CN113607307B - Tactile sensor, preparation method thereof and force and/or moment measuring device - Google Patents
Tactile sensor, preparation method thereof and force and/or moment measuring device Download PDFInfo
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- CN113607307B CN113607307B CN202111024983.9A CN202111024983A CN113607307B CN 113607307 B CN113607307 B CN 113607307B CN 202111024983 A CN202111024983 A CN 202111024983A CN 113607307 B CN113607307 B CN 113607307B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/14—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators
- G01L1/142—Measuring force or stress, in general by measuring variations in capacitance or inductance of electrical elements, e.g. by measuring variations of frequency of electrical oscillators using capacitors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/16—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring several components of force
- G01L5/165—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring several components of force using variations in capacitance
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Abstract
The invention discloses a tactile sensor, a preparation method thereof and a force and/or moment measuring device, wherein the tactile sensor sequentially comprises the following components from top to bottom: the upper substrate, the upper electrode, the dielectric layer, the lower electrode and the lower substrate can be used for sensing positive pressure, shearing force and moment. According to the invention, a plurality of pairs of interdigital electrodes which are opposite in mirror image and symmetrically distributed in an array manner are arranged as the upper layer electrode and the lower layer electrode, so that high-sensitivity induction of multi-dimensional force and/or moment based on a single-layer structure is realized, and the spatial resolution capability of normal positive pressure is improved. By adopting the film pressing molding method to expand the dielectric layer in an array manner, the preparation cost of the touch sensor is reduced, and the preparation process of the touch sensor is simplified. The touch sensor is connected with the processor, the processor is used for determining the stress type according to the sensing signals of the touch sensor, and corresponding force and/or moment values are obtained through calculation, so that the measurement of the multi-dimensional force and/or moment is realized.
Description
Technical Field
The invention relates to the field of sensing devices, in particular to a touch sensor, a preparation method thereof and a force and/or moment measuring device.
Background
With the continuous development of robot intelligence, many daily works can be completed by replacing human with an intelligent robot, for example, the intelligent robot replaces human to enter forest fire for fire extinguishing, and a scalpel is held by hand for small-sized surgery for a patient, and the above environments mainly play a role in robot dexterity, which is based on the environment. The dexterous robot hand is composed of a plurality of fingers by simulating the hand of a human, and each finger can be regarded as a flexibly moving tandem robot.
In order to complete the tasks of grabbing and operating objects, a plurality of fingers are required to be coordinated, and the precondition of the coordination is that the dexterous hand can acquire enough environment information, such as shape and size, so as to adjust the grabbing state according to the acquired external environment information. Since the dexterous robot hand is to imitate human beings to complete the grabbing and releasing actions of various objects, it is necessary to acquire related sensing information. The touch sensor used on the dexterous fingertip of the robot can effectively acquire information such as the shape and the position of a contact object, is important for improving the actual operation capacity of the dexterous hand of the robot, can be called as a second pair of eyes of the robot, and has the most prominent characteristic of small volume.
The information of the relevant force of the fingertips when the dexterous hand of the robot is grabbed cannot be comprehensively reflected only by single-degree-of-freedom detection. In order to adapt to various external stimuli, the dexterous hand of the robot needs to have high-sensitivity sensing capability of normal positive pressure, shearing force, moment and other related information. In the research course of the touch sensor, the touch sensor formed by stacking a plurality of dielectric layers can only realize the detection of three-degree-of-freedom force and moment. However, the multi-path signal lines led out from the electrode array easily cause complex wiring, and influence of irrelevant capacitance signals exists, so that high precision of the sensor cannot be realized. Meanwhile, the array expansion of the electrodes and the dielectric layer can lead to large volume of the sensor, and the sensor is not easy to be applied to the force perception of the fingertips at the tail ends of the dexterous hands of the robot.
Currently, the existing media structures and fabrication processes limit the integration and sensitivity of tactile sensors. The touch sensor formed by stacking the multiple dielectric layers is complex in manufacturing process, the transfer dielectric layers need to be transferred by using the transfer film in the process of integrating the sensor through the steps of die reversing and the like, the transfer dielectric layers are difficult to avoid dragging in the transfer process, the dielectric layers are extremely easy to damage, the sensitivity detection of the sensor is finally influenced, time and labor are wasted, and the measuring range of the sensor is greatly limited due to the fact that the manufacturing process is immature and the problem that the bonding strength between the stacked structures of the multiple layers is not enough.
At present, single-point detection cannot meet the fingertip requirements of dexterous hands of robots, and in order to achieve more comprehensive reflection of actions such as inserting, pulling, rotating and screwing of objects, omnibearing array type expansion is urgently needed to achieve space multipoint detection.
In conclusion, the existing touch sensor has the problems of low sensitivity, large volume, complex and unreliable process manufacturing flow, incapability of meeting the requirement of single-point detection and the like, can not accurately reflect the relevant information of force when the robot captures the dexterous fingertip, and has the conditions of mistaken grasping, mistaken placement and the like. Therefore, the touch sensor applied to the dexterous fingertips of the robot is required to have the characteristics of multi-dimension, high sensitivity, miniaturization, simple and convenient process, high spatial resolution and the like.
Disclosure of Invention
The invention aims to provide a touch sensor, a preparation method thereof and a force and/or moment measuring device, which can improve the sensitivity and the spatial resolution of the touch sensor, reduce the preparation cost of the touch sensor, simplify the preparation process of the touch sensor and simultaneously realize the measurement of multi-dimensional force and/or moment.
