Array substrate and tactile sensor applying array substrate

Abstract

The invention discloses an array substrate and a tactile sensor applying the array substrate. The array substrate comprises an array electrode plate, an ionic gel layer and a common electrode plate, the ionic gel layer is arranged between the array electrode plate and the common electrode plate; a plurality of array electrodes arranged in an array are arranged in the array electrode plate; a capacitor structure is formed between each array electrode and the common electrode plate; when normal force acts, the ionic gel layer is compressed, the distance between the array electrode and the common electrode plate in each capacitor structure changes, and a plurality of first capacitance difference signals are generated. When the tangential force acts, the opposite area of the array electrode and the common electrode plate in each capacitor structure is changed, and a plurality of second capacitance difference signals are generated; according to the invention, multi-dimensional and multi-point stress sensing can be realized, and the resolution and the sensitivity of stress sensing are improved, so that high resolution and high sensitivity are realized at the same time.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to an array substrate and a tactile sensor using the array substrate. Background Art

[0002] In the field of modern industrial manufacturing, the demand for automated manufacturing has increased dramatically. Robots have been widely used in the production and manufacturing of factory workshops due to their unique advantages in industrial manufacturing. Simple, tedious and dangerous work can be handed over to robots or robots can assist workers in completing. In order for robots to have stronger versatility in work scenarios, robots must have the ability to perceive the surrounding environment parameters like human workers and feedback processing, such as vision and touch. At present, robot vision has been maturely applied to visual environment perception and object recognition, but visual perception is easily affected by environmental restrictions, such as ambient brightness, visual occlusion, etc. The ability of tactile sensation to perceive the environment in similar environments has a huge advantage over vision. Therefore, in order to improve the perception dimension of robots, robots need to have the ability of tactile perception in addition to visual perception. Therefore, tactile sensors are crucial for the interaction between robot systems and the external environment.

[0003] The function of a tactile sensor is to measure the contact force it receives. When applied to a robot, it can measure the contact between the robot's end effector and the target object and feed it back to the robot. The robot then adjusts its position to adapt the end effector to different surfaces and complete different tasks. Common tactile sensing methods include optical, piezoresistive, piezoelectric, and capacitive. Most piezoresistive and piezoelectric sensors can only measure one-dimensional force, are easily affected by the environment, and have low repeatability. Although optical array sensors can infer three-dimensional force distribution through visual information, their measurement accuracy is low and they are limited by the principle, and their volume is often large. Capacitive tactile sensing methods are expected to become an effective sensing method for mapping the contact characteristics between the robot's end effector and the target object through tactile means because of their high measurable sensitivity, ability to measure multi-dimensional forces, fast response speed, and simple device structure. However, existing capacitive tactile sensing methods are difficult to achieve both high sensitivity and high resolution when performing more sophisticated multi-dimensional measurements of tactile actions. Summary of the invention

[0004] The purpose of the present application is to provide an array substrate and a tactile sensor using the array substrate, which can realize multi-dimensional and multi-point force perception, improve the resolution and sensitivity of force perception, and have both high resolution and high sensitivity.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In the first aspect, the present application provides an array substrate, which includes: an array electrode plate, an ion gel layer and a common electrode plate; the ion gel layer is arranged between the array electrode plate and the common electrode plate; a plurality of array electrodes arranged in an array are arranged in the array electrode plate; a capacitor structure is formed between each of the array electrodes, the ion gel layer and the common electrode plate; when a normal force acts, the ion gel layer is compressed, and the distance between the array electrode and the common electrode plate in each capacitor structure changes, generating a plurality of first capacitance difference signals; when a tangential force acts, the facing area between the array electrode and the common electrode plate in each capacitor structure changes, generating a plurality of second capacitance difference signals; the normal force is a force applied in a direction perpendicular to the array substrate; and the tangential force is a force applied in a direction horizontal to the array substrate.

