Mobile control system

Abstract

To provide a movement control system capable of promptly guiding an autonomous moving object that has an abnormality in an external sensor to a destination.SOLUTION: In a movement control system according to this embodiment, a managing device includes: a detecting unit that detects, as a first autonomous moving object, an autonomous moving object that has an abnormality in an external sensor; and an instructing unit that instructs a second autonomous moving object so as to guide the first autonomous moving object. The first autonomous moving object includes: a first own position estimating unit which estimates the own position using an internal sensor, and which calculates the dispersion value of the estimated own position; and a first movement control unit that causes the first autonomous moving object to move toward a destination set by the second autonomous moving object while estimating the own position. The second autonomous moving object includes: a measuring unit that measures the position of the first autonomous moving object when the dispersion value of the own position estimated by the first autonomous moving object is greater than or equal to a threshold; and a second communicating unit that transmits, to the first autonomous moving object, the destination and measured positional information on the first moving object.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a movement control system.

Background Art

[0002] In recent years, among a plurality of autonomous mobile bodies, it has been required to quickly guide an autonomous mobile body whose accurate self-position estimation has become difficult due to a failure of an external sensor or the like to a destination. Related technologies are disclosed in, for example, Patent Document 1.

[0003] In the rescue robot system disclosed in Patent Document 1, when a management server receives a rescue notification from an autonomous mobile robot, it instructs a subordinate robot to perform a rescue. The rescue robot that has received the rescue instruction searches for the rescued robot, calculates the position of the rescued robot, and notifies the calculated position information to the rescued robot to recover the self-position estimation of the rescued robot.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the system disclosed in Patent Document 1, it is premised that after the rescued robot acquires information on its own position from the rescue robot, it can continue to move autonomously using an external sensor. The system disclosed in Patent Document 1 has a problem that it cannot move an autonomous mobile body for which accurate autonomous movement is difficult due to a failure of an external sensor or the like to a destination.

[0006] The present disclosure has been made in view of the above background, and an object thereof is to provide a movement control system capable of quickly guiding an autonomous mobile body with an abnormality in an external sensor to a destination.​ [Means for solving the problem]

[0007] The mobility control system according to this disclosure is a mobility control system comprising a management device and a plurality of autonomous mobile bodies, wherein the management device includes a detection unit that detects an autonomous mobile body among the plurality of autonomous mobile bodies that has an abnormality in an external sensor used for self-position estimation as a first autonomous mobile body, and an instruction unit that instructs a second autonomous mobile body, which is an autonomous mobile body other than the first autonomous mobile body among the plurality of autonomous mobile bodies, to guide the first autonomous mobile body, and the first autonomous mobile body includes a first self-position estimation unit that estimates its own position using an internal sensor and calculates a variance value of the estimated self-position, and a second unit that transmits the estimated variance value of its own position to the second autonomous mobile body. The system comprises a communication unit and a first movement control unit that moves the first autonomous mobile unit toward a destination set by the second autonomous mobile unit while estimating its own position using the first self-position estimation unit. The second autonomous mobile unit comprises a second self-position estimation unit that estimates its own position using external sensors, a second movement control unit that moves the second autonomous mobile unit while estimating its own position using the second self-position estimation unit, a measurement unit that measures the position of the first autonomous mobile unit when the variance value of the self-position estimated by the first autonomous mobile unit is greater than or equal to a threshold, and a second communication unit that transmits the destination and the measured position information of the first autonomous mobile unit to the first autonomous mobile unit. This movement control system can quickly guide an autonomous mobile unit with an abnormal external sensor to its destination using another autonomous mobile unit. [Effects of the Invention]

[0008] This disclosure provides a mobility control system that can quickly guide an autonomous mobile object with abnormal external sensors to its destination. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example configuration of the movement control system according to Embodiment 1. [Figure 2]This is a block diagram showing examples of the configurations of the autonomous mobile body to be guided and the autonomous mobile body that provides guidance, among the multiple autonomous mobile bodies provided in the mobility control system according to Embodiment 1. [Figure 3] This is a flowchart showing the operation of the movement control system according to Embodiment 1. [Figure 4] This is a diagram illustrating the operation of the motion control system according to Embodiment 1. [Modes for carrying out the invention]

[0010] The present invention will be described below through embodiments, but the claims are not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential for solving the problem. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary.