In order to achieve the purpose, the invention provides the following scheme:
a tactile sensor, the tactile sensor from top to bottom includes in proper order:
the top layer of the upper layer substrate is integrally coated with copper and is connected with a source shielding electrode;
the upper layer electrode is arranged at the bottom layer of the upper layer substrate and consists of a plurality of pairs of interdigital electrodes which are symmetrically distributed in an array manner; each pair of interdigital electrodes of the upper layer electrode comprises two first working electrodes; the two first working electrodes are respectively connected with the grounding electrode and the active shielding electrode;
the dielectric layer is composed of a plurality of dielectric blocks distributed in an array manner;
the lower layer electrode consists of a plurality of pairs of interdigital electrodes which are distributed in a mirror image opposite mode with the pairs of interdigital electrodes of the upper layer electrode; each pair of interdigital electrodes of the lower layer electrode comprises two second working electrodes; the two second working electrodes are respectively connected with two paths of signal electrodes led out by the digital signal processing chip; the upper electrode, the dielectric layer and the lower electrode together form a plurality of capacitors; the number of the capacitors is equal to the number of the first working electrodes or the second working electrodes;
the top layer is used for arranging the lower electrode, and the bottom layer is used for packaging the digital signal processing chip; the digital signal processing chip is used for acquiring capacitance value variation of the capacitors to obtain corresponding sensing signals, so that force and/or moment can be determined according to the sensing signals.
Optionally, theThe dielectric layers are evenly arranged in arrays of 3*3
The silicon RTV silicon rubber is composed of rectangular blocks made of silicon rubber; the filling rate of the dielectric layer is 19%.
Optionally, the upper layer electrode and the lower layer electrode are both composed of 4 pairs of interdigital electrodes in 2*2 array-type symmetrical distribution.
Optionally, the interdigital electrodes are structurally divided into two types of transverse penetration and longitudinal penetration; in the pairs of interdigital electrodes of the upper layer electrode and the lower layer electrode, the interdigital electrodes which are transversely inserted and the interdigital electrodes which are longitudinally inserted are alternately distributed.
Optionally, there is a displacement of a set magnitude in alignment between the pairs of interdigitated electrodes of the upper layer electrode and the pairs of interdigitated electrodes of the lower layer electrode.
Optionally, the tactile sensor further comprises:
the FPC connector is welded on the lower surface of the lower substrate and is connected with the digital signal processing chip;
the adapter plate is welded on the lower surface of the lower-layer substrate and connected with the FPC connector.
Optionally, the upper substrate is a four-layer plate; the upper substrate sequentially comprises from top to bottom:
a first layer, a second layer, a third layer and a fourth layer;
the first layer is a top layer of the upper substrate; the fourth layer is the bottom layer of the upper substrate;
the second layer is tightly attached to the first layer, integrally coated with copper and connected with a source shielding electrode;
the third layer is tightly attached to the second layer and the fourth layer, integrally covers copper, and is connected with a source shielding electrode.
Optionally, the lower substrate is a four-layer plate; the lower floor's base plate includes from top to bottom in proper order:
a fifth layer, a sixth layer, a seventh layer, and an eighth layer;
the fifth layer is the top layer of the lower substrate; the eighth layer is the bottom layer of the lower substrate;
the sixth layer is tightly attached to the fifth layer, integrally coated with copper and connected with a source shielding electrode;
the seventh layer is closely attached to the sixth layer and the eighth layer and used for wiring distribution.
The invention also provides a preparation method of the touch sensor, wherein the upper layer electrode is tightly attached to the upper layer substrate to form an upper layer printed circuit board; the lower electrode is tightly attached to the lower substrate to form a lower printed circuit board; the preparation method comprises the following steps:
preparing an SMT steel mesh;
scraping a layer of adhesive layer on the upper surface of the lower electrode by using a blade to serve as a first adhesive layer;
pouring a dielectric material on the first adhesive layer;
uniformly coating a medium material on the first adhesive layer;
after the surface coated with the medium material is vacuumized, placing the SMT steel mesh and covering a PET film;
compacting for 12 hours by using a heavy object after turning;
after the heavy object is taken down, turning over again, removing the PET film, taking down the SMT steel mesh, and forming a dielectric layer consisting of a plurality of dielectric blocks distributed in an array manner on the upper surface of the lower electrode;
scraping a bonding layer on the lower surface of the upper electrode by using a blade to serve as a second bonding layer, and positioning and integrating the upper printed circuit board and the lower printed circuit board together through pins;
compacting for 12 hours by using a heavy object;
and (5) taking down the weight to obtain the touch sensor.
