JPWO2019026761A1 - Mobile and computer programs - Google Patents

Abstract

(EN) Stabilizing the traveling of a mobile body including two types of positioning devices having different sensing methods. The moving body includes a motor, a drive device that controls the motor to move the moving body, and first sensor data and a second sensor that indicate sensing results obtained according to movement of the moving body by different sensing methods. Using a first sensor and a second sensor that respectively output data, a first positioning device that estimates the position of the moving body by performing a first estimation calculation using the first sensor data, and the second sensor data Whether the reliability data indicating the certainty of the estimation result by the first positioning device and the second positioning device that estimates the position of the moving body by performing the second estimation calculation according to the predetermined condition are satisfied. Accordingly, an arithmetic circuit that selects one of the estimation result by the first positioning device and the estimation result by the second positioning device as the position of the moving body.

Description

The present disclosure relates to a mobile body and a computer program for controlling the movement of the mobile body.

A position estimation technique for estimating the position of a moving body (hereinafter, simply referred to as “moving body”) such as a drone (unmanned aerial vehicle), an autonomous driving car, and an autonomous mobile robot with high accuracy is under development. A moving body that performs self-position estimation includes an external sensor such as a laser range sensor, senses a surrounding space while moving, and acquires sensor data. For example, it is possible to identify the self position on the environment map by collating the local map data around the moving body created from the sensor data with the environment map data in a wider range.

Japanese Unexamined Patent Application Publication No. 2016-224680 discloses a self-position estimation device that includes a first self-position estimation unit and a second self-position estimation unit, and that performs estimation processing for each step. The first self-position estimating unit obtains a probability distribution of the latest position of the moving body from the sensor data and the environment map, and estimates the first self-position based on this probability distribution. The second self-position estimation unit estimates the second self-position by adding the movement distance and the movement direction from the previous step to the current step acquired by the odometry to the final self-position estimated in the previous step. To do. In this self-position estimation device, the weighted average value of the first self-position and the second self-position is set as the final self-position in the current step.

International Publication No. 2013/002067 discloses a self-position estimation system for an autonomous mobile robot using a particle filter. This system estimates the position and orientation of the robot using the measurement data from the distance sensor, the map data, and the odometry data from the encoder. The reliability evaluation value of the position and orientation estimation result is calculated based on the dispersion of the particles. According to this system, it is determined whether the position and orientation of the mobile robot is estimated normally, and if not, it indicates that the robot is decelerated, emergency stopped, or not performed normally. It can output a signal.

JP, 2016-224680, A International Publication No. 2013/002067

The present disclosure provides a technique for further stabilizing the traveling of a mobile body including two types of positioning devices having different sensing methods.

In an exemplary embodiment, a moving body according to the present disclosure includes at least one motor, a drive device that controls the at least one motor to move the moving body, and a moving device that moves the moving body by a first sensing method. A first sensor that outputs first sensor data indicating the sensing result acquired accordingly, and a second sensor indicating the sensing result acquired according to the movement of the moving body by a second sensing method different from the first sensing method. A second sensor that outputs data, a first positioning device that estimates the position of the moving body by performing a first estimation calculation using the first sensor data, and the first estimation that uses the second sensor data Whether the second positioning device that estimates the position of the moving body by performing a second estimation calculation different from the calculation and the reliability data indicating the certainty of the estimation result by the first positioning device meet a predetermined condition. And an arithmetic circuit that selects one of the estimation result by the first positioning device and the estimation result by the second positioning device as the position of the moving body depending on whether or not the position is determined.

These comprehensive or specific aspects may be implemented by a system, a method, an integrated circuit, a computer program, or a recording medium. Alternatively, it may be realized by any combination of the system, the apparatus, the method, the integrated circuit, the computer program, and the recording medium.

According to the embodiment of the mobile body of the present invention, the estimation result by the first positioning device and the estimation result by the first positioning device are determined according to whether or not the reliability data indicating the certainty of the estimation result by the first positioning device meets a predetermined condition. One of the estimation results by the second positioning device is selected as the position of the mobile body. Thereby, for example, even when the reliability of the estimation result by the first positioning device is low, more stable operation can be performed by using the estimation result by the second positioning device.

FIG. 1 is a block diagram showing a basic configuration example of a moving body in an exemplary embodiment of the present disclosure. FIG. 2 is a diagram illustrating an overview of a control system that controls traveling of each AGV according to the present disclosure. FIG. 3 is a diagram showing an example of the moving space S in which the AGV exists. FIG. 4A is a diagram showing an AGV and a tow truck before being connected. FIG. 4B is a diagram showing a connected AGV and tow truck. FIG. 5 is an external view of an exemplary AGV according to this embodiment. FIG. 6A is a diagram showing a first hardware configuration example of the AGV. FIG. 6B is a diagram showing a second hardware configuration example of the AGV. FIG. 7A is a diagram showing an AGV that generates a map while moving. FIG. 7B is a diagram showing an AGV that generates a map while moving. FIG. 7C is a diagram showing an AGV that generates a map while moving. FIG. 7D is a diagram showing an AGV that generates a map while moving. FIG. 7E is a diagram showing an AGV that generates a map while moving. FIG. 7F is a diagram schematically showing a part of the completed map. FIG. 8 is a diagram illustrating a hardware configuration example of the operation management device. FIG. 9: is a figure which shows typically an example of the movement route of AGV determined by the operation management apparatus. FIG. 10 is a block diagram showing a configuration example of the moving body 10. FIG. 11 is a diagram schematically showing the flow of signals between the constituent elements in this embodiment. FIG. 12 is a flowchart showing an example of the operation of the mobile unit 10. FIG. 13 is a diagram for explaining the map switching area. FIG. 14: is a figure which shows an example of operation|movement of the mobile body 10 typically. FIG. 15: is a figure which shows the time change of the speed of the mobile body 10 in one embodiment. FIG. 16 is a flowchart showing a traveling operation using encoder coordinates according to an embodiment. FIG. 17 is a diagram schematically showing a normal map switching process in which the LRF coordinate is highly reliable. FIG. 18 is a diagram schematically showing a map switching process when the reliability of the LRF coordinate becomes low during traveling in the map switching area. FIG. 19 is a diagram showing an example of changes in LRF coordinates and encoder coordinates.

<Terms>
Before describing the embodiments of the present disclosure, a definition of terms used in the present specification will be explained.

An "automated guided vehicle" (AGV) means a trackless vehicle in which a main body is manually or automatically loaded with luggage, the vehicle automatically travels to a designated location, and the cargo is unloaded manually or automatically. "Unmanned guided vehicles" include unmanned towing vehicles and unmanned forklifts.

The term "unmanned" means that no person is required to steer the vehicle and does not exclude that an automated guided vehicle carries "a person (eg, a person who loads and unloads luggage)."

An "unmanned towing vehicle" is a trackless vehicle that pulls a truck that loads or unloads luggage manually or automatically and automatically travels to a designated location.

An "unmanned forklift" is a trackless vehicle that has a mast that moves a fork for loading and unloading up and down, automatically transfers the luggage to the fork, and automatically travels to a designated location for automatic cargo handling work.

A "trackless vehicle" is a vehicle that includes wheels and an electric motor or engine that rotates the wheels.

The “moving body” is a device for moving a person or luggage on it, and includes a driving device such as a wheel that generates a driving force (traction) for moving, a bipedal or multipedal walking device, and a propeller. The term "mobile" in this disclosure includes mobile robots and drones as well as unmanned guided vehicles in the narrow sense.

The "automatic traveling" includes traveling based on a command of an operation management system of a computer to which an automatic guided vehicle is connected by communication and autonomous traveling by a control device included in the automatic guided vehicle. The autonomous traveling includes not only traveling of an automated guided vehicle toward a destination along a predetermined route but also traveling of following a tracking target. In addition, the automatic guided vehicle may temporarily perform the manual traveling based on the instruction of the operator. Although “automatic traveling” generally includes both “guided” traveling and “guideless” traveling, in the present disclosure, “guideless” traveling is meant.

The “guide type” is a method in which the guide is installed continuously or intermittently and the guide is used to guide the automatic guided vehicle.

The "guideless method" is a method of guiding without installing a derivative. The automatic guided vehicle according to the embodiment of the present disclosure includes a self-position estimation device and travels in a guideless manner.

The "self-position estimation device" is a device that estimates the self-position on the environment map based on sensor data acquired by an external sensor such as a laser range finder.

"SLAM" is an abbreviation for Simultaneous Localization and Mapping, which means that self-position estimation and environment mapping are performed at the same time.

<Basic configuration example>
Before describing specific embodiments of the moving body according to the present disclosure, a basic configuration example of the moving body according to the present disclosure will be described.

FIG. 1 is a block diagram showing a basic configuration example of a moving body in an exemplary embodiment of the present disclosure. The moving body 10 in this example includes a first sensor 101, a second sensor 102, a first positioning device 103, a second positioning device 104, an arithmetic circuit 105, and at least one electric motor (hereinafter, simply “motor”). “) and a drive device 107. The first positioning device 103 is connected between the first sensor 101 and the arithmetic circuit 105. The second positioning device 104 is connected between the second sensor 102 and the arithmetic circuit 105. The drive device 107 controls at least one motor 106 to move the moving body 10.

