Proximity-contact global sensing electronic skin oriented to man-machine safety collaboration and preparation method of proximity-contact global sensing electronic skin

Abstract

The invention discloses an approach-contact global sensing electronic skin oriented to man-machine safety cooperation and a preparation method thereof. The electronic skin is composed of a tactile sensing layer (1), an elastic buffer layer (2) and an electromagnetic coupling layer (3) which are sequentially arranged according to an array structure; the tactile sensing layer (1) is used for tactile sensing of objects made of different materials in a contact mode; the elastic buffer layer (2) is used for providing elastic buffer for the touch sensing layer (1); the electromagnetic coupling layer (3) is used for being connected with a multi-channel decoding circuit and sensing the approaching-contact state of an invader through high-frequency electromagnetic coupling of the heterogeneous invader in a near-field area. According to the invention, a double safety protection mechanism of approaching early warning and collision sudden stop in the man-machine cooperation process is established, and consideration and balance of man-machine cooperation operation efficiency and safe operation are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic skin, and particularly relates to a proximity-contact global perception electronic skin for human-robot safe collaboration and a preparation method thereof. Background Art

[0002] In the global strategic competition pattern of manufacturing, human-robot collaboration technology has become the core path to promote the upgrading of intelligent manufacturing. Relevant policies clearly point out that we should unswervingly take intelligent manufacturing as the main attack direction and overcome common technologies such as intelligent perception and active protection in human-robot collaboration technology. Compared with traditional industrial equipment, the human-robot collaboration system breaks through the physical isolation operation mode and realizes an efficient collaboration architecture with complementary advantages through the shared dynamic operation space between humans and robots. However, the cancellation of the physical isolation mechanism leads to significant safety challenges when humans and robots share the same operation space. System logic anomalies, hardware failures or human operation errors may cause accident risks such as mechanical extrusion and dynamic collision. The current corresponding application specifications clearly stipulate that when the operator enters the collaborative space, the operating speed of the robot end does not exceed 0.25 m / s. However, in actual industrial scenarios, the operating speed of high-speed robot systems can reach the order of 2 m / s. Due to insufficient perception ability caused by high-speed operation, the protection mechanism lags behind, resulting in a significant contradiction between safety protection and production efficiency.

[0003] At the information perception level, the electronic skin can be used as the core carrier for the environment perception of collaborative robots, breaking through the inherent limitations of traditional visual perception solutions in high-speed scenarios, such as dynamic delay, image blurring, and near-field blind spots. With its unique flexibility, stretchability, and sensing performance, the electronic skin forms a tight attachment on the skin surface of dynamic and irregular robots, enabling rapid perception of multi-physical quantity coupling in the near-field interaction domain. Currently, electronic skin is mainly developed for wearable application scenarios, and a multi-modal perception system based on capacitance coupling, triboelectric effect, and static magnetic sensing principles has been successfully constructed. However, in industrial scenarios, broadband electromagnetic noise formed by inverter harmonics, motor transient surges, and arc discharges of welding machines will interfere with the sensitive units of sensors through near-field coupling paths, resulting in a significant deterioration of the signal-to-noise ratio of electrostatic / magnetic field sensing, seriously restricting the reliability of such systems in intelligent manufacturing scenarios.

[0004] At the level of protection mechanisms, the existing pre-collision (proximity) and post-collision (contact) perception-response frameworks of electronic skins have their respective limitations. Pre-collision perception has an advantage in predicting the motion information of intruders through distance warning, but the single proximity perception mode has the potential risk of probabilistic missed detection. Although post-collision perception provides feedback on contact mechanical characteristics and has high detection reliability, its "post-event response" characteristic results in the inability to effectively suppress the peak impact force generated within 0.1 s after collision, with limitations such as response latency and lack of prediction ability. Flexible sensor devices with both proximity and contact dual-mode perception capabilities have inherent defects such as mode-switching latency and perception blind spots between modes, resulting in the lack of spatio-temporal correlation information in the proximity-contact continuous domain and causing decision-making biases in dynamic control strategies. Due to the lack of full-range proximity-contact perception, only passive protection that stops suddenly beyond the safety threshold can be designed, and it is difficult to construct an intelligent decision-making mechanism that combines over-limit emergency stop and active obstacle avoidance based on the prediction of multi-feature information of the motion state.