The invention also provides a force and/or moment measuring device, which comprises the tactile sensor and a processor;
the processor is connected with the digital signal processing chip and used for determining the stress type of the touch sensor according to the sensing signal, calculating corresponding capacitance value variation according to the sensing signal and the stress type, and obtaining the value of the force and/or the moment according to the corresponding relation between the capacitance value variation and the force and/or the moment.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a touch sensor, a preparation method thereof and a force and/or moment measuring device, wherein the touch sensor sequentially comprises the following components from top to bottom: the upper substrate, the upper electrode, the dielectric layer, the lower electrode and the lower substrate can be used for sensing positive pressure, shearing force and moment and obtaining corresponding sensing signals. According to the invention, a plurality of pairs of interdigital electrodes which are opposite in mirror image and symmetrically distributed in an array mode are arranged as the upper electrode and the lower electrode, so that high-sensitivity induction of five-degree-of-freedom force and/or moment based on a single dielectric layer structure is realized, and the spatial resolution capability of normal positive pressure is improved. By adopting the film pressing molding method to expand the dielectric layer in an array manner, the preparation cost of the touch sensor is reduced, and the preparation process of the touch sensor is simplified. The touch sensor is connected with the processor, the processor is used for determining the stress type according to the sensing signals sensed by the touch sensor, and corresponding force and/or moment values are calculated, so that the measurement of the multi-dimensional force and/or moment is realized.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a schematic three-dimensional exploded view of a tactile sensor according to the present invention;
FIG. 2 is a top view of a lower electrode of a tactile sensor according to the present invention;
FIG. 3 is a schematic diagram illustrating the operation of a tactile sensor according to the present invention;
FIG. 4 is a circuit diagram of a digital signal processing chip and its peripheral circuits of a touch sensor according to the present invention;
FIG. 5 is a schematic diagram of the working principle of a force and/or moment measuring device provided by the present invention;
fig. 6 is a flowchart of a method for manufacturing a touch sensor according to the present invention.
Description of the symbols: the touch sensor comprises a touch sensor-1, an upper substrate-2, an upper electrode-3, a dielectric layer-4, a lower electrode-5 and a lower substrate-6.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
The invention aims to provide a touch sensor, a preparation method thereof and a force and/or moment measuring device, which can improve the sensitivity and the spatial resolution of the touch sensor, reduce the preparation cost of the touch sensor, simplify the preparation process of the touch sensor and simultaneously realize the measurement of multi-dimensional force and/or moment based on a single dielectric layer structure.
The specific arrangement and the working principle of the tactile sensor provided by the invention are shown in embodiment 1, the specific arrangement and the working principle of the force and/or moment measuring device realized based on the tactile sensor are shown in embodiment 2, and the preparation method of the tactile sensor provided by the invention is shown in embodiment 3.
Example 1
Fig. 1 is a schematic three-dimensional explosion diagram of a tactile sensor according to the present invention, and as shown in fig. 1, the tactile sensor 1 sequentially includes an upper substrate 2, an upper electrode 3, a dielectric layer 4, a lower electrode 5, and a lower substrate 6 from top to bottom.
Specifically, the top layer of the upper substrate 2 is entirely coated with copper and is connected with a source shield.
The upper layer electrode 3 is arranged at the bottom layer of the upper layer substrate 2 and consists of a plurality of pairs of interdigital electrodes which are symmetrically distributed in an array manner; each pair of interdigital electrodes of the upper layer electrode 3 comprises two first working electrodes; the two first working electrodes are respectively connected with the grounding electrode and the active shielding electrode. According to the invention, the grounding electrode and the active shielding electrode are alternately distributed, so that the interference of stray capacitance is eliminated, and the sensitivity and accuracy of the touch sensor are improved.
The dielectric layer 4 is composed of a plurality of dielectric blocks distributed in an array. In this embodiment, the dielectric layer 4 is used as a sensing element of the touch sensor, and is preferably a layer of 3*3 rectangular small blocks made of silicone rubber and uniformly arranged in an array manner; the type of silicone rubber is preferably one having a high shear modulus of elasticity
Silicone RTV Silicone rubber; the height of the dielectric layer 4 is about 80 μm; the filling rate of the dielectric layer 4 is 19%, and compared with a solid dielectric layer with the filling rate of 100% in the prior art, the touch sensor provided by the invention improves the sensitivity of the multi-dimensional force and/or torque induction by reducing the filling rate of the dielectric layer 4.
The lower electrode 5 consists of a plurality of pairs of interdigital electrodes which are distributed in a mirror image opposite manner with the plurality of pairs of interdigital electrodes of the upper electrode 3; each pair of interdigital electrodes of the lower electrode 5 comprises two second working electrodes; the two second working electrodes are respectively connected with two paths of signal electrodes led out by the digital signal processing chip; the upper electrode 3, the dielectric layer 4 and the lower electrode 5 together form a plurality of capacitors; the number of the capacitors is equal to the number of the first working electrodes or the second working electrodes.
The top layer of the lower substrate 6 is used for arranging the lower electrode 5; the bottom layer of the lower substrate 6 is used for packaging the digital signal processing chip; the digital signal processing chip is used for acquiring capacitance value variation of the capacitors to obtain corresponding sensing signals; the sensor signals are used to determine forces and/or torques in subsequent processing. According to the invention, the digital signal processing chip and the peripheral circuit thereof are integrated in the touch sensor, so that the digital signal processing chip and the peripheral circuit thereof can be used for realizing capacitance signal analog-to-digital conversion, signal active shielding and the like, and the influence of other interference signals is obviously reduced.
In this embodiment, the upper substrate 2 and the lower substrate 6 are made of FR-4 grade flame-retardant material. Meanwhile, the distance between the upper electrode 3 and the lower electrode 5 is limited by the current PCB processing technology and is 100 μm. The touch sensor provided by the invention has the advantages that the two working electrodes of each pair of interdigital electrodes are closely arranged while the sensitivity is ensured as much as possible, and the electrical elements on the touch sensor are highly integrated and closely arranged, so that the problem of overlarge volume of the conventional touch sensor is solved, the touch sensor is miniaturized, and the touch sensor can be flexibly applied to smart finger tips.
