CN116007805A - Sensor, robot and preparation method of sensor - Google Patents

Abstract

The application relates to a sensor, a robot and a preparation method of the sensor. The sensor includes a light source, a brightness detector, and a flexible sensing portion. The flexible sensing part comprises a flexible pipe sleeve and a flexible pipe core; the flexible tube sleeve wraps the flexible tube core; the flexible sensing part comprises an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; wherein the refractive index of the flexible tube core is higher than the refractive index of the flexible tube sleeve. The sensor is driven by light, so that electromagnetic interference is avoided, potential safety hazards such as electric leakage and short circuit are avoided, and the safety is high. In addition, since the refractive index of the flexible tube core is higher than that of the flexible tube sleeve, light from the light source can be transmitted from the input end to the output end in the flexible sensing part in a total reflection mode, so that the damage of the flexible sensing part to the light is reduced, and the detection precision of the sensor is improved.

Description

Sensor, robot and preparation method of sensor

Technical Field

The application relates to the technical field of robots, in particular to a sensor, a robot and a preparation method of the sensor.

Background

The rapid development of the information age also brings about the requirement of people on higher and more diversified sensors, and in the field of intelligent robots, the improvement of the motion capability of robots needs to accurately sense the plantar pressure distribution in real time. These application scenarios typically require sensors with a large measurement range, fast response times and high spatial resolution.

The traditional electrical sensor is difficult to improve in response speed, complex environment adaptability and the like due to the limitation of factors such as electromagnetic interference, parasitic capacitance effect, signal crosstalk and the like. The sensor is gradually developed towards automation, miniaturization and integration, and is also pursued to be more sensitive and faster in response.

Disclosure of Invention

The application provides a sensor, a robot and a preparation method of the sensor, which are used for solving the defects in the related technology.

A first aspect of the present application provides a sensor comprising a light source, a brightness detector, and a flexible sensing portion. The flexible sensing part comprises a flexible pipe sleeve and a flexible pipe core; the flexible tube sleeve wraps the flexible tube core; the flexible sensing part comprises an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; wherein the refractive index of the flexible tube core is higher than the refractive index of the flexible tube sleeve.

Further, the flexible sensing part further includes: the input optical fiber is arranged between the input end and the light source so as to connect the input end and the light source; and/or an output optical fiber is arranged between the output end and the brightness detector to connect the output end and the brightness detector.

Further, the number of flexible sensing parts includes a plurality; the input end of each flexible sensing part is connected with the light source through the input optical fiber; and/or, the output end of each flexible sensing part is connected with the brightness detector through the output optical fiber.

Further, the sensor further comprises a housing; the shell is formed on the outer surface of the flexible sensing part; at least part of the flexible sensing part is arranged in the shell; the hardness of the housing is greater than the hardness of the flexible sensing portion.

Further, the flexible sensing portion extends along an arc from the input end to the output end.

Further, the arc angle range of the arc is greater than or equal to 250 ° and less than or equal to 290 °.

Further, the diameter of the circular arc is greater than or equal to 10mm and less than or equal to 14mm.

Further, the sensor has a dimension in the thickness direction of 3mm or more and 5mm or less.

A second aspect of the present application provides a robot comprising a robot lower limb; the robot lower limb comprises a foot, a leg and a sensor; the foot is connected with the leg; the sensor is arranged on one side of the foot away from the leg; the sensor includes a light source, a brightness detector, and a flexible sensing portion. The flexible sensing part comprises a flexible pipe sleeve and a flexible pipe core; the flexible tube sleeve wraps the flexible tube core; the flexible sensing part comprises an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; wherein the refractive index of the flexible tube core is higher than the refractive index of the flexible tube sleeve.

Further, the flexible sensing part further includes: the input optical fiber is arranged between the input end and the light source so as to connect the input end and the light source; and/or an output optical fiber is arranged between the output end and the brightness detector to connect the output end and the brightness detector.

Further, the number of flexible sensing parts includes a plurality; the input end of each flexible sensing part is connected with the light source through the input optical fiber; and/or, the output end of each flexible sensing part is connected with the brightness detector through the output optical fiber.

