CN114700975B - Flexible optical waveguide-based attitude sensor and robot - Google Patents

Abstract

The invention relates to a flexible optical waveguide-based attitude sensor and a robot. The attitude sensor comprises an optical waveguide, a rack and a weight; the optical waveguide is arranged on the frame, the weight is slidably arranged on the frame along a preset direction, the weight is connected with the surface of the cladding of the optical waveguide and corresponds to the inner core of the optical waveguide, and the preset direction is perpendicular to the axis of the inner core and parallel to the surface of the cladding. The weight of the attitude sensor can only be arranged on the rack in a sliding manner along a preset direction, so that the optical waveguide can realize the perception of the absolute attitude through the gravity component of the weight, and compared with a gyroscope which realizes the attitude perception by means of angular velocity integration, the attitude sensor perceives the absolute attitude, and the problem of accumulated errors caused by the integration process is avoided; the sliding direction of the weight is perpendicular to the axis of the inner core and parallel to the surface of the cladding, so that the output of the optical waveguide has good linear relation with the sine value of the attitude angle, the optical waveguide has convenience in use, and the detection sensitivity is ensured.

Description

Attitude sensor and robot based on flexible optical waveguide

Technical field

The invention relates to the field of robotic technology, and in particular to an attitude sensor and a robot based on a flexible optical waveguide.

Background technique

The perception of one's own posture is an important prerequisite for humans to move in the environment, especially the absolute posture perception with gravity as the reference direction. Obtaining its own posture in space is equally important for robots (such as mobile robots and robotic arms). Currently, gyroscope technology is often used for robot attitude perception, and the attitude is obtained by integrating the angular velocity. This method of attitude perception causes errors in angular velocity measurement to accumulate, which may eventually lead to attitude deviations.

Contents of the invention

Based on this, it is necessary to provide an attitude sensor and robot based on a flexible optical waveguide to solve the problem of deviation in attitude perception due to the use of gyroscope technology in robots.

An attitude sensor based on a flexible optical waveguide, the attitude sensor includes: an optical waveguide, a frame and a heavy object;

The optical waveguide is disposed on the frame, and the weight is disposed on the frame slidably along a preset direction. The weight is also connected to the surface of the cladding of the optical waveguide and is connected to the cladding surface of the optical waveguide. Corresponding to the inner core of the optical waveguide, the preset direction is perpendicular to the axis of the inner core and parallel to the surface of the cladding.

For the above-mentioned attitude sensor, the weight can only be slid on the frame in a preset direction. This allows the optical waveguide to realize the absolute attitude perception through the gravity component of the weight. Compared with the gyroscope that relies on the angular velocity integral to achieve attitude perception. , the absolute attitude is perceived, without the integration process and the cumulative error problem it brings; since the sliding direction of the weight is perpendicular to the axis of the inner core and parallel to the surface of the cladding, the output of the optical waveguide is related to the attitude angle The sine value has a good linear relationship, which is convenient in use and ensures the sensitivity of detection; using flexible materials as the sensitive unit (i.e. optical waveguide), it has large deformation even under the action of a small force. It is equivalent to having an amplification effect on force, which makes the attitude sensor have high sensitivity; the optical waveguide is robust. As a sensitive unit, the optical waveguide can not only resist overload loads, but also has a certain shock absorption and buffering effect. This kind of robustness The stickability will enhance the ease of use of the attitude sensor.

In one embodiment, the number of the inner cores of the optical waveguide is one, and the shape of the inner core of the optical waveguide is linear.

In one embodiment, the frame is provided with a slide rail, and the slide rail is provided with a slide block that can slide in the preset direction, and the slide block is connected to the weight.

In one embodiment, the attitude sensor further includes a first mounting member connected between the slider and the weight.

In one embodiment, the attitude sensor further includes a force transmission member connected between the weight and the cladding of the optical waveguide. Corresponding to the inner core, the area of the side of the force transmission member close to the optical waveguide is smaller than the area of the side of the weight close to the optical waveguide.