[0005] Facing the problems of insufficient anti-interference ability of the perception signals of electronic skins in complex electromagnetic environments, lack of full-range proximity-contact perception information, and fuzzy control mechanisms leading to difficulties in intelligent obstacle avoidance decisions, it is urgent to propose a full-range proximity-contact perception electronic skin for human-robot safe cooperation. Summary of the Invention

[0006] To solve the above technical problems, the present invention proposes a full-range proximity-contact perception electronic skin for human-robot safe cooperation and a preparation method thereof, realizing a highly integrated and high-frequency flexible sensor device for continuous perception of information from proximity to contact, acting as the "electronic skin" of the robot, thereby establishing a dual safety protection mechanism of proximity warning and collision emergency stop during human-robot cooperation, achieving the balance between the operation efficiency and safe operation of human-robot cooperation, and having important significance for the practical application of artificial intelligence perception technology.

[0007] On the one hand, to achieve the above object, the present invention provides a full-range proximity-contact perception electronic skin for human-robot safe cooperation, including:

[0008] The electronic skin is composed of a tactile sensing layer 1, an elastic buffer layer 2, and an electromagnetic coupling layer 3, and is arranged in an array structure in sequence;

[0009] The tactile sensing layer 1 is used for tactile sensing of objects with different materials in the contact mode;

[0010] The elastic buffer layer 2 is used to provide elastic buffering for the tactile sensing layer 1;

[0011] The electromagnetic coupling layer 3 is used to connect with a multi-channel decoding circuit, and perceive the proximity-contact state of the intruder through the high-frequency electromagnetic coupling of the heterogeneous intruder in the near-field region.

[0012] Optionally, the electromagnetic coupling layer 3 is a printed circuit board with a polyimide PI as the insulating substrate and copper foil as the conductive layer, with a thickness of 10 to 100 micrometers, and the layers are insulated from each other, and the thickness of the copper conductor is 3 to 20 micrometers.

[0013] Optionally, the electromagnetic coupling layer 3 includes a first inductor coil 31, a second inductor coil 33, and capacitor plates 32, and they are arranged in sequence in the order of the first inductor coil 31, the capacitor plates 32, and the second inductor coil 33.

[0014] Optionally, the working process of the multi-channel decoding circuit includes: successively connecting the sensing units in the electronic skin to a time-division multiplexing architecture, sharing 1 LC sine oscillation circuit in the array, converting the collected output response signal through an analog-to-digital converter, accurately measuring the frequency of the square wave output by the oscillator through the input capture function of the microcontroller unit, calculating the resistance value according to the measured frequency, and uploading the detected resistance value to the upper computer through the data bus according to the array position information.

[0015] On the other hand, to achieve the above object, the present invention also provides a preparation method of a proximity-contact global perception electronic skin for human-machine safe collaboration, including:

[0016] Obtaining the structural parameters of the attachment area;

[0017] Determining the design parameters of the electronic skin according to the structural parameters;

[0018] Preparing the tactile sensing layer 1, the elastic buffer layer 2, and the electromagnetic coupling layer 3 respectively according to the design parameters, and assembling the tactile sensing layer 1, the elastic buffer layer 2, and the electromagnetic coupling layer 3 together according to the lamination method; wherein, the design parameters include the shape, size, and spatial resolution of the electronic skin.

[0019] Optionally, preparing the tactile sensing layer 1 includes:

[0020] Preparing a silicone prepolymer by mixing the main agent and the curing agent in a ratio of 1:1, adding reduced graphene oxide powder, iron-cobalt powder, or manganese-zinc iron oxide powder into a beaker containing the silicone prepolymer, and then adding a small amount of polyvinylpyrrolidone;

[0021] Under normal temperature conditions, stirring the mixture at a constant speed with a stirrer for 60 minutes, and pouring the mixture into a mold pre-sprayed with a release agent to prepare a composite electromagnetic film state;

[0022] Putting the entire composite electromagnetic film and the mold into a nitrogen atmosphere and operating at a nitrogen temperature of 120 °C for 20 minutes;

[0023] Putting the composite electromagnetic film into a variable temperature oven and curing it at a high temperature of 150 °C for 120 minutes to eliminate bubbles;

[0024] Cool the composite electromagnetic film at room temperature for 60 minutes and perform demolding treatment to obtain the composite electromagnetic film, which serves as the tactile sensing layer 1.