[0011] <Embodiment 1> Figure 1 shows an example of the configuration of the movement control system 1 according to Embodiment 1. The movement control system 1 according to this embodiment is a system for managing multiple autonomous mobile units placed in a predetermined work area. In this embodiment, the movement control system 1 can detect among the multiple autonomous mobile units an autonomous mobile unit in which an abnormality has occurred in its external sensor and accurate autonomous movement is difficult, and can quickly guide the detected autonomous mobile unit to its destination by another autonomous mobile unit. A detailed explanation follows below.

[0012] As shown in Figure 1, the mobile control system 1 comprises a management device 10, autonomous mobile units 20_1 to 20_n (where n is an integer of 2 or more), a map database (map DB) 30 storing map information for a predetermined work area, and a network 50. The management device 10, the autonomous mobile units 20_1 to 20_n, and the map database 30 are configured to communicate with each other via a wired or wireless network 50. Hereinafter, any autonomous mobile unit among the autonomous mobile units 20_1 to 20_n will be simply referred to as autonomous mobile unit 20.

[0013] Autonomous mobile units 20_1 to 20_n are mobile robots that autonomously move within a predetermined work area while estimating their own position. However, autonomous mobile units 20_1 to 20_n are not limited to autonomously mobile robots, but may also be autonomously mobile vehicles, etc. Autonomous mobile vehicles include commercial vehicles, passenger cars, and construction machinery.

[0014] The management device 10, also called the management server, manages the autonomous mobile units 20_1 to 20_n that are located in a designated work area. For example, the management device 10 instructs each of the autonomous mobile units 20_1 to 20_n on what to do. As a result, the autonomous mobile units 20_1 to 20_n operate according to the work instructions given by the management device 10. For example, the autonomous mobile units 20_1 to 20_n move from their current location to their destination according to the work instructions given by the management device 10.

[0015] Furthermore, the management device 10 detects among the autonomous mobile bodies 20_1 to 20_n that have experienced abnormalities in their external sensors and are unable to move accurately autonomously as guided mobile body A (first autonomous mobile body), and selects from among the autonomous mobile bodies 20_1 to 20_n, different from guided mobile body A, as guided mobile body B (second autonomous mobile body) to guide guided mobile body A to a destination such as an emergency evacuation area.

[0016] Specifically, the management device 10 comprises a detection unit 11 and an instruction unit 12. The detection unit 11 detects among the autonomous mobile bodies 20_1 to 20_n that have an abnormality in their external sensors and are unable to move accurately autonomously as the guided mobile body A. The detection unit 11 may also detect the autonomous mobile body 20 that has an abnormality in its external sensors as the guided mobile body A if it receives a notification from that autonomous mobile body 20. The instruction unit 12 selects a guided mobile body B from among the autonomous mobile bodies 20_1 to 20_n that are different from the guided mobile body A, and instructs the selected guided mobile body B to guide the guided mobile body A to a destination such as an emergency evacuation area. The instruction unit 12 may prioritize instructing guidance to an autonomous mobile body 20 located near the guided mobile body A, or it may prioritize instructing guidance to an autonomous mobile body 20 that has not been instructed to perform any work. Details of the method by which the guided mobile unit B guides the guided mobile unit A will be described later.

[0017] Figure 2 is a block diagram showing example configurations for guided mobile body A and guided mobile body B. In the example in Figure 2, autonomous mobile body 20_1 is detected as guided mobile body A, and autonomous mobile body 20_2 is selected as guided mobile body B. However, any autonomous mobile body 20 other than 20_1 may be detected as guided mobile body A, and any autonomous mobile body 20 other than 20_2 may be selected as guided mobile body B. The configurations of each autonomous mobile body 20_3 to 20_n are the same as those of autonomous mobile bodies 20_1 and 20_2, so their explanation is omitted.

