JP2023112721A - Mobile robot, vibration control method for mobile robot, and program - Google Patents

Abstract

A mobile robot, a vibration damping method for the mobile robot, and a program that can more effectively reduce vibrations generated in an environment sensor are provided.
A mobile robot according to one aspect of the present invention is a mobile robot that includes a robot main body and a mobile mechanism configured to move the robot main body, and detects an environment around the mobile robot. a sensor unit, a vibration detection unit that detects vibrations generated in the mobile robot, and a vibration suppression unit that is arranged between the robot main body and the environment sensor unit to suppress the vibrations detected by the vibration detection unit. , a mobile robot.
[Selection drawing] Fig. 1

Description

The present invention relates to a mobile robot, a vibration damping method for a mobile robot, and a program.

In recent years, various types of mobile robots equipped with environmental sensors (cameras, LiDAR, etc.) that detect the surrounding environment have been developed in various industries. Responsible for dangerous and difficult work such as rescue. A mobile robot equipped with an environment sensor has problems such as difficulty in estimating its own position (localization) due to noise generated in the environment sensor due to vibrations caused by road surface undulations and movement of the mobile robot itself.

In this regard, various techniques have been proposed to deal with vibrations that occur in robots. For example, Patent Literature 1 describes a system that actively removes vibrations generated in a robot arm by a motor. Further, for example, Patent Literature 2 describes a robot apparatus that treats the motion of a movable part of a robot as a periodic motion and adjusts the phase of the motion to perform global attitude stability control.

JP-A-2003-71767 JP-A-2005-96068

However, none of the above robots proposes a method for more effectively reducing the vibration generated in the environment sensor for sensing the surrounding environment.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a mobile robot, a vibration damping method for the mobile robot, and a program that can more effectively reduce the vibration generated in the environment sensor.

A mobile robot according to an aspect of the present invention is a mobile robot comprising a robot main body and a moving mechanism configured to be able to move the robot main body, wherein the mobile robot detects an environment surrounding the mobile robot; A movement comprising a vibration detection unit that detects vibrations occurring in a mobile robot, and a vibration suppression unit arranged between a robot body and an environment sensor unit that suppresses the vibrations detected by the vibration detection unit. robot.

According to this aspect, the vibration damping unit for damping vibrations detected by the vibration detection unit for detecting vibrations occurring in the mobile robot is arranged between the robot main body and the environment sensor, It is possible to more efficiently reduce the vibration that propagates from the robot body to the environment sensor.

According to the present invention, it is possible to provide a mobile robot, a vibration damping method for a mobile robot, and a program that can more effectively reduce vibrations generated in an environment sensor.

1 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 1 according to this embodiment; FIG. 1 is a functional block diagram showing an example of the functional configuration of a mobile robot 1 according to this embodiment; FIG. 4 is an operation flow showing an example of vibration damping processing executed by the mobile robot 1 according to the present embodiment; FIG. 4 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 2 according to a first modified example of the present embodiment; FIG. 11 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 3 according to a second modified example of the embodiment; FIG. 11 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 4 according to a third modified example of the present embodiment; FIG. 14 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 5 according to a fourth modified example of the present embodiment;

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. (In addition, in each figure, those with the same reference numerals have the same or similar configurations.)

[First Embodiment]
(1) Overall Configuration FIG. 1 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 1 according to this embodiment. As shown in FIG. 1, the mobile robot 1 according to the present embodiment is configured as a quadrupedal walking leg type, and includes, for example, a robot main body 100, a neck unit 200, a head unit 300, a leg unit 400, have 1 is a side view of the mobile robot 1, and the left side of FIG. 1 may be called the front side, and the right side of the paper side may be called the rear side.

The robot body 100 is configured as a base of the mobile robot 1 and may be called a body unit or the like. As transparently shown in FIG. 1, the robot body 100 has a control circuit 101 provided inside the housing. The control circuit 101 controls, for example, the damping device 201, the environment sensor 301, the leg unit 400, etc., as will be described later. In particular, in the mobile robot 1 according to this embodiment, the control circuit 101 controls vibration damping by the vibration damping device 201 based on the vibration detected by the IMU 302, as will be described later.