In one embodiment, the attitude sensor further includes a second mounting member, and the second mounting member is connected between the force transmission member and the weight.

In one embodiment, the rack includes: a base, a mounting base, and a column that supports the mounting base above the base;

The optical waveguide is disposed on the base, and the weight is slidably disposed on the mounting base.

In one embodiment, the mounting base can slide up and down along the column.

In one embodiment, the upright is a screw rod, and the frame further includes a nut threadedly connected to the upright, and the nut is used to lock the mounting base at any height.

A robot, the robot includes an attitude sensor based on a flexible optical waveguide as described in any one of the above.

In the above-mentioned robot, the weight of the attitude sensor can only be set on the frame to slide in the preset direction. This allows the optical waveguide to realize the absolute attitude perception through the gravity component of the weight, unlike the gyroscope that relies on the angular velocity integral to realize attitude perception. In contrast, what is perceived is the absolute attitude, without the integration process and the cumulative error problem it brings; because the sliding direction of the weight is perpendicular to the axis of the inner core and parallel to the surface of the cladding, this makes the output of the optical waveguide and The sine value of the attitude angle has a good linear relationship, which is convenient in use and ensures the sensitivity of detection; using flexible materials as the sensitive unit (i.e., optical waveguide) has a large sensitivity even under a small force. Deformation is equivalent to an amplification effect on force, which makes the attitude sensor have high sensitivity; the optical waveguide is robust. As a sensitive unit, the optical waveguide can not only resist overload loads, but also has a certain shock absorption and buffering effect. This robustness will enhance the ease of use of the attitude sensor.

Description of the drawings

Figure 1 is a schematic structural diagram of an attitude sensor based on a flexible optical waveguide provided by an embodiment of the present invention;

Figure 2 is a schematic diagram of the working principle of an attitude sensor based on a flexible optical waveguide provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the relationship between the light loss signal intensity of the attitude sensor based on a flexible optical waveguide and the sine value of the angle between the inclined planes according to an embodiment of the present invention.

Among them, the description of the symbols in the attached drawings is as follows:

10. Attitude sensor; 100. Optical waveguide; 200. Frame; 210. Base; 220. Mounting base; 230. Column; 300. Weight; 400. Slide rail; 500. Slider; 600. First mounting piece; 700. Force transmitting parts; 800. Second mounting parts; 20. Inclined surface.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, the present invention can be implemented in many other ways different from those described here. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis" The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply the device or device referred to. Elements must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated into one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements, unless otherwise specified restrictions. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise expressly stated and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. touch. Furthermore, the terms "above", "above" and "above" the first feature is above the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "below" and "beneath" the first feature to the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

It should be noted that when an element is referred to as being "mounted" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may also be intervening elements present. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation manner.

The perception of one's own posture is an important prerequisite for humans to move in the environment, especially the absolute posture perception with gravity as the reference direction. Obtaining its own posture in space is equally important for robots (such as mobile robots and robotic arms). Currently, gyroscope technology is often used for robot attitude perception, and the attitude is obtained by integrating the angular velocity. This method of attitude perception causes errors in angular velocity measurement to accumulate, which may eventually lead to attitude deviations.

In this regard, one embodiment of the present invention provides an attitude sensor 10 based on a flexible optical waveguide. As shown in Figure 1 , the attitude sensor 10 based on a flexible optical waveguide includes: an optical waveguide 100, a frame 200 and a weight 300; The optical waveguide 100 is disposed on the frame 200, and the weight 300 is slidably disposed on the frame 200 along a preset direction. The weight 300 is also connected to the surface of the cladding of the optical waveguide 100 and in contact with the inner core of the optical waveguide 100. Correspondingly, the preset direction is perpendicular to the axis of the inner core of the optical waveguide 100 and parallel to the surface of the cladding of the optical waveguide 100 .