[0025] Optionally, preparing the elastic buffer layer 2 includes:

[0026] Put the main agent and the curing agent into a beaker in a ratio of 1:1, and stir with a stirrer at a constant speed for 60 minutes to fully mix and form a silicone prepolymer;

[0027] Put the silicone prepolymer into a rectangular 3D printing resin mold to form a silicone prepolymer film state;

[0028] When the ratio of the silicone main agent to the curing agent exceeds 10:1, place the silicone prepolymer film in a nitrogen atmosphere, run it at a nitrogen temperature of 120 °C for 20 minutes, and cool it under natural air at 25 °C for 30 minutes to form a flexible elastic buffer layer 2.

[0029] Optionally, preparing the electromagnetic coupling layer 3 includes:

[0030] Take three single-sided copper foil base plates and cut them into the shapes required for the sensing unit / array, drill holes at the centers of the three base plates and plate through holes;

[0031] Use the photoimaging graphic transfer and etching process methods to print circuits, and print the first inductance coil 31, the second inductance coil 33, the capacitor plate 32, and the leads at the centers of the two layers connected in parallel on the three base plates respectively;

[0032] The capacitor plates 32 are respectively connected to the first inductance coil 31 and the second inductance coil 33;

[0033] With all the copper foil sides of the base plates facing up, attach the insulating base plate to the printed circuit board and use polyethylene glue to thermally fix and bond them into a printed circuit board.

[0034] Technical effects of the present invention:

[0035] (1) Compared with the traditional flexible electronic skin, the traditional flexible electronic skin can only sense single-modal signals, and the measurement range and sensitivity are fixed. The flexible electronic skin in the present invention can detect two sensing modalities, namely the proximity position and the contact stress. And this flexible electronic skin can adjust the stress detection range and sensitivity by changing the film material modulus of the elastic buffer layer, and achieve non-contact sensing at different distances by setting the outer diameter of the inductance coil.

[0036] (2) Break through the limitations of the traditional static mechanical-electromagnetic field correlation framework of electronic skin. By means of the high-frequency electromagnetic coupling effect of heterogeneous intruders in the near-field region, avoid the interference source frequency band to detect intruders, and solve the problem of distorted sensing signals caused by multi-source interference (power frequency harmonics, radio frequency noise) in the complex industrial electromagnetic environment.

[0037] (3) Construct an electronic skin to achieve full-domain blind-zone-free information perception from close distance to contact stress perception, solve the problem of modal switching blind zone caused by the single-field detection mode of traditional flexible devices, and then construct a human-machine collaboration active obstacle avoidance strategy for full-domain perception of intruder approach-contact, providing a solution with both theoretical completeness and engineering feasibility for the adaptive safety protection of human-machine collaboration robots. Brief Description of the Drawings

[0038] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0039] Figure 1 It is a schematic structural diagram of an approach-contact full-domain perception electronic skin according to an embodiment of the present invention; wherein 1 - tactile sensing layer, 2 - elastic buffer layer, 3 - electromagnetic coupling layer; 31 and 33 - inductance coils, 32 - capacitor plates;

[0040] Figure 2 It is a multi-channel decoding circuit diagram of the electronic skin according to an embodiment of the present invention;

[0041] Figure 3 It is a comparison of the output characteristic test results of the inductance coil and capacitor plate sensing unit according to an embodiment of the present invention; wherein, (a) is the inductance mode - graphene / silicone; (b) is the inductance mode - ferrite / silicone; (c) is the inductance mode - iron cobalt / silicone; (d) is the capacitance mode - graphene / silicone; (e) is the capacitance mode - ferrite / silicone; (f) is the capacitance mode - iron cobalt / silicone;

[0042] Figure 4 It is the output electrical signal of the electronic skin unit according to an embodiment of the present invention; wherein, (a) is graphene / silicone; (b) is ferrite / silicone; (c) is iron cobalt / silicone. Detailed Description of the Embodiments

[0043] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0044] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0045] As Figure 1 shown, in this embodiment, a proximity-contact global perception electronic skin for human-machine safe collaboration is provided, including: a tactile sensing layer 1, an elastic buffer layer 2, and an electromagnetic coupling layer 3; the diameter and thickness of the sensing units are designed to be in the range of 30-60 mm and 1-3 mm, arranged in an array structure, and can be expanded according to requirements;

[0046] The tactile sensing layer 1 is a composite electromagnetic film, and the preparation method is to disperse and fill electromagnetic particles in a polymer carrier. The mechanical deformation of the material or device under external force causes the migration of the electromagnetic particles, thereby causing a change in the impedance response signal, realizing tactile sensing of different material objects such as metal conductors, organisms, and insulators in the contact mode.

