Photoelectric or acoustic tactile sensor, electronic skin, and robot

Abstract

The invention relates to a photoelectric or acoustic tactile sensor, an electronic skin, and a robot, comprising at least one sensor unit, each sensor unit comprising at least one flexible body, a corresponding light-tight area being formed below each flexible body, the flexible body being a partial boundary of the light-tight area; the surface of each flexible body is fixedly provided with a flexible structure which protrudes downwards towards the light sealing area, the flexible structures are made of light-proof materials, light-emitting channels are correspondingly arranged in the light sealing area below the flexible structures, and the light-emitting channels are used for emitting light rays which are emitted to the flexible structures through a light source; the flexible structure deforms under the pressing of external force to change the shielding area of light passing through the light emitting channel; each light sealing area comprises at least one light sensing part for receiving light reflected by the flexible structure, and the light sensing parts are used for outputting electric signals representing external force according to the condition of the light reflected by deformation of the flexible structure.

Description

Technical Field

[0001] The present invention relates to robot tactile perception, and in particular to a photoelectric or acoustic wave tactile sensor, electronic skin, robot, and intelligent prosthesis. Background Art

[0002] Intelligent machines and equipment such as industrial robots and household service robots rely on electronic skin on the outer surface to achieve tactile perception functions, and form intelligent responses through the collection and processing of tactile information, such as sensing object picking and placement, collision avoidance, etc.

[0003] In the prior art, there is a method of using capacitive technology to realize the tactile sensor of electronic skin. Capacitive tactile sensors have many advantages such as high detection accuracy, easy layout, and low cost. However, due to the existence of capacitor charging and discharging time, the conversion speed is difficult to reach a very high level. At present, the response speed of capacitive tactile sensors is basically in the millisecond level. The millisecond level response can meet the needs of most occasions, but it is not enough for occasions with very high response requirements. In addition, electricity is easily disturbed by water, humid air and other environments.

[0004] Light is insensitive to water, humid air, etc., and the response speed is very fast, often reaching nanoseconds or above. Photoelectric tactile sensors have advantages in situations where the response requirements are very high.

[0005] Patent document CN202010568170.5 proposes an arrayed pressure measurement method and device based on visual halo. After the flexible transparent micro-column array is subjected to pressure, the halo image formed by the deformation of the micro-columns and the substrate is obtained for model calculation and processing, and the pressure information is analyzed from the visual image. This is called visual touch in the industry, which reflects the tactile problem in a visual way. The problem with visual touch is that the structure of the flexible transparent micro-column array is complex, and the cost of a single sensor is high when combined with the camera device underneath. It is difficult to miniaturize and is not conducive to the large-scale deployment of electronic skin. In addition, visual touch requires image acquisition and processing time, and the upper limit of the response speed is limited.

[0006] Patent document CN202210072574.4 proposes a three-dimensional tactile sensor based on a photosensitive element. The flexible sensor cover and the sensor base form a light-enclosed space. The light-emitting device is arranged in the enclosed space to emit light to the inner surface of the flexible sensor cover. Four photosensitive devices surround the light-emitting device. The flexible sensor cover is deformed by pressing to change the reflection of light. The four photosensitive devices measure three-dimensional force based on the change in the reflection of light. This photoelectric tactile sensor structure can achieve the advantage of response speed by using light, but the sensor uses the deformation of the flexible cover to only change the reflection path of light. The continuous reflection of light in the enclosed space and the influence of diffuse reflection make the change of light intensity before and after pressing not obvious, and the detection sensitivity is difficult to meet high requirements. Summary of the invention

[0007] The present invention aims to achieve a high response speed of machine tactile perception and be not susceptible to environmental interference. The sensor implementation structure should be simple and low-cost to facilitate large-area deployment. At the same time, a high sensor detection sensitivity should be achieved to meet high-precision detection requirements.