A typical example of the moving body 10 has at least one drive wheel (not shown) mechanically coupled to the motor 106, and can travel on the ground by the traction of the drive wheel.

The first sensor 101 and the second sensor 102 acquire information according to the movement of the mobile body 10 by different sensing methods while the mobile body 10 is moving. The respective sensing results are used to estimate the position of the moving body 10. The data output from the first sensor 101 and the second sensor 102 are referred to as first sensor data and second sensor data, respectively.

Each of the first sensor 101 and the second sensor 102 may be an external sensor or an internal sensor. The “outside world sensor” is a sensor that senses an external state of the moving body 10. Examples of the external sensor include a laser range finder, a camera (or an image sensor), a LIDAR (Light Detection and Ranging), a millimeter wave radar, and a magnetic sensor. The “inner world sensor” is a sensor that senses an internal state of the moving body 10. The internal sensor includes, for example, a rotary encoder (hereinafter sometimes simply referred to as “encoder”), an acceleration sensor, and an angular acceleration sensor (eg, gyro sensor).

The first sensor 101 and the second sensor 102 are different types of sensors. For example, the first sensor 101 may be an external sensor and the second sensor 102 may be an internal sensor. In an embodiment, the first sensor 101 includes a laser range finder (hereinafter sometimes referred to as LRF), and the second sensor 102 includes at least one rotary encoder. However, the present disclosure is not limited to such a form. Each of the first sensor 101 and the second sensor 102 is not limited to a particular type of sensor as long as it outputs data used for estimating the position of the moving body 10. Each of the first sensor 101 and the second sensor 102 may be a device such as a camera, an imaging device, an imaging element, a magnetic sensor, a LIDAR, a millimeter wave radar, an angular velocity sensor, or an acceleration sensor.

While the moving body 10 is moving, the first positioning device 103 estimates the current position of the moving body 10 by performing a first estimation calculation using the first sensor data output from the first sensor 101. For example, when the first sensor 101 is a laser range finder, the first positioning device 103 collates the map data prepared in advance with the data acquired by the laser range finder, and moves the mobile object to any position on the map. Estimate where is located. The first positioning device 103 may estimate not only the position of the moving body but also the direction (or orientation). The first positioning device 103 outputs data indicating the estimation result as the first position information.

The second positioning device 104 uses the second sensor data output from the second sensor 102 to perform a second estimation calculation to estimate the current position of the mobile body 10. For example, when the second sensor 102 includes at least one rotary encoder, the second positioning device 104 indicates the initial position information recorded in advance in a recording medium such as a memory and the rotation state of the wheels output from the rotary encoder. The current position can be estimated from the information. The second positioning device 104 may also estimate the direction as well as the position of the moving body. The second positioning device 104 outputs the data indicating the estimation result as the second position information.

The moving body 10 may further include a storage device that stores map data created in advance based on the sensor data periodically output from the laser range finder. The laser range finder (LRF) used to create the map data may be the LRF (first sensor 101) mounted on the moving body 10 or another LRF. In this case, the first positioning device 103 collates the first sensor data with the map data to estimate the position of the moving body 10. This operation is called "self-position estimation". The self-position estimation may include not only the coordinates but also the estimation of the angle from the reference axis.

The moving body 10 may be a vehicle including a plurality of wheels including a first wheel and a second wheel. In that case, the at least one motor 106 may include a first motor mechanically connected to the first wheel and a second motor mechanically connected to the second wheel. The moving body 10 includes a first rotary encoder that measures the rotation of the power transmission mechanism from the first motor to the first wheel at any position, and a position of the power transmission mechanism from the second motor to the second wheel. And a second rotary encoder that measures the rotation of the. "Measure rotation" means to measure at least the "rotation direction" and the "rotation position" (considering the number of rotations).

In one embodiment, the first rotary encoder and the second rotary encoder measure rotations of the first wheel and the second wheel, respectively. In that case, the second positioning device 104 measures the relative displacement amount from a given initial position by using the second sensor data output from each of the first rotary encoder and the second rotary encoder, The position moved by the displacement amount can be estimated as the position of the moving body 10. The initial position may be updated regularly or irregularly while the mobile body 10 is traveling. For example, the arithmetic circuit 105 may update the above-described initial position value with the position (coordinate) value estimated by the first positioning device 103. While the moving body 10 is traveling, the arithmetic circuit 105 may update the initial position at a predetermined cycle or aperiodically.

Generally, there is a difference in the reliability of the first position information and the second position information. For example, when the first sensor 101 includes an LRF and the second sensor 102 includes an encoder, the first position information acquired using the LRF is higher than the second position information acquired using the encoder. Tends to be reliable. This is because an error is likely to occur in the odometry data output from the encoder and the error is likely to be accumulated due to a wheel idling that occurs depending on the road surface condition or a deviation due to a step. Such a mismatch in reliability can occur not only in the combination of the LRF and the encoder but also in the combination of the other two types of sensors (for example, the camera and the gyro sensor). Therefore, of the first position information and the second position information, the one with higher reliability is mainly used, and the other one is used auxiliary.

However, the first position information may be less reliable than the second position information. For example, in the form in which the first positioning device 103 performs self-position estimation by matching the first sensor data from the LRF and the map data, the first positioning device 103 may erroneously output coordinates that are completely different from the actual coordinates. .. This is likely to occur, for example, when there are a plurality of locations on the route that include similar feature points, or when there is an object that did not exist at the time of map creation (especially an object that is easily confused with a wall or the like). In such a case, if the self-position estimation using the first position information is continued, it becomes impossible to travel on an accurate route. As a result, not only is the destination inaccessible, but there is the risk of overrun or collision.

Therefore, in the embodiment of the present disclosure, while the moving body 10 is moving, the arithmetic circuit 105 outputs the estimation result that is estimated to be higher in accuracy among the estimation results of the first positioning device 103 and the second positioning device 104. Select and control running. As a result, for example, when the vehicle normally travels using the position information estimated by the first positioning device 103, and when it is determined that the reliability of the position information by the first positioning device 103 is low, the second positioning device 04 determines It is possible to switch to traveling using position information.

The arithmetic circuit 105 determines the current position of the moving body 10 based on the first position information and the second position information, and controls the drive device 107. The arithmetic circuit 105 acquires, in addition to the first and second position information, reliability data indicating the certainty of the estimation result by the first positioning device 103. The arithmetic circuit 105 selects one of the estimation result by the first positioning device 103 and the estimation result by the second positioning device 104 as the position of the mobile body 10 according to whether or not the reliability data matches a predetermined condition. To do. The arithmetic circuit 105 receives a destination instruction from an external device, controls the drive device 107 using the selected position of the moving body 10, and moves the moving body 10 toward the destination.

The reliability data may be output from the first positioning device 103 or may be generated by the arithmetic circuit 105 itself. For example, in the form in which the first sensor 101 includes the LRF, the first positioning device 103 may output the data indicating the degree of coincidence between the first sensor data and the map data as the first reliability data. In this case, the arithmetic circuit 105 selects the second positioning when the value of the first reliability data becomes equal to or less than the switching threshold value while the estimation result by the first positioning device 103 is selected as the position of the moving body 10. The estimation result by the device 104 can be selected as the position of the moving body 10. Conversely, the arithmetic circuit 105 selects the first positioning data when the value of the first reliability data becomes equal to or greater than the return threshold value while the estimation result of the second positioning device 104 is selected as the position of the moving body 10. The estimation result by the device 103 can be returned to the state of being selected as the position of the moving body 10. The return threshold may be the same value as the switching threshold, or may be a value larger than the switching threshold. For example, when the first reliability data is represented by a numerical value with “%” as a unit, the operation can be made more stable by setting the return threshold value to a value that is several percent to 30% higher than the switching threshold value. it can.

Even when the value of the first reliability data is equal to or greater than the return threshold, the arithmetic circuit 105 does not approximate the movement of the coordinates indicated by the first position information and the movement of the coordinates indicated by the second position information. In this case, the position indicated by the second position information may be selected as the position of the moving body 10. When the movement of the coordinates indicated by the first position information and the movement of the coordinates indicated by the second position information do not approximate each other, there are the following two cases.
(1) Within the fixed time estimated based on the estimation result by the first positioning device 103 and within the fixed time estimated based on the estimation result by the second positioning device 104 within a fixed time (for example, several seconds). When the difference between the moving distance of the moving body 10 and the moving distance of the moving body 10 is larger than the first threshold value (2), the angle change amount of the moving body 10 within the certain time period estimated based on the estimation result by the first positioning device 103, and 2 When the difference with the amount of change in angle of the moving body 10 within the certain period of time estimated based on the estimation result by the positioning device 104 is larger than the second threshold value.

In the case where at least one of (1) and (2) above is satisfied, the arithmetic circuit 105 uses the estimation result by the second positioning device 104 as the moving object even if the reliability of the first position information is higher than the return threshold. You may choose as 10 positions and continue operation.