[0018] As shown in FIG. 2, the guided mobile body A (autonomous mobile body 20_1 in the example of FIG. 2) includes a communication unit 211, an external sensor 212, an internal sensor 213, a self-position estimation unit 214, a control unit 215, a wheel drive unit 216, and a measurement unit 217. The guided mobile body B (autonomous mobile body 20_2 in the example of FIG. 2) includes a communication unit 221, an external sensor 222, an internal sensor 223, a self-position estimation unit 224, a control unit 225, a wheel drive unit 226, and a measurement unit 227. The communication unit 221, the external sensor 222, the internal sensor 223, the self-position estimation unit 224, the control unit 225, the wheel drive unit 226, and the measurement unit 227 respectively correspond to the communication unit 211, the external sensor 212, the internal sensor 213, the self-position estimation unit 214, the control unit 215, the wheel drive unit 216, and the measurement unit 217.

[0019] (Configuration of the Guided Mobile Body A) In the guided mobile body A, the communication unit 211 communicates with other autonomous mobile bodies 20, the management device 10, and the map database 30 via the network 50. The external sensor 212 is, for example, a camera, LiDAR (Light Detection And Ranging), a distance measuring sensor, etc., and detects the surrounding environment (surrounding objects, etc.) of the guided mobile body A. Further, the external sensor 212 detects an AR marker or the like attached to another autonomous mobile body 20. However, when the guided mobile body A has a camera separately from the external sensor 212, the AR marker may be photographed using the camera, and the AR marker may be specified from the analysis result of the photographed image. For example, OpenCV or the like is used for image analysis. The internal sensor 213 is wheel odometry, an IMU (Inertial Measurement Unit), etc., and detects the rotation speed and rotation angle of the wheels from the driving status of the wheels by the wheel drive unit 216.

[0020] The self-position estimation unit 214 estimates the self-position by comparing the detection result by the external sensor 212 with the map information stored in the map database 30, or calculates the moving direction and moving distance from the reference position from the detection result by the internal sensor 213 to estimate the self-position. The self-position estimation unit 214 can estimate the self-position with higher accuracy by using the external sensor 212 than by using the internal sensor 213. However, in the guided mobile body A, since there is an abnormality in the external sensor 212, the self-position estimation unit 214 estimates the self-position using the internal sensor 213.

[0021] In addition, the self-position estimation unit 214 calculates the variance value of the estimated self-position. Specifically, the self-position estimation unit 214 calculates the size of the area estimated to be the self-position with a probability of a predetermined rate or more as the variance value. The larger the variance value, the lower the reliability of the estimation result of the self-position of the guided mobile body A, and the smaller the variance value, the higher the reliability of the estimation result of the self-position of the guided mobile body A. The communication unit 211 periodically transmits the calculated variance value to the guided mobile body B.

[0022] For example, the self-position estimation unit 214 probabilistically and sequentially estimates the self-position by using a probabilistic estimation method called UKF (Unscented Kalman Filter). In the self-position estimation using UKF, the position coordinates and orientation of the guided mobile body A are represented by a multivariate Gaussian distribution. This Gaussian distribution is updated by the control information of the guided mobile body A and the observation information from the sensor, and the variance (covariance matrix) of this Gaussian distribution is used as the variance value of the self-position estimated by the self-position estimation unit 214. Specifically, the sum of the long side and the short side of the error ellipse obtained from the variance of this Gaussian distribution is used as the variance value.

[0023] The control unit 215 controls the operation of the guided mobile body A according to an instruction from the management device 10. For example, the control unit 215 moves the guided mobile body A by driving the wheels by the wheel drive unit 216 while estimating the self-position by the self-position estimation unit 214 according to an instruction from the management device 10.