[0007] In a second aspect, the present application further provides a tactile sensor using an array substrate, wherein the tactile sensor using the array substrate is connected to a host computer, and the tactile sensor using the array substrate comprises: a main board, a flexible flat cable, and the array substrate described above; the array substrate is connected to the main board through the flexible flat cable, and the array substrate is used to generate a plurality of first capacitance difference signals when a normal force acts, and transmit the plurality of first capacitance difference signals to the main board through the flexible flat cable; when a tangential force acts, a plurality of second capacitance difference signals are generated, and the plurality of second capacitance difference signals are transmitted to the main board through the flexible flat cable; the main board is connected to the host computer, and the main board is used to perform analog-to-digital conversion on the plurality of first capacitance difference signals and the plurality of second capacitance difference signals to obtain a plurality of first capacitance difference digital signals and a plurality of second capacitance difference digital signals, and calculate a plurality of normal force values ​​based on the plurality of first capacitance difference digital signals, and calculate a plurality of tangential force values ​​based on the plurality of second capacitance difference digital signals, and transmit each normal force value and its corresponding position of the array electrode, as well as each tangential force value and its corresponding position of the array electrode to the host computer.

[0008] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0009] The present application realizes multi-dimensional and multi-point force perception by means of a plurality of array electrodes arranged in an array, thereby improving the resolution of force perception, and improving the sensitivity of force perception by using an ion gel layer as a dielectric, thereby achieving both high resolution and high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A schematic structural diagram of an array substrate provided in an embodiment of the present application.

[0012] Figure 2 A schematic diagram of the structure of an array substrate and a flexible flat cable provided in an embodiment of the present application.

[0013] Figure 3 A schematic diagram of the mainboard structure provided in an embodiment of the present application.

[0014] Figure 4 A schematic diagram of the structure of the array electrode plate provided in an embodiment of the present application.

[0015] Figure 5 A schematic diagram of the normal force provided in an embodiment of the present application.

[0016] Figure 6 This is a schematic diagram of the tangential force provided in an embodiment of the present application.

[0017] Reference numerals:

[0018] Array electrode plate-1, ion gel layer-2, common electrode plate-3, array electrode-11, CDC conversion module-31, main control module-32, communication module-33 and voltage stabilization module-34. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] Embodiment 1, as Figure 1 As shown, this embodiment provides an array substrate, which includes: an array electrode plate 1 , an ion gel layer 2 and a common electrode plate 3 .

[0022] The ion gel layer 2 is arranged between the array electrode plate 1 and the common electrode plate 3 ; a plurality of array electrodes 11 arranged in an array are arranged in the array electrode plate 1 ; a capacitor structure is formed between each array electrode 11 , the ion gel layer 2 and the common electrode plate 3 .

[0023] When a normal force acts, the ion gel layer 2 is compressed, and the distance between the array electrode 11 and the common electrode plate 3 in each capacitor structure changes, generating a plurality of first capacitance difference signals; when a tangential force acts, the facing area between the array electrode 11 and the common electrode plate 3 in each capacitor structure changes, generating a plurality of second capacitance difference signals; the normal force is a force applied in a direction perpendicular to the array substrate; the tangential force is a force applied in a direction horizontal to the array substrate.

[0024] Optionally, the ion gel layer 2 is an ion gel specially made according to different usage scenarios, which serves as the dielectric layer of the sensing unit capacitor. The main components of the ion gel layer 2 are polyvinyl alcohol PVA-210, polyacrylic acid PAA, and methylimidazole trifluoromethanesulfonate [EMIM] [OTF], which are mixed in a certain proportion as needed. The ion gel layer 2 has a double electric layer effect and a high relative dielectric constant, which can achieve highly sensitive force measurement. The double electric layer effect and high relative dielectric constant on the contact surface with different materials can greatly improve the tactile sensitivity of the sensor.

[0025] Optionally, the common plate is connected to a square wave excitation terminal of the CDC conversion module 31 .

[0026] In actual application, the array electrode plate 1 is a four-layer circuit board, and the top and bottom layers of the circuit board are copper-plated and connected to active shielding, which can reduce noise and improve the signal-to-noise ratio. The inner two layers are used for routing, and the bottom layer is an array of gold fingers and multiple array electrodes 11. The array electrodes 11 correspond to the common electrodes of the lower electrode plate to form an array capacitor. Its array structure can meet the normal force and tangential force measurement requirements. The gold fingers are responsible for transmitting capacitance signals (multiple first capacitance difference signals and multiple second capacitance difference signals) to the mainboard.