The reliability data may include data indicating the difference between the coordinates indicated by the first position information and the coordinates indicated by the second position information (referred to as “second reliability data”). In this case, the arithmetic circuit 105 outputs the difference between the position obtained as the estimation result by the first positioning device 103 and the position obtained as the estimation result by the second positioning device 104 as the second reliability data. When the coordinates indicated by the first position information are (x1, x1) and the coordinates indicated by the second position information are (x2, y2), the second reliability data is, for example, the absolute value of (x1-x2), The data may be the absolute value of (y1-y2) or the value of (x1-x2) ² +(y1-y2) ² or the square root thereof. The arithmetic circuit 105, when the estimation result by the first positioning device 103 is selected as the position of the moving body 10 and the value of the second reliability data becomes equal to or greater than a predetermined allowable value, the second positioning is performed. The estimation result by the device 104 can be selected as the position of the moving body 10. On the contrary, the arithmetic circuit 105, when the estimation result by the second positioning device 104 is selected as the position of the moving body 10, the value of the second reliability data becomes less than the permissible value or a value smaller than the permissible value. At this time, the measurement result by the first positioning device 103 can be returned to the state of being selected as the position of the moving body 10.

The present disclosure also includes a computer program executed by an arithmetic circuit in a mobile body. Such a program is stored in the memory provided in the mobile body. The computer program causes the arithmetic circuit to calculate the estimation result by the first positioning device and the first positioning device according to whether or not the reliability data indicating the certainty of the estimation result by the first positioning device meets a predetermined condition. 2 One of the estimation results by the positioning device is selected as the position of the moving body.

<Exemplary embodiment>
Hereinafter, more specific embodiments of a mobile body and a mobile body system according to the present disclosure will be described with reference to the accompanying drawings. In addition, more detailed description than necessary may be omitted. For example, detailed description of well-known matters and duplicate description of substantially the same configuration may be omitted. This is for avoiding unnecessary redundancy in the following description and for facilitating understanding by those skilled in the art. The inventors provide the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure. They are not intended to limit the claimed subject matter.

The present embodiment relates to a system including an automatic guided vehicle as an example of a mobile body. In the following description, the automatic guided vehicle is referred to as “AGV” using abbreviations. In the present embodiment, the first sensor 101 includes a laser range finder, and the second sensor 102 includes two rotary encoders that measure the rotational speeds (rotations per unit time) of the two wheels.

(1) Basic Configuration of System FIG. 2 shows an example of the basic configuration of an exemplary mobile management system 100 according to the present disclosure. The mobile management system 100 includes at least one AGV 10, a terminal device 20 operated by the user 1, and an operation management device 50 that manages the operation of the AGV 10.

The AGV 10 is an unmanned carrier truck capable of “guideless” traveling, which does not require a magnetic tape or the like for traveling. The AGV 10 can perform self-position estimation and send the estimation result to the terminal device 20 and the operation management device 50. The AGV 10 can automatically travel in the moving space S according to a command from the operation management device 50.

The operation management device 50 is a computer system that tracks the position of each AGV 10 and manages the travel of each AGV 10. The operation management device 50 may be a desktop PC, a notebook PC, and/or a server computer. The operation management device 50 communicates with each AGV 10 via the plurality of access points 2. For example, the operation management device 50 transmits the data of the coordinates of the position to which each AGV 10 should head next to each AGV 10. Each AGV 10 periodically transmits data indicating its own position and attitude to the operation management device 50, for example, every 100 milliseconds. When the AGV 10 reaches the instructed position, the operation management device 50 transmits the coordinate data of the position to which the vehicle should further head. The AGV 10 can also travel in the moving space S according to the operation of the user 1 input to the terminal device 20. An example of the terminal device 20 is a tablet computer. Typically, the traveling of the AGV 10 using the terminal device 20 is performed at the time of creating the map, and the traveling of the AGV 10 using the operation management device 50 is performed after creating the map.

FIG. 3 shows an example of the moving space S in which three AGVs 10a, 10b and 10c exist. It is assumed that both AGVs are traveling in the depth direction in the figure. The AGVs 10a and 10b are carrying the luggage placed on the top plate. The AGV 10c is running following the AGV 10b in front of it. For convenience of explanation, reference numerals 10a, 10b and 10c are attached in FIG. 3, but in the following, it is described as “AGV10”.

The AGV 10 is also capable of transporting luggage using a tow truck connected to itself, other than the method of transporting luggage placed on the top plate. FIG. 4A shows the AGV 10 and the tow truck 5 before being connected. A caster is provided on each foot of the tow truck 5. The AGV 10 is mechanically connected to the tow truck 5. FIG. 4B shows the AGV 10 and tow truck 5 connected. When the AGV 10 travels, the tow truck 5 is towed by the AGV 10. By towing the towing truck 5, the AGV 10 can carry the luggage placed on the towing truck 5.

The method of connecting the AGV 10 and the towing vehicle 5 is arbitrary. An example will be described. The plate 6 is fixed to the top plate of the AGV 10. The tow truck 5 is provided with a guide 7 having a slit. The AGV 10 approaches the tow truck 5 and inserts the plate 6 into the slit of the guide 7. When the insertion is completed, the AGV 10 causes an electromagnetic lock type pin (not shown) to penetrate the plate 6 and the guide 7 to apply an electromagnetic lock. As a result, the AGV 10 and the towing vehicle 5 are physically connected.

Referring back to FIG. Each AGV 10 and the terminal device 20 can be connected, for example, in a one-to-one manner and can communicate in accordance with the Bluetooth (registered trademark) standard. Each AGV 10 and the terminal device 20 can also perform communication conforming to Wi-Fi (registered trademark) using one or a plurality of access points 2. The plurality of access points 2 are connected to each other via, for example, a switching hub 3. In FIG. 2, two access points 2a and 2b are shown. The AGV 10 is wirelessly connected to the access point 2a. The terminal device 20 is wirelessly connected to the access point 2b. The data transmitted by the AGV 10 is received by the access point 2a, transferred to the access point 2b via the switching hub 3, and transmitted from the access point 2b to the terminal device 20. The data transmitted by the terminal device 20 is received by the access point 2b, transferred to the access point 2a via the switching hub 3, and transmitted from the access point 2a to the AGV 10. Thereby, bidirectional communication between the AGV 10 and the terminal device 20 is realized. The plurality of access points 2 are also connected to the operation management device 50 via the switching hub 3. Thereby, bidirectional communication is also realized between the operation management device 50 and each AGV 10.

(2) Creation of Environmental Map A map in the moving space S is created so that the AGV 10 can travel while estimating its own position. The AGV 10 is equipped with a positioning device and a laser range finder, which will be described later, and can use the output of the laser range finder to create a map.

The AGV 10 makes a transition to the data acquisition mode by a user operation. In the data acquisition mode, the AGV 10 starts acquisition of sensor data using the laser range finder. The laser range finder periodically emits a laser beam of infrared rays or visible light to the surroundings to scan the surrounding space S. The laser beam is reflected by, for example, a structure such as a wall or a pillar, or a surface such as an object placed on the floor. The laser range finder receives the reflected light of the laser beam, calculates the distance to each reflection point, and outputs the measurement result data indicating the position of each reflection point. The arrival direction and distance of the reflected light are reflected in the position of each reflection point. The measurement result data may be referred to as “measurement data” or “sensor data”.

The positioning device stores the sensor data in the storage device. When the acquisition of the sensor data in the moving space S is completed, the sensor data accumulated in the storage device is transmitted to the external device. The external device is, for example, a computer having a signal processor and having a map creation program installed therein.

The signal processor of the external device superimposes the sensor data obtained for each scan. A map of the space S can be created by the signal processor repeatedly performing the overlapping process. The external device transmits the created map data to the AGV 10. The AGV 10 saves the created map data in the internal storage device. The external device may be the operation management device 50 or another device.

The AGV 10 may create the map instead of the external device. The processing performed by the signal processor of the external device described above may be performed by a circuit such as a microcontroller unit (microcomputer) of the AGV 10. When creating a map within the AGV 10, it is not necessary to transmit the accumulated sensor data to an external device. The data capacity of sensor data is generally considered to be large. Since it is not necessary to transmit the sensor data to the external device, occupation of the communication line can be avoided.

The movement in the movement space S for acquiring the sensor data can be realized by the AGV 10 traveling in accordance with the user's operation. For example, the AGV 10 wirelessly receives a traveling command from the user via the terminal device 20 instructing movement in the front, rear, left, and right directions. The AGV 10 travels forward, backward, leftward and rightward in the moving space S in accordance with the travel command to create a map. When the AGV 10 is connected to a control device such as a joystick by wire, the map may be created by traveling back and forth, left and right in the moving space S according to a control signal from the control device. The sensor data may be acquired by a person walking on a measuring carriage equipped with a laser range finder.

Although a plurality of AGVs 10 are shown in FIGS. 2 and 3, the number of AGVs may be one. When there are a plurality of AGVs 10, the user 1 can use the terminal device 20 to select one AGV 10 from the plurality of registered AGVs and create a map of the moving space S.

After the map is created, each AGV 10 can automatically drive while estimating its own position using the map. The process of estimating the self position will be described later.