[0024] The measurement unit 217 measures the position of another autonomous mobile object detected as a guided mobile object A when the autonomous mobile object 20_1 is used as a guided mobile object B. However, in this example, measurement by the measurement unit 217 is not performed because there is a malfunction in the external sensor 212. The method of measurement by the measurement unit 217 when the autonomous mobile object 20_1 is used as a guided mobile object B is the same as the method of measurement by the measurement unit 227 described later.

[0025] (Configuration of guided mobile unit B) In the guided mobile body B, the communication unit 221 communicates with other autonomous mobile bodies 20, the management device 10, and the map database 30 via the network 50. The external sensor 222 is, for example, a camera, LiDAR, or distance sensor, and detects the surrounding environment of the guided mobile body B (such as surrounding objects). The external sensor 222 also detects AR markers attached to other autonomous mobile bodies 20. However, if the guided mobile body B has a camera separate from the external sensor 222, the AR markers may be photographed using the camera, and the AR markers may be identified from the analysis results of the captured images. For image analysis, for example, OpenCV may be used. The internal sensor 223 is, for example, a wheel odometry unit or IMU, and detects the rotation speed and rotation angle of the wheels from the driving status of the wheels by the wheel drive unit 226.

[0026] The self-position estimation unit 224 estimates its own position by comparing the detection results from the external sensor 222 with the map information stored in the map database 30, or by calculating the direction of movement and distance of movement from a reference position from the detection results from the internal sensor 223. The self-position estimation unit 224 can estimate its own position with greater accuracy by using the external sensor 222 than by using the internal sensor 223. In this case, since the external sensor 222 is functioning normally in the guided mobile body B, the self-position estimation unit 224 estimates its own position with greater accuracy using the external sensor 222. Of course, the self-position estimation unit 224 may also estimate its own position using both the external sensor 222 and the internal sensor 223.

[0027] Furthermore, the self-position estimation unit 224 calculates the variance of the estimated self-position. Specifically, the self-position estimation unit 224 calculates the size of the area estimated to be the self-position with a probability of a predetermined rate or higher as the variance. The larger the variance, the lower the reliability of the self-position estimation result of the guided mobile body B, and the smaller the variance, the higher the reliability of the self-position estimation result of the guided mobile body B. However, in the case of the guided mobile body B, the external sensor 222 is functioning normally and the possibility of the variance being large is low, so the calculation of the variance does not need to be performed.

[0028] For example, the self-position estimation unit 224 probabilistically estimates its own position sequentially by using a parameter called UKF. In self-position estimation using UKF, the position coordinates and orientation of the guided mobile body B are represented by a multivariable Gaussian distribution. This Gaussian distribution is updated by control information and observation information from sensors of the guided mobile body B, and the variance (covariance matrix) of this Gaussian distribution is used as the variance value of the self-position estimated by the self-position estimation unit 224. Specifically, the sum of the long and short sides of the error ellipse obtained from the variance of this Gaussian distribution is used as the variance value.

[0029] The control unit 225 controls the operation of the guided mobile body B according to instructions from the management device 10. For example, the control unit 225 moves the guided mobile body B by driving the wheels with the wheel drive unit 226 while estimating its own position with the self-position estimation unit 224 according to instructions from the management device 10.

[0030] The measurement unit 227 measures the position of the guided mobile object A if the variance value of its own position estimated by the guided mobile object A is greater than or equal to a threshold. Specifically, first, the measurement unit 227 uses the external sensor 222 (or a separately provided camera) to detect an AR marker or the like attached to the guided mobile object B, thereby measuring the relative position and relative angle of the guided mobile object B with respect to the guided mobile object A. Subsequently, the measurement unit 227 calculates the position information (including orientation information) of the guided mobile object B from its own position estimated by the self-position estimation unit 224 and the measured relative position and relative angle of the guided mobile object B. Then, the communication unit 221 transmits the destination (including relay points to the final destination) and the position information of the guided mobile object B measured by the measurement unit 227 to the guided mobile object B.