[0027] The common electrode plate 3 is a two-layer circuit board. The top circuit board is used for the common electrodes arranged in an array, which corresponds to the array electrode 11 of the array electrode plate 1. The common electrode is connected to active excitation, which can effectively suppress noise, improve the signal-to-noise ratio, and improve measurement stability. The bottom circuit board is used for routing. The top circuit board and the bottom circuit board are copper-plated as a whole and connected to active shielding. The array electrode plate 1 and the common electrode plate 3 are connected by welding through the upper and lower pads in the connection area, thereby realizing active excitation signal transmission and ground shielding.

[0028] like Figure 4 As shown, c1, c2, c3 and c4 are array electrodes 11, the bottom layer is a common electrode, and the middle layer is a capacitor intermediate ion gel dielectric layer. Figure 5 The measurement principle of normal force is shown. When the normal force F z When applied to the upper surface of the array substrate, the middle ion gel dielectric layer is compressed. Through the difference in the distance between the front and rear plates Δd, the first capacitance change ΔC1 can be obtained according to the parallel plate capacitance calculation formula. The elastic body positive pressure-strain model can establish ΔC1 and F z The relationship between. Figure 6 The tangential force measurement principle is shown. When the tangential force F x , applied to the upper surface of the array substrate, the facing area changes, and the second capacitance change ΔC2 can be obtained according to the parallel plate capacitance calculation formula through the front and rear plate facing area difference Δx. ΔC2 and F can be established through the elastic body positive pressure-strain model. x The relationship between the normal force and the tangential force can be measured.

[0029] Furthermore, the array substrate also includes: a first optically clear adhesive (OCA) layer 14 and a second optical adhesive layer; the first optical adhesive layer is arranged between the array electrode plate 1 and the ion gel layer 2; the first optical adhesive layer is used to bond the array electrode plate 1 and the ion gel layer 2; the second optical adhesive layer is arranged between the ion gel layer 2 and the common electrode plate 3; the second optical adhesive layer is used to bond the ion gel layer 2 and the common electrode plate 3.

[0030] Optionally, the first optical adhesive layer and the second optical adhesive layer are both organic capacitive pressure-sensitive adhesives, and the first optical adhesive layer and the second optical adhesive layer have good physical and chemical stability and viscosity, which can improve the integration rate and working stability of the array substrate.

[0031] Optionally, when integrating the array substrate, a silane coupling agent is used as an adhesive between the array electrode plate 1, the ion gel layer 2, the common electrode plate 3, the first optical adhesive layer and the second optical adhesive layer to enhance the structural stability between the dielectric layers.

[0032] Furthermore, the array arrangement of the plurality of array electrodes 11 is a 2×6 arrangement.

[0033] Furthermore, the first side length of the array electrode plate 1 ranges from 3mm to 5mm, and the second side length of the array electrode plate 1 ranges from 8mm to 12mm; the first side length of the array electrode 11 ranges from 0.8mm to 1.5mm, and the second side length of the array electrode 11 ranges from 0.8mm to 1.5mm.

[0034] Furthermore, the spacing distance between the array electrodes 11 is 0.3 mm to 0.6 mm.

[0035] Furthermore, a plurality of common electrodes are arranged in the common electrode plate 3 .

[0036] Embodiment 2, as Figure 2-Figure 3 As shown, the present application also discloses a tactile sensor using an array substrate. The tactile sensor using the array substrate is connected to a host computer. The tactile sensor using the array substrate includes: a mainboard, a flexible flat cable and the above array substrate.

[0037] The array substrate is connected to the main board through a flexible flat cable. The array substrate is used to generate multiple first capacitance difference signals when a normal force is applied, and transmit the multiple first capacitance difference signals to the main board through the flexible flat cable; when a tangential force is applied, it generates multiple second capacitance difference signals, and transmits the multiple second capacitance difference signals to the main board through the flexible flat cable.

[0038] The main board is connected to a host computer, and is used to perform analog-to-digital conversion on multiple first capacitance difference signals and multiple second capacitance difference signals to obtain multiple first capacitance difference digital signals and multiple second capacitance difference digital signals, and calculate multiple normal force values ​​based on the multiple first capacitance difference digital signals, calculate multiple tangential force values ​​based on the multiple second capacitance difference digital signals, and transmit each normal force value and its corresponding position of the array electrode 11, as well as each tangential force value and its corresponding position of the array electrode 11 to the host computer.