(3) Configuration of AGV FIG. 5 is an external view of an exemplary AGV 10 according to this embodiment. The AGV 10 has two drive wheels 11a and 11b, four casters 11c, 11d, 11e, and 11f, a frame 12, a transport table 13, a travel control device 14, and a laser range finder 15. The two drive wheels 11a and 11b are provided on the right side and the left side of the AGV 10, respectively. The four casters 11c, 11d, 11e, and 11f are arranged at the four corners of the AGV 10. The AGV 10 also has a plurality of motors connected to the two drive wheels 11a and 11b, but is not shown in FIG. Further, in FIG. 5, one drive wheel 11a and two casters 11c and 11e located on the right side of the AGV 10 and a caster 11f located on the left rear part are shown, but the left drive wheel 11b and the left front part are shown. The caster 11d is not shown because it is hidden behind the frame 12. The four casters 11c, 11d, 11e, and 11f can freely swivel. In the following description, the drive wheels 11a and 11b are also referred to as wheels 11a and wheels 11b, respectively.

The travel control device 14 is a device that controls the operation of the AGV 10, and mainly includes an integrated circuit including a microcomputer (described later), electronic components, and a board on which the electronic components are mounted. The traveling control device 14 performs the above-described data transmission/reception with the terminal device 20 and the pre-processing calculation.

The laser range finder 15 is an optical device that emits an infrared laser beam 15a, for example, and detects the reflected light of the laser beam 15a to measure the distance to the reflection point. In the present embodiment, the laser range finder 15 of the AGV 10 has a pulsed laser beam, for example, in a space of 135 degrees to the left and right (total 270 degrees) with respect to the front of the AGV 10 while changing the direction every 0.25 degrees. 15a is emitted, and the reflected light of each laser beam 15a is detected. This makes it possible to obtain data on the distance to the reflection point in the direction determined by the angle of 1081 steps in total for every 0.25 degree. In this embodiment, it is assumed that the scan of the surrounding space performed by the laser range finder 15 is substantially parallel to the floor surface and is planar (two-dimensional). However, scanning in the height direction may be performed.

The AGV 10 can create a map of the space S based on the position and orientation of the AGV 10 and the scan result of the laser range finder 15. The map can reflect the arrangement of the walls around the AGV, structures such as columns, and objects placed on the floor. The map data is stored in the storage device provided in the AGV 10.

In general, the position and posture of a moving body is called a pose. The position and orientation of the moving body in the two-dimensional plane are represented by the position coordinates (x, y) in the XY orthogonal coordinate system and the angle θ with respect to the X axis. Hereinafter, the position and orientation of the AGV 10, that is, the pose (x, y, θ) may be simply referred to as “position”.

The position of the reflection point viewed from the radiation position of the laser beam 15a can be expressed using polar coordinates determined by the angle and the distance. In this embodiment, the laser range finder 15 outputs the sensor data expressed in polar coordinates. However, the laser range finder 15 may convert the position expressed in polar coordinates into Cartesian coordinates and output it.

Since the structure and operating principle of the laser range finder are known, further detailed description is omitted in this specification. Examples of objects that can be detected by the laser range finder 15 are people, luggage, shelves, and walls.

The laser range finder 15 is an example of an external sensor for sensing the surrounding space and acquiring sensor data. Image sensors and ultrasonic sensors are conceivable as other examples of such external sensors.

The traveling control device 14 can estimate the current position of itself by comparing the measurement result of the laser range finder 15 with the map data held by itself. The stored map data may be map data created by another AGV 10.

FIG. 6A shows a first hardware configuration example of the AGV 10. FIG. 6A also shows a specific configuration of the traveling control device 14.

The AGV 10 includes a travel control device 14, a laser range finder 15, two motors 16a and 16b, a drive device 17, wheels 11a and 11b, and two rotary encoders 18a and 18b (hereinafter, simply "encoder 18a"). And sometimes referred to as "encoder 18b").

The travel control device 14 has a microcomputer 14a, a memory 14b, a storage device 14c, a communication circuit 14d, and a positioning device 14e. The microcomputer 14a, the memory 14b, the storage device 14c, the communication circuit 14d, and the positioning device 14e are connected by the communication bus 14f, and can exchange data with each other. The laser range finder 15 is also connected to the communication bus 14f via a communication interface (not shown), and transmits the measurement data as the measurement result to the microcomputer 14a, the positioning device 14e and/or the memory 14b.

The microcomputer 14a is a processor or a control circuit (computer) that performs a calculation for controlling the entire AGV 10 including the travel control device 14. The microcomputer 14a is typically a semiconductor integrated circuit. The microcomputer 14a transmits a PWM (Pulse Width Modulation) signal, which is a control signal, to the drive device 17 to control the drive device 17 and adjust the voltage applied to the motor. This causes each of the motors 16a and 16b to rotate at a desired rotation speed. Note that one or more control circuits (for example, a microcomputer) that controls driving of the left and right motors 16a and 16b may be provided independently of the microcomputer 14a. For example, the motor driving device 17 may include two microcomputers that respectively control the driving of the motors 16a and 16b. These two microcomputers may respectively perform coordinate calculation using the encoder information output from the encoders 18a and 18b to estimate the moving distance of the AGV 10 from a given initial position. Further, the two microcomputers may control the motor drive circuits 17a and 17b using the encoder information.

The memory 14b is a volatile storage device that stores a computer program executed by the microcomputer 14a. The memory 14b can also be used as a work memory when the microcomputer 14a and the positioning device 14e perform calculations.

The storage device 14c is a non-volatile semiconductor memory device. However, the storage device 14c may be a magnetic recording medium represented by a hard disk or an optical recording medium represented by an optical disc. Further, the storage device 14c may include a head device for writing and/or reading data in any recording medium and a control device for the head device.

The storage device 14c stores map data M of the traveling space S and data of one or more traveling routes (traveling route data) R. The map data M is created by the AGV 10 operating in the map creation mode and is stored in the storage device 14c. The travel route data R is transmitted from the outside after the map data M is created. In this embodiment, the map data M and the travel route data R are stored in the same storage device 14c, but may be stored in different storage devices.

An example of the travel route data R will be described.

When the terminal device 20 is a tablet computer, the AGV 10 receives travel route data R indicating a travel route from the tablet computer. The traveling route data R at this time includes marker data indicating the positions of the plurality of markers. The “marker” indicates the passing position (route point) of the traveling AGV 10. The travel route data R includes at least position information of a start marker indicating a travel start position and an end marker indicating a travel end position. The travel route data R may further include position information of markers at one or more intermediate waypoints. When the travel route includes one or more intermediate waypoints, the route from the start marker to the end marker via the travel waypoints in order is defined as the travel route. The data of each marker may include, in addition to the coordinate data of the marker, data on the direction (angle) and traveling speed of the AGV 10 until the marker moves to the next marker. When the AGV 10 temporarily stops at the position of each marker and performs self-position estimation and notification to the terminal device 20, the data of each marker includes the acceleration time required for acceleration to reach the traveling speed, and/or , And may include data of deceleration time required for deceleration from the traveling speed to stop at the position of the next marker.

Instead of the terminal device 20, the operation management device 50 (for example, a PC and/or a server computer) may control the movement of the AGV 10. In that case, the operation management device 50 may instruct the AGV 10 to move to the next marker each time the AGV 10 reaches the marker. For example, the AGV 10 receives, from the operation management device 50, coordinate data of a destination position to be headed next, or data of a distance to the destination position and an angle to travel as traveling route data R indicating a traveling route.

The AGV 10 can travel along the stored travel route while estimating its own position using the created map and the sensor data output by the laser range finder 15 acquired during travel.

The communication circuit 14d is, for example, a wireless communication circuit that performs wireless communication conforming to the Bluetooth (registered trademark) and/or Wi-Fi (registered trademark) standards. Each standard includes a wireless communication standard using a frequency in the 2.4 GHz band. For example, in the mode in which the AGV 10 is driven to create a map, the communication circuit 14d performs wireless communication in compliance with the Bluetooth (registered trademark) standard and communicates with the terminal device 20 on a one-to-one basis.

The positioning device 14e performs map creation processing and self-position estimation processing during traveling. The positioning device 14e creates a map of the moving space S based on the position and orientation of the AGV 10 and the scan result of the laser range finder. When traveling, the positioning device 14e receives sensor data from the laser range finder 15 and reads the map data M stored in the storage device 14c. By comparing (matching) the local map data (sensor data) created from the scan result of the laser range finder 15 with the map data M in a wider range, the self position (x, y, θ) on the map data M Identify. The positioning device 14e generates “reliability” data indicating the degree to which the local map data matches the map data M. The data of the self position (x, y, θ) and the reliability can be transmitted from the AGV 10 to the terminal device 20 or the operation management device 50. The terminal device 20 or the operation management device 50 can receive the respective data of the self position (x, y, θ) and the reliability and display the data on the built-in or connected display device.

In this embodiment, the microcomputer 14a and the positioning device 14e are separate components, but this is an example. It may be a single chip circuit or semiconductor integrated circuit capable of independently performing each operation of the microcomputer 14a and the positioning device 14e. FIG. 6A shows a chip circuit 14g including the microcomputer 14a and the positioning device 14e. In the following, an example in which the microcomputer 14a and the positioning device 14e are provided separately and independently will be described.