[0008] To this end, a photoelectric tactile sensor is provided, comprising at least one sensor unit, each sensor unit comprising at least one flexible body, a corresponding light-enclosed area being formed below each flexible body, and the flexible body serving as a partial boundary of the light-enclosed area; a flexible structure protruding downward toward the light-enclosed area is fixed on the surface of each flexible body, the flexible structure is made of an opaque material, a light-emitting channel is correspondingly arranged in the light-enclosed area below the flexible structure, the light-emitting channel is used to emit light to the flexible structure through a light source, and the flexible structure is deformed under external force to change the shielding area of ​​the light passing through the light-emitting channel; each light-enclosed area contains at least one photosensitive element for receiving light reflected by the flexible structure, and is used to output an electrical signal representing the external force according to the reflected light changed by the deformation of the flexible structure.

[0009] Photosensitive components such as light receiving diodes form a conversion from optical signals to electrical signals. As the flexible structure is pressed under external force to change the blocking area of ​​the channel, the light conditions passing through the channel are changed, which in turn causes a large change in the light intensity of the light projected onto the flexible structure in the light-enclosed area. The output fluctuation range of the electrical signal output by the photosensitive component based on the reflected light conditions changed by the deformation of the flexible structure is greatly improved, thereby achieving higher sensor detection sensitivity and accuracy.

[0010] As an optional implementation, the photoelectric tactile sensor can directly output the original signal to the outside, or, further, a processing module is set up, the processing module is coupled to the photosensitive element, and is used to receive the electrical signal of the photosensitive element for processing, and the tactile sensor outputs the tactile processing result to the outside.

[0011] As an optional implementation scheme, a light-shielding member and a light source are provided in the light-enclosed area below each flexible structure corresponding to the flexible structure. The light-shielding member is provided with a light-transmitting hole as a light-emitting channel. The light source emits light toward the flexible structure through the light-transmitting hole. A light-transmitting member is provided in the light-transmitting hole as a support in physical contact with the flexible structure. The flexible structure is pressed to the surface of the light-transmitting member under the action of an external force to cause deformation, thereby changing the light-shielding area. Furthermore, the light-transmitting member is a gradient filter plate that gradually changes outward with a vertical line as the center. The gradient filter plate is used to correct the nonlinearity of the brightness of light shining on the flexible structure. As another optional implementation scheme, a surface light source is provided in the light-enclosed area below each flexible structure corresponding to the flexible structure. The light-emitting surface of the surface light source is reused as a light-emitting channel and a support for the flexible structure. The flexible structure is pressed to the light-emitting surface of the surface light source under the action of an external force to cause deformation, thereby changing the light-shielding area. As another optional implementation, a light shielding member and a light source are provided in the light-enclosed area below each flexible structure corresponding to the flexible structure, the light shielding member is provided with a light-transmitting hole as a light-emitting channel, the light source emits light toward the flexible structure through the light-transmitting hole, and the flexible structure changes the blocking condition of the light-transmitting hole under external pressure, thereby changing the light shielding area. Further, the flexible structure is configured to be made of elastic metal and / or the bottom is covered with elastic metal.

[0012] As an improvement, the shape of the flexible structure is configured to increase the shielding area of ​​the light output channel when pressed. Further, the surface of the flexible structure gradually converges downward. Specifically, the lower surface of the flexible structure is an arc, an inverted cone or an inverted stepped pyramid.

[0013] As an improvement, there are at least three photosensitive members, each of which is distributed around the flexible structure. Further, the lower surface of the flexible structure forms an axisymmetry, and the center of the flexible structure and the light outlet channel is located on the same vertical line; each photosensitive member is in the same plane and is evenly distributed around the vertical line. Further, the flexible body is a cover body with a surface that is folded upward, and the flexible structure is fixed to the inner surface of the cover body; and / or the flexible body and the flexible structure are integrally formed or separately arranged.