The neck unit 200 is mounted on the front end of the robot body 100 . As transparently shown in FIG. 1, the neck unit 200 has a damping device 201 provided inside the housing. The damping device 201 is an example of a damping unit, and damps vibrations that occur in the mobile robot 1 . In particular, the damping device 201 damps vibrations detected by an IMU 302, which will be described later, under the control of the control circuit 101. FIG. Note that the entire neck unit 200 may be configured as the vibration damping device 201 .

As will be described later, a head unit 300 having an environment sensor 301 provided therein is mounted on the neck unit 200 . As described above, since the damping device 201 is arranged between the robot body 100 and the environment sensor 301 , the damping device 201 can effectively reduce the vibration generated in the environment sensor 301 . Become.

Here, in the present embodiment, "arranged between the robot main body 100 and the environment sensor 301" includes being arranged on a path along which vibration propagates from the robot main body 100 to the environment sensor 301. Provided at any position inside or outside a unit (neck unit 200 in this embodiment) provided between a unit provided with sensor 301 (head unit 300 in this embodiment) and robot main body 100 may include being

The damping device 201 has a damping actuator and performs damping under the control of the control circuit 101 . The direction (damping direction) and angle (damping angle) in which the damping actuator is installed may be arbitrarily set according to the type of the environment sensor 301, for example. Further, the degree of freedom of the damping actuator may be arbitrarily set, for example, from one degree of freedom to six degrees of freedom according to the type of the environment sensor 301 and the like.

Head unit 300 is mounted on neck unit 200 . As transparently shown in FIG. 1, the head unit 300 has at least one environment sensor 301 and an IMU (Inertial Measurement Unit) 302 provided inside the housing.

The environment sensor 301 is an example of an environment sensor unit, and is a sensor for detecting the environment around the mobile robot 1 . The environment sensor 301 may be, for example, an imaging device such as a CCD (Charge Coupled Device) camera capable of acquiring moving and still images around the mobile robot 1 as image data. Also, the environment sensor 301 may be a depth sensor capable of measuring the distance to the target (obstacle). The method of the depth sensor is not particularly limited, and may be, for example, a stereo method, a ToF (Time Of Flight) method, a structured illumination method, or the like.

The IMU 302 is a device that detects movement of the mobile robot 1 . In particular, the IMU 302 is an example of a vibration detection unit and detects vibrations of the mobile robot 1 . Specifically, the IMU 302 has a three-axis gyro for detecting three-dimensional angular velocity and a three-directional accelerometer for detecting acceleration in three directions. An angular velocity signal) and a signal indicating acceleration (acceleration signal) are generated and output to the control circuit 101, for example. The number of gyro axes that the IMU 302 has is not limited to three, and may be one or two. Also, the number of accelerometer directions of the IMU 302 is not limited to three, and may be one or two. Note that the IMU 302 may be equipped with other types of sensors such as a pressure gauge, a flow meter, and a GPS for improved reliability. Also, the IMU 302 may be provided in another unit such as the robot body 100 instead of the head unit 300 .

The leg unit 400 is an example of a moving mechanism, and is configured to move the robot body 100 . The leg unit 400 includes four leg units 400a to 400d connected to the robot body 100 respectively. The leg unit 400a is connected to the front left side of the robot main body 100, the leg unit 400b is connected to the front right side of the robot main body 100, and the leg unit 400c is connected to the rear left side of the robot main body 100. The leg unit 400 d is connected to the rear right side of the robot body 100 . Specifically, the leg units 400a and 400b constitute left and right front legs, respectively, and the leg units 400c and 400d constitute left and right rear legs, respectively. In the present disclosure, the leg units 400a to 400d may be generically referred to simply as the leg unit 400.

(2) Functional Configuration Next, details of the internal circuitry of the mobile robot 1 according to the present embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram showing an example of the functional configuration of the mobile robot 1 according to this embodiment.