Regarding the structure of the optical waveguide 100, as an example, the optical waveguide 100 includes: a cladding, an inner core, and optoelectronic components and circuits; the cladding is used to wrap the inner core, optoelectronic components, and circuits, and the optoelectronic components and circuits include light-emitting diodes and light sources. Power supply circuit, phototransistor, signal acquisition circuit. Among them, the cladding and the inner core of the optical waveguide 100 are both flexible materials with a refractive index that meets the total reflection of the optical waveguide. The refractive index of the inner core material of the optical waveguide 100 is higher than the refractive index of the cladding material of the optical waveguide 100. For example, The material of the cladding of the optical waveguide 100 may be silicone rubber, and the material of the inner core of the optical waveguide 100 may be polyurethane or polyacrylate. In addition, the shape of the inner core is linear. The linear inner core not only facilitates the manufacture of the inner core, but also makes it easier to meet the total reflection requirements of the optical waveguide 100 .

The working principle of the above-mentioned optical waveguide 100 can be described as follows: the light source power supply circuit supplies power to the light-emitting diode and converts electrical energy into light energy; the original optical signal emitted by the light-emitting diode propagates in the inner core. When a strong stimulus acts on the inner core, the inner core The core deforms, causing the original light signal in the core to attenuate and become a lossy light signal. The lossy light signal is detected by the phototransistor arranged at the end of the core, where the lossy light signal is converted into an analog electrical signal. Signal; the signal acquisition circuit captures the analog electrical signal sent by the phototransistor, and finally sends the analog electrical signal to an external device (such as a wireless receiving module). The external device receives, records and analyzes it, through linear interpolation and neural network Wait for operations to decode and restore the original force stimulation information.

Among them, the dimension of the posture sensed by the optical waveguide 100 is related to the number of inner cores of the optical waveguide 100. For example, in order to realize the perception of one-dimensional posture, the optical waveguide 100 itself can be felt along a defined angular direction (i.e., predetermined direction). direction), and at the same time, it is insensitive to the attitude changes in the other two perpendicular directions in space. At this time, an inner core can be set in the optical waveguide 100. At this time, the weight 300 can be set on the axis of the inner core. Directly above the position, when the weight 300 drives the optical waveguide 100 to move, the maximum displacement can be detected by the inner core, improving the sensitivity of the optical waveguide 100; in order to realize the perception of two-dimensional postures, 2 can be set in the optical waveguide 100 The two inner cores intersect in a cross shape. Correspondingly, the weight 300 is arranged directly above the axes of the two inner cores and can slide in the plane along two perpendicular preset directions. Of course, two optical waveguides 100 capable of realizing one-dimensional attitude sensing can also be directly placed vertically to realize two-dimensional attitude sensing. The following takes an inner core provided in the optical waveguide 100 as an example to describe the working principle and structure of the attitude sensor 10 one by one.

In order to describe the sensitivity of the attitude sensor 10 to the attitude inclination angle, referring to FIG. 2 , the attitude sensor 10 is fixed on the inclined plane 20 with an inclination angle of θ. Among them, the working principle of the attitude sensor 10 can be described as follows: the optical waveguide 100 of the attitude sensor 10 serves as a sensitive element and can respond to the changing tangential force acting on its surface (i.e., G×sinθ,G shown in Figure 2 responds to the gravity of the weight 300). The gravity of the weight 300 will produce changes in the component perpendicular to the surface of the optical waveguide 100 (i.e. G×cosθ shown in Figure 2) and the component parallel to the surface of the optical waveguide 100 ( That is (G The portion of the component parallel to the surface of the optical waveguide 100 is not constrained. Then when the attitude angle of the attitude sensor 10 gradually increases from the horizontal home position to the defined angular direction, the component force of the weight 300 parallel to the surface of the optical waveguide 100 gradually increases, and the response of the optical waveguide 100 gradually increases, and is consistent with The magnitude of this force is linearly related, that is, it increases sinusoidally with the attitude angle (see Figure 3). It should be noted that the "outward stroke" in Figure 3 means that the inclination angle θ of the inclined plane gradually increases from 0° to 90°, and the "return stroke" means that the inclination angle θ of the inclined plane gradually decreases from 90° to 0°.

