Light sensor for robot and robot

Abstract

To provide a light sensor enabling reduction of load applied to an actuator of a robot having limbs such as legs and arms.SOLUTION: There is provided a light sensor for a robot including a body portion, and an actuator-driven limb portion connected to the body portion, wherein a detection surface for detecting a predetermined object is set on the limb portion. The light sensor comprises: a light source and a light receiving element mounted on the body portion; a light projecting fiber paired with the light source and transmitting, to the detection surface, light emitted from the light source; and a light receiving fiber paired with the light receiving element and transmitting, to the light receiving element, reflected light from the object detected on the detection surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an optical sensor for a robot and a robot equipped with the optical sensor. [Background technology]

[0002] Conventionally, there are known robots such as cow-shaped robots that walk on the ground in the style of four-legged animals (Patent Document 1). Such walking robots have actuator-driven legs, and in many cases, optical sensors such as reflective light-emitting and receiving sensors are provided on the legs to sense information about the area around their feet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-255816 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned walking robot, the optical sensors are mounted at the ends of the legs that have contact with the ground, which places a significant load on the actuator, resulting in increased power consumption. This problem applies not only to walking robots with legs, but also to all robots that have actuator-driven limbs such as legs and arms.

[0005] The present invention has been made in view of the above problems, and its main object is to provide an optical sensor that can reduce the load on the actuators of a robot having limbs such as legs and arms. [Means for solving the problem]

[0006] In other words, the optical sensor for a robot according to the present invention is an optical sensor for a robot having a torso and actuator-driven limbs connected to the torso, with a detection surface for detecting a predetermined object set on the limb, and is characterized in that it comprises a light source and a light-receiving element mounted on the torso, a light-emitting fiber paired with the light source for transmitting light emitted from the light source to the detection surface, and a light-receiving fiber paired with the light-receiving element for transmitting reflected light from the object detected on the detection surface to the light-receiving element.

[0007] In such a device, the light source and light receiving element are placed in the torso, and light is transmitted between the detection surface of the limb using a light emitting fiber and a light receiving fiber. This reduces the weight of the light source and light receiving element on the actuator-driven limb, reduces the load on the robot's actuator, and also reduces the power consumption caused by driving the actuator.

[0008] Furthermore, it is preferable that the robot optical sensor has one end face of the light emitting fiber facing the light emitting surface of the light source and the other end face exposed from the detection surface, and that one end face of the light receiving fiber is exposed at a position on the detection surface adjacent to the other end face of the light emitting fiber and the other end face facing the light receiving surface of the light receiving element. In this way, the end faces of the light emitting fiber and the light receiving fiber are exposed at positions adjacent to each other on the detection surface, so that reflected light from the object can be efficiently received by the end faces of the light receiving fiber, thereby improving sensing accuracy.

[0009] In the robot optical sensor, it is preferable that the light emitting fiber and the light receiving fiber are each formed by bundling a plurality of optical fibers. In this way, by configuring the light receiving optical fiber and the light receiving optical fiber by bundling a plurality of optical fibers, a sufficient amount of reflected light can be received by the light receiving element, and sensing accuracy can be improved.

[0010] In the robot optical sensor, it is preferable that the light emitting fiber and the light receiving fiber are each configured by bundling a plurality of optical fibers together at both ends and so as to be separated in the center. In this way, the multiple optical fibers that make up the light emitting fiber and the light receiving fiber are bound only at both ends and are designed to separate in the center. Therefore, when the light emitting fiber and the light receiving fiber are bent, the multiple optical fibers that make them up separate, allowing the force acting on the limbs to be distributed in multiple directions, further reducing the load on the actuator.

[0011] In a specific embodiment of the robot optical sensor, the plurality of optical fibers are all plastic optical fibers.

[0012] It is preferable that the robot optical sensor comprises a plurality of pairs of the light source and the light emitting optical fiber, and a plurality of pairs of the light receiving element and the light receiving optical fiber, and that the other end faces of the plurality of light emitting optical fibers and one end faces of the plurality of light receiving optical fibers are exposed on the detection surface so as to be staggered. In this way, the light reflected from the object can be efficiently received at the end face of the receiving fiber.

[0013] If the robot has a plurality of limbs on which the detection surfaces are set, it is preferable that the robot optical sensor is exposed to the detection surfaces of each of the plurality of limbs so that the other end faces of the plurality of light-emitting fibers and one end faces of the plurality of light-receiving fibers are staggered.