Further, the sensor further comprises a housing; the shell is formed on the outer surface of the flexible sensing part; at least part of the flexible sensing part is arranged in the shell; the hardness of the housing is greater than the hardness of the flexible sensing portion.

Further, the flexible sensing portion extends along an arc from the input end to the output end.

Further, the arc angle range of the arc is greater than or equal to 250 ° and less than or equal to 290 °.

Further, the diameter of the circular arc is greater than or equal to 10mm and less than or equal to 14mm.

Further, the sensor has a dimension in the thickness direction of 3mm or more and 5mm or less.

A third aspect of the present application provides a method of manufacturing a sensor comprising a light source, a luminance detector, and a flexible sensing portion; the flexible sensing part comprises a flexible pipe sleeve, an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; the flexible tube sleeve includes a cavity; the preparation method comprises the following steps:

step one, obtaining a flexible tube core material; wherein the refractive index of the flexible tube core material is higher than the refractive index of the material of the flexible tube sleeve;

and step two, forming a flexible tube core in the cavity to obtain the flexible sensing part.

Further, the flexible die material is a die fluid; the second step comprises the following steps: injecting die fluid into the cavity; curing the die fluid to form the flexible die, resulting in a flexible sensing portion.

Further, after injecting the die fluid into the cavity, further comprising: an optical fiber is inserted into the die fluid at the input and/or output.

Further, the temperature of the curing is greater than or equal to 55 ℃ and less than or equal to 80 ℃; the curing time is 4 hours or more and 6 hours or less.

Further, after the second step, the method further includes: and thirdly, forming a shell on the outer surface of the flexible sensing part.

Further, the third step includes:

pouring the shell fluid in a mould and solidifying and forming to obtain a shell prefabricated member;

placing a portion of the flexible sensing portion on a top surface of the housing preform;

casting a housing fluid on the top surface and curing to form a housing on the outer surface of the flexible sensing portion.

Further, the temperature of the solidification forming is more than or equal to 60 ℃ and less than or equal to 80 ℃; the curing molding time is greater than or equal to 6 hours and less than or equal to 8 hours.

The technical scheme provided by the embodiment of the application can comprise the following beneficial effects:

according to the embodiment, the sensor is driven by light, so that electromagnetic interference is avoided, potential safety hazards such as electric leakage and short circuit are avoided, and the safety is high. In addition, since the refractive index of the flexible tube core is higher than that of the flexible tube sleeve, light from the light source can be transmitted from the input end to the output end in the flexible sensing part in a total reflection mode, so that the damage of the flexible sensing part to the light is reduced, and the detection precision of the sensor is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 illustrates an overall schematic of one embodiment of a sensor of the present application.

Fig. 2 shows an overall schematic of another embodiment of the sensor of the present application.

Fig. 3 shows a schematic bottom view of an embodiment of the robot of the present application.

FIG. 4 illustrates a flow chart of one embodiment of a method of making a sensor of the present application.

Fig. 5 shows a flow chart of an embodiment of step two of the preparation method of the present application.

Fig. 6 shows a flow chart of another embodiment of step two of the preparation method of the present application.

Fig. 7 shows a flow chart of another embodiment of a method of manufacturing a sensor of the present application.

Fig. 8 shows a flow chart of an embodiment of step three of the preparation method of the present application.

The device comprises a sensor 100, a light source 1, a brightness detector 2, a flexible sensing part 3, a flexible pipe sleeve 31, a flexible pipe core 32, an input end 33, an output end 34, an input optical fiber 35, an output optical fiber 36, a shell 4, an upper end surface 41, a lower end surface 42, a foot part 200, a preparation method 300 and a Z thickness direction.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The manner described in the following exemplary embodiments does not represent all manners consistent with the present application. Rather, they are merely examples of apparatus consistent with some aspects of the present application as detailed in the accompanying claims.