[0014] As an improvement, the flexible body is made of conductive material and serves as a sensing electrode for detecting proximity. The photoelectric tactile sensor includes a capacitance-to-digital conversion circuit and a processing module. The capacitance-to-digital conversion circuit is coupled to each sensing electrode to obtain the capacitance change caused by the approach of an external object. The processing module is coupled to the capacitance-to-digital conversion circuit to output a proximity sensing signal based on the capacitance change. Further, the capacitor is configured as a self-capacitor; and / or, the flexible body has at least two, and each flexible body is configured to form at least one mutual capacitance for detecting the approach of an external object through the capacitance-to-digital conversion circuit. Further, the flexible body is coupled to the capacitance-to-digital conversion circuit through an analog switch or a digital switch; and the flexible body is configured to be grounded through a switch during the detection of external force.

[0015] A sonic wave tactile sensor is also provided, comprising at least one sensor unit, each sensor unit comprising at least one flexible body, a corresponding sonic wave enclosed area is formed below each flexible body, and the flexible body serves as a partial boundary of the sonic wave enclosed area; a flexible structure protruding downward toward the sonic wave enclosed area is fixed on the surface of each flexible body, and a channel is correspondingly arranged in the sonic wave enclosed area below the flexible structure, and the channel is used to emit a sound wave directed toward a sonic wave receiver through a sound source, and the flexible structure is deformed under external force to change the shielding area of ​​the sound wave passing through the channel; each sonic wave enclosed area contains at least one sonic wave receiver for receiving the sound wave, and is used to output an electrical signal representing the external force according to the condition of the sound wave changed by the deformation of the flexible structure. Further, the sonic wave tactile sensor comprises a processing module coupled to the sonic wave receiver.

[0016] Also provided is an electronic skin comprising the above-mentioned tactile sensor.

[0017] A robot is also provided, comprising the electronic skin as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The overall example structure of the photoelectric tactile sensor is given;

[0019] Figure 2 The internal formation of the photoelectric tactile sensor is shown;

[0020] Figure 3a An example of the first relative structural design of the light outlet channel, the flexible structure and the light source is given;

[0021] Figure 3b An example of a second relative structural design of the light outlet channel, the flexible structure and the light source is given;

[0022] Figure 3c The third relative structural design of the light outlet channel, the flexible structure and the light source is illustrated;

[0023] Figure 4a The arc shape of the lower surface of the flexible structure is illustrated;

[0024] Figure 4b An inverted stepped pyramid shape of the lower surface of the flexible structure is illustrated;

[0025] Figure 4c An inverted tapered shape of the lower surface of the flexible structure is illustrated;

[0026] Figure 5 A schematic diagram of the circuit topology for proximity detection is given; and

[0027] Figure 6 An example structure of an acoustic wave tactile sensor is given. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] Example 1

[0030] Embodiment 1 exemplifies the technology of implementing tactile acquisition by a sensor using a photoelectric method. According to this exemplary embodiment, these technologies can be applied to the surface electronic skin of intelligent machine devices such as industrial robots and home service robots, or can be used for the tactile perception of the fingertips of mechanical fingers.

[0031] Figure 1 The overall example structure of the photoelectric tactile sensor is given. Figure 2 The internal formation of the example structure is further demonstrated. As an example, the photoelectric tactile sensor is composed of a housing 101 and a metal cover plate 102 that are locked by fastening screws 103 to form a structural member, a circuit board 104 and a sensor unit 200 are located in the structural member, and the sensor unit 200 extends from the hollow hole on the surface of the metal cover plate 102 to the outside to contact the object. The photoelectric tactile sensor includes one or more sensor units 200, each sensor unit 200 independently completes the tactile perception of the contact object, such as the knuckle part of a mechanical finger, the photoelectric tactile sensor is provided with two sensor units 200 arranged along the extension direction of the knuckle, or such as the perception of the robot's electronic skin, the photoelectric tactile sensor is provided with more sensor units 200 to form a mechanical distribution measurement.

[0032] See also Figure 2 The sensor unit 200 includes a flexible body 201, a light source 202, and a photosensitive element 203. A corresponding light-enclosed area is formed below the flexible body 201, and the flexible body 201 can cooperate with the opaque structural member below or the side wall of the shell to form a light-enclosed space. The flexible body 201 serves as a partial boundary of the light-enclosed area. The surface of the flexible body 201 protrudes downward toward the light-enclosed area to form a flexible structure 2011. The flexible body 201 is a cover body with an upwardly contracted surface to lift and bear force. The flexible structure 2011 is fixed to the inner surface of the cover body. The flexible body 201 and the flexible structure 2011 can be integrally formed, or can be separately set and fixed by gluing. The flexible body 201 and the flexible structure 2011 are made of opaque materials to form a pressing effect on light reflection.