[0047] The elastic buffer layer 2 is a polymer material such as silica gel or PDMS, and uses the excellent mechanical properties of the polymer material as a flexible substrate film to provide elastic buffering for the tactile sensing layer 1;

[0048] The electromagnetic coupling layer 3 is a printed circuit board with a polyimide (PI) as the insulating substrate and copper foil as the conductive layer, with a thickness of 10-100 microns. Each layer is insulated from each other, and the copper conductor has a thickness of 3-20 microns. A printed circuit board is prepared by connecting the inductance coils 31 and 33 in parallel with the capacitor plate 32, and the two ends of the leads are connected to a multi-channel decoding circuit. The proximity-contact state of the intruder is sensed through the high-frequency electromagnetic coupling of the heterogeneous intruder in the near-field region;

[0049] The multi-channel decoding circuit is as Figure 2 shown. The sensing units in the electronic skin sensing array are sequentially connected to a time-division multiplexing architecture. The array shares 1 LC sine oscillation circuit, and a Colpitts oscillator with a fundamental frequency of 10 MHz is selected. Then, the output response signal collected is converted by an analog-to-digital converter (ADC), and the input capture function of a microcontroller unit (MCU) such as STM32 is used to accurately measure the frequency of the square wave output by the oscillator, and the resistance value is calculated according to the measured frequency. The detected resistance value is uploaded to the host computer through the data bus according to the array position information.

[0050] The substantial features of the present invention are as follows: A multi-layer electronic skin is proposed to achieve the global perception of the approaching-contact motion state of intruders by the sensing unit / array. A printed circuit thin film prepared by paralleling planar capacitance and inductance is used as the electromagnetic coupling layer of the electronic skin. A flexible substrate thin film is prepared based on the excellent mechanical properties of silicone as the elastic buffer layer. A composite electromagnetic thin film prepared by dispersing and filling ferromagnetic particles is used as the tactile sensing layer. Based on the high-frequency near-field coupling mechanism of planar capacitance and inductance for different media, the proximity sensing of metal conductor / biological body intruders is realized; based on the displacement of electromagnetic particles in the composite electromagnetic thin film under external force, the contact sensing of heterogeneous intruders such as metal conductors / biological bodies / insulators is realized through the change of the response signal of the electromagnetic coupling layer.

[0051] The present invention proposes to design the flexible sensing unit of the electronic skin as a multi-layer structure to achieve the global perception of the approaching-contact motion state of intruders by the sensing unit / array. A printed circuit thin film prepared by paralleling planar capacitance and inductance is used as the electromagnetic coupling layer of the electronic skin. A flexible substrate thin film is prepared based on the excellent mechanical properties of silicone as the elastic buffer layer. A composite electromagnetic thin film prepared by dispersing and filling ferromagnetic particles is used as the tactile sensing layer. Based on the high-frequency near-field coupling mechanism of planar capacitance and inductance for different media, the proximity sensing of metal conductor / biological body intruders is realized; based on the displacement of electromagnetic particles in the composite electromagnetic thin film under external force, the contact sensing of heterogeneous intruders such as metal conductors / biological bodies / insulators is realized through the change of the response signal of the electromagnetic coupling layer.

[0052] During the movement process of heterogeneous intruders from approaching to contacting the coil and the electrode plate, there is a one-to-one correspondence between their motion states and the changes in impedance response signals, without sudden changes or blind spots. Therefore, their motion states can be globally perceived. The sensing unit outputs the characteristics of the approaching-contact motion of heterogeneous intruders through a single lead, which can reduce the number of array channels and save the software and hardware costs of the sensing system while improving the integration. Based on the continuous characteristic of the impedance time-variation caused by the movement of the intruder, the resonant frequency point is adjusted in real time, so that the system always operates in the frequency band with the least interference, greatly simplifying the design and manufacturing of the electronic skin and improving the reliability.