The control circuit 101 of the robot body 100 includes a communication unit 102 configured by a communication interface circuit, a memory 103 configured by a non-volatile rewritable storage device, and a main control unit configured by a processor such as a CPU. 104 and a computer including. The control circuit 101 may be attached to any location inside the robot body 100 . Note that the control circuit 101 may be provided not only in the robot main body 100 but also in other units (for example, the neck unit 200, the head unit 300, etc.).

The communication unit 102 transmits and receives data to and from an external information processing device using various wireless communication methods such as Bluetooth (registered trademark) and Wi-Fi (registered trademark). do. Specifically, the communication unit 102 transmits data supplied from the main control unit 104 to an external information processing device, for example. Also, the communication unit 102 receives data transmitted by an external information processing device, for example, and supplies the data to the main control unit 104 .

The memory 103 stores, for example, a control program 103a for the mobile robot 1 and threshold information 103b. The control program 103a may, for example, be supplied from a computer-readable storage medium or downloaded via a predetermined communication network. The control program 103a is a program for causing the main control unit 104 to realize various functions, which will be described later, for controlling each unit of the mobile robot 1. FIG.

The threshold information 103b is a threshold for the vibration period of the mobile robot 1 as a condition for causing the vibration damping device 201 to perform vibration damping, as will be described later. That is, as will be described later, the vibration damping device 201 controls the vibration of the mobile robot 1 under the control of the vibration damping device control unit 104e on the condition that the vibration cycle of the mobile robot 1 is equal to or greater than the threshold defined in the threshold information 103b. Damping against vibration may be performed. The threshold information 103b may define different thresholds according to the mode of movement of the mobile robot 1. FIG. Specifically, for example, different thresholds may be defined according to the speed of movement of the mobile robot 1, or the threshold may be defined to increase as the speed of movement of the mobile robot 1 increases. Further, for example, different threshold values may be defined according to the movement gait of the mobile robot 1 . Here, the gait may be a gait pattern that represents the order and timing of leg movements during walking, for example, regular gait, symmetrical gait, wavy gait, parallelogram gait, tripod ( Alternating three-point contact) gait, amble gait, etc. may be included.

The main control unit 104 executes a control program for the mobile robot 1 stored in the memory 103 . Thereby, the main control section 104 functions as an environment information acquisition section 104a, a vibration detection processing section 104b, a self-position estimation section 104c, a leg unit control section 104d, a damping device control section 104e, and the like.

The environment information acquisition unit 104 a acquires from the environment sensor 301 information (environment information) indicating the environment around the mobile robot 1 detected by the environment sensor 301 . The environmental information may be image data of moving images or still images, information indicating the distance (depth) to the object (obstacle), or the like, depending on the type of the environment sensor 301 . The environment information acquisition section 104a may supply the acquired environment information to the self-position estimation section 104c, the leg unit control section 104d, and the like.

The vibration detection processing unit 104b executes processing for detecting vibrations occurring in the mobile robot 1 based on the output value of the IMU 302. FIG. The result of detection of vibration by the vibration detection processing unit 104b may be any information that quantitatively indicates the vibration, and may be, for example, a vibration period. Specifically, for example, the vibration detection processing unit 104b generates each frequency component by performing frequency analysis on the output value (angular velocity signal, acceleration signal, etc.) of the IMU 302, and then converts the frequency component into Based on this, the vibration period generated in the mobile robot 1 is calculated.

The self-position estimator 104c, for example, estimates the current position of the mobile robot 1 in real space. For example, the self-position estimating unit 104c receives image data of the surroundings of the mobile robot 1 acquired by the environment sensor 301, and distance information indicating the distance to objects located around the mobile robot 1 detected by the environment sensor 301. By referring to this, the current position of the mobile robot 1 may be estimated using an algorithm such as V-SLAM (Visual Localization And Mapping). Alternatively, the self-position estimator 104c may estimate the current position of the mobile robot 1 by a known method such as dead reckoning using output values obtained from the encoder 402 of the leg unit 400, which will be described later. In the mobile robot 1 according to this embodiment, since the damping device 201 is arranged between the robot main body 100 and the environment sensor 301, it is possible to more efficiently reduce the vibration generated in the environment sensor 301, thereby By separating the estimation calculation and the vibration elimination process, the delay in the self-position estimation calculation can be reduced.