[0031] Thus, the movement control system 1 according to this disclosure can detect an autonomous mobile object as a guided mobile object A due to an abnormality in the external sensor making accurate autonomous movement difficult, and can quickly guide the guided mobile object A to its destination by another autonomous mobile object, the guided mobile object B.

[0032] (Operation of the movement control system 1) Next, the operation of the mobile control system 1 will be explained using Figures 3 and 4. Figure 3 is a flowchart illustrating the operation of the mobile control system 1. Figure 4 is a diagram illustrating the operation of the mobile control system 1. In Figure 3, the dotted arrows represent the exchange of information between the guided mobile body A, the guided mobile body B, and the management device 10. The displayed content of each step in Figure 4 corresponds to the processing content of the corresponding step in Figure 3. In the following explanation, we will use the case where the autonomous mobile body 20_1 is detected as the guided mobile body A and the autonomous mobile body 20_2 is selected as the guided mobile body B as an example.

[0033] First, an abnormality occurs in the external sensor 212 of the autonomous mobile unit 20_1 (step S101). As a result, it becomes difficult for the autonomous mobile unit 20_1 to accurately estimate its own position using the external sensor 212, making accurate autonomous movement difficult.

[0034] When the management device 10 detects an autonomous mobile body 20_1 with an abnormality detected by the external sensor 212 as a guided mobile body A (step S301), it selects a guiding mobile body B from among the autonomous mobile bodies 20_2 to 20_n to guide guided mobile body A (step S302), and instructs the selected guiding mobile body B to guide guided mobile body A to a destination such as an emergency evacuation area (step S303).

[0035] When the guided mobile unit B receives a guidance instruction (step S201), it autonomously moves while searching for the guided mobile unit A (step S202), and measures the position of the found guided mobile unit A using its own external sensors, etc. (step S203). Then, the guided mobile unit B transmits the measured position information of the guided mobile unit A and the destination (including relay points to the final destination) to the guided mobile unit A (steps S204, S205).

[0036] When guided mobile A receives information about its own position and destination (including relay points) transmitted from guided mobile B (steps S102, S103), it moves toward the destination while estimating its own position using the internal sensor 213 (step S104). Guided mobile B also guides guided mobile A while moving autonomously (step S206).

[0037] Here, the guided mobile object A moves toward a destination set by the guided mobile object B, calculates the estimated variance of its own position, and periodically transmits it to the guided mobile object B (step S105). The guided mobile object B receives the variance values ​​periodically transmitted from the guided mobile object A (step S207).

[0038] Then, the guided mobile unit B continues to guide the guided mobile unit A until the guided mobile unit A reaches its destination (including the relay station) (step S211 → step S206). Also, the guided mobile unit A continues to move while estimating its own position using the internal sensor 213 until it reaches the destination set by the guided mobile unit B (step S211 → step S104).

[0039] Here, if the variance value exceeds a threshold (NO in step S208), that is, if the guided mobile body B determines that the difference between its own position estimated by the guided mobile body A and the actual position of the guided mobile body A has become unacceptably large, it interrupts its movement and searches for the guided mobile body A. After that, it measures the position of the guided mobile body A using the external sensor 222, etc. (step S209) and transmits it to the guided mobile body A (step S210). The guided mobile body A also interrupts its movement, receives the information on its own position transmitted from the guided mobile body B (step S106), and updates its own position. After that, the guided mobile body A and the guided mobile body B start moving again.

[0040] Then, when the guided mobile object A reaches its destination (YES in step S211), if the destination is an intermediate RP on the way to the final destination (NO in step S212), the guiding mobile object B sets a new destination and repeats the guidance process for the guided mobile object A (step S205). If the destination is the final destination FP (YES in step S212), the process is terminated.

[0041] Thus, the movement control system 1 according to this disclosure can detect an autonomous mobile object as a guided mobile object A due to an abnormality in the external sensor making accurate autonomous movement difficult, and can quickly guide the guided mobile object A to its destination by another autonomous mobile object, the guided mobile object B.