The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Also, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one, and the terms "a" and "an" are used individually. "plurality" or "plurality" means two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. The word "comprising" or "comprises", and the like, means that elements or items appearing before "comprising" or "comprising" are encompassed by the element or item recited after "comprising" or "comprising" and equivalents thereof, and that other elements or items are not excluded. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, a first aspect of the present application provides a sensor 100. The sensor 100 includes a light source 1, a luminance detector 2, and a flexible sensing portion 3. The flexible sensing portion 3 includes a flexible tube sleeve 31 and a flexible tube core 32. Flexible tube sleeve 31 encases flexible tube core 32. The flexible sensing portion 3 includes an input 33 and an output 34: the input 33 is connected to the light source 1 and the output 34 is connected to the luminance detector 2. Wherein the refractive index of flexible tube core 32 is higher than the refractive index of flexible tube sleeve 31.

The light emitted by the light source 1 can enter the flexible sensing portion 3 through the input end 33 and then leave the flexible sensing portion 3 through the output end 34 and enter the luminance detector 2, so that the luminance detector 2 can detect the luminance of the light from the flexible sensing portion 3. When the flexible sensing part 3 is deformed by pressure, a light transmission path is broken, resulting in a decrease in light transmittance. Therefore, there is a difference between the light intensity entering the flexible sensing portion 3 from the input end 33 and the light intensity exiting the flexible sensing portion 3 from the output end 34. The brightness detector 2 is configured to detect the difference, and calculate a pressure value according to the difference, so that the sensor 100 can implement a function of pressure detection.

The sensor 100 of the present application is driven by light, and thus is not subject to electromagnetic interference, and is not subject to potential safety hazards such as leakage and short circuit, and has high safety. In addition, since the refractive index of the flexible tube core 32 is higher than that of the flexible tube cover 31, light from the light source 1 can be transmitted from the input end 33 toward the output end 34 in a form of total reflection within the flexible sensing portion 3, so that the breakage of the flexible sensing portion 3 to light is reduced, and the detection accuracy of the sensor 100 is improved.

In some embodiments, flexible tube 31 may be a low index silicone flexible tube 31 and flexible tube core 32 may be a high index silicone flexible tube core 32. The low hardness of the silica gel enables the flexible sensing part 3 to be easily deformed under external force, and sensitive sensing of pressure is achieved. Moreover, the high transparency of the silicone facilitates light transmission within the flexible tube core 32, reduces light loss, and improves the detection accuracy of the sensor 100. Indeed, in other embodiments, flexible tube sleeve 31 and flexible tube core 32 may be made of other materials, as this application is not limiting.

The flexible nature of the flexible sensing portion 3 allows for a wide variety of sensor 100 arrangements. As shown in fig. 1 and 2, the flexible sensing part 3 extends from the input end 33 to the output end 34 along an arc of a circle, thereby reducing the overall volume of the sensor 100 and enabling pressure detection at one point. In other embodiments, the flexible sensing part 3 may also extend along a straight line, so that the sensor 100 is able to detect pressure in a certain straight line direction. Indeed, the manner of extension of the flexible sensing portion 3 may be set by those skilled in the art according to actual needs, for example, along a triangular path, along a plurality of curved paths, which is not limited in this application.

In the embodiment of fig. 1 and 2, the arc angle range of the arc may be greater than or equal to 250 ° and less than or equal to 290 °, so that the flexible sensing part 3 can be formed in an approximately circular structure. By providing this, the detection range of the "point location" by the sensor 100 can be increased. For example, the sensor 100 may be arranged to: the center of the flexible sensing part 3 coincides with the detection point. In this way, the sensor 100 can establish a circular detection range around the detection point as the center of the circle. When pressure is applied near the detection point, the pressure can be captured by the sensor 100 regardless of the orientation in the vicinity of the detection point. Therefore, this arrangement can increase the detection range of the "point location" by the sensor 100.

Further, in this embodiment, the diameter of the circular arc may be greater than or equal to 10mm and less than or equal to 14mm. It is easy to understand that the larger the diameter of the circular arc is, the larger the detection range of the flexible sensing portion 3 is. However, the excessively large diameter makes the flexible sensing part 3 itself far from the position of the detection point, and thus may cause a problem in that the pressure at the position of the detection point is difficult to detect. And the smaller the diameter of the arc, the smaller the detection range and the higher the loss in the light propagation process. Therefore, the circular arc diameter set in the present application can expand the detection range of the sensor 100 as much as possible on the premise that the sensor 100 can detect the pressure at the detection point. The inventors have tested many times, and in the case where the circular arc diameter is, for example, 10mm, 12mm, or 14mm, the sensor 100 can sense the pressure at the detection point position well, and can sense the pressure at the position slightly deviated from the detection point.