As described above for the attitude sensor 10 based on the flexible optical waveguide, the weight 300 can only be slidably disposed on the frame 200 in a preset direction, which allows the optical waveguide 100 to realize absolute attitude perception through the gravity component of the weight 300 , compared with gyroscopes that rely on angular velocity integration to achieve attitude perception, what is perceived is the absolute attitude, without the integration process and the cumulative error problem it brings; because the sliding direction of the weight 300 is perpendicular to the axis of the inner core and to the cladding The surface of the optical waveguide 100 is parallel, which makes the output of the optical waveguide 100 have a good linear relationship with the sine value of the attitude angle, which is convenient in use and ensures the sensitivity of detection; a flexible material is used as the sensitive unit (i.e., the optical waveguide 100 ), has a large deformation even under the action of a small force, which is equivalent to an amplification effect on the force, which makes the attitude sensor 10 have high sensitivity; the optical waveguide 100 has robustness, and the optical waveguide 100 as a sensitive unit Not only can it resist overload loads, but it also has a certain shock-absorbing and buffering effect. This robustness will enhance the ease of use of the attitude sensor 10.

As shown in Figure 1, in some embodiments of the present invention, the rack 200 is provided with a slide rail 400, and the slide rail 400 is provided with a slide block 500 that can slide in a preset direction. The slide block 500 and the weight 300 connect. Through the cooperation of the slide rail 400 and the slide block 500, the weight 300 can only slide in a preset direction, and the structure of the attitude sensor 10 can also be simplified.

Regarding how the slide block 500 and the slide rail 400 cooperate, as an example, the cross-sectional shape of the slide rail 400 is T-shaped, the slide block 500 is provided with a T-shaped sliding groove, and the slide rail 400 is inserted into the sliding groove of the slide block 500 in so that the slider 500 slides along itself.

Optionally, the slide rail 400 can be installed on the frame 200 by welding, threaded connection, snap connection, etc.

Further, in some embodiments of the present invention, as shown in FIG. 1 , the attitude sensor 10 further includes a first mounting part 600 , and the first mounting part 600 is connected between the slider 500 and the weight 300 . The first mounting part 600 facilitates the connection between the slider 500 and the weight 300 .

Optionally, the first mounting part 600 may be a plastic part, which may be produced and processed using additive manufacturing. The first mounting part 600 can be installed on the slider 500 using screws, adhesives, buckles, etc., and the first mounting part 600 can be connected to the weight 300 using adhesives, screws, interference fit, etc., where the weight 300 can be a metal block.

As shown in Figure 1, in some embodiments of the present invention, the attitude sensor 10 further includes a force transmission member 700. The force transmission member 700 is connected between the weight 300 and the cladding of the optical waveguide 100. The force transmission member 700 is connected to the optical waveguide 100. Corresponding to the inner core of the waveguide 100 , the area of the side of the force transmission member 700 close to the optical waveguide 100 is smaller than the area of the side of the weight 300 close to the optical waveguide 100 . It should be noted that the side of the force transmission member 700 close to the optical waveguide 100 refers to the side of the force transmission member 700 that is directly in contact with the cladding of the optical waveguide 100; if there is no set between the weight 300 and the cladding of the optical waveguide 100 When the force transmission member 700 is disposed, the side of the weight 300 close to the optical waveguide 100 is in direct contact with the cladding of the optical waveguide 100 . By arranging a smaller force transmission member 700 between the weight 300 and the optical waveguide 100, the weight of the weight 300 can be concentrated on the optical waveguide 100 as much as possible, which can increase the sensitivity of the optical waveguide 100.

Regarding the connection method of the force transmission member 700 , as one method, the force transmission member 700 can be connected to the cladding surface of the optical waveguide 100 by bonding, screws, interference fit, etc.