Two motors 16a and 16b are attached to two wheels 11a and 11b, respectively, and rotate each wheel. That is, the two wheels 11a and 11b are drive wheels. In the present specification, the motor 16a and the motor 16b are described as motors that drive the right wheel and the left wheel of the AGV 10, respectively.

The AGV 10 further includes an encoder unit 18 that measures the rotational position or rotational speed of the wheels 11a and 11b. The encoder unit 18 includes a first rotary encoder 18a and a second rotary encoder 18b. The first rotary encoder 18a measures the rotation of the power transmission mechanism from the motor 16a to the wheel 11a at any position. The second rotary encoder 18b measures the rotation of the power transmission mechanism from the motor 16b to the wheel 11b at any position. The encoder unit 18 transmits the signals acquired by the rotary encoders 18a and 18b to the microcomputer 14a. The microcomputer 14a can control the movement of the AGV 10 using not only the signal received from the positioning device 14e but also the signal received from the encoder unit 18.

The drive device 17 has motor drive circuits 17a and 17b for adjusting the voltage applied to each of the two motors 16a and 16b. Each of motor drive circuits 17a and 17b includes a so-called inverter circuit. The motor drive circuits 17a and 17b turn on or off the current flowing in each motor according to the PWM signal transmitted from the microcomputer 14a or the microcomputer in the motor drive circuit 17a, thereby adjusting the voltage applied to the motor.

FIG. 6B shows a second hardware configuration example of the AGV 10. The second hardware configuration example is different from the first hardware configuration example (FIG. 6A) in that it has a laser positioning system 14h and that the microcomputer 14a is connected to each component in a one-to-one manner. To do.

The laser positioning system 14h has a positioning device 14e and a laser range finder 15. The positioning device 14e and the laser range finder 15 are connected by, for example, an Ethernet (registered trademark) cable. The operations of the positioning device 14e and the laser range finder 15 are as described above. The laser positioning system 14h outputs information indicating the pose (x, y, θ) of the AGV 10 to the microcomputer 14a.

The microcomputer 14a has various general-purpose I/O interfaces or general-purpose input/output ports (not shown). The microcomputer 14a is directly connected to other components inside the travel control device 14, such as the communication circuit 14d and the laser positioning system 14h, via the general-purpose input/output port.

Except for the configuration described above with respect to FIG. 6B, the configuration is common to that of FIG. Therefore, the description of the common configuration is omitted.

The AGV 10 in the embodiment of the present disclosure may include a safety sensor such as an obstacle detection sensor and a bumper switch, which are not shown. The AGV 10 may include an inertial measurement device such as a gyro sensor. By using the measurement data obtained by the rotary encoders 18a and 18b or an internal sensor such as an inertial measurement device, it is possible to estimate the amount of movement (angle) of the movement distance and posture of the AGV 10. The estimated values of these distances and angles are called odometry data, and can exert a function of assisting the position and orientation information obtained by the positioning device 14e.

(4) Map Data FIGS. 7A to 7F schematically show the AGV 10 moving while acquiring sensor data. The user 1 may manually move the AGV 10 while operating the terminal device 20. Alternatively, the sensor data may be acquired by placing the unit including the traveling control device 14 shown in FIGS. 6A and 6B, or the AGV 10 itself on a dolly, and the user 1 manually pushing or pulling the dolly.

FIG. 7A shows an AGV 10 that scans the surrounding space using a laser range finder 15. A laser beam is emitted at a predetermined step angle and scanning is performed. The illustrated scan range is a schematic example, and is different from the above-described scan range of 270 degrees in total.

In each of FIGS. 7A to 7F, the position of the reflection point of the laser beam is schematically shown using a plurality of black dots 4 represented by the symbol “·”. The scanning of the laser beam is executed in a short cycle while the position and orientation of the laser range finder 15 change. Therefore, the actual number of reflection points is much larger than the number of reflection points 4 shown in the figure. The positioning device 14e stores the position of the black dot 4 obtained along with traveling in, for example, the memory 14b. The map data is gradually completed by continuously scanning while the AGV 10 is traveling. 7B to 7E, only the scan range is shown for simplification. The scan range is an example, and is different from the example of the total of 270 degrees described above.

The map may be created using the microcomputer 14a in the AGV 10 or an external computer based on the sensor data after acquiring the amount of sensor data necessary for creating the map. Alternatively, the map may be created in real time based on the sensor data acquired by the moving AGV 10.

FIG. 7F schematically shows a part of the completed map 40. In the map shown in FIG. 7F, the free space is partitioned by a point cloud (Point Cloud) corresponding to a collection of reflection points of the laser beam. Another example of the map is an occupied grid map that distinguishes the space occupied by an object from the free space in grid units. The positioning device 14e stores map data (map data M) in the memory 14b or the storage device 14c. The number or density of black dots shown in the figure is an example.

The map data thus obtained can be shared by a plurality of AGVs 10.

A typical example of an algorithm in which the AGV 10 estimates the self-position based on map data is ICP (Iterative Closest Point) matching. As described above, by comparing the local map data (sensor data) created from the scan result of the laser range finder 15 with the map data M in a wider range, the self position (x , y, θ) can be estimated.

(5) Configuration Example of Operation Management Device FIG. 8 shows a hardware configuration example of the operation management device 50. The operation management device 50 includes a CPU 51, a memory 52, a position database (position DB) 53, a communication circuit 54, a map database (map DB) 55, and an image processing circuit 56.

The CPU 51, the memory 52, the position DB 53, the communication circuit 54, the map DB 55, and the image processing circuit 56 are connected by the communication bus 57, and can exchange data with each other.

The CPU 51 is a signal processing circuit (computer) that controls the operation of the operation management device 50. The CPU 51 is typically a semiconductor integrated circuit.

The memory 52 is a volatile storage device that stores a computer program executed by the CPU 51. The memory 52 can also be used as a work memory when the CPU 51 performs a calculation.

The position DB 53 stores position data indicating each position that can be a destination of each AGV 10. The position data can be represented by coordinates virtually set in the factory by the administrator, for example. Location data is determined by the administrator.

The communication circuit 54 performs wired communication based on, for example, the Ethernet (registered trademark) standard. The communication circuit 54 is connected to the access point 2 (FIG. 1) by wire and can communicate with the AGV 10 via the access point 2. The communication circuit 54 receives data to be transmitted to the AGV 10 from the CPU 51 via the bus 57. Further, the communication circuit 54 transmits the data (notification) received from the AGV 10 to the CPU 51 and/or the memory 52 via the bus 57.

The map DB 55 stores data of a map inside a factory or the like in which the AGV 10 runs. The map may be the same as the map 40 (FIG. 7F) or may be different. The data format does not matter as long as the map has a one-to-one correspondence with the position of each AGV 10. For example, the map stored in the map DB 55 may be a map created by CAD.

The position DB 53 and the map DB 55 may be constructed on a non-volatile semiconductor memory, or may be constructed on a magnetic recording medium represented by a hard disk or an optical recording medium represented by an optical disc.

The image processing circuit 56 is a circuit for generating video data displayed on the monitor 58. The image processing circuit 56 operates exclusively when an administrator operates the operation management device 50. In the present embodiment, particularly detailed description will be omitted. The monitor 59 may be integrated with the operation management device 50. Further, the CPU 51 may perform the processing of the image processing circuit 56.

(6) Operation of Operation Management Device An outline of the operation of the operation management device 50 will be described with reference to FIG. FIG. 9 is a diagram schematically showing an example of the movement route of the AGV 10 determined by the operation management device 50.

The outline of the operation of the AGV 10 and the operation management device 50 is as follows. In the following, an example in which an AGV 10 is currently at the position M ₁ and passes through several positions to travel to the final destination position M _n+1 (n: a positive integer of 1 or more) explain. In the position DB 53, coordinate data indicating each position such as a position M ₂ to be passed next to the position M _{1 and} a position M ₃ to be passed next to the position M ₂ are recorded.

The CPU 51 of the operation management device 50 reads the coordinate data of the position M ₂ with reference to the position DB 53 and generates a traveling command to move to the position M ₂ . The communication circuit 54 transmits a travel command to the AGV 10 via the access point 2.

The CPU 51 periodically receives data indicating the current position and posture from the AGV 10 via the access point 2. In this way, the operation management device 50 can track the position of each AGV 10. CPU51 determines that the current position of the AGV10 matches the position M _2, reads the coordinate data of the position M _3, and transmits the AGV10 generates a travel command to direct the position M _3. In other words, when the operation management device 50 determines that the AGV 10 has reached a certain position, the operation management device 50 transmits a traveling command to move the vehicle to the next position. As a result, the AGV ₁₀ can reach the final target position M _n+1 . The passing position and the target position of the AGV 10 described above may be referred to as “marker”.