Furthermore, to further optimize the volume of the sensor 100, in some embodiments, the dimension of the sensor 100 in the thickness direction is greater than or equal to 3mm and less than or equal to 5mm. In this way, the sensor 100 can be disposed in a narrow area, and the flexibility of the arrangement of the sensor 100 is improved. Further, since the thickness of the sensor 100 is thin, the sense of presence of the sensor 100 can be weakened when the sensor 100 is provided on the device. Especially when the device is a motion enabled device, the sensor 100 can avoid interfering with the motion of the device.

The direct connection between the light source 1 and the input 33 and between the brightness detector 2 and the output 34 may be possible. In this way, light from the light source 1 can enter the flexible sensing section 3 directly through the input end 33 and directly into the luminance detector 2 at the output end 34, reducing the loss rate of light. Alternatively, as shown in fig. 1 and 2, the flexible sensing section 3 further includes an input optical fiber 35 provided between the input end 33 and the light source 1, and an output optical fiber 36 provided between the output end 34 and the luminance detector 2. An input fiber 35 is used to connect the input 33 with the light source 1 and an output fiber 36 is used to connect the output 34 with the brightness detector 2.

The output optical fiber 36 and the input optical fiber 35 can function like "wires" to connect the light source 1 and the flexible sensing section 3 and the luminance detector 2 and the flexible sensing section 3. In this way, the sensor 100 can dispose the light source 1 and the luminance detector 2, which are relatively large in volume, away from the flexible sensing portion 3. Therefore, in the case where the space for the detection position is limited, the sensor 100 can still perform pressure detection by placing the flexible sensing part 3 at the detection position, transmitting light through the output optical fiber 36 and the input optical fiber 35. By this arrangement, the space requirement of the sensor 100 for the detection position is reduced, and thus the arrangement increases the flexibility and the application range of the sensor 100.

Indeed, the flexible sensing portion 3 may be provided with the input optical fiber 35 only at the input end 33 or the output optical fiber 36 only at the output end 34, so as to reduce the possibility of optical loss caused by the input optical fiber 35 and the output optical fiber 36, which is not limited in the present application.

As shown in fig. 1, in some embodiments, the sensor 100 further comprises a housing 4. The housing 4 is molded to an outer surface of the flexible sensing portion 3, and at least part of the flexible sensing portion 3 is disposed within the housing 4. Wherein the hardness of the housing 4 is greater than the hardness of the flexible sensing portion 3. The flexible nature of the flexible sensing portion 3 is such that the flexible sensing portion 3 is also subject to a large deformation when subjected to very slight forces. While an excessive sensitivity may result in a reduced range of detection forces of the sensor 100.

For example, in one experiment, the first sensor 100 was not provided with the housing 4, and the second sensor 100 was provided with the housing 4. When the first sensor 100 and the second sensor 100 are subjected to the same pressure, the flexible sensing part 3 of the first sensor 100 is directly stressed; while the housing 4 of the second sensor 100 is able to resist part of the pressure so that the flexible sensing part 3 may in fact only be subjected to 30% of the pressure. Therefore, the deformation of the flexible sensing portion 3 of the second sensor 100 is smaller than the deformation of the flexible sensing portion 3 of the first sensor 100. If the deformation of the flexible sensing portion 3 of the second sensor 100 is the same as the deformation of the flexible sensing portion 3 of the first sensor 100 at this time, a larger pressure is applied to the second sensor 100.

It can be seen that the sensor 100 provided with the housing 4 can receive a larger pressure, and thus the provision of the housing 4 can well expand the pressure detection range of the sensor 100. Meanwhile, the shell 4 can also play a good role in protecting the flexible sensing part 3, so that the flexible sensing part 3 can carry out repeated stress detection, thereby being beneficial to improving the robustness of the sensor 100 and prolonging the service life of the sensor 100.