Further, in some embodiments of the present invention, as shown in FIG. 1 , the attitude sensor 10 further includes a second mounting member 800 , and the second mounting member 800 is connected between the force transmission member 700 and the weight 300 . The second mounting member 800 facilitates the connection between the force transmission member 700 and the weight 300 .

Optionally, the second mounting part 800 can be a plastic part, which can be processed by additive manufacturing, and can be connected to the force transmission part 700 and the weight 300 by bonding, screws, interference fit, etc.

As shown in Figure 1, in some embodiments of the present invention, the rack 200 includes: a base 210, a mounting base 220, and a column 230 that supports the mounting base 220 above the base 210; the optical waveguide 100 is disposed on the base 210. The object 300 is slidably disposed on the mounting base 220. The frame 200 of this type of structure has a simple structure and is easy to manufacture. As an example, the slide rail 400 is provided on the mounting base 220 .

Regarding the number of uprights 230 , as an example, it can be set to four, and each upright 230 is disposed between the base 210 and the corner of the mounting base 220 .

Further, in some embodiments of the present invention, the mounting base 220 can slide up and down along the column 230 . By moving the mounting base 220 up and down, the weight 300 can be leveled on the surface of the optical waveguide 100 and the initial pre-pressure of the weight 300 on the optical waveguide 100 can be controlled.

Specifically, in some embodiments of the present invention, as shown in FIG. 1 , the upright 230 is a threaded rod, and the rack 200 further includes a nut threadedly connected to the upright 230 , and the nut is used to lock the mounting base 220 at any height. It can be understood that the mounting base 220 is provided with a through hole for the column 230 to pass through. As an example, two nuts are provided on each column 230. When the mounting base 220 reaches the preset height, the mounting base 220 is clamped by the cooperation of the two nuts and the screw rod, thereby realizing the mounting base 220. locking.

Another embodiment of the present invention provides a robot, which includes the attitude sensor 10 as described in any one of the above.

As an example, the above-mentioned robot may be a mobile robot or a robotic arm.

In order to describe the sensitivity of the robot's attitude sensor 10 to the attitude inclination angle, referring to FIG. 2 , the attitude sensor 10 is fixed on the inclined plane 20 with an inclination angle of θ. Among them, the working principle of the attitude sensor 10 can be described as follows: the optical waveguide 100 of the attitude sensor 10 serves as a sensitive element and can respond to the changing tangential force acting on its surface (i.e., G×sinθ, G shown in Figure 2 responds to the gravity of the weight 300). The gravity of the weight 300 will produce changes in the component perpendicular to the surface of the optical waveguide 100 (i.e. G×cosθ shown in Figure 2) and the component parallel to the surface of the optical waveguide 100 ( That is, G×sinθ) shown in FIG. 2 , in which the weight 300 can only be disposed on the frame 200 slidingly along the preset direction, which makes the component acting perpendicular to the surface of the optical waveguide 100 remain constant, and for The portion of the component parallel to the surface of the optical waveguide 100 is not constrained. Then when the attitude angle of the attitude sensor 10 gradually increases from the horizontal home position to the defined angular direction, the component force of the weight 300 parallel to the surface of the optical waveguide 100 gradually increases, and the response of the optical waveguide 100 gradually increases, and is consistent with The magnitude of this force is linearly related, that is, it increases sinusoidally with the attitude angle (see Figure 3).

As with the mobile robot as described above, the weight 300 of the attitude sensor 10 can only be disposed on the frame 200 in a sliding manner along a preset direction, which allows the optical waveguide 100 to realize absolute attitude perception through the gravity component of the weight 300. Compared with gyroscopes that rely on angular velocity integration to realize attitude perception, the absolute attitude is sensed, without the integration process and the cumulative error problem it brings; because the sliding direction of the weight 300 is perpendicular to the axis of the inner core and to the axis of the cladding The surfaces are parallel, which makes the output of the optical waveguide 100 have a good linear relationship with the sine value of the attitude angle, which is convenient in use and ensures the sensitivity of detection; a flexible material is used as the sensitive unit (ie, the optical waveguide 100) , has a large deformation even under the action of a small force, which is equivalent to an amplification effect on the force, which makes the attitude sensor 10 have high sensitivity; the optical waveguide 100 has robustness, and the optical waveguide 100 as a sensitive unit not only It can resist overload loads and also has a certain shock-absorbing and buffering effect. This robustness will enhance the ease of use of the attitude sensor 10.