In this embodiment, the upper electrode 3 is closely attached to the upper substrate 2 to form an upper printed circuit board; the lower electrode 5 is closely attached to the lower substrate 6 to form a lower printed circuit board.
In this embodiment, the size of the upper printed circuit board is 11mm × 11mm, and the size of the lower printed circuit board is 11mm × 24mm. The upper layer electrode 3 and the lower layer electrode 5 are composed of 4 pairs of interdigital electrodes which are symmetrically distributed in a 2*2 array mode. But not limited to this, the sizes of the upper printed circuit board and the lower printed circuit board, and the number of pairs and arrangement of the interdigital electrodes can be adjusted according to actual needs. According to the invention, the 2*2 array type expansion is carried out on the upper layer electrode 3 and the lower layer electrode 5, the traditional single-point detection is replaced, the high spatial resolution detection of 4 blocks of areas is realized, and the captured information can be reflected more comprehensively.
In this embodiment, the interdigital electrodes are structurally divided into two types, namely, a transverse penetration and a longitudinal penetration; in the pairs of interdigital electrodes of the upper layer electrode 3 and the lower layer electrode 5, the interdigital electrodes which are transversely inserted and the interdigital electrodes which are longitudinally inserted are alternately distributed.
The upper layer electrode 3 and the lower layer electrode 5 are exemplified by 4 pairs of interdigital electrodes in 2*2 array distribution, fig. 2 is a top view of the lower layer electrode 5 of the tactile sensor provided by the present invention, as shown in fig. 2, the upper left pair of interdigital electrodes is a longitudinal insertion structure, the lower left and upper right pairs of interdigital electrodes adjacent to the upper left pair of interdigital electrodes are both in a transverse insertion structure, and so on, thereby realizing that the interdigital electrodes which are transversely inserted and the interdigital electrodes which are longitudinally inserted are alternately distributed.
Further, there is a small amount of displacement in alignment between the pairs of interdigital electrodes of the upper layer electrode 3 and the pairs of interdigital electrodes of the lower layer electrode 5 to generate a pair of differential signals between every two adjacent capacitor plates, thereby further improving the sensitivity of the touch sensor in the sensing direction of the shear force. The specific value of the displacement is obtained by adjusting according to a plurality of tests.
Preferably, the tactile sensor further comprises: FPC connector and keysets. Specifically, the FPC connector is soldered to the lower surface of the lower substrate 6 and connected to the digital signal processing chip; the adapter plate is welded on the lower surface of the lower-layer substrate 6 and connected with the FPC connector.
Compared with the mode that the touch sensor is connected with processors such as an external MCU singlechip and the like by DuPont wires in the prior art, the touch sensor is connected with the processors such as the external MCU singlechip and the like by welding the FPC connector and the adapter plate on the lower surface of the lower layer substrate 6, so that the touch sensor can be plugged in and pulled out of the processors such as the external MCU singlechip and the like at any time, and the operation is simpler and more convenient.
Further, the upper substrate 2 is a four-layer substrate; the upper substrate 2 sequentially comprises from top to bottom: a first layer, a second layer, a third layer and a fourth layer; specifically, the first layer is a top layer of the upper substrate 2; the fourth layer is the bottom layer of the upper substrate 2; the second layer is tightly attached to the first layer, and the whole body is coated with copper and is connected with a source shielding electrode; the third layer is closely attached to the second layer and the fourth layer, and the whole body is coated with copper and is connected with a source shielding electrode.
Further, the lower substrate 6 is a four-layer board; lower floor's base plate 6 includes from top to bottom in proper order: a fifth layer, a sixth layer, a seventh layer, and an eighth layer; the fifth layer is the top layer of the lower substrate 6; the eighth layer is the bottom layer of the lower substrate 6; the sixth layer is tightly attached to the fifth layer, and the whole body is coated with copper and is connected with a source shielding electrode; the seventh layer is tightly attached to the sixth layer and the eighth layer and used for wiring distribution.
The touch sensor provided by the invention is based on a capacitive working mechanism, is the same as signal acquisition units for normal pressure, shearing force and bending moment, and is of a three-layer sandwich structure consisting of an upper electrode 3, a dielectric layer 4 and a lower electrode 5. The signal acquisition unit of the touch sensor can change under the action of external force, so that the output capacitance value changes, and the magnitude of positive pressure Fz, tangential force Fx/Fy and moment Mx/My acting on the touch sensor can be sensed by acquiring the variable quantity of the capacitance of the signal acquisition unit.
9 dielectric layers 4 are uniformly arranged in 3*3 array type
The silicon RTV silicon rubber material is a rectangular block, and the working principle diagram of the touch sensor provided by the invention is shown in FIG. 3.
Under the action of a tangential force Fx in the x-axis direction or a shearing force Fy in the y-axis direction of the tactile sensor (as shown in (a) in fig. 3), a shearing electrode strip (namely, an upper electrode 3) of a bifurcate finger-shaped structure on an upper printed circuit board generates a tangential displacement delta L relative to a fixed electrode strip (namely, a lower electrode 5) on a lower printed circuit board, so that the facing area S of a capacitor plate of a signal acquisition unit is influenced, the output of a capacitance value C of the signal acquisition unit is changed, and the measurement of the tangential force can be realized by measuring the variation of the capacitance value. Wherein, the bifurcate finger-shaped structure electrode arranged on the upper layer printed circuit board can improve the sensitivity of the touch sensor to the shearing force by realizing the difference.