It can be understood that the larger the thickness of the housing 4 is, the lower the detection sensitivity of the flexible sensing part 3 is; the smaller the thickness of the housing 4 is, the limited the housing 4 has an ability to expand the detection range and to protect the flexible sensing portion 3. Thus, in some embodiments, the minimum distance of the flexible sensing part 3 from the upper end surface 41 in the thickness direction is 0.8mm or more and 1.2mm or less. Similarly, the minimum distance between the flexible sensing part 3 and the lower end surface 42 in the 5-thickness direction is 0.8mm or more and 1.2mm or less.

In this way, the housing 4 can provide good protection for the flexible sensing portion 3, while also being able to effectively maintain the detection sensitivity of the flexible sensing portion 3.

The case 4 may be made of a high-hardness material such as polyurethane, polyvinyl chloride, or a material having superior elasticity and recovery such as rubber, which is not limited in this application. These materials have higher hardness than the flexible 0 sensing part 3 and are good in rebound ability. The housing 4 is capable of when the sensor 100 is subjected to pressure

The flexible sensing part 3 is deformed and pressed, and then the shell 4 can be restored to the original state after the pressure is lost, so that the flexible sensing part 3 is not stressed, and the robustness and the service life of the sensor 100 can be improved.

In embodiments where the flexible sensing portion 3 comprises an input optical fiber 35, an output optical fiber 36, the sensor 100 may further comprise a plurality of flexible sensing portions 3. Wherein the input end 33 of each flexible sensing part 3 is connected with the light source 1 through a 5-input optical fiber 35, and the output end 34 is connected with the brightness detector 2 through an output optical fiber 36.

By so doing, the sensor 100 can be used to detect pressures at a plurality of positions, and ensure pressure detection accuracy and sensitivity for each position.

Indeed, in embodiments in which the flexible sensing portion 3 comprises only the input optical fiber 35, a plurality of flexible sensing portions 3

May be directly connected to the luminance detector 2. In embodiments where the flexible sensing part 3 includes only the output optical fiber 360, the input ends 33 of the plurality of flexible sensing parts 3 may be directly connected to the light source 1, which is not limited in this application.

Referring to fig. 3, a second aspect of the present application provides a robot (not shown). The robot includes a robot lower limb. The robotic lower limb includes the foot 200, leg, and sensor 100 described in the previous embodiments. Foot 200 is connected to the leg. Sensor 100 is disposed on a side of foot 200 remote from the leg. By this arrangement, 5 when the foot 200 is in contact with the ground, the sensor 100 is in direct contact with the ground, and thus the sensor 100 is able to detect the stress situation of the foot 200 of the robot. For example, in embodiments requiring the robot to walk, the sensor 100 can detect whether the foot 200 is in contact with the ground, whether the force of contact is in a normal range, and thus whether the robot is operating properly.

The robot generally needs to be electrified to perform normal operation, and the sensor 100 is driven by light, so that electromagnetic interference cannot be received, the influence of the power supply of the robot and the power supply in the environment where the robot is located on the sensor 100 can be reduced to the greatest extent, and the normal operation of the sensor 100 is guaranteed.

In the embodiment shown in fig. 3, the sensor 100 further comprises a plurality of flexible sensing parts 3. Those skilled in the art can flexibly set the flexible sensing portion 3 at a plurality of positions according to actual needs, so that the sensor 100 can realize pressure detection in a large range and multiple points, which is beneficial to improving the performance of the sensor 100. Furthermore, this arrangement eliminates the need for a separate sensor 100 for each detection point on the foot 200, and simplifies the construction of the foot 200.

The arrangement positions and the number of the flexible sensing parts 3 shown in the drawings should be taken as exemplary and not limiting, and those skilled in the art may arrange more or less flexible sensing parts 3 or arrange the flexible sensing parts 3 at other positions according to actual demands, which is not limited in this application.

Further, since the sensor 100 further includes the input optical fiber 35 and the output optical fiber 36, the light source 1 and the brightness detector 2 can be flexibly disposed at other positions of the lower limb of the robot without being disposed at the position of the foot 200 in a concentrated manner. For example, the flexible sensor 3 is disposed on a side of the foot 200 facing the ground, and the light source 1 and the brightness detector 2 can be disposed on a side of the foot 200 away from the ground or at a lower leg position of a lower limb of the robot. In this way, the flexibility of the arrangement of the sensor 100 can be improved so as not to interfere with the contact of the foot 200 with the ground by the presence of the light source 1 and the luminance detector 2.