[0053] In this embodiment, a preparation method of a proximity-contact global perception electronic skin for human-machine safe cooperation is also provided, including:

[0054] Preparing the tactile sensing layer 1 and the elastic buffer layer 2, including the following steps:

[0055] First, in order to improve the flexibility and stability of the silicone substrate, flexibility and repeatability experiments were conducted on flexible substrates prepared with different ratios to determine the optimal ratio of the main agent to the curing agent as 1:1. The main agent and the curing agent were placed in a beaker according to the optimal ratio (1:1) and stirred with a stirrer at a constant speed for 60 minutes to fully mix them and form a silicone prepolymer. The silicone prepolymer was placed in a rectangular 3D printing resin mold to form a silicone prepolymer film state. When the ratio of the silicone main agent to the curing agent exceeds 10:1, the viscosity on the silicone surface will increase. To eliminate its surface stickiness, the silicone prepolymer film was placed in a nitrogen atmosphere and operated at a nitrogen temperature of 120°C for 20 minutes. Subsequently, it was cooled for 30 minutes under the condition of natural air at 25°C to form a flexible elastic buffer layer.

[0056] Next, a composite electromagnetic film was fabricated as the tactile sensing layer, and the silicone prepolymer was prepared according to the above ratio of the main agent to the curing agent. Redox graphene powder, iron-cobalt powder, or manganese-zinc iron oxide powder was added to the beaker containing the silicone prepolymer, and then a small amount of polyvinylpyrrolidone (PVP) was added. Adding PVP can enable the mixed particles and powders to quickly fuse. At room temperature, it was stirred with a stirrer at a constant speed for 60 minutes. The mixture was poured into a mold pre-sprayed with a release agent to be prepared into a composite electromagnetic film state. The entire composite electromagnetic film and the mold were placed in a nitrogen atmosphere and operated at a nitrogen temperature of 120°C for 20 minutes to eliminate the surface stickiness of the composite electromagnetic film. The composite electromagnetic film was placed in a variable temperature oven and cured at a high temperature of 150°C for 120 minutes to eliminate bubbles. Next, the composite electromagnetic film was cooled at room temperature for 60 minutes and demolded to obtain the composite electromagnetic film.

[0057] Prepare the electromagnetic coupling layer 3, including the following steps:

[0058] Take three single-sided copper foil base plates (the base is a 25-micron polyimide insulating layer, and the conductive layer is a 12-micron copper foil) and cut them into the shapes required for the sensing unit / array. Drill holes and plate through-holes at the centers of the three base plates (for leading wires at the centers of the planar coils), and use the photoimaging graphic transfer and etching process methods to print circuits. Print inductance coils 31 and 33, capacitor plates 32, and two layers of center leading wires connected in parallel in the middle on the three base plates respectively; the capacitor plates 32 are respectively connected to the two inductance coils 31 and 33, where the wire diameter and wire spacing are both 0.07 mm, the coils are all 15 turns, and the capacitor plates are circular with a radius of 32 mm; with the copper foil sides of all the base plates facing up, attach the insulating base plates to the printed circuit boards and use polyethylene glue to thermally cure and bond them into a printed circuit board;

[0059] Finally, according to the lamination method, assemble the flexible tactile sensing layer 1, the elastic buffer layer 2, and the electromagnetic coupling layer 3 together to form a proximity-contact global perception electronic skin for human-robot safe collaboration.

[0060] Method for constructing multi-channel decoding circuit of electronic skin

[0061] Connect the lead of the electromagnetic coupling layer of the sensing unit in the electronic skin sensing array to an inductance digital converter (LDC), so that the sensor device measures impedance in the frequency range of 1 kHz to 10 MHz. Use STM32F103 and DLC1614 for I2C communication. The current generated by the LDC chip is passed into the sensor device, and then the resonant frequency of the inductance capacitor is detected to detect the proximity position and contact stress. The detected resistance value is uploaded to the host computer through the data bus according to the array position information.

[0062] The application examples of the present invention are as follows:

[0063] Example 1: Comparative tests were carried out using an inductance coil and a capacitor plate sensing structure under the same conditions to study the sensing performance of different sensing structures.

[0064] Experimental platform construction: A safe electronic skin unit with multi-material composite electromagnetic films of graphene / silicone, ferrite / silicone, and iron cobalt / silicone was designed. An experimental platform for the output characteristics of a multi-modal sensing unit with a proximity distance of 70 mm to a contact stress of 50 N was built, and the signal response characteristics of the sensing unit to metal conductors, organisms, and insulators during the entire proximity-contact process were tested.