The leg unit control section 104d controls the leg unit 400 based on a predetermined movement command that defines the mode of movement (including gait) of the mobile robot 1, the route, and the like. Here, the content of the movement command may be generated by the main control unit 104, or may be acquired from another information processing device or the like operated by the user via the communication unit 102, for example. As shown in FIG. 2, each leg unit 400a to 400d has at least one joint, and each joint includes motors 401a to 401d for rotationally driving the joint and rotation angle positions of the motors 401a to 401d. Detecting encoders 402a-402d are provided. The leg unit control section 104d generates a control signal based on a predetermined movement command, the environment information acquired by the environment information acquisition section 104a, and information such as the self-position estimated by the self-position estimation section 104c, and controls each motor 401a. 401d to control the rotational drive of each of the motors 401a to 401d. In addition, the leg unit control section 104d obtains output values indicating the rotational angular positions of the motors 401a to 401d from the encoders 402a to 402d, and based on the output values, determines the rotational speeds of the motors 401a to 401d. may be calculated. Information indicating the rotational speed of each motor 401a to 401d may be used, for example, to calculate the speed of the mobile robot 1, as will be described later.

The vibration damping device control unit 104e controls the vibration damping device 201 so as to damp vibrations occurring in the mobile robot 1. FIG. Here, damping may include not only complete elimination of vibration but also at least partial reduction of vibration. Specifically, the vibration damping device control unit 104e generates a control signal for driving the vibration damping device 201 with the same period (including substantially the same period) as the vibration period of the mobile robot 1 and the opposite phase. A control signal is supplied to the damping device 201 . As a result, the vibration damping device 201 is driven in the same period as the vibration period of the mobile robot 1 and in the opposite phase, so that the vibration generated in the mobile robot 1 is reduced.

The vibration damping device control unit 104e may control the vibration damping device 201 to perform vibration damping on condition that the vibration period of the mobile robot 1 is equal to or greater than a predetermined threshold value. The predetermined threshold may be, for example, a value stored in the memory 103 as the threshold information 103b. The threshold may be defined according to the movement mode of the mobile robot 1 . Specifically, different values may be defined according to the movement speed of the mobile robot 1 or the gait of the mobile robot 1 . Note that the vibration damping device control unit 104e may calculate the moving speed of the mobile robot 1 based on, for example, the output value of the IMU 302. More specifically, for example, the acceleration signal, which is the output value of the IMU 302, The moving speed may be calculated by integration. Alternatively, the vibration damping device control section 104e calculates the movement speed of the mobile robot 1 based on the rotation angle positions of the motors 401a to 401d, which are the output values of the encoders 402a to 402d of the leg units 400a to 400d. You may

(3) Operation Processing FIG. 3 is an operation flow showing an example of vibration damping processing executed by the mobile robot 1 according to this embodiment. In the damping process, for example, it is assumed that the mobile robot 1 is moving as the leg units 400a to 400d are controlled by the leg unit control section 104d. As a result, vibrations generated in the leg unit 400 and the robot main body 100 are propagated to the head unit 300 via the neck unit 200 . It is assumed that the IMU 302 included in the head unit 300 outputs an angular velocity signal and an acceleration signal as a motion detection result of the mobile robot 1 at a predetermined cycle.

(S11) First, the vibration detection processing unit 104b executes processing for detecting vibration occurring in the mobile robot 1 based on the output value of the IMU 302. FIG. Specifically, the vibration detection processing unit 104b calculates the vibration period occurring in the mobile robot 1 by performing frequency analysis on the output values (angular velocity signal, acceleration signal, etc.) of the IMU 302 .

(S12) Next, the damping device control section 104e acquires the threshold information 103b from the memory 103. FIG. At this time, after obtaining the speed of the mobile robot 1, the vibration damping device control unit 104e may obtain from the memory 103 the threshold information 103b associated with the speed. The velocity of the mobile robot 1 may be calculated, for example, by integrating the acceleration signal, which is the output value of the IMU 302 , or may be calculated based on the output value of the encoder 402 of the leg unit 400 . Alternatively, the vibration damping device control unit 104e acquires the movement command supplied to the leg unit control unit 104d, identifies the threshold information 103b associated with the information included in the movement command, and stores the threshold information 103b may be obtained.