[0033] A light exit channel is correspondingly arranged in the light-enclosed area below the flexible structure 2011, and the light exit channel is used to emit light toward the flexible structure 2011 through the light source 202. The relative designs of the light exit channel, the flexible structure and the light source can be diversified, and the core is to realize that the flexible structure deforms under external pressure to change the shielding area of ​​the light passing through the light exit channel. To help understand the diversity allowed here, three implementation schemes are given below. It can be understood that these schemes are only used as an illustration of exemplary structural implementation methods.

[0034] As an example implementation, Figure 2 A structural design method for light output channel, flexible structure and light source is given. Figure 3a The optical path of the structure is schematically shown. A light shielding member 204 is arranged in the light-enclosed area below the flexible structure 2011. A light-transmitting hole 2041 is provided in the middle of the light shielding member 204 as a light-emitting channel. The light shielding member 204 covers the light source. The light source emits light toward the flexible structure 2011 through the light-transmitting hole 2041. A light-transmitting member 2012 is built into the light-transmitting hole 2011 as a carrier in physical contact with the flexible structure 2011. The light-transmitting member 2012 is, for example, a transparent plate with a flat surface. The flexible structure 2011 is pressed to the surface of the light-transmitting member 2012 under the action of an external force. Since the bottom is an elastic downward convex hemisphere, the light-transmitting member 2012 is deformed by the collision, thereby changing the light-shielding area relative to the light-transmitting hole 2041. Furthermore, the light shielding member 204 is arranged as a gradient filter plate that gradually changes outward with a vertical line as the center, so as to correct the nonlinearity of the light brightness irradiating the flexible structure 2011 and improve the linearity.

[0035] As another example embodiment, Figure 3b A second relative structural design of the light output channel, the flexible structure and the light source is provided. The light source 202 is a surface light source which is arranged in a light-enclosed area below the flexible structure 2011. The light-emitting surface of the surface light source is reused as the light output channel to support the flexible structure 2011. The flexible structure 2011 is pressed by an external force to directly contact the light-emitting surface of the surface light source, causing deformation and thus changing the shading area.

[0036] As another example embodiment, Figure 3cA third relative structural design of a light-emitting channel, a flexible structure, and a light source is provided. A light-shielding member 204 is correspondingly arranged in the light-enclosed area below the flexible structure 2011. The light-shielding member 204 is provided with a light-transmitting hole 2041 as a light-emitting channel. The light source 202 emits light toward the flexible structure 2011 through the light-transmitting hole 2041. The flexible structure 2011 changes the blocking condition of the light-transmitting hole 2041 under external pressure, thereby changing the light-shielding area. In this example solution, a corresponding design is generated between the flexible structure and the hole according to the number of light-transmitting holes. In an example embodiment, the light-transmitting holes 2041 are numerous and small, distributed on the surface of the light-shielding member 204. The light-shielding member 204 acts as a load-bearing member. The hemispherical surface of the pressed lower part of the flexible structure 2011 abuts against the light-shielding member 204 to deform, and the light-transmitting holes 2041 in the contact area are completely blocked. In another exemplary embodiment, the light-transmitting holes 2041 are few and large. For example, when only one hole is set, there is no need to form a support on the bottom surface of the flexible structure 2011. The flexible structure 2011 is pressed and displaced toward the hole to form an incomplete blockage of the hole, thereby changing the light-shielding area. At this time, as a further step, the flexible structure is made of elastic metal and / or covered with elastic metal at the bottom, and the detection sensitivity is improved by utilizing the large non-contact deformation of the metal surface under pressure.