[0065] Experimental process and results: The research results are as Figure 3 shown, Figure 3 (a)-(c) of show the detection performance of the inductance mode sensing unit for the proximity-contact dynamic process of the intruder. All three composite film samples show good response signals; in the proximity state, the inductance signal response caused by the metal conductor is the most significant, followed by the organism, and no obvious effective signal change is observed for the insulator; in the contact state, the inductance signal of the iron cobalt / silicone composite film shows a linear change trend for the insulator, which is significantly improved compared with the composite film samples of the other two materials. According to Figure 3 (d)-(f) of show the detection performance of the capacitance mode sensing unit for the proximity-contact dynamic process of the intruder. All three composite film samples show relatively chaotic induction signals for metal objects; in the proximity mode, the capacitance signal response caused by the organism is the most significant, followed by the metal conductor, and no obvious effective signal change is observed for the insulator; in the contact mode, compared with the other two composite film samples, the iron cobalt / silicone composite film shows an obvious linear change trend for the capacitance signals of the metal conductor, organism, and insulator. Experiments prove that a single sensing structure of an inductance coil and a capacitor plate cannot achieve the perception of typical obstacles in a human-machine collaboration scenario.

[0066] Example 2: Based on the built test platform, the output characteristics of the safe electronic skin sensing unit were analyzed.

[0067] Experimental platform construction: The output characteristic test platform consists of an impedance analyzer, a tensiometer, and an electronic skin sensing unit. Through the impedance analyzer, the corresponding equivalent resistance value can be read, thereby reflecting the approaching-contact motion state of invasive objects of different materials.

[0068] Experimental process and results: The test results are as Figure 4 shown. The parallel resistance parameter Rp is used to clearly sense the approaching-contact full-process information of metal conductors, organisms, and insulators. After using the iron-cobalt / silica composite film as the tactile sensing layer, its sensing effect is significantly better than that of the other two materials after the invasive object comes into contact. The multi-material composite electromagnetic films such as iron-cobalt / silica composite film are placed on the top of the safe electronic skin sensing unit, the silica is prepared as an elastic buffer layer and placed in the middle layer, and the induction coil and the planar circuit LC resonance are connected in parallel and designed as an electromagnetic coupling layer at the bottom; Figure 4 The parallel resistance parameter Rp is used to clearly sense the approaching-contact full-process information of metal conductors, organisms, and insulators. The parallel resistance signals of the metal conductor and the organism of the capacitance-inductance mode electronic skin unit both show obvious change trends. Figure 4 (a)-(c) are the parallel resistance output results when the composite films of graphene / silica, ferrite / silica, and iron-cobalt / silica are used as the tactile sensing layer, respectively, among which the iron-cobalt / silica composite film has the highest sensitivity.

[0069] Technical advantages of the present invention: Compared with the traditional flexible electronic skin, the traditional flexible electronic skin can only sense single-modal signals, and the measurement range and sensitivity are fixed. The flexible electronic skin in the present invention can detect two sensing modalities, namely the approaching position and the contact stress. And this flexible electronic skin can adjust the stress detection range and sensitivity by changing the film material modulus of the elastic buffer layer, and realize non-contact sensing at different distances by setting the outer diameter of the inductance coil. Break through the limitations of the traditional electronic skin static mechanical-electromagnetic field correlation framework, and avoid the interference source frequency band to detect the invasive object through the high-frequency electromagnetic coupling effect of the heterogeneous invasive object in the near-field region, and solve the problem of perception signal distortion caused by multi-source interference (power frequency harmonics, radio frequency noise) in the complex industrial electromagnetic environment. Construct an electronic skin to realize the full-domain non-blind area information perception from the approaching distance to the contact stress perception, solve the modal switching blind area problem caused by the single-field detection mode of the traditional flexible device, and then construct a human-machine cooperation active obstacle avoidance strategy for the approaching-contact full-domain perception of the invasive object, providing a solution with both theoretical completeness and engineering feasibility for the adaptive safety protection of human-machine cooperation robots.

[0070] The above are only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A proximity-contact global perception electronic skin for human-machine safe collaboration, characterized in that The electronic skin is composed of a tactile sensing layer (1), an elastic buffer layer (2), and an electromagnetic coupling layer (3), and they are arranged in sequence according to an array structure; The tactile sensing layer (1) is used for tactile sensing of objects with different materials in the contact mode; The elastic buffer layer (2) is used to provide elastic buffering for the tactile sensing layer (1); The electromagnetic coupling layer (3) is used to connect with a multi-channel decoding circuit, and sense the approaching-contact state of the intruder through the high-frequency electromagnetic coupling of the heterogeneous intruder in the near-field region.