[0014] It is also preferable that the robot optical sensor further includes a correlation data storage unit that stores correlation data indicating the correlation between the output signal of the light receiving element and the type of one or more types of objects that the detection surface may come into contact with, and an object identification unit that identifies the type of object that the detection surface has come into contact with based on the output signal from the light receiving element that has received the reflected light and the correlation data stored in the correlation data storage unit. In this way, it is possible to identify the type of object that has come into contact with the detection surface based on the output signal of the light receiving element.

[0015] In addition, it is preferable that the correlation data of the robot optical sensor is a machine learning model that calculates the correlation between the output signal of the light receiving element and the type of object by machine learning.

[0016] Furthermore, the robot of the present invention has a torso and actuator-driven limbs connected to the torso, with a detection surface for detecting a predetermined object set on the limb, and is characterized in that it is equipped with a light source and a light-receiving element mounted on the torso, a light-emitting fiber paired with the light source for transmitting light emitted from the light source to the detection surface, and a light-receiving fiber paired with the light-receiving element for transmitting reflected light from the object detected on the detection surface to the light-receiving element.

[0017] Such a robot of the present invention can achieve the same effects as the above-described optical sensor for a robot of the present invention. [Effects of the Invention]

[0018] According to the present invention, an optical sensor can be provided that can reduce the load on the actuators of a robot having limbs such as legs and arms. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view schematically showing the overall configuration of a robot equipped with an optical sensor for a robot according to an embodiment of the present invention; [Figure 2] FIG. 2 is a plan view schematically showing the overall configuration of the robot according to the embodiment. [Figure 3] 3A and 3B are diagrams showing the schematic configuration of a light emitting fiber or a light receiving fiber of the robot of the embodiment, in which FIG. 3A shows the base end side and FIG. 3B shows the end side. [Figure 4] 2 is a diagram showing a schematic configuration of a light emitting fiber or a light receiving fiber of the robot according to the embodiment; FIG. [Figure 5]FIG. 2 is a plan view showing a schematic structure of the top surface of the torso of the robot according to the embodiment. [Figure 6] 4A and 4B are diagrams illustrating the arrangement of light-emitting fibers and light-receiving fibers in a limb of the robot according to the embodiment. [Figure 7] FIG. 2 is a functional block diagram showing the equipment configuration of the robot according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] An optical sensor 3 for a robot (hereinafter referred to as an optical sensor) according to one embodiment of the present invention will be described below with reference to the drawings.

[0021] The optical sensor 3 of this embodiment is attached to and used on a robot 100 having actuator-driven limbs 2 (legs or arms) provided with a detection surface 2s for detecting a predetermined object. Specifically, as shown in Figures 1 and 2, the optical sensor 3 of this embodiment is attached to a robot 100 modeled after a four-legged animal, and is used to sense information about the area around the robot's feet.

[0022] This robot 100 has a box-shaped torso 1 that houses a control device C, and four actuator-driven legs 2 (two front legs 21 and two rear legs 22) that are connected to the front and rear of the torso 1. Each leg 2 is configured using a link mechanism. The robot 100 is configured to walk and move on the ground by operating the four legs 2 in response to control signals output from the control device C.

[0023] A contact surface 2c that comes into contact with the ground when walking is provided at the end of each leg 2. A part or all of this contact surface 2c is set as a detection surface 2s for detecting a predetermined object, and the optical sensor 3 is configured to sense information about the feet through the detection surface 2s. In this embodiment, the object to be detected is grass, leaves, soil, stone, or other materials present on the ground.

[0024] The optical sensor 3 has a light-projecting unit 31 that emits detection light toward an object via the detection surface 2s, and a light-receiving unit 32 that receives light reflected from the object via the detection surface 2s. The light-projecting unit 31 has a light source 311 and a light-projecting optical fiber 312 that is paired with the light source 311. The light-projecting unit 31 also has a light-receiving element 321 and a light-receiving optical fiber 322 that is paired with the light-receiving element 321.

[0025] The light source 311 emits detection light such as infrared light, and is specifically a light-emitting diode. The light source 311 is installed in the torso 1 of the robot 100, and in this embodiment, is installed facing upward on the top surface 11 of the torso 1. More specifically, the light source 311 is housed in a light-blocking cylindrical member 313 provided on the top surface 11 of the torso 1. In this embodiment, the light source 311 includes a light-emitting diode that emits visible light and a light-emitting diode that emits infrared light.