[0037] See also Figures 3a to 3c , the photosensitive member 203 is arranged in the light-sealed area to receive the reflected light of the flexible structure 2011. The photosensitive member 203 can be any position capable of receiving the reflected light in the light-sealed area. When the sensor only needs to measure the normal unidimensional force, the number of the photosensitive member 203 can be one. When the sensor only needs to measure the tangential normal multidimensional force, the number of the photosensitive member 203 is set to at least two and distributed around the flexible structure 2011. The photosensitive member 203 can adopt a light receiving device, such as a light receiving diode, to further realize the miniaturization of the sensor. The light receiving device such as the light receiving diode forms a transformation from an optical signal to an electrical signal. Since the flexible structure 2011 is pressed under the action of an external force to change the shielding area of ​​the channel, the light condition passing through the channel is changed, thereby causing the light projected to the flexible structure 2011 in the light-sealed area to produce a large change in light intensity. The output fluctuation range of the electrical signal output by the light receiving device according to the condition of the reflected light changed by the deformation of the flexible structure is greatly improved, thereby realizing a higher sensor detection sensitivity and accuracy. Each sensor unit independently corresponds to a light sealing area and light source, avoiding mutual light coupling between sensor units and further improving detection accuracy.

[0038] When the flexible structure is pressed, the shielding area of ​​the light output channel can be positive or negative. Negative, such as the design of pressing to make the flexible structure collapse inward, such as the side wall collapses inward, so that the covering area decreases with the pressing, or positive, such as pressing to spread the flexible structure on the bearing surface to increase the shielding. Compared with negative changes, positive changes contribute to the simple implementation of the structure and the reliability of the sensor. For positive changes, the surface of the flexible structure can be further arranged to gradually contract downward, and when pressed downward, a gradual change from point contact to surface contact is formed, and the contact surface from point contact to surface contact increases exponentially, further increasing the amplitude of the change in the reflected light intensity and improving the detection sensitivity. Figures 4a to 4c Given the gradually shrinking shape design of the lower surface of the flexible structure, it can form Figure 4a The arc shape makes the pressing shading area increase smoothly, which is beneficial for weak pressing force application scenarios, or forming Figure 4b The inverted stepped pyramid can increase the granularity of the shading area, which is beneficial for strong pressure application scenarios, or form Figure 4c The inverted cone produces a centering change.

[0039] In addition to being able to sense the normal force at the contact point, the human sense of touch can also sense the tangential force at the contact point. The tangential force is divided into the X-direction and the Y-direction, and together with the Z-direction normal force, it forms the three-dimensional force perception of the human skin. Figure 2 , at least three photosensitive members 203 are provided in the photoelectric tactile sensor, and each photosensitive member 203 is distributed around the flexible structure 2011. When the flexible structure 2011 is pressed, the bottom surface of the hemisphere produces normal and tangential deformations that affect the corresponding changes in reflected light, and the light is correspondingly received by the photosensitive member 203 in this position. The three-dimensional force perception of artificial touch can be obtained through the difference in the output of each photosensitive member 203. Further, the lower surface of the flexible structure 2011 forms an axisymmetric, the center of the flexible structure 2011 and the light outlet channel are located on the same vertical line, and each photosensitive member 203 is in the same plane and evenly distributed around the vertical line, which can balance the detection sensitivity of each tangential direction while saving computing power. On this basis, the photosensitive members 203 are set to be four symmetrically distributed in the plane to achieve optimization.