(7) Example of Travel Control Using Odometry Data Next, an example of travel control using the odometry data from the rotary encoders 18a and 18b will be described. In the following description, the AGV 10 has the configuration shown in FIG. FIG. 10 is a block diagram showing a configuration example of the AGV 10. The configuration of FIG. 10 is the same as the configuration of FIG. 6B except that the second positioning device 19 and the display 30 are provided. The second positioning device 19 is connected between the encoder unit 18 and the microcomputer 14a. The display 30 is connected to the microcomputer 14a. In the following description, the positioning device 14e is referred to as a "first positioning device 14e" to distinguish it from the second positioning device 19. In this embodiment, the laser range finder 15 and the encoder unit 18 have functions as the first sensor 101 and the second sensor 102 in FIG. 1, respectively. The microcomputer 14a corresponds to the arithmetic circuit 105 in FIG.

The second positioning device 19 includes a processing circuit such as a processor and a memory. The second positioning device 19 acquires data output from the rotary encoders 18a and 18b, generates data (x, y, θ) indicating the position and orientation of the AGV 10, and outputs the data to the microcomputer 14a. The functions of the second positioning device 19 may be integrated in the microcomputer 14a. In that case, a configuration similar to that shown in FIG. 6A or FIG. 6B is used. The function of the second positioning device 19 may be included in the control circuit of the drive device 17.

FIG. 11 is a diagram schematically showing the flow of signals between the constituent elements in this embodiment. The first positioning device 14e performs a first estimation calculation using the data (first sensor data) output from the LRF 15 to estimate the position and orientation of the AGV 10. The first estimation calculation in this embodiment is a process of collating the first sensor data and the map data to generate data indicating the coordinates (x, y), the angle θ, and the reliability (unit: %). .. The first positioning device 14e sends data indicating the coordinates (x, y), the angle θ, and the reliability to the microcomputer (arithmetic circuit) 14a.

The second positioning device 19 performs a second estimation calculation using the data (second sensor data) output from the two encoders 18a and 18b to estimate the position and orientation of the AGV 10. The second sensor data includes information regarding the rotation state or rotation speed of the motor or the wheel. The moving distance of the wheel per unit time can be estimated from the rotation speed and the diameter of the wheel. The second estimation calculation includes a process of integrating the initial values of the coordinates and angles of the AGV 10 with the amounts of change in the coordinates and angles calculated based on the outputs of the two encoders 18a and 18b, respectively. The initial values of the coordinates and the angles may be updated regularly with the values of the coordinates and the angles calculated by the first positioning device 14e, for example. The second positioning device 19 sends data indicating the coordinates (x, y) and the angle θ to the microcomputer 14a.

In the following description, the coordinates and angles estimated by the first positioning device 14e may be collectively referred to as "LRF coordinates", and the coordinates and angles estimated by the second positioning device 19 may be collectively referred to as "encoder coordinates". is there.

The microcomputer 14a uses the estimation result of the first positioning device 14e and the second positioning device 19 according to whether or not the reliability data indicating the certainty of the estimation result of the first positioning device 14e matches a predetermined condition. One of the estimation results is selected as the coordinate and angle of the AGV 10. The microcomputer 14a notifies the drive device 17 of the selected coordinates and angle. The drive device 17 determines the command value of the rotation speed of each of the motors 16a and 16b from the difference between the current coordinates and angle and the coordinates and angle at the destination. The drive device 17 controls the motors 16a and 16b based on the determined command value.

The “reliability data” in the present embodiment includes reliability data (first reliability data) output from the first positioning device 14e, coordinates and angles estimated by the first positioning device 14e, and the second positioning device. Data (second reliability data) indicating respective differences between the coordinates and the angle estimated by 19. The microcomputer 14a basically controls the drive device 17 to travel using LRF coordinates which are considered to have relatively high reliability. At that time, the encoder coordinates held by the second positioning device 19 are periodically overwritten with the LRF coordinates. Thereby, the coordinates of both are regularly synchronized. However, under the situation where the reliability of the output of the first positioning device 14e is considered to be low, the microcomputer 14a stops the synchronization of the coordinates and continues the traveling of the AGV 10 using the encoder coordinates. In this case, the microcomputer 14a issues a command that causes the first positioning device 14e to execute the initial position identification, and tries to recover the reliability. In other words, when the microcomputer 14a selects the estimation result by the second positioning device 19, the first positioning device 14e uses the first sensor data and the estimation result by the second positioning device to identify the initial position ( The first estimation calculation) is performed.

“Initial position identification” refers to a process of searching where on the map the AGV 10 is located. In the initial position identification, the map data and the LRF 15 data are matched over the entire area or a part of the map (for example, an area of about 1 m×1 m to 50 m×50 m). In the present embodiment, the initial position identification is performed after the power of the AGV 10 is turned on or the map is switched. When the position of the AGV 10 is specified by the initial position identification, “position identification” is performed to search for a narrower range centered on the position (for example, within a range of several tens cm from the position). This position identification can be performed while the AGV 10 is moving, for example, at regular intervals (for example, 100 milliseconds). The position identification has a narrower search range and a shorter execution time than the initial position identification. In the present embodiment, both the “initial position identification” and the “position identification” correspond to the above-mentioned “first estimation calculation”.

During traveling, the microcomputer 14a switches between a traveling mode using LRF coordinates and a traveling mode using encoder coordinates based on the reliability data. The microcomputer 14a switches between these two modes according to the conditions shown in Table 1 below, for example.

Under the conditions of Table 1, not only when the reliability output from the first positioning device 14e is reduced, but also when the difference between the X-axis component or the difference between the Y-axis components of the LRF coordinate and the encoder coordinate is equal to or more than the allowable value. Also, the mode using the LRF coordinates can be switched to the mode using the encoder coordinates. The reason for imposing these two conditions is that a position that is significantly different from the actual position may be estimated as the current position even if the reliability of the first positioning device 14e outputs is high. In the example of Table 1, in order to stabilize the operation, the reliability return threshold is set higher than the switching threshold.

Next, the operation of the AGV 10 will be described with reference to FIG. FIG. 12 is a flowchart showing an example of the operation of the AGV 10. When the power of the AGV 10 is turned on, the microcomputer 14a causes the first positioning device 14e to execute initial position identification (step S101). The first positioning device 14e performs a search over the entire area or a part of the map (for example, a range of about 1 m×1 m to 50 m×50 m) to specify the initial position of the AGV 10. When the initial position of the AGV 10 is specified, the microcomputer 14a causes the first positioning device 14e to perform position identification for a narrower area centered on the position (for example, within a range of several tens of cm from the position) (step). S102). When the position and orientation (x, y, θ) of the AGV 10 are determined by this position identification, the microcomputer 14a determines whether or not the vehicle is traveling in the map switching area (step S103). The map switching area refers to an area of the map in use which overlaps with another adjacent map.

FIG. 13 is a diagram for explaining the map switching area. FIG. 13 shows an example in which one map data covers an area of 50 m×50 m, and four map data M1, M2, M3, and M4 cover the entire area of one floor of one factory. In this example, a rectangular overlapping area having a width of 5 m is provided at the boundary between two adjacent maps. This overlapping area is a map switching area. The size of the map data and the width of the overlapping area are not limited to this example, and may be set arbitrarily.

In the present embodiment, when the microcomputer 14a determines that the AGV 10 is traveling in the map switching area, the microcomputer 14a performs a process of switching the map to be used to another adjacent map (step S121). This map switching process will be described later with reference to FIGS. 17 and 18.

When the microcomputer 14a determines that the AGV 10 is not traveling in the map switching area, it determines whether the condition (A) in Table 1 above is satisfied (step S104). Here, when neither (1) nor (2) of the condition (A) is satisfied, it can be said that the reliability of the LRF coordinate is sufficiently high. In this case, the microcomputer 14a overwrites the encoder coordinates held by the second positioning device 19 with the LRF coordinates. Then, after a lapse of a predetermined time (for example, 100 milliseconds), the process returns to step S102, and the same operation is performed thereafter.

In step S104, if either (1) or (2) of the condition (A) in Table 1 is satisfied, the microcomputer 14a switches from traveling using LRF coordinates to traveling using encoder coordinates (step S111). After that, the microcomputer 14a performs initial position identification every predetermined time (step S112). Based on the LRF coordinates estimated by this initial position identification, the microcomputer 14a determines whether the condition (B) in Table 1 is satisfied (step S113). If the condition (B) is satisfied here, it is determined that the reliability of the LRF coordinate is restored. In this case, the microcomputer 14a returns from traveling using the encoder coordinates to traveling using the encoder coordinates (step S114). After that, the process returns to step S102 and the same operation is performed.

As described above, in the example illustrated in FIG. 12, the microcomputer 14a selects the value of the first reliability data (the first positioning in the present embodiment when the estimation result by the first positioning device 14e is selected as the position of the AGV 10). When the reliability calculated by the device 14e) becomes equal to or lower than the switching threshold, the estimation result by the second positioning device 19 is selected as the position of the AGV 10. Further, the microcomputer 14a determines the value of the second reliability data (difference between the LRF coordinate and the encoder coordinate in the present embodiment) in advance when the estimation result by the first positioning device 14e is selected as the position of the AGV 10. When it becomes equal to or larger than the allowed value, the estimation result by the second positioning device 19 is selected as the position of the AGV 10. When the microcomputer 14a selects the estimation result by the second positioning device 19, the first positioning device 14e uses the first sensor data and the estimation result (coordinates and angles) by the second positioning device 19 to initialize the initial position. Position identification (first estimation calculation) is performed. On the other hand, the microcomputer 14a, when the estimation result by the second positioning device 19 is selected as the position of the AGV 10, the value of the first reliability data becomes equal to or greater than the predetermined return threshold, and the second reliability When the value of the data becomes less than the predetermined allowable value, the estimation result by the first positioning device 14e is selected as the position of the AGV 10.