The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-mentioned embodiments only express several implementation modes of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Claims (10)

1. An attitude sensor based on a flexible optical waveguide, characterized in that the attitude sensor (10) includes: an optical waveguide (100), a frame (200) and a heavy object (300); the optical waveguide (100) It includes: a cladding layer, an inner core, and a photoelectric component and a circuit. The cladding layer is used to wrap the inner core and the photoelectric component and circuit. The optoelectronic component and circuit include a light-emitting diode, a light source power supply circuit, a photoelectric transistor, and a signal. Acquisition circuit; Wherein, the light source power supply circuit is used to supply power to the light-emitting diode to convert electrical energy into light energy; the original light signal emitted by the light-emitting diode can propagate in the inner core. When a strong stimulus acts on the inner core, When the core is placed on the core, the inner core deforms, causing the original optical signal in the inner core to attenuate and become a lossy optical signal. The lossy optical signal is arranged in the phototransistor at the end of the inner core. When detected, it can be converted into an analog electrical signal; the signal acquisition circuit is used to capture the analog electrical signal sent by the phototransistor and send the analog electrical signal to an external device; The optical waveguide (100) is disposed on the frame (200), and the weight (300) is disposed on the frame (200) slidably along a preset direction. The weight (300) It is also connected to the surface of the cladding of the optical waveguide (100) and corresponds to the inner core of the optical waveguide (100). The preset direction is perpendicular to the axis of the inner core of the optical waveguide (100) and parallel to the surface of the cladding of the optical waveguide (100). 2. The attitude sensor according to claim 1, characterized in that the number of the inner cores of the optical waveguide (100) is one, and the shape of the inner core of the optical waveguide (100) is linear. 3. The attitude sensor according to claim 1, characterized in that the frame (200) is provided with a slide rail (400), and the slide rail (400) is provided with a device capable of moving along the preset direction. Sliding slider (500), the slider (500) is connected with the weight (300). 4. The attitude sensor according to claim 3, characterized in that the attitude sensor (10) further includes a first mounting part (600), the first mounting part (600) is connected to the slider (500) ) and the weight (300). 5. The attitude sensor according to claim 1, characterized in that the attitude sensor (10) further includes a force transmission member (700), and the force transmission member (700) is connected between the weight (300) and Between the cladding layers of the optical waveguide (100), the force transmission member (700) corresponds to the inner core of the optical waveguide (100), and the force transmission member (700) is close to the optical waveguide ( The side area of 100) is smaller than the side area of the weight (300) close to the optical waveguide (100). 6. The attitude sensor according to claim 5, characterized in that the attitude sensor (10) further includes a second mounting part (800), the second mounting part (800) is connected to the force transmission part ( 700) and the weight (300). 7. The attitude sensor according to any one of claims 1 to 6, characterized in that the frame (200) includes: a base (210), a mounting base (220) and a support for the mounting base (220). A column (230) above the base (210); The optical waveguide (100) is disposed on the base (210), and the weight (300) is slidably disposed on the mounting base (220). 8. The attitude sensor according to claim 7, wherein the mounting base (220) can slide up and down along the column (230). 9. The attitude sensor according to claim 8, characterized in that the upright column (230) is a screw rod, and the frame (200) further includes a nut threadedly connected to the upright column (230), and the nut is To lock the mounting base (220) at any height. 10. A robot, characterized in that the robot includes the attitude sensor (10) based on a flexible optical waveguide according to any one of claims 1-9.