[0026] The light-emitting fiber 312 transmits detection light emitted from a light source 311 installed in the torso 1 of the robot 100 to a detection surface 2s provided at the end of the leg 2. Specifically, the light-emitting fiber 312 is attached so that one end face (the end face on the base end side) in the light transmission direction faces the light-emitting surface of the light source 311 and the other end face (the end face on the distal end side) is exposed from the detection surface 2s. The end on the base end side of the light-emitting fiber 312 is fitted and fixed in an opening of a cylindrical member 313 that houses the light source 311 and is provided on the top surface 11 of the torso 1. The end on the distal end side of the light-emitting fiber 312 is fitted and fixed in a through-hole 314 formed in the distal end of the leg 2. The end of the through-hole 314 opens to the detection surface 2s, and the other end face of the light-emitting fiber 312 faces the ground.

[0027] The light receiving element 321 senses light reflected from an object. This light receiving element 321 utilizes the photovoltaic effect of, for example, a photodiode or a phototransistor. The light receiving element 321 has a light receiving unit 32 that receives light and is configured to output a signal proportional to the amount of light received by the light receiving unit 32 to the control device C. The light receiving element 321 is installed in the torso 1 of the robot 100, and in this embodiment, is installed facing upward on the top surface 11 of the torso 1. More specifically, it is housed in a light-shielding cylindrical member 323 provided on the top surface 11 of the torso 1. The cylindrical member 323 that houses the light receiving element 321 is provided separately from the cylindrical member 313 that houses the light source 311. In this embodiment, the light receiving element 321 includes a visible light phototransistor that detects visible light and an infrared light phototransistor that detects infrared light.

[0028] The optical fiber 322 transmits light reflected from an object received by a detection surface 2s provided at the distal end of the leg 2 of the robot 100 to a light-receiving element 321 provided in the torso 1. Specifically, the optical fiber 322 is attached so that one end face (the distal end face) in the light transmission direction is exposed from the detection surface 2s of the robot 100 and the other end face (the proximal end face) faces the light-receiving surface of the light-receiving element 321. The distal end of the optical fiber 322 is fitted and fixed in a through-hole 324 formed in the distal end of the leg 2. The end of the through-hole 324 opens to the detection surface 2s, and one end face of the optical fiber 322 faces the ground. The proximal end of the optical fiber 322 is fitted and fixed in an opening of a cylindrical member 323 provided on the top surface 11 of the torso 1 and housing the light-receiving element 321.

[0029] On the detection surface 2s of the leg 2 of the robot 100, the distal end face of the light emitting fiber 312 and the distal end face of the light receiving fiber 322 are exposed at positions adjacent to each other, so that light emitted from the end face of the light emitting fiber 312 and reflected by the object is incident on the end face of the light receiving fiber 322.

[0030] As shown in FIG. 3, each of the projecting optical fiber 312 and the receiving optical fiber 322 of this embodiment is formed by bundling a plurality of optical fibers F. Any optical fiber may be used, but plastic optical fibers are preferred. The plurality of optical fibers F preferably have the same specifications (i.e., the same material, length, and diameter). As shown in FIG. 4, each of the projecting optical fiber 312 and the receiving optical fiber 322 is preferably formed by bundling a plurality of optical fibers F at both ends in the optical transmission direction and dispersing them in the center without bundling them. The plurality of optical fibers F may be tightly bundled at both ends using, for example, a cable tie. The projecting optical fiber 312 and the receiving optical fiber 322 are preferably formed by bundling, for example, three or more optical fibers, and more preferably, for example, ten or more optical fibers so that the overall cross section is substantially circular, but are not limited to this.

[0031] The optical sensor 3 of this embodiment includes a plurality of light projecting units 31 (i.e., a plurality of pairs of light sources 311 and light projecting fibers 312) and a plurality of light receiving units 32 (i.e., a plurality of pairs of light receiving elements 321 and light receiving fibers 322). More specifically, a plurality of pairs (two pairs in this case) of light projecting units 31 and light receiving units 32 are set for each of the plurality of legs 2.

[0032] As shown in Fig. 5, a plurality of (eight in this example) light sources 311 and a plurality of (eight in this example) light receiving elements 321 are arranged side by side on the top surface 11 of the torso 1 of the robot 100. Then, as shown in Fig. 6, end faces of a plurality of (two) light emitting fibers 312 and end faces of a plurality of (two) light receiving fibers 322 are exposed adjacent to each other on the detection surface 2s of each leg 2. More specifically, on the detection surface 2s of each leg 2, the end faces of the light emitting fibers 312 and the end faces of the light receiving fibers 322 are exposed alternately.