[0040] Furthermore, the flexible body is made of a conductive material, such as conductive silicone, which has both touch, elasticity and conductivity, and the conductive silicone is used as a sensing electrode for detecting proximity. Figure 5The circuit topology diagram of proximity detection is given. The photoelectric tactile sensor is provided with a CDC capacitance-to-digital conversion circuit 400, a processing module 500, and two sensing electrodes 310, 320. The processing module 500 is coupled with the capacitance-to-digital conversion circuit 400. The capacitance-to-digital conversion circuit 400 is coupled with each sensing electrode 310, 320 to obtain the capacitance change caused by the approach of an external object. The capacitance change can be configured as a change in self-capacitance and / or mutual capacitance. In the self-capacitance scheme, the capacitance-to-digital conversion circuit 400 inputs excitation to each electrode respectively and receives a self-capacitance signal from itself. The approach of an external conductor is coupled with the self-capacitance of the sensing electrode to form a self-capacitance change. The processing module 500 determines the proximity of the conductor based on the self-capacitance change, which has the advantage of a long detection distance. In the mutual capacitance scheme, one of the sensing electrodes 310, 320 is used as an excitation and the other as a receiver. The dielectric constant of the conductor or non-conductor is different from that of the air. The mutual capacitance sensing electric field formed by the conductor or non-conductor entering the electrodes 310, 320 causes the dielectric constant to change, and the mutual capacitance output changes. The processing module 500 outputs a proximity sensing signal based on the mutual capacitance change. Furthermore, the flexible body is coupled to the capacitor digital conversion circuit 400 through an analog switch or a digital switch. The digital conversion circuit 400 controls the electrode to switch between being connected to the ground and being connected to the CDC through the switch, and in the process of detecting external force, the flexible body is configured to be grounded through the switch to achieve internal electric field shielding during force measurement.

[0041] Example 2

[0042] Embodiment 2 exemplifies the technology of implementing tactile collection by using sound waves in the sensor. Compared with Embodiment 1, the difference is that light changes are changed into sound wave changes. Figure 6 An example structure of an acoustic wave tactile sensor is given. As an example implementation scheme, the acoustic wave tactile sensor includes at least one sensor unit, each sensor unit includes at least one flexible body 201, a corresponding acoustic wave enclosed area is formed below each flexible body 201, and the flexible body serves as a partial boundary of the acoustic wave enclosed area; a flexible structure 2011 protruding downward toward the acoustic wave enclosed area is fixed on the surface of each flexible body 201, and a channel 202 is correspondingly arranged in the acoustic wave enclosed area below the flexible structure 2011, and the channel is used to emit acoustic waves directed to an ultrasonic receiver 204 through a sound source 203 such as an ultrasonic generator, and the flexible structure 201 is deformed under external force to change the shielding area of ​​the acoustic waves passing through the channel, thereby affecting the acoustic waves received by the ultrasonic receiver 204; each acoustic wave enclosed area contains at least one ultrasonic receiver 204 for receiving acoustic waves, and is used to output an electrical signal representing the external force according to the acoustic waves changed by the deformation of the flexible structure.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A photoelectric tactile sensor, characterized in that: The photoelectric touch sensor includes at least one sensor unit, each sensor unit includes at least one flexible body, a corresponding light-enclosed area is formed under each flexible body, and the flexible body serves as a partial boundary of the light-enclosed area; A flexible structure protruding downward toward the light-enclosed area is fixed on the surface of each flexible body. The flexible structure is made of opaque material. A light-emitting channel is correspondingly arranged in the light-enclosed area below the flexible structure. The light-emitting channel is used to emit light toward the flexible structure through a light source. The flexible structure is deformed under external pressure to change the shielding area of ​​the light passing through the light-emitting channel. Each light-enclosed area includes at least one photosensitive element for receiving light reflected from the flexible structure, and is used to output an electrical signal representing the external force according to the reflected light changed by the deformation of the flexible structure.

2. The photoelectric tactile sensor according to claim 1, characterized in that: A shading member and a light source are arranged in the light-enclosed area below each flexible structure corresponding to the flexible structure. The shading member is provided with a light-transmitting hole as the light outlet channel. The light source emits light toward the flexible structure through the light-transmitting hole. A light-transmitting member is arranged in the light-transmitting hole as a support in physical contact with the flexible structure. Under the action of external force, the flexible structure is pressed to the surface of the light-transmitting member to cause deformation, thereby changing the shading area.

3. The photoelectric tactile sensor according to claim 2, characterized in that: The light-transmitting component is a gradient filter plate which gradually changes outwards with the vertical line as the center. The gradient filter plate is used to correct the nonlinearity of the brightness of light irradiating to the flexible junction.