(S13) Next, the vibration damping device control unit 104e determines whether or not the vibration period calculated by the vibration detection processing unit 104b in step S11 is equal to or greater than the threshold indicated by the threshold information 103b acquired in step S12. . When it is determined that the vibration period calculated by the vibration detection processing unit 104b in step S11 is not equal to or greater than the threshold indicated by the threshold information 103b acquired in step S12 (S13; No), vibration suppression by the vibration suppression device 201 is not performed. Without doing so, the process returns to step S11. Then, detection of the vibration of the mobile robot 1 is executed again (S11).

(S14) On the other hand, when it is determined that the vibration period calculated by the vibration detection processing unit 104b in step S11 is equal to or greater than the threshold indicated by the threshold information 103b acquired in step S12 (S13; Yes), vibration damping device control The unit 104 e generates a control signal having the same period and opposite phase as the vibration period calculated by the vibration detection processing unit 104 b in step S 11 and supplies the control signal to the vibration damping device 201 . As a result, the vibration damping device 201 is driven in the same period as the vibration period of the mobile robot 1 and in the opposite phase based on the control signal, so that the vibration of the mobile robot 1 is reduced. Then, the process returns to step S11, and detection of the vibration of the mobile robot 1 is executed again.

[Modification]
(1) First Modification FIG. 4 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 2 according to a first modification of the present embodiment. The mobile robot 2 according to the first modification is configured as a six-legged walking robot. That is, unlike the mobile robot 1 according to the first embodiment, it has a leg unit 410 instead of the leg unit 400, as shown in FIG.

The leg unit 410 is an example of a moving mechanism, and is configured to move the mobile robot 1 under the control of the main control section 104 of the control circuit 101 of the robot body 100, for example. The leg unit 410 is configured as a leg unit for hexapedal locomotion and includes six leg units 410a-410f. The leg unit 410a is connected to the front left side of the robot main body 100, the leg unit 410b is connected to the front right side of the robot main body 100, and the leg unit 410c is connected to the rear left side of the robot main body 100. The leg unit 410d is connected to the rear right side of the robot body 100. As shown in FIG. Further, the leg unit 410e is connected to the left side of the center of the robot body 100, and the leg unit 410f is connected to the right side of the center of the robot body 100. As shown in FIG.

(2) Second Modification FIG. 5 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 3 according to a second modification of the present embodiment. The mobile robot 3 according to the second modification is configured as a crawler type. That is, as shown in FIG. 5, the mobile robot 3 has a crawler 420 instead of the leg unit 400, unlike the mobile robot 1 according to the first embodiment. Note that the crawler can also be called a crawler belt, a caterpillar, or the like.

The crawler 420 is an example of a moving mechanism, and is configured to move the mobile robot 1 under the control of the main control section 104 of the control circuit 101 of the robot body 100 . The crawler 420 has a structure in which a plurality of wheels 420a are surrounded by a belt 420b. The plurality of wheels 420a are classified into starting wheels, rolling wheels, guiding wheels, etc. according to their functions. The crawler-type mobile robot 3 is a robot that moves on uneven ground using the crawler 420. Compared to leg-type robots, the crawler-type mobile robot 3 has a relatively simple mechanism, is capable of high-speed travel, and can handle the load of the vehicle body. There are advantages such as high energy efficiency due to support.

(3) Third Modification FIG. 6 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 4 according to a third modification of the present embodiment. The mobile robot 3 according to the third modification is configured as a wheeled robot. Specifically, as shown in FIG. 6, the mobile robot 4 has a wheel mechanism 430 instead of the leg unit 400, unlike the mobile robot 1 according to the first embodiment.