In order to improve the decoupling capability to the positive pressure during the detection of the shearing force, in this embodiment, the width of the interdigital electrode on the lower printed circuit board is increased, so that the total facing area of the upper electrode and the lower electrode is ensured to be unchanged when the touch sensor is subjected to the shearing force, and a good decoupling capability is realized. Mutual decoupling between the shearing forces perpendicular to each other (i.e. decoupling between the shearing force in the x-axis direction and the shearing force in the y-axis direction) can be realized by increasing the length of the interdigital electrodes.
Under the action of positive pressure Fz (as shown in (b) of FIG. 3), the dielectric layer 4 deforms, which results in a change in the distance d between the upper electrode 3 and the lower electrode 5, and thus the capacitance of the signal acquisition unit changes, and thus the measurement of the positive pressure can be realized by measuring the capacitance value change.
Under the action of the moment Mx in the x-axis direction or the moment My in the y-axis direction (as shown in (c) of FIG. 3), the capacitance values of the signal acquisition units will generate differences, and data calculation processing is performed by combining the capacitance value distribution difference and the distance between the capacitor plates, so that the moment measurement is realized.
Fig. 4 is a schematic diagram of a digital signal processing chip of a tactile sensor and peripheral circuits thereof according to the present invention. Table 1 shows IIC addresses corresponding to high and low levels of different ADD0 pins and ADD1 pins of the digital signal processing chip. As shown in fig. 4, in the present embodiment, the digital signal processing chip is preferably a digital capacitance conversion chip AD7147.
TABLE 1 IIC address corresponding to high and low levels of different ADD0 pins and ADD1 pins of digital signal processing chip
In actual operation, different addresses of the touch sensor can be obtained by welding two of the four resistors R5, R6, R8 and R9, and by combining the table 1, the method can obtain that ADD1=1 and ADD0=0 by welding R5 and R9, and the corresponding IIC address is 0101110 at this time; welding R5 and R8 can obtain ADD1=1 and ADD0=1, where the corresponding IIC address is 0101111; welding R6, R9 can result in ADD1=0, ADD0=0, when the corresponding IIC address is 0101100; welding R6, R8 may result in ADD1=0, ADD0=1, with the corresponding IIC address being 0101101.
As a specific implementation manner of this embodiment, the tactile sensors with different addresses are installed on the smart fingertip of the robot, the tactile sensors are connected with the MCU singlechip through the IIC protocol, and the MCU singlechip is used to identify the tactile sensors with different addresses to determine the corresponding fingertip of the finger, so that the grabbing pose can be adjusted according to the corresponding sensing information.
Example 2
The invention provides a force and/or moment measuring device which comprises a touch sensor and a processor.
The processor is connected with the digital signal processing chip and used for determining the stress type of the touch sensor according to the sensing signal output by the digital signal processing chip, calculating corresponding capacitance value variation according to the sensing signal and the stress type, and obtaining the value of the force and/or the moment according to the corresponding relation between the capacitance value variation and the force and/or the moment.
The stress types of the touch sensor comprise positive pressure in the z-axis direction, shearing force in the x-axis direction, shearing force in the y-axis direction, moment in the x-axis direction and moment in the y-axis direction.
The corresponding relation between the capacitance value variation and different types of forces and/or moments is obtained through a plurality of experimental measurements performed in advance.
As a specific implementation manner of this embodiment, the processor is preferably an MCU singlechip, but is not limited thereto, and may be adjusted according to actual needs.
Fig. 5 is a schematic view of the working principle of the force and/or moment measuring device provided by the invention. As shown in fig. 5, for example, the upper electrode and the lower electrode of the tactile sensor provided by the present invention are composed of 4 pairs of interdigital electrodes which are 2*2 in an array-type symmetric distribution, the digital signal processing chip is a digital capacitance conversion chip, and the processor is an MCU single chip microcomputer, 8 working electrodes of the 4 pairs of interdigital electrodes in the lower layer are respectively connected with 8 channels of the digital capacitance conversion chip, and then communicate with the MCU single chip microcomputer through an IIC (i.e., I2C) protocol, and the MCU single chip microcomputer is used to read and process the variation of the sensing signal output by each working electrode in real time, so as to finally obtain the corresponding force and/or torque value.
Because the output signal of digital capacitance conversion chip is the count number, consequently, the MCU singlechip needs to utilize specific formula to convert digital capacitance conversion chip output count number into the capacitance value, and specific formula is as follows:
Further, in the early test process, the MCU singlechip can also utilize a TTL-USB converter to transmit the obtained data of the capacitance variation to an upper computer through USART communication, and a computer serial port is utilized to read the data in real time and record the relative capacitance variation of Fz, fx, fy, mx and My. And then, the corresponding relation between the capacitance value and the force (namely the corresponding relation between the capacitance value variation and different types of forces and/or moments) is obtained by fitting the capacitance value variation and the corresponding acting force variation. By storing the corresponding relation between the capacitance value and the force in the MCU singlechip, the force can be reversely calculated according to the sensing signal and the corresponding relation between the capacitance value and the force. In the actual use process, the upper computer can acquire the change of the acting force in real time, so that the grabbing condition of the dexterous hand of the robot is reflected.