4. The photoelectric tactile sensor according to claim 1, characterized in that: A surface light source is arranged corresponding to the flexible structure in the light-enclosed area below each flexible structure. The light-emitting surface of the surface light source is reused as a light output channel and a support for the flexible structure. Under the action of external force, the flexible structure is pressed to the light-emitting surface of the surface light source to deform and thus change the shading area.

5. The photoelectric tactile sensor according to claim 1, characterized in that: A shading member and a light source are arranged corresponding to the flexible structure in the light-enclosed area below each flexible structure. The shading member is provided with a light-transmitting hole as the light-emitting channel. The light source emits light toward the flexible structure through the light-transmitting hole. When pressed by an external force, the flexible structure changes the blocking condition of the light-transmitting hole and thus changes the shading area.

6. The photoelectric tactile sensor according to claim 5, characterized in that: The flexible structure is configured to be made of elastic metal and / or the bottom is covered with elastic metal.

7. The photoelectric tactile sensor according to claim 1, characterized in that: The shape of the flexible structure is configured to increase the shielding area of ​​the light output channel when pressed.

8. The photoelectric tactile sensor according to claim 7, characterized in that: The surface of the flexible structure gradually converges downwards.

9. The photoelectric tactile sensor according to claim 8, characterized in that: The lower surface of the flexible structure is in the shape of an arc, an inverted cone or an inverted stepped pyramid.

10. The photoelectric tactile sensor according to claim 1, characterized in that: There are at least three photosensitive members, each of which is distributed around the flexible structure.

11. The photoelectric tactile sensor according to claim 10, characterized in that: The lower surface of the flexible structure forms an axisymmetry, and the center of the flexible structure and the light output channel are located on the same vertical line; The photosensitive members are located in the same plane and are evenly distributed along the vertical circumference.

12. The photoelectric tactile sensor according to claim 10, characterized in that: The flexible body is a cover body with a surface that is folded upward, and the flexible structure is fixed to the inner surface of the cover body; And / or, the flexible body and the flexible structure are integrally formed or separately provided.

13. The photoelectric tactile sensor according to claim 1, characterized in that: The flexible body is made of conductive material and serves as a sensing electrode for detecting proximity. The photoelectric tactile sensor includes a capacitance-to-digital conversion circuit and a processing module. The capacitance-to-digital conversion circuit is coupled to each sensing electrode to obtain the capacitance change caused by the approach of an external object. The processing module is coupled to the capacitance-to-digital conversion circuit to output a proximity sensing signal according to the capacitance change.

14. The photoelectric tactile sensor according to claim 13, characterized in that: The capacitor is configured as a self-capacitor; And / or, the flexible bodies include at least two, and the flexible bodies are configured to form at least one mutual capacitance for detecting the approach of an external object through a capacitance-to-digital conversion circuit.

15. The photoelectric tactile sensor according to claim 13 or 14, characterized in that: The flexible body is coupled to the capacitance-to-digital conversion circuit via an analog switch or a digital switch; During the external force detection process, the flexible body is configured to be grounded through a switch.

16. An acoustic wave tactile sensor, characterized in that: The acoustic wave tactile sensor comprises at least one sensor unit, each sensor unit comprises at least one flexible body, a corresponding acoustic wave enclosed area is formed under each flexible body, and the flexible body serves as a partial boundary of the acoustic wave enclosed area; A flexible structure protruding downward toward the sound wave enclosed area is fixed on the surface of each flexible body, and a channel is correspondingly arranged in the sound wave enclosed area below the flexible structure. The channel is used to emit sound waves from a sound source to a sound wave receiver, and the flexible structure is deformed under external force to change the shielding area of ​​the sound waves passing through the channel; Each sound wave enclosed area includes at least one sound wave receiver for receiving sound waves, which is used to output an electrical signal representing the external force according to the sound wave conditions changed by the deformation of the flexible structure.

17. An electronic skin, characterized in that: Comprising the tactile sensor according to any one of claims 1-16.

18. A robot, characterized in that: Comprising the electronic skin as described in claim 17.

Images