[0033] 2, the plurality of light sources 311 and the plurality of light receiving elements 321 are mounted on a circuit board CB, and this circuit board CB is attached to the torso 1 of the robot 100. In this way, the plurality of light sources 311 and the plurality of light receiving elements 321 can be gathered together on the circuit board CB and installed at the center of gravity (torso 1) of the robot 100, which reduces the moment of inertia when, for example, the leg 2 is moved at high speed, reduces the load on the actuator, and makes posture control easier.

[0034] The control device C is a so-called computer having a CPU, memory, A / D converter, D / A converter, etc. The control device C performs at least the functions of a robot control unit C1, a correlation data storage unit C2, and an object identification unit C3, as shown in Fig. 7, by the CPU and peripheral devices working together in accordance with a predetermined program stored in the memory.

[0035] The robot control unit C1 operates the legs 2 by outputting control signals to actuators based on a preset control program.

[0036] The correlation data storage unit C2 stores correlation data indicating the correlation between the output signal of the light receiving element 321 and one or more types of objects with which the ground surface 2c may come into contact. The correlation data of this embodiment stores the correlation between a signal indicating the intensity of light received by the light receiving element 321 and grass, leaves, soil, stones, etc. The correlation data of this embodiment is a machine learning model that has been calculated in advance by machine learning to determine the correlation between the intensity of reflected light obtained by irradiating an object with detection light and the type of object.

[0037] The object identification unit C3 identifies the type of object that the contact surface 2c has come into contact with, based on the output signal from the light receiving element 321 that receives the reflected light and the correlation data stored in the correlation data storage unit. When the object identification unit C3 receives an output signal indicating the intensity of the reflected light from the target object from the light receiving element 321, it identifies the type of object (grass, leaves, soil, stone, etc.) by referring to the correlation data. Then, it outputs identification data indicating the identified type of object to the robot control unit C1. The robot control unit C1 operates the robot 100 by referring to the received identification data.

[0038] <Effects of the optical sensor 3 of this embodiment> According to the optical sensor 3 of this embodiment configured as described above, the light source 311 and the light receiving element 321 are arranged in the torso 1, and the light transmitting optical fiber 312 and the light receiving optical fiber 322 are used to transmit light between the detection surface 2s of the leg 2. This reduces the weight of the light source 311 and the light receiving element 321 on the actuator-driven leg 2, reduces the load on the actuator of the robot 100, and also reduces the power consumption due to the driving of the actuator.

[0039] Furthermore, since the end face of the light emitting fiber 312 and the end face of the light receiving fiber 322 are exposed at positions adjacent to each other on the detection surface 2s, the reflected light from the object can be efficiently received at the end face of the light receiving fiber 322, thereby improving sensing accuracy.

[0040] Furthermore, by configuring the light receiving optical fiber 322 and the light receiving optical fiber 322 by bundling a plurality of optical fibers F, a sufficient amount of reflected light can be received by the light receiving element 321, and the sensing accuracy can be improved.

[0041] Furthermore, the multiple optical fibers F (specifically, plastic optical fibers) that make up each of the light projecting fiber 312 and the light receiving fiber 322 are bundled only at both ends and are designed to separate in the center. Therefore, when the light projecting fiber 312 and the light receiving fiber 322 are bent, the multiple optical fibers F that make them up separate, allowing the force acting on the leg 2 to be distributed in multiple directions, further reducing the load on the actuator.

[0042] Furthermore, on the detection surface 2s of each of the plurality of legs 2, the other end faces of the plurality of light emitting fibers 312 and one end faces of the plurality of light receiving fibers 322 are exposed on the detection surface 2s in a staggered manner, so that reflected light from the object can be efficiently received at the end faces of the light receiving fibers 322 on the detection surface 2s of each leg 2.

[0043] The robot optical sensor 3 also includes a correlation data memory unit that stores correlation data indicating the correlation between the output signal of the light receiving element 321 and the type of one or more types of objects that the detection surface 2s may come into contact with, and an object identification unit C3 that identifies the type of object that the detection surface 2s has come into contact with based on the output signal from the light receiving element 321 that receives the reflected light and the correlation data stored in the correlation data memory unit.Therefore, it is possible to identify the type of object that the detection surface 2s has come into contact with based on the output signal of the light receiving element 321.

[0044] <Other embodiments> The present invention is not limited to the above-described embodiment. For example, the optical sensor 3 in the above embodiment is applied to a four-legged robot 100, but is not limited to this and may be applied to a two-legged robot 100. Furthermore, the optical sensor 3 is not limited to being provided to a robot 100 having legs 2, but may be provided to a robot 100 having arms, for example, and may be applied to a robot arm.