It should be noted that the beneficial effects described above for the various embodiments of the sensor 100 can be equally used to describe the robot of the present application, and for brevity of description, the present application is not repeated here.

Referring to fig. 4, a third aspect of the present application provides a method 300 of manufacturing a sensor. The sensor mentioned in this third aspect may include all the features of the sensor 100 described in the above embodiments without generating a conflict. The preparation method 300 comprises the following steps:

step 310: obtaining a flexible die material; wherein the refractive index of the flexible tube core material is higher than the refractive index of the material of the flexible tube sleeve;

step 320: a flexible die is formed in the cavity, resulting in a flexible sensing portion.

Because the refractive index of the flexible tube core is higher than that of the flexible tube sleeve, light from the light source can be transmitted from the input end to the output end in the flexible sensing part in a total reflection mode, so that the damage of the flexible sensing part to the light is reduced, and the detection precision of the sensor is improved.

In some embodiments, the flexible tube may be a low index silicone flexible tube and the flexible tube core may be a high index silicone flexible tube core. The low hardness of the silica gel enables the flexible sensing part to be easily deformed under external force, and sensitive sensing of pressure is achieved. Indeed, in other embodiments, the flexible tube sleeve and the flexible tube core may be made of other materials, as this application is not limiting.

The flexible core material may be a solid body that has been molded, and the flexible core is formed by plugging the flexible core material into the cavity, resulting in a flexible sensing portion. Alternatively, referring to fig. 5, in some embodiments, the flexible die material is a die fluid. And step 320 comprises:

step 321: injecting die fluid into the cavity.

Step 322: the die fluid is cured to form the flexible die, resulting in a flexible sensing portion.

By injecting the die fluid into the cavity and then curing, the flexible die can be fully filled into the cavity to ensure the effect of total reflection of light, thereby reducing the breakage of the light.

The material of the die fluid may be a high refractive index silica gel. The silica gel has the characteristics of high transparency and softness, can be well deformed, and can reduce the loss of light rays during transmission inside the flexible tube core, thereby being beneficial to improving the detection precision of the sensor. In addition, the silica gel can be subjected to injection molding, so that the cavity can be fully filled, and the influence on light transmission caused by impurities entering the cavity is avoided.

In embodiments where the flexible sensing portion includes optical fibers (e.g., input fibers, output fibers), the optical fibers may be bonded to the input or output ends. In other embodiments, referring to fig. 6, step 320 further comprises, prior to step 322:

step 323: optical fibers are inserted into the die fluid at the input and output ends.

When the tube core fluid is solidified, the flexible tube core can be combined with the optical fiber into a whole, so that the combination tightness between the optical fiber and the flexible tube core is improved, and the risk of falling off of the optical fiber when the sensor is used is reduced.

In this embodiment, the depth of insertion of the optical fiber into the die fluid may be in the range of 0.5cm-1 cm. Too small a depth makes it difficult to form a stable bond with the flexible tube core and there is a risk of detachment. While too deep an insertion results in waste of fiber optic material. Thus, through the experiments of the inventor, the optical fiber can ensure good bonding strength when the insertion depth of the optical fiber is 0.5cm, 0.8cm and 1 cm.

Indeed, in step 323, only the input end or only the output end may be inserted with the optical fiber, which is not limited in this application.

In various embodiments described above, the curing in step 322 may be by heating the flexible tube sleeve injected with the die fluid between 55-80 ℃ for 4-6 hours until the silicone gel is fully cured. For example, the heating may be performed at 55℃and 65℃or 80℃for 4 hours, 5 hours or 6 hours. The heating temperature interval and the heating time interval can effectively solidify the die fluid without causing excessive energy consumption. In embodiments in which the optical fiber is inserted, this heating temperature interval also avoids damage to the optical fiber structure.

Referring to fig. 7, in some embodiments, to enable an increase in the pressure detection range of the sensor and to form a protection for the flexible sensing portion, the preparation method 300 further includes, after step 320:

step 330: a housing is formed on an outer surface of the flexible sensing portion.