As a specific implementation manner of this embodiment, the method for determining the force type of the touch sensor by the processor and calculating the corresponding capacitance variation according to the sensing signal and the corresponding force type is as follows:
taking 4 pairs of interdigital electrodes symmetrically distributed in an array of 2*2 as an example of the upper electrode and the lower electrode of the tactile sensor provided by the present invention, as shown in fig. 2, C1 to C8 respectively represent capacitance values of capacitors where 8 working electrodes in the lower electrode of the tactile sensor are located.
When the tactile sensor is subjected to a normal positive pressure, C1, C2, C3, C4, C5, C6, C7, C8 all change, and the total capacitance value change of the tactile sensor is equal to the sum of 8 capacitance value changes, i.e., Δ C = Δ (C1 + C2+ C3+ C4+ C5+ C6+ C7+ C8).
When the touch sensor is subjected to a shearing force in the x-axis direction, the facing areas of the upper and lower layer polar plates of the C2, C6, C4 and C8 are changed, so that the capacitance value is changed, and the facing areas of the upper and lower layer polar plates of the capacitance values of the rest 4 capacitors are unchanged, so that the capacitance value is unchanged.
Meanwhile, since C2 and C6 form a pair of interdigital capacitors and C4 and C8 form a pair of interdigital capacitors, C2 and C6 form a pair of differential signals, and C4 and C8 form a pair of differential signals. Therefore, the total capacitance value change amount of the tactile sensor under the action of the shear force in the x-axis direction is equal to (capacitance change amount of C2-C6) + (capacitance change amount of C4-C8), i.e., Δ C = Δ (C2-C6) + Δ (C4-C8).
When the touch sensor is subjected to a shearing force in the y-axis direction, the facing areas of the upper and lower layer polar plates of the capacitors C1, C3, C5 and C7 are changed, so that the capacitance value is changed, and the facing areas of the upper and lower layer polar plates of the capacitance values of the other 4 capacitors are unchanged, so that the capacitance value is unchanged.
Meanwhile, since C1 and C3 form a pair of interdigital capacitors and C5 and C7 form a pair of interdigital capacitors, C1 and C3 form a pair of differential signals and C5 and C7 form a pair of differential signals. Therefore, the total capacitance value change amount of the tactile sensor under the action of the shear force in the y-axis direction is equal to (capacitance change amount of C1-C3) + (capacitance change amount of C5-C7), i.e., Δ C = Δ (C1-C3) + Δ (C5-C7).
The bending moment in the x-axis direction can be regarded as two normal parallel forces with equal magnitude and opposite directions, wherein all the C1, C2, C3, C4, C5, C6, C7 and C8 change, the changing directions of the C1, C3, C4 and C8 are the same, and the changing directions of the C2, C6, C5 and C7 are the same. The total capacitance value change amount of the tactile sensor is therefore (capacitance change amount of C1+ C3+ C4+ C8) - (capacitance change amount of C2+ C6+ C5+ C7), i.e., Δ C = Δ (C1 + C3+ C4+ C8) - Δ (C2 + C6+ C5+ C7).
The bending moment in the y-axis direction can be regarded as two normal parallel forces with equal magnitude and opposite directions, the C1, C2, C3, C4, C5, C6, C7 and C8 all change, the changing directions of C1, C3, C2 and C6 are the same, and the changing directions of C5, C7, C4 and C8 are the same. The total capacitance value change amount of the tactile sensor is therefore (capacitance change amount of C1+ C3+ C2+ C6) - (capacitance change amount of C5+ C7+ C4+ C8), i.e., Δ C = Δ (C1 + C3+ C2+ C6) - Δ (C5 + C7+ C4+ C8).
In this embodiment, the processor determines the force type of the tactile sensor by determining whether the capacitance value of each capacitor in the tactile sensor changes and the change direction thereof, calculates the corresponding capacitance value change according to the capacitance value change of each capacitor, the force type, and a calculation formula of the capacitance value change under the corresponding force type, and obtains the value of the force and/or the moment according to the corresponding relationship between the capacitance value change and the force and/or the moment.
Example 3
Fig. 6 is a flowchart of a method for manufacturing a tactile sensor according to the present invention. As shown in fig. 6, the method for manufacturing the tactile sensor according to the present invention is as follows:
step (a): an SMT steel mesh was prepared.
Step (b): and scraping an adhesive layer on the upper surface of the lower electrode by using a blade to form a first adhesive layer.
Step (c): a dielectric material is poured over the first adhesive layer.
A step (d): and uniformly coating a medium material on the first adhesive layer.
A step (e): and after the surface coated with the medium material is vacuumized, placing the SMT steel mesh and covering the PET film. Under the action of gravity, the medium material overflows from the pores of the SMT steel mesh and is laid between the SMT steel mesh and the PET film (as shown in (e) in FIG. 6).
Step (f): after turning over, the mixture is compacted for 12h by a heavy object.
A step (g): after the heavy object is taken down, turning over again, removing the PET film, taking down the SMT steel mesh, and forming a dielectric layer consisting of a plurality of dielectric blocks distributed in an array manner on the upper surface of the lower electrode; and scraping a bonding layer on the lower surface of the upper electrode by using a blade to serve as a second bonding layer, and positioning and integrating the upper printed circuit board and the lower printed circuit board together through pins.
A step (h): compacting with a weight for 12h.
Step (i): and (5) taking down the weight to obtain the touch sensor.