[0039] Optionally, the flexible flat cable includes a signal transmission section and a connection area, and the sensing unit is responsible for collecting capacitance signals (multiple first capacitance difference signals and multiple second capacitance difference signals) generated by the contact between the sensor and the target object (normal force and tangential force).

[0040] Furthermore, the main board includes: a CDC conversion module 31 , a main control module 32 and a communication module 33 .

[0041] The CDC conversion module 31 is connected to the flexible flat cable and the main control module 32 respectively; the main control module 32 is connected to the host computer through the communication module 33.

[0042] The CDC conversion module 31 obtains a plurality of first capacitance difference digital signals and a plurality of second capacitance difference digital signals by performing analog-to-digital conversion on a plurality of first capacitance difference signals and a plurality of second capacitance difference digital signals; the main control module 32 calculates a plurality of normal force values ​​based on the plurality of first capacitance difference digital signals, calculates a plurality of tangential force values ​​based on the plurality of second capacitance difference digital signals, and transmits each normal force value and its corresponding position of the array electrode 11, as well as each tangential force value and its corresponding position of the array electrode 11 to the host computer through the communication module 33.

[0043] Furthermore, the CDC conversion module 31 adopts the AD7142 chip.

[0044] Furthermore, the main control module 32 adopts an STM32 chip.

[0045] Optionally, the mainboard further includes: a voltage stabilizing module 34; the voltage stabilizing module 34 is used to regulate the input voltage of the mainboard.

[0046] In actual application, the mainboard in this implementation is responsible for real-time processing of 12 capacitance signals (multiple first capacitance difference signals and multiple second capacitance difference signals) collected by the array substrate and uploading them to the host computer. Among them, the mainboard is a four-layer circuit board, which is the top device layer, the internal wiring layer, the internal shielding layer, and the bottom shielding layer from top to bottom. The top device layer includes main modules such as CDC conversion module 31, communication module 33, main control module 32, voltage stabilization module 34, etc. These modules can realize the main functions of the mainboard.

[0047] The function of the CDC conversion module 31 is mainly realized by the programmable CDC conversion chip. The array electrode plate 1 in the array substrate is connected to the 12 channels of the CDC conversion module 31, and the common electrode plate 3 is connected to the square wave excitation of the CDC conversion module 31. The programmable CDC conversion chip converts the capacitance variation (multiple first capacitance difference signals and multiple second capacitance difference signals) generated by the array capacitor into a digital variation (multiple first capacitance difference digital signals and multiple second capacitance difference digital signals) in real time, which is sent to the host computer by the STM32 chip via the communication module 33, thereby realizing the measurement of the capacitance variation caused by the normal force and the tangential force and hardware decoupling. In addition, the active shielding is used to isolate the wiring of each detection channel drawn from the programmable CDC conversion chip, thereby reducing the generation of coupling capacitance between the lines.

[0048] Optionally, the communication module 33 includes: a gold finger connection port, a USB connection port, a download port and a serial port; the gold finger connection port is used for connecting between the array substrate and the sensor main board to realize the transmission of capacitance signals (multiple first capacitance difference signals and multiple second capacitance difference signals) from the array substrate to the main board; the serial port and USB communication are used for connecting and communicating with the host computer; the download port is used to burn the required program.

[0049] Optionally, the chip of the main control module 32 is composed of an STM32 chip. As the main control chip, STM32 is responsible for managing each module and processing the main functions such as uploading and collecting data. The internal wiring layer of the sensor mainboard is responsible for signal wiring and connecting each channel of the sensor. The internal shielding layer and the bottom shielding layer structure are mainly used to isolate the internal wiring and the bottom and top layer signals, reduce the coupling capacitance in the circuit, reduce noise interference, and improve the signal-to-noise ratio.

[0050] The technical effects of this application are as follows.

[0051] The present application realizes multi-dimensional and multi-point force sensing through multiple array electrodes arranged in an array, improves the resolution of force sensing, and improves the sensitivity of force sensing by using an ion gel layer as a dielectric, thereby achieving both high resolution and high sensitivity. In addition, traditional array sensors have large noise and crosstalk. Based on the sensor array substrate structure design and sensor mainboard shielding and routing design of the present invention, noise and crosstalk suppression of multi-channel capacitive signals are achieved, achieving efficient signal acquisition.