The sensor provided with the shell can receive larger pressure, so that the pressure detection range of the sensor can be well enlarged by the shell. Meanwhile, the shell can also play a good role in protecting the flexible sensing part, so that the flexible sensing part can carry out repeated stress detection, the robustness of the sensor is improved, and the service life of the sensor is prolonged.

The molding may be molding only on either side of the flexible sensing part in the thickness direction, for example, directly assembling a hard case on the outer surface of the flexible sensing part. Alternatively, referring to fig. 8, step 330 may include:

step 331: and pouring the shell fluid in a mould, and solidifying and forming to obtain a shell prefabricated member.

In some embodiments, the shell preform has a dimension in the thickness direction in the range of 1.6cm-2.5cm, such as 1.6cm, 2.0cm, or 2.5cm. If the dimensions of the shell preform are too small, the bending radius of the flexible sensing portion within the shell preform needs to be reduced, however too small a bending radius of the flexible sensing portion may result in excessive losses in the light propagation process. And oversized, then takes up space. Thus, this size range enables the volume of the sensor to be controlled within a certain range so as not to cause excessive occupation of space. And also to ensure that the flexible sensing portion remains within a suitable bending radius.

Step 332: a portion of the flexible sensing portion is placed on the top surface of the shell preform.

Step 333: the housing fluid is poured over the top surface and cured to form a shell over the outer surface of the flexible sensing portion.

Through setting up like this, can form inseparable connection between flexible sensing portion and the casing, avoid having the air between flexible sensing portion and the casing for the pressure of exerting on the casing can be effectively caught by flexible sensing portion.

The curing of the sheath fluid may be heating between 60 ℃ and 80 ℃ for 6-8 hours. For example, heating is performed at 60 ℃, 70 ℃, or 80 ℃ for 6 hours, 7 hours, or 8 hours. Too high a curing temperature can easily result in structural effects on the flexible sensing portion, while too low a temperature can result in incomplete curing. Likewise, too long a heating time does not further aid in curing, resulting in increased processing costs; too low a level may result in incomplete curing. The heating temperature interval and the heating time interval of the present application can effectively and sufficiently solidify the sheath fluid.

In some embodiments, the flexible sensing portion has a dimension in the thickness direction of 1/3 of the shell thickness, and the shell preform has a thickness of 1/3 of the shell thickness. For example, the thickness of the shell preform is 0.8mm-1mm, the thickness of the flexible sensing portion is 0.8mm-1mm, and the overall thickness of the shell after casting is 2.4mm-3mm.

Thus, when the flexible sensing part is placed on the shell prefabricated member and casting is conducted for the second time, the flexible sensing part can be arranged on the middle layer of the shell, so that the distance between the flexible sensing part and the upper end face of the shell in the thickness direction is the same as the distance between the flexible sensing part and the lower end face of the shell, and the pressure on two sides is effectively captured.

The housing fluid may be a rigid plastic material that is not cured, such as polyurethane, polyvinyl chloride, or the like; or may be a material such as rubber, to which the present application is not limited. The cavity of the mold may be, for example, prismatic, cylindrical, as the application is not limited in this regard.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the present application. Those skilled in the art may make various modifications, additions, or substitutions to the described embodiments without departing from the spirit of the invention or the scope thereof as defined in the accompanying claims.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

Claims (23)

1. A sensor, comprising:

a light source;

a brightness detector; and

a flexible sensing portion comprising a flexible tube sleeve and a flexible tube core; the flexible tube sleeve wraps the flexible tube core; the flexible sensing part comprises an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; wherein the refractive index of the flexible tube core is higher than the refractive index of the flexible tube sleeve.

2. The sensor of claim 1, wherein the flexible sensing portion further comprises:

the input optical fiber is arranged between the input end and the light source so as to connect the input end and the light source; and/or the number of the groups of groups,

and the output optical fiber is arranged between the output end and the brightness detector so as to connect the output end and the brightness detector.

3. The sensor of claim 2, wherein the number of flexible sensing portions comprises a plurality;

the input end of each flexible sensing part is connected with the light source through the input optical fiber; and/or, the output end of each flexible sensing part is connected with the brightness detector through the output optical fiber.