2. The proximity-contact global perception electronic skin for human-machine safe collaboration according to claim 1, characterized in that, The electromagnetic coupling layer (3) is a printed circuit board with polyimide (PI) as the insulating substrate and copper foil as the conductive layer, with a thickness of 10-100 microns, and each layer is insulated from each other, and the thickness of the copper conductor is 3-20 microns.

3. The proximity-contact global perception electronic skin for human-machine safe collaboration according to claim 1, wherein The electromagnetic coupling layer (3) includes a first inductor coil (31), a second inductor coil (33), and a capacitor plate (32), and they are arranged in sequence in the order of the first inductor coil (31), the capacitor plate (32), and the second inductor coil (33).

4. The proximity-contact global perception electronic skin for human-machine safe collaboration according to claim 1, characterized in that The working process of the multi-channel decoding circuit includes: sequentially connecting the sensing units in the electronic skin to a time-division multiplexing architecture, sharing 1 LC sine oscillation circuit in the array, passing the collected output response signal through an analog-to-digital converter, accurately measuring the frequency of the square wave output by the oscillator through the input capture function of the microcontroller unit, calculating the resistance value according to the measured frequency, and uploading the detected resistance value to the host computer through the data bus according to the array position information.

5. A preparation method of a proximity-contact global perception electronic skin for human-robot safe collaboration according to any one of claims 1-4, characterized in that, Including: Obtaining the structural parameters of the attachment area; Determining the design parameters of the electronic skin according to the structural parameters; According to the design parameters, respectively prepare the tactile sensing layer (1), the elastic buffer layer (2), and the electromagnetic coupling layer (3), and assemble the tactile sensing layer (1), the elastic buffer layer (2), and the electromagnetic coupling layer (3) together according to the lamination method; wherein, the design parameters include the shape, size, and spatial resolution of the electronic skin.

6. The preparation method according to claim 5, characterized in that Preparing the tactile sensing layer (1) includes: Preparing a silicone prepolymer by mixing the main agent and the curing agent in a ratio of 1:1, adding reduced graphene oxide powder, iron-cobalt powder, or manganese-zinc iron oxide powder into a beaker containing the silicone prepolymer, and then adding a small amount of polyvinylpyrrolidone; Under normal temperature conditions, stir with a stirrer at a constant speed for 60 minutes, pour the mixture into a mold pre-sprayed with a release agent, and prepare it into a composite electromagnetic film state; Put the entire composite electromagnetic film and the mold into a nitrogen atmosphere and operate at a nitrogen temperature of 120 °C for 20 minutes; Put the composite electromagnetic film into a variable-temperature oven and cure it at a high temperature of 150 °C for 120 minutes to eliminate bubbles; Cool the composite electromagnetic film at room temperature for 60 minutes and perform a demolding process to obtain the composite electromagnetic film, and the composite electromagnetic film is used as the tactile sensing layer (1).

7. The preparation method according to claim 5, characterized in that Preparing the elastic buffer layer (2) includes: Put the main agent and the curing agent into a beaker in a ratio of 1:1, stir with a stirrer at a constant speed for 60 minutes, and mix well to form a silicone prepolymer; Put the silicone prepolymer into a rectangular 3D printing resin mold to form a silicone prepolymer film state; When the ratio of the silicone main agent to the curing agent exceeds 10:1, place the silicone prepolymer film in a nitrogen atmosphere and run it at a nitrogen temperature of 120 °C for 20 minutes, and then cool it for 30 minutes under the condition of natural air at 25 °C to form a flexible elastic buffer layer (2).

8. The preparation method according to claim 5, wherein Preparing the electromagnetic coupling layer (3) includes: Cut three single-sided copper foil base plates into the shapes required for the sensing unit / array, drill holes at the centers of the three base plates and plate through holes; Use the photoimaging graphic transfer and etching process methods to print circuits, and print the first inductance coil (31), the second inductance coil (33) and the capacitor plate (32) and the leads at the centers of the two layers connected in parallel on the three base plates respectively; The capacitor plates (32) are respectively connected to the first inductance coil (31) and the second inductance coil (33); With all the copper foil sides of the base plates facing up, attach the insulating base plates to the printed circuit boards and use polyethylene glue to thermally cure and bond them into a printed circuit board.

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