping in different directions, which meets the operator's needs of grasping at will from different angles and orientations, indicating that the prepared handle has high detection accuracy.

2. The tactile handle according to claim 1, characterized in that The handle body is a cylindrical handle formed by 3D printing with PLA material, and a 2mm gap is opened on the edge of the outer surface.

3. The tactile handle according to claim 1, characterized in that The dielectric layer is a polyurethane sponge with a thickness of 3mm; the buffer layer is a dust-free cloth woven from polyester fibers; the electrode width of the upper electrode layer is 4mm, and the spacing between two adjacent electrodes is 1mm; the electrode width of the lower electrode layer is 4mm, and the spacing between two adjacent electrodes is 1.1mm. The number of arrays is 28.

4. The tactile handle according to claim 1, characterized in that The working principle and workflow of the handle are as follows: during the movement of the operator grasping the handle, the capacitor unit of the capacitor array flexible pressure sensor wrapped on the outer surface of the handle body is affected by the external pressure, resulting in a change in capacitance, which in turn causes a change in the voltage across the series resistor; the tension pressure sensor at the upper end of the handle is affected by force, causing the resistance inside the tension and compression sensor to change, and the electrical signal changes accordingly; the inertial measurement unit IMU produces changes in position and speed as the handle moves, and generates corresponding electrical signals with the help of the built-in acceleration sensor and gyroscope; the three are connected to a data acquisition card, and the collected data is transmitted to the host computer in real time through a wireless transmission device; the host computer collects the change value of the electrical signal, and after data processing, displays the pressure distribution image of the human hand grasping in different postures, the force change curve of the tension pressure sensor, and the linear acceleration and rotation angular rate from three directions measured by the IMU, and the posture, speed and displacement information of the tactile handle are obtained through calculation by the host computer.

5. A method for manufacturing a capacitive tactile handle based on a multi-sensory system according to any one of claims 1 to 4, the steps of the method are: (1) Preparation of electrode layer The pure cotton twill cloth is cut into pieces of suitable size and ironed flat, and then placed and fixed on the screen printing table. The customized screen printing plate is placed on the twill cloth and separated from the twill cloth by a height of 1.5-2.5 cm. Graphene conductive silver paste with a silver content of 40-60% is poured on the screen printing plate, and scraped with a scraper until the conductive silver paste covers the entire pattern. This step is repeated 2-3 times, and the screen printing plate is lifted, and the printed cloth piece is removed and placed in an industrial oven until the conductive silver paste becomes dry and taken out; the conductive performance is measured with a multimeter, and the resistance value of a single electrode is 3-3.2 ohms, and the resistance value difference between any two electrodes does not exceed 0.2 ohms; the upper and lower electrode layers are obtained respectively; (2) Sensor wiring Select one end of all parallel electrodes of the upper and lower electrode layers, cut the pure cotton twill cloth to a suitable length along the gap between adjacent electrodes, fix the electrodes and wires by pressing with copper sheets, and insulate the joints; (3) Handle packaging The electrodes of the upper and lower electrode layers are placed vertically to each other, and polyurethane sponge is used as the intermediate dielectric layer; the external packaging shielding layer uses vinyl acetate copolymer single-sided sponge tape, and a dust-free cloth is used as a buffer layer, and then the whole is wrapped on the printed cylindrical handle body. The circuit part is concentrated along the gap of the handle body in the hollowed-out area inside the handle body, and the inertial measurement unit IMU is placed at the lower position inside the handle body; a tension and pressure sensor is installed on the top of the handle body; (4) Sensor calibration The packaged handle is calibrated using a tactile sensor calibration experiment platform. The sensor unit is continuously loaded in the range of 0-60N by automatic pressurization. Ten sensor units at different positions are randomly selected on the sensor for pressure loading experiments. The corresponding loading experiment numerical curves of the ten sensor units at different positions are fitted to ensure that the consistency characteristics of the capacitor unit composed of the upper and lower electrode layers are good.

Images