[0045] In the optical sensor 3 of the above embodiment, a plurality of light-projecting units 31 and light-receiving units 32 are provided for each leg 2, but this is not limited thereto. In other embodiments, one light-projecting unit 31 and one light-receiving unit 32 may be provided for each leg 2. In this case, an end face of one light-projecting optical fiber 312 and an end face of one light-receiving optical fiber 322 are exposed adjacent to each other on the detection surface 2s of each leg 2.

[0046] In the optical sensor 3 of the above embodiment, the projecting optical fiber 312 and the receiving optical fiber 322 are configured by bundling a plurality of optical fibers F, but this is not limiting. In other embodiments, the projecting optical fiber 312 and the receiving optical fiber 322 may each be configured by a single optical fiber.

[0047] In the above embodiment, the projecting optical fiber 312 and the receiving optical fiber 322 are each configured by bundling a plurality of optical fibers F at both ends in the optical transmission direction and separating them at the center without bundling them, but this is not limiting. In other embodiments, the projecting optical fiber 312 and the receiving optical fiber 322 may each be configured by bundling a plurality of optical fibers F at the center as well.

[0048] In the above embodiment, the multiple light sources 311 and the light receiving elements 321 are collectively installed on the top surface 11 of the torso 1 of the robot 100, but this is not limiting. In other embodiments, the multiple light sources 311 and the light receiving elements 321 may be installed at any position on the torso 1 of the robot 100.

[0049] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0050] 100...Robot 1. Torso 2... Limbs (legs) 2s Detection surface 3. Optical sensor 311...Light source 312···Projection fiber 321....Photodetector 322....receiving fiber

Claims

1. An optical sensor for a robot having a torso and an actuator-driven limb connected to the torso, wherein a detection surface for detecting a predetermined object is set on the limb, a light source and a light receiving element mounted on the body; a light projecting fiber paired with the light source, which transmits the light emitted from the light source to the detection surface; An optical sensor for a robot comprising: a light receiving optical fiber paired with the light receiving element, which transmits reflected light from the object detected on the detection surface to the light receiving element.

2. one end surface of the light projecting fiber faces the light emitting surface of the light source, and the other end surface is exposed from the detection surface; 2. The robot optical sensor according to claim 1, wherein one end face of the light-receiving fiber is exposed at a position on the detection surface adjacent to the other end face of the light-emitting fiber, and the other end face faces the light-receiving surface of the light-receiving element.

3. 3. The optical sensor for a robot according to claim 1, wherein the light emitting fiber and the light receiving fiber are each formed by bundling a plurality of optical fibers.

4. 4. The optical sensor for a robot according to claim 3, wherein the light emitting fiber and the light receiving fiber are each constructed by bundling a plurality of optical fibers together at both ends and so as to be separated in the center.

5. 5. The optical sensor for a robot according to claim 4, wherein all of said plurality of optical fibers are plastic optical fibers.

6. a plurality of pairs of the light source and the light emitting fiber, and a plurality of pairs of the light receiving element and the light receiving fiber; 3. The optical sensor for a robot according to claim 2, wherein the other end faces of the plurality of light emitting fibers and the one end faces of the plurality of light receiving fibers are exposed on the detection surface in a staggered manner.

7. the robot includes a plurality of limbs on which the detection surfaces are set, 7. The optical sensor for a robot according to claim 6, wherein the other end faces of the plurality of light emitting fibers and one end faces of the plurality of light receiving fibers are exposed on the detection surface of each of the plurality of limbs in a staggered manner.

8. a correlation data storage unit that stores correlation data indicating a correlation between an output signal of the light receiving element and one or more types of objects that may come into contact with the detection surface; 2. The optical sensor for a robot according to claim 1, further comprising an object identification unit that identifies the type of object that has come into contact with the detection surface based on an output signal from the light receiving element that receives the reflected light and the correlation data stored in the correlation data storage unit.

9. The optical sensor for a robot according to claim 8 , wherein the correlation data is a machine learning model obtained by calculating the correlation between the output signal of the light receiving element and the type of the object through machine learning.

10. A robot having a torso and actuator-driven limbs connected to the torso, wherein a detection surface for detecting a predetermined object is set on the limb, a light source and a light receiving element mounted on the body; a light projecting fiber paired with the light source, which transmits the light emitted from the light source to the detection surface; The robot includes a light receiving optical fiber that is paired with the light receiving element and transmits reflected light from the object detected on the detection surface to the light receiving element.

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