[0052] All actions to obtain signals, information or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where they are located, and with the authorization given by the owner of the corresponding device.

[0053] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. An array substrate, characterized in that: The array substrate comprises: an array electrode plate, an ion gel layer and a common electrode plate; The ion gel layer is arranged between the array electrode plate and the common electrode plate; a plurality of array electrodes arranged in an array are arranged in the array electrode plate; a capacitor structure is formed between each of the array electrodes, the ion gel layer and the common electrode plate; When a normal force acts, the ion gel layer is compressed, and the distance between the array electrode and the common electrode plate in each capacitor structure changes, generating a plurality of first capacitance difference signals; when a tangential force acts, the facing area between the array electrode and the common electrode plate in each capacitor structure changes, generating a plurality of second capacitance difference signals; the normal force is a force applied in a direction perpendicular to the array substrate; and the tangential force is a force applied in a direction horizontal to the array substrate.

2. The array substrate according to claim 1, characterized in that: The array substrate further comprises: a first optical adhesive layer and a second optical adhesive layer; The first optical adhesive layer is disposed between the array electrode plate and the ion gel layer; the first optical adhesive layer is used to bond the array electrode plate and the ion gel layer; The second optical adhesive layer is arranged between the ion gel layer and the common electrode plate; the second optical adhesive layer is used for bonding the ion gel layer and the common electrode plate.

3. The array substrate according to claim 1, characterized in that: The array arrangement of the plurality of array-type electrodes is 2×6.

4. The array substrate according to claim 1, characterized in that: The first side length of the array electrode plate ranges from 3mm to 5mm, and the second side length of the array electrode plate ranges from 8mm to 12mm; the first side length of the array electrode ranges from 0.8mm to 1.5mm, and the second side length of the array electrode ranges from 0.8mm to 1.5mm.

5. The array substrate according to claim 1, characterized in that: The spacing distance between the array electrodes is 0.3 mm to 0.6 mm.

6. The array substrate according to claim 1, characterized in that: A plurality of common electrodes are arranged in the common electrode plate.

7. A tactile sensor using an array substrate, wherein the tactile sensor using the array substrate is connected to a host computer, characterized in that: The tactile sensor using the array substrate comprises: a mainboard, a flexible flat cable and the array substrate according to any one of claims 1 to 6; The array substrate is connected to the mainboard through the flexible flat cable. The array substrate is used to generate a plurality of first capacitance difference signals when a normal force acts, and transmit the plurality of first capacitance difference signals to the mainboard through the flexible flat cable; when a tangential force acts, it generates a plurality of second capacitance difference signals, and transmits the plurality of second capacitance difference signals to the mainboard through the flexible flat cable; The mainboard is connected to the host computer, and the mainboard is used to perform analog-to-digital conversion on multiple first capacitance difference signals and multiple second capacitance difference signals to obtain multiple first capacitance difference digital signals and multiple second capacitance difference digital signals, and calculate multiple normal force values ​​based on the multiple first capacitance difference digital signals, calculate multiple tangential force values ​​based on the multiple second capacitance difference digital signals, and transmit each normal force value and its corresponding position of the array electrode, as well as each tangential force value and its corresponding position of the array electrode to the host computer.

8. The tactile sensor using the array substrate according to claim 7, characterized in that: The main board includes: a CDC conversion module, a main control module and a communication module; The CDC conversion module is connected to the flexible flat cable and the main control module respectively; the main control module is connected to the host computer through the communication module; The CDC conversion module obtains multiple first capacitance difference digital signals and multiple second capacitance difference digital signals by performing analog-to-digital conversion on multiple first capacitance difference signals and multiple second capacitance difference digital signals; the main control module calculates multiple normal force values ​​based on the multiple first capacitance difference digital signals, calculates multiple tangential force values ​​based on the multiple second capacitance difference digital signals, and transmits each normal force value and its corresponding position of the array electrode, as well as each tangential force value and its corresponding position of the array electrode to the host computer through the communication module.

9. The tactile sensor using the array substrate according to claim 8, characterized in that: The CDC conversion module adopts the AD7142 chip.

10. The tactile sensor using the array substrate according to claim 8, characterized in that: The main control module adopts the STM32 chip.

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