Preferably, the time interval between step (b) and step (c) is less than 5min.
Preferably, the dielectric material is
Silicone RTV Silicone rubber.
Preferably, the binder is Sil-Poxy glue; the Sil-Poxy adhesive for bonding the dielectric layer and the upper and lower printed circuit boards is a special connecting agent for silica gel and other substrate materials, has strong viscosity, is easy to adhere to the surface of a substrate to form a compact film, can ensure the adhesion between the dielectric layer and the upper and lower printed circuit boards, and breaks through the problem of insufficient range of the touch sensor.
Compared with the prior art, the invention has the following advantages:
1) Five-degree-of-freedom high-sensitivity detection: in order to respond to various external stimuli, the tactile sensor provided by the invention can simultaneously sense the positive pressure F z Shear force F x 、F y And bending moment M x 、M y . The upper and lower electrodes are made into an interdigital structure, and the dielectric layer is made into rectangular small squares distributed in an array manner, so that the filling rate of the dielectric layer is reduced, and high-sensitivity detection of positive pressure, shearing force and moment is realized.
2) The process is simple and miniaturized: according to the preparation method of the touch sensor, the dielectric layer is expanded in an array manner through the film pressing forming process, compared with the mode that the dielectric layer is manufactured in the traditional process firstly and then is transferred and integrated onto the electrode of the printed circuit board through the transfer film, the method adopts the SMT steel mesh to directly perform film pressing forming on the printed circuit board, eliminates the damage to the dielectric layer in the transfer process and avoids the introduction of bubbles, and has the advantages of being simple in process operation, low in cost and miniaturized in preparation.
3) High spatial resolution detection: the touch sensor provided by the invention expands the interdigital electrodes of the upper electrode and the lower electrode in an array manner, and realizes spatial force detection with high spatial resolution. As a small tactile sensor applied to a robot fingertip, sufficient spatially distributed force information can be provided for the robot.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to assist in understanding the core concepts of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (10)
1. The utility model provides a tactile sensor which characterized in that, tactile sensor includes from top to bottom in proper order:
the top layer of the upper layer substrate is integrally coated with copper and is connected with a source shielding electrode;
the upper layer electrode is arranged at the bottom layer of the upper layer substrate and consists of a plurality of pairs of interdigital electrodes which are symmetrically distributed in an array manner; each pair of interdigital electrodes of the upper layer electrode comprises two first working electrodes; the two first working electrodes are respectively connected with the grounding electrode and the active shielding electrode;
the dielectric layer is composed of a plurality of dielectric blocks distributed in an array manner;
the lower layer electrode consists of a plurality of pairs of interdigital electrodes which are distributed in a mirror image opposite mode with the plurality of pairs of interdigital electrodes of the upper layer electrode; each pair of interdigital electrodes of the lower layer electrode comprises two second working electrodes; the two second working electrodes are respectively connected with two paths of signal electrodes led out by the digital signal processing chip; the upper electrode, the dielectric layer and the lower electrode jointly form a plurality of capacitors; the number of the capacitors is equal to the number of the first working electrodes or the second working electrodes;
the top layer is used for arranging the lower electrode, and the bottom layer is used for packaging the digital signal processing chip; the digital signal processing chip is used for acquiring capacitance value variation of the capacitors to obtain corresponding sensing signals so as to determine force and/or moment according to the sensing signals;
the upper layer electrode is tightly attached to the upper layer substrate to form an upper layer printed circuit board; the lower electrode is tightly attached to the lower substrate to form a lower printed circuit board; the preparation method of the touch sensor comprises the following steps:
preparing an SMT steel mesh;
scraping a layer of adhesive layer on the upper surface of the lower electrode by using a blade to serve as a first adhesive layer;
pouring a dielectric material on the first adhesive layer;
uniformly coating a medium material on the first adhesive layer;
after the surface coated with the medium material is vacuumized, placing the SMT steel mesh and covering a PET film;
compacting for 12 hours by using a heavy object after turning;
after the heavy object is taken down, turning over again, removing the PET film, taking down the SMT steel mesh, and forming a dielectric layer consisting of a plurality of dielectric blocks distributed in an array manner on the upper surface of the lower electrode;
scraping a bonding layer on the lower surface of the upper electrode by using a blade to serve as a second bonding layer, and positioning and integrating the upper printed circuit board and the lower printed circuit board together through pins;
compacting for 12 hours by using a heavy object;
and (5) taking down the weight to obtain the touch sensor.
2. The tactile sensor of claim 1, wherein the dielectric layer is formed from 9 of 3*3 in an array uniform arrangement
The silicon RTV silicon rubber is composed of rectangular blocks made of silicon rubber RTV silicon rubber; the filling rate of the dielectric layer is 19%.
3. The tactile sensor according to claim 1, wherein the upper and lower electrodes each comprise 4 pairs of interdigitated electrodes arranged symmetrically in a 2*2 array.
4. The tactile sensor according to claim 3, wherein the interdigital electrodes are structurally divided into two types of transverse penetration and longitudinal penetration; in the pairs of interdigital electrodes of the upper layer electrode and the lower layer electrode, the interdigital electrodes which are transversely inserted and the interdigital electrodes which are longitudinally inserted are alternately distributed.
5. The tactile sensor according to claim 3, wherein the pairs of interdigitated electrodes of the upper layer of electrodes are aligned with the pairs of interdigitated electrodes of the lower layer of electrodes with a displacement of a set magnitude.