4. The sensor of claim 1, wherein the sensor further comprises:

a housing; the shell is formed on the outer surface of the flexible sensing part; at least part of the flexible sensing part is arranged in the shell; the hardness of the housing is greater than the hardness of the flexible sensing portion.

5. The sensor of claim 1, wherein the flexible sensing portion extends along an arc from the input end to the output end.

6. The sensor of claim 5, wherein the arc has an arc angle range of greater than or equal to 250 ° and less than or equal to 290 °.

7. The sensor of claim 5, wherein the circular arc has a diameter greater than or equal to 10mm and less than or equal to 14mm.

8. The sensor according to claim 1, wherein a dimension of the sensor in a thickness direction is greater than or equal to 3mm and less than or equal to 5mm.

9. A robot, comprising a robot lower limb; the robot lower limb comprises a foot, a leg and a sensor; the foot is connected with the leg; the sensor is arranged on one side of the foot away from the leg; characterized in that the sensor comprises:

a light source;

a brightness detector; and

a flexible sensing portion comprising a flexible tube sleeve and a flexible tube core; the flexible tube sleeve wraps the flexible tube core; the flexible sensing part comprises an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; wherein the refractive index of the flexible tube core is higher than the refractive index of the flexible tube sleeve.

10. The robot of claim 9, wherein the flexible sensing portion further comprises:

the input optical fiber is arranged between the input end and the light source so as to connect the input end and the light source; and/or the number of the groups of groups,

and the output optical fiber is arranged between the output end and the brightness detector so as to connect the output end and the brightness detector.

11. The robot of claim 10, wherein the number of flexible sensing portions comprises a plurality of;

the input end of each flexible sensing part is connected with the light source through the input optical fiber; and/or, the output end of each flexible sensing part is connected with the brightness detector through the output optical fiber.

12. The robot of claim 9, wherein the sensor further comprises:

a housing; the shell is formed on the outer surface of the flexible sensing part; at least part of the flexible sensing part is arranged in the shell; the hardness of the housing is greater than the hardness of the flexible sensing portion.

13. The robot of claim 9, wherein the flexible sensing portion extends along an arc from the input end to the output end.

14. The robot of claim 13, wherein the arc has an arc angle range of greater than or equal to 250 ° and less than or equal to 290 °.

15. The robot of claim 13, wherein the diameter of the arc is greater than or equal to 10mm and less than or equal to 14mm.

16. The robot of claim 9, wherein a dimension of the sensor in a thickness direction is greater than or equal to 3mm and less than or equal to 5mm.

17. A method of manufacturing a sensor comprising a light source, a brightness detector and a flexible sensing portion; the flexible sensing part comprises a flexible pipe sleeve, an input end and an output end; the input end is connected with the light source; the output end is connected with the brightness detector; the flexible tube sleeve includes a cavity; the preparation method is characterized by comprising the following steps:

step one, obtaining a flexible tube core material; wherein the refractive index of the flexible tube core material is higher than the refractive index of the material of the flexible tube sleeve;

and step two, forming a flexible tube core in the cavity to obtain the flexible sensing part.

18. The method of manufacturing of claim 17, wherein the flexible die material is a die fluid;

the second step comprises the following steps: injecting die fluid into the cavity; curing the die fluid to form the flexible die, resulting in a flexible sensing portion.

19. The method of manufacturing of claim 18, further comprising, after injecting die fluid into the cavity:

an optical fiber is inserted into the die fluid at the input and/or output.

20. The method of claim 18, wherein the temperature of curing is greater than or equal to 55 ℃ and less than or equal to 80 ℃; the curing time is 4 hours or more and 6 hours or less.

21. The method of claim 17, further comprising, after step two:

and thirdly, forming a shell on the outer surface of the flexible sensing part.

22. The method of claim 21, wherein the third step comprises:

pouring the shell fluid in a mould and solidifying and forming to obtain a shell prefabricated member;

placing a portion of the flexible sensing portion on a top surface of the housing preform;

casting a housing fluid on the top surface and curing to form a housing on the outer surface of the flexible sensing portion.

23. The method of claim 22, wherein the curing and molding temperature is greater than or equal to 60 ℃ and less than or equal to 80 ℃; the curing molding time is greater than or equal to 6 hours and less than or equal to 8 hours.

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