The wheel mechanism 430 is an example of a moving mechanism, and is configured to move the mobile robot 1 under the control of the main control section 104 of the control circuit 101 of the robot body 100 . The wheel mechanism 430 has front wheels 430a and rear wheels 430b. The wheeled mobile robot 4 is a robot that moves on uneven ground using a wheel mechanism 430. Compared to legged robots, the wheeled mobile robot 4 has a relatively simple mechanism, can travel at high speeds, and can withstand the weight of the vehicle body. There are advantages such as high energy efficiency because it supports

(4) Fourth Modification FIG. 7 is a schematic diagram for explaining an example of the overall configuration of a mobile robot 5 according to a fourth modification of the present embodiment. A mobile robot 5 according to the fourth modification has a neck unit 200 and a head unit 300 provided inside a robot body 100 . The robot body 100 is provided with an opening 105 , and the neck unit 200 and the head unit 300 are accommodated in the opening 105 . Specifically, the neck unit 200 is connected to the bottom surface within the opening 105 and the head unit 300 is connected to the top of the neck unit 200 . In other words, the vibration damping device 201 included in the neck unit 200 is arranged between the robot body 100 and the environment sensor 301 .

(5) Others As described above, in the present disclosure, the leg-type moving mechanism, the crawler-type moving mechanism, and the wheel-type moving mechanism are exemplified. In the present disclosure, the movement mechanism of the mobile robot may be configured by appropriately combining these leg-type movement mechanism, crawler-type movement mechanism, and wheel-type movement mechanism.

The embodiments described above are for facilitating understanding of the present invention, and are not intended to limit and interpret the present invention. Each element included in the embodiment and its arrangement, materials, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. Also, it is possible to partially replace or combine the configurations shown in different embodiments.

1, 2, 3, 4, 5... Mobile robot 100... Robot body 101... Control circuit 102... Communication unit 103... Memory 103a... Control program 103b... Threshold information 104... Main control unit 104a... Environment information acquisition unit 104b Vibration detection processing unit 104c Self position estimation unit 104d Leg unit control unit 104e Vibration damping device control unit 200 Neck unit 201 Vibration damping device 300 Head Unit 301 Environment sensor 302 IMU 400, 400a to 400d Leg unit 401, 401a to 401d Motor 402, 402a to 402d Encoder

Claims (10)

A mobile robot comprising a robot body and a moving mechanism capable of moving the robot body,
an environment sensor unit that detects the environment around the mobile robot;
a vibration detection unit that detects vibrations occurring in the mobile robot;
a vibration damping unit disposed between the robot body and the environment sensor unit that damps the vibration detected by the vibration detection unit;
A mobile robot with 2. The mobile robot according to claim 1, wherein said damping unit has an actuator. 3. The mobile robot according to claim 1, wherein the actuator has one to six degrees of freedom. 4. The mobile robot according to any one of claims 1 to 3, wherein said vibration detection section is provided inside a unit provided with said environment sensor section. 4. The mobile robot according to any one of claims 1 to 3, wherein said vibration detector is provided inside said robot body. The mobile robot according to any one of claims 1 to 5, wherein the locomotion mechanism is a leg-type locomotion mechanism, a crawler-type locomotion mechanism, a wheel-type locomotion mechanism, or a combination thereof. 7. The mobile robot according to any one of claims 1 to 6, wherein said damping section performs said damping when the period of said vibration detected by said vibration detecting section is equal to or greater than a predetermined threshold. . 8. The mobile robot according to claim 7, wherein said predetermined threshold value is defined according to a movement mode of said mobile robot. A vibration damping method for a mobile robot comprising a robot body, a movement mechanism configured to move the robot body, and an environment sensor unit for detecting an environment around the mobile robot,
detecting vibrations occurring in the mobile robot;
controlling a damping unit disposed between the robot main body and the environment sensor unit to damp the detected vibration;
Damping method including. A program for causing a computer to execute a vibration damping method for a mobile robot comprising a robot main body, a moving mechanism configured to move the robot main body, and an environment sensor unit for detecting an environment around the mobile robot, the program comprising: ,
the computer,
an environment sensor unit that detects the environment around the mobile robot;
a vibration damping unit disposed between the robot body and the environment sensor unit that damps the vibration detected by the vibration detection unit;
A program to function as

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