6. A tactile sensor according to claim 1, further comprising:
the FPC connector is welded on the lower surface of the lower substrate and is connected with the digital signal processing chip;
the adapter plate is welded on the lower surface of the lower-layer substrate and connected with the FPC connector.
7. A tactile sensor according to claim 1, wherein said upper substrate is a four-layer plate; the upper substrate sequentially comprises from top to bottom:
a first layer, a second layer, a third layer and a fourth layer;
the first layer is a top layer of the upper substrate; the fourth layer is the bottom layer of the upper substrate;
the second layer is tightly attached to the first layer, integrally coated with copper and connected with a source shielding electrode;
the third layer is tightly attached to the second layer and the fourth layer, integrally coated with copper and connected with a source shielding electrode.
8. A tactile sensor according to claim 1, wherein the lower substrate is a four-layer plate; the lower floor's base plate includes from top to bottom in proper order:
a fifth layer, a sixth layer, a seventh layer, and an eighth layer;
the fifth layer is the top layer of the lower substrate; the eighth layer is the bottom layer of the lower substrate;
the sixth layer is tightly attached to the fifth layer, integrally coated with copper and connected with a source shielding electrode;
the seventh layer is closely attached to the sixth layer and the eighth layer and used for wiring distribution.
9. A method for manufacturing a tactile sensor according to any one of claims 1 to 8, wherein the upper electrode is closely attached to the upper substrate to form an upper printed circuit board; the lower electrode is tightly attached to the lower substrate to form a lower printed circuit board; the preparation method comprises the following steps:
preparing an SMT steel mesh;
scraping a bonding layer on the upper surface of the lower electrode by using a blade to form a first bonding layer;
pouring a dielectric material on the first adhesive layer;
uniformly coating a medium material on the first adhesive layer;
after the surface coated with the medium material is vacuumized, placing the SMT steel mesh and covering a PET film;
compacting for 12 hours by using a heavy object after turning;
after the heavy object is taken down, turning over again, removing the PET film, taking down the SMT steel mesh, and forming a dielectric layer consisting of a plurality of dielectric blocks distributed in an array manner on the upper surface of the lower electrode;
scraping a bonding layer on the lower surface of the upper electrode by using a blade to serve as a second bonding layer, and positioning and integrating the upper printed circuit board and the lower printed circuit board together through pins;
compacting for 12 hours by using a heavy object;
and (5) taking down the weight to obtain the touch sensor.
10. A force and/or torque measuring device, wherein the measuring device comprises a tactile sensor according to any one of claims 1-8 and a processor;
the processor is connected with the digital signal processing chip and used for determining the stress type of the touch sensor according to the sensing signal, calculating corresponding capacitance value variation according to the sensing signal and the stress type, and obtaining the value of the force and/or the moment according to the corresponding relation between the capacitance value variation and the force and/or the moment.
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| CN114754904B (en) * | 2022-03-30 | 2023-09-29 | 青岛歌尔智能传感器有限公司 | MEMS capacitive sensor and preparation method thereof |
| CN115031884B (en) * | 2022-06-02 | 2024-03-15 | 中国科学院苏州纳米技术与纳米仿生研究所 | Flexible sensor array with multi-mode force sensing and method of making the same |
| CN116929198B (en) * | 2023-07-26 | 2024-04-09 | 北方工业大学 | Robot fish tail fin integrated strain sensing structure and motion information resolving method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP5439068B2 (en) * | 2009-07-08 | 2014-03-12 | 株式会社ワコー | Force detection device |
| KR101979680B1 (en) * | 2012-12-05 | 2019-05-20 | 삼성전자주식회사 | Tactile sensor |
| US9599524B2 (en) * | 2013-04-04 | 2017-03-21 | University Of Utah Research Foundation | High-resolution flexible tactile imager system based on floating comb electrode |
| CN104964778A (en) * | 2015-07-28 | 2015-10-07 | 芜湖科创生产力促进中心有限责任公司 | Contact-type parallel plate three-dimensional force pressure sensor |
| US10267690B2 (en) * | 2016-09-13 | 2019-04-23 | The Board Of Trustees Of The Leland Stanford Junior University | Capacitive force/torque sensor |
| US11860048B2 (en) * | 2017-07-10 | 2024-01-02 | The Board Of Trustees Of The Leland Stanford Junior University | Capacitive and tactile sensors and related sensing methods |
| CN108731849B (en) * | 2018-06-01 | 2020-01-07 | 北京航空航天大学 | Six-degree-of-freedom touch sensor and decoupling design method thereof |
| CN112673338A (en) * | 2018-07-10 | 2021-04-16 | 小利兰·斯坦福大学托管委员会 | Capacitive and tactile sensor and related sensing method |
| CN109238519B (en) * | 2018-10-22 | 2024-03-15 | 河北工业大学 | Hybrid flexible touch sensor |
| CN110542494A (en) * | 2019-05-13 | 2019-12-06 | 浙江大学 | capacitive flexible three-dimensional force touch sensor based on composite structure dielectric layer |
| CN111238545B (en) * | 2020-01-17 | 2021-10-12 | 腾讯科技（深圳）有限公司 | Sensor, intelligent device, sensing method and storage medium |
| CN113125055B (en) * | 2021-03-03 | 2022-11-08 | 上海大学 | Piezoresistive and capacitive fused three-dimensional flexible touch sensor |
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