By such an operation, the mode can be switched according to the reliability of the LRF coordinate, and stable traveling can be realized.

In addition to the operation of FIG. 12, the microcomputer 14a may control the speed of the AGV 10 according to the reliability of the LRF coordinate. For example, when the estimation result by the second positioning device 19 is selected, the microcomputer 14a moves the AGV 10 at a slower speed than when the estimation result by the first positioning device 14e is selected. You may instruct 17. Further, when the value of the first reliability data (reliability) output by the first positioning device 14e after performing the first estimation calculation (initial position identification) becomes equal to or greater than a predetermined return threshold, the driving device 17 In addition, the speed of the AGV 10 may be further reduced, and the first positioning device 14e may be caused to execute the first estimation calculation again. When the value of the first reliability data output by the first positioning device 14e again after the first estimation calculation is performed maintains the return threshold value or more, the driving device 17 may increase the speed of the AGV 10. .. On the other hand, when the value of the first reliability data re-outputted by the first positioning device 14e after performing the first estimation calculation does not maintain the return threshold value or more, the driving device 17 is caused to increase the speed of the AGV 10, After the lapse of a predetermined time, the first positioning device 14e may be made to execute the first estimation calculation again. When "not exceeding the return threshold" is maintained, the state where the value of the first reliability data does not reach the return threshold continues even if the first estimation calculation (initial position identification in this embodiment) is performed a plurality of times. Including the case.

Hereinafter, a more specific example of the operation will be described with reference to FIGS. 14 to 16.

FIG. 14 is a diagram schematically showing an example of the operation of the AGV 10. FIG. 15 is a diagram showing a time change of the speed of the AGV 10 in this example. FIG. 16 is a flowchart showing a traveling operation using the encoder coordinates in this example.

In this example, when it is determined that the reliability of the LRF coordinate is high, the AGV 10 travels while performing position identification at the first speed (for example, 50 m/min) using the LRF coordinate. In this state, when the reliability of the LRF coordinate is lowered or the difference between the LRF coordinate and the encoder coordinate is suddenly increased to satisfy the switching condition (A), the microcomputer 14a uses the encoder coordinate. Switch to running. At this time, the microcomputer 14a reduces the speed of the AGV 10 to a second speed lower than the first speed (for example, 20 m/min) (step S201). This is because when traveling using the encoder coordinates at high speed, there is a high possibility that collision or overrun will occur. However, if the second speed is set too low, it may take a long time to get out of the section where the reliability of the LRF coordinate becomes low. Therefore, the second speed is set to an appropriate value that is neither too low nor too high.

While the AGV 10 is traveling at the second speed, the microcomputer 14a instructs the first positioning device 14e to repeat the initial position identification until the reliability of the LRF coordinate is restored. Receiving this instruction, the first positioning device 14e repeats the initial position identification until the reliability is restored to the return threshold or higher (steps S202-S204). In this example, the upper limit number of repetitions (for example, 20 times) is set. When the reliability does not recover to the return threshold even after repeating the initial position identification for the set upper limit number of times, the microcomputer 14a stops the AGV 10 and transmits an error signal to the operation management device 50 or the terminal device 20 (step S205). ..

When the reliability of the LRF coordinate is restored to the return threshold value or more by the initial position identification in step S202, the microcomputer 14a reduces the speed of the AGV 10 to a third speed lower than the second speed (for example, 7.5 m/min). (Step S211). Then, the first positioning device 14e is made to execute the initial position identification again (step S212). In this initial position identification as well, if the reliability is equal to or higher than the return threshold value (Yes in step S213), the microcomputer 14a determines that the difference between the X-axis component and the difference between the Y-axis components of the LRF coordinate and the encoder coordinate is an allowable value (eg: It is determined whether the distance is less than 30 cm) (step S221). When the determination in step S213 or S221 is No, the microcomputer 14a repeats the initial position identification (step S211) until these determinations become Yes. In the present embodiment, the upper limit number of repetitions is set to 5 times. If the condition of step S221 is not satisfied even after repeating five times, the microcomputer 14a accelerates the speed of the AGV 10 to the fourth speed (for example, 20 m/min) (step S215). In this example, the fourth speed is the same as the second speed, but it may be different. Then, it returns to step S201 again. By accelerating to the fourth speed, there is a high possibility that the section with low reliability can be exited early. Note that instead of step S215, the process may transition to step S205, the AGV 10 may be stopped, and an error signal may be transmitted to the operation management device 50 or the terminal device 20.

When the determination in step S221 is Yes, the microcomputer 14a causes the first positioning device 14e to execute the position identification process (step S230). In the position identification processing, the first positioning device 14e performs matching with LRF data for a relatively narrow area around the position determined by the initial position identification (for example, within a range of several tens cm from the position). , AGV 10 coordinates and angles are determined. As a result of this position identification, when the above-mentioned “encoder→LRF” switching condition is satisfied, the microcomputer 14a overwrites the encoder coordinate with the LRF coordinate (step S231) and switches to the traveling using the LRF coordinate ( Step S232). Then, the speed is increased to the first speed (for example, 50 m/min) (step S233). After that, it returns to the normal operation.

In this embodiment, after the initial position identification by the second speed (20 m/min) is successful, the speed is reduced to the third speed (7.5 m/min). The reason for this is that the search range for position identification after the initial position identification is narrow. When the search range for position identification is within a range of several tens of centimeters from the starting coordinates, if the AGV 10 travels at 20 m/min, the search range may be exceeded within a few seconds. If it takes, for example, a few seconds for the microcomputer 14a to instruct the first positioning device 14e to perform the initial position identification and then to perform the position identification, there is a possibility that the position cannot be identified at 20 m/min. Therefore, in this embodiment, the third speed is reduced to 7.5 m/min.

Next, an example of the map switching process (step S121 in FIG. 12) will be described with reference to FIGS. 17 and 18. FIG. 17 is a diagram schematically showing a normal map switching process in which the LRF coordinate is highly reliable. FIG. 18 is a diagram schematically showing a map switching process when the reliability of the LRF coordinate becomes low during traveling in the map switching area. In this example, one map covers an area of 50m x 50m, and two adjacent maps have an overlapping area with a width of 5m. The center of each map is the origin of coordinates, and the area 20 to 25 m away from the origin in each of the horizontal direction (X direction) and the vertical direction (Y direction) is a map switching area. The AGV 10 enters the map switching area at the first speed (50 m/min in this example) in the X direction.

As shown in FIG. 17, when the AGV 10 exceeds the point of X=22.5 m, the microcomputer 14a reduces the speed of the AGV 10 to the third speed (7.5 m/min). After that, when the point of X=23.75 m is exceeded, the microcomputer 14a switches the coordinate to be used from the LRF coordinate to the encoder coordinate, and instructs the first positioning device 14e to perform the initial position identification using the switched map. If the reliability of the LRF coordinates obtained by this initial position identification is sufficiently high and the difference from the encoder coordinates is sufficiently low, the microcomputer 14a continuously instructs the first positioning device 14e to perform position identification. If the reliability of the LRF coordinate obtained by this position identification is also sufficiently high and the difference from the encoder coordinate is sufficiently low, the microcomputer 14a updates the value of the encoder coordinate with the value of the LRF coordinate, and the moving speed of the AGV 10 is changed. Is returned to the first speed of 50 m/min, and the mode is switched to travel using LRF coordinates.

In the present embodiment, the first positioning device 14e performs the initial position identification after map switching using encoder coordinates instead of LRF coordinates. As a result, the success rate of initial position identification after map switching can be increased.

On the other hand, when the reliability of the LRF coordinate is low during the map switching process, the microcomputer 14a continues traveling using the encoder coordinate until the reliability is restored, as shown in FIG. When the AGV 10 exceeds the point of X=23.75 m, the map to be used is switched, and the first positioning device 14e repeats the initial position identification and tries to restore the reliability of the LRF coordinates. When the reliability is restored, the microcomputer 14a overwrites the encoder coordinate with the LRF coordinate, increases the speed of the AGV 10 from the third speed to the first speed, and switches to traveling using the LRF coordinate.

As described above, according to the present embodiment, when the reliability of the LRF coordinate is lowered, the mode is switched to the drive using the encoder coordinate, and after the reliability is restored, the drive is returned to the drive using the LRF coordinate. Furthermore, by controlling the speed as well, more stable running becomes possible.