[0042] Furthermore, in the movement control system 1 according to this disclosure, the guiding mobile body B measures the position of the guided mobile body A on behalf of the guided mobile body A only when the variance value of the self-position estimated by the guided mobile body A exceeds a threshold. This reduces the processing burden compared to the case where the guiding mobile body B always measures the position of the guided mobile body A on behalf of the guided mobile body A. In particular, if an external sensor for detecting the guided mobile body A is provided only in front of the guiding mobile body B, the frequency with which the guiding mobile body B turns around to detect the guided mobile body A is reduced, enabling the guiding mobile body B to guide the guided mobile body A more quickly.

[0043] The present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention.

[0044] This disclosure can be realized by having a CPU (Central Processing Unit) execute a computer program to perform some or all of the processing for the management device 10 and each autonomous mobile unit 20_1 to 20_n.

[0045] The program described above includes, when loaded into a computer, a set of instructions (or software code) for causing the computer to perform one or more of the functions described in the embodiments. The program may be stored in a non-temporary computer-readable medium or a physical storage medium. Examples, but not limited to, include RAM (Random-Access Memory), ROM (Read-Only Memory), flash memory, SSD (Solid-State Drive), or other memory technologies, CD-ROM, DVD (Digital Versatile Disc), Blu-ray® disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted over a temporary computer-readable medium or a communication medium. Examples, but not limited to, include temporary computer-readable medium or a communication medium that includes electrically, optically, acoustically, or otherwise propagating signals. [Explanation of Symbols]

[0046] 1. Mobility control system 10 Management device 11 Detection Unit 12 Instruction part 20_1~20_n Autonomous Mobile Units 30 Map Databases 50 Networks 211 Communications Department 212 External Sensors 213 Internal Sensors 214 Self-position estimation part 215 Control Unit 216 Wheel drive unit 217 Measurement Unit 221 Communications Department 222 External Sensors 223 Internal Sensor 224 Self-position estimation part 225 Control Unit 226 Wheel drive unit 227 Measurement Unit A Guided moving object B Guided moving body

Claims

1. Management device and Multiple autonomous mobile units, A mobility control system equipped with, The aforementioned control device is A detection unit detects, as the first autonomous mobile body, an autonomous mobile body among the plurality of autonomous mobile bodies in which an external sensor used for self-position estimation has an abnormality, An instruction unit that instructs a second autonomous mobile unit, which is an autonomous mobile unit different from the first autonomous mobile unit among the plurality of autonomous mobile units, to guide the first autonomous mobile unit, It has, The first autonomous mobile unit is A first self-position estimation unit estimates its own position using an internal sensor and calculates the variance of the estimated self-position, A first communication unit transmits the estimated variance value of its own position to the second autonomous mobile unit, A first movement control unit moves the first autonomous mobile body toward a destination set by the second autonomous mobile body while estimating its own position using the first self-position estimation unit, It has, The second autonomous mobile unit, A second self-position estimation unit that estimates its own position using external sensors, A second movement control unit moves the second autonomous mobile body while estimating its own position using the second self-position estimation unit, A measurement unit measures the position of the first autonomous mobile unit when the variance value of its own position estimated by the first autonomous mobile unit is greater than or equal to a threshold, A second communication unit transmits the destination and the measured location information of the first autonomous mobile unit to the first autonomous mobile unit, Having, A mobile control system.

2. In the first autonomous mobile unit, the first self-position estimation unit calculates the size of the area estimated to be its own position with a probability of a predetermined rate or higher as a variance value. The motion control system according to claim 1.

3. The first autonomous mobile unit further has an AR marker, The second autonomous mobile unit, The measurement unit measures the position of the first autonomous mobile body from the AR marker identified by analyzing the image captured by the camera. The motion control system according to claim 1.

4. The first autonomous mobile unit is configured to notify the management device of any abnormality in the external sensor. In the management device, the detection unit detects the first autonomous mobile body that has notified the external sensor that there is an abnormality. The motion control system according to claim 1.

5. The aforementioned multiple autonomous mobile units are all autonomous mobile robots. The motion control system according to claim 1.

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