The microcomputer 14a may be configured to output a signal indicating which of the estimation result by the first positioning device 14e and the estimation result by the second positioning device 19 is selected when the AGV 10 is moved. .. For example, the signal may be output to the display 30 shown in FIG. In response to the signal, the display 30 can display information indicating which of the first positioning device 14e and the second positioning device 19 is selected. The microcomputer 14a may transmit the signal to a device external to the AGV 10. The external device may be, for example, the operation management device 50 or the terminal device 20. The external device may be a device such as a light source mounted on the AGV 10 or a speaker. Upon receiving the signal, the external device can present which of the positioning methods of the first positioning device 14e and the second positioning device 19 is selected, as light, sound, or character information. This allows the user to know which positioning method the AGV 10 is currently operating at.

(Modification)
Next, a modified example of this embodiment will be described.

The switching conditions in Table 1 above are examples, and other conditions may be applied. For example, the microcomputer 14a may select the estimation result by the second positioning device 19 as the position of the AGV 10 if any of the following (1) and (2) is satisfied regardless of the conditions in Table 1. Good.
(1) Difference between the moving distance of the AGV 10 within a certain time estimated based on the estimation result by the first positioning device 14e and the moving distance of the AGV 10 within the certain time estimated based on the estimation result by the second positioning device 19 Or, when the ratio is larger than the first threshold value (2) Estimated based on the angle change amount of the AGV 10 within a fixed time estimated based on the estimation result by the first positioning device 14e and the estimation result by the second positioning device 19 When the difference or ratio with the amount of change in angle of the AGV 10 within the fixed time is larger than the second threshold value.

It can be said that the above determination is a determination as to whether the movement of the LRF coordinate output by the first positioning device 14e and the movement of the encoder coordinate are similar. This determination will be referred to as “LRF coordinate reliability determination”. By making this determination, it is possible to prevent the situation in which the position estimation is inaccurate even when the reliability of the first positioning device 14e outputs is relatively high. On the other hand, even if the difference between the coordinates of both is large (for example, 30 cm or more), if both of the above (1) and (2) are satisfied, it is determined that the coordinates of the first positioning device 14e are correct. The encoder coordinates may be overwritten with the coordinates of the first positioning device 14e.

More specifically, when all of the following three conditions are satisfied, it may be determined that the coordinates of the first positioning device 14e are correct.
A difference of 20% between the movement distance calculated based on the coordinates output by the first positioning device 14e and the movement distance calculated based on the coordinates output by the second positioning device 19 in a unit time (for example, 1 second). Being below.
Between the amount of change in angle calculated based on the coordinates output by the first positioning device 14e and the amount of change in angle calculated based on the coordinates output by the second positioning device 19 per unit time (for example, 1 second) The difference is 10% or less.
The absolute value of the difference between the current angle output by the first positioning device 14e and the current angle output by the second positioning device 19 is 45 degrees or less.

The specific calculation formula is as follows, for example.
The coordinates and angles output by the first positioning device 14e one second before are (Xr1, Yr1, θr1),
-The current coordinates and angle output by the first positioning device 14e are (Xr2, Yr2, θr2),
The coordinates and angles output by the second positioning device 19 one second before are (Xe1, Ye1, θe1),
・The current coordinates and angle output by the second positioning device 19 are (Xe2, Ye2, θe2),
And FIG. 19 shows an example of these coordinates and angles. During normal traveling, it is determined that the LRF coordinate is correct (pass) if all of the following three inequalities (1) to (3) are satisfied.
0.64 ≤ ((Xr2-Xr1) ² +(Yr2-Yr1) ² ) /( (Xe2-Xe1) ² +(Ye2-Ye1) ² ) ≤ 1.44 (1)
|(θe2-θe1)-(θr2-θr1) | ≤ 10° (2)
|θe2 -θr2|≦ 45° (3)
However, if the distance calculated from the encoder coordinates ((Xe2-Xe1) ² +(Ye2-Ye1) ² ) is so small that it can be considered that the vehicle is stopped, it is inappropriate to judge based on the distance ratio. In that case, the distance ((Xr2-Xr1) ² +(Yr2-Yr1) ² ) calculated from the coordinates output by the first positioning device 14e falls within the normal range of the coordinate values of the first positioning device 14e. You may judge by whether it is included. For example, if the square value of the normal shaking of the coordinate values of the first positioning device 14e is 500 (mm), the following equation (4) may be used instead of the above equation (1).
((Xr2-Xr1) ² +(Yr2-Yr1) ² ) ≤ 500 (mm) (4)

Even when the microcomputer 14a does not satisfy the return conditions in Tables 1(B) and (2) above when traveling by the encoder coordinates, the microcomputer 14a uses the LRF coordinates to determine the encoder coordinates when the following conditions are all satisfied. May be overwritten and the vehicle may be returned to the traveling by the LRF coordinate.
-The reliability judgment of the above-mentioned LRF coordinate is passed.-The reliability of the current LRF coordinate is the return threshold (for example, 40%) or more. (For example, 40%) or more-The difference between the X component and the Y component between the LRF coordinate and the encoder coordinate is less than a threshold value (for example, 2 m).

According to this condition, even if one of the differences between the X component and the Y component between the LRF coordinate and the encoder coordinate is equal to or more than the allowable value (for example, 30 cm), the LRF is determined to be acceptable if the above reliability determination is successful. Return to traveling by coordinates. For this reason, it tends to return to traveling using the LRF coordinates more easily than when the conditions in Table 1 above are applied.

(8) Other Embodiments In the above description, the embodiment is mainly described in which the moving body is a guideless AGV, the first sensor is a laser range finder, and the second sensor includes two rotary encoders. Illustrated. However, the present disclosure is not limited to such an embodiment.

For example, the moving body may be a “guide type” moving body that moves along a magnetic tape provided on the road surface or a guide such as a white line. In that case, the first sensor or the second sensor may be a magnetic sensor that reads a magnetic tape or a camera that reads a white line by image recognition. The positioning device can generate various information as reliability data such as the degree of damage to the magnetic tape, the degree of dirt on the white line, the degree of matching in matching during image processing.

An acceleration sensor or an angular acceleration sensor may be used as the first sensor or the second sensor. The positioning device can generate various information such as the distribution of data output from these sensors or the ratio of data that changes sharply as reliability data.

In the above description of the embodiment, the AGV traveling in the two-dimensional space (floor surface) is taken as an example. However, the present disclosure can be applied to a moving body that moves in a three-dimensional space, for example, a flying body (drone). When making a three-dimensional space map while the drone is flying, the two-dimensional space can be extended to the three-dimensional space.

All the processing executed by the arithmetic circuit or the microcomputer in each of the above embodiments can be realized by a computer program (software) or a dedicated circuit (hardware).

INDUSTRIAL APPLICABILITY The moving body and the moving body management system of the present disclosure can be suitably used for moving and transporting goods such as luggage, parts and finished products in factories, warehouses, construction sites, physical distribution, hospitals and the like.

1 user, 2a, 2b access point, 10 AGV (moving body), 11a, 11b drive wheel (wheel), 11c, 11d, 11e, 11f caster, 14 traveling control device, 14a microcomputer (arithmetic circuit), 14b memory, 14c Storage device, 14d communication circuit, 14e positioning device, 16a, 16b motor, 15 laser range finder, 17 drive device, 17a, 17b motor drive circuit, 18 encoder unit, 18a, 18b rotary encoder, 20 terminal device (tablet computer, etc.) Mobile computer), 21 CPU, 22 memory, 23 communication circuit, 24 image processing circuit, 25 display, 26 touch screen sensor, 30 display, 50 operation management device, 51 CPU, 52 memory, 53 position database (position DB), 54 Communication circuit, 55 map database (map DB), 56 image processing circuit, 100 mobile management system, 101 first sensor, 102 second sensor, 103 first positioning device, 104 second positioning device, 105 arithmetic circuit, 106 motor , 107 Drive

Claims (24)

Is a mobile,
At least one motor,
A drive device that controls the at least one motor to move the moving body;
A first sensor that outputs first sensor data indicating a sensing result obtained according to the movement of the moving body by a first sensing method;
A second sensor that outputs second sensor data indicating a sensing result obtained according to the movement of the moving body by a second sensing method different from the first sensing method;
A first positioning device that estimates the position of the moving body by performing a first estimation calculation using the first sensor data;
A second positioning device that estimates a position of the moving body by performing a second estimation calculation different from the first estimation calculation using the second sensor data;
One of the estimation result by the first positioning device and the estimation result by the second positioning device depending on whether or not the reliability data indicating the certainty of the estimation result by the first positioning device matches a predetermined condition. And a computing circuit for selecting as the position of the moving body. The moving body according to claim 1, wherein the first sensor is a laser range finder, and the second sensor is at least one rotary encoder. Further comprising a storage device for storing map data created in advance based on sensor data periodically output from the laser range finder or another laser range finder,
The mobile body according to claim 2, wherein the first positioning device estimates the position of the mobile body by matching the first sensor data with the map data. Further comprising a first wheel and a second wheel,
The at least one motor includes a first motor and a second motor,
The first motor and the first wheel are mechanically connected,
The second motor and the second wheel are mechanically connected,
The at least one rotary encoder includes a first rotary encoder that measures rotation at any position of a power transmission mechanism from the first motor to the first wheel, and a second motor to the second wheel. The moving body according to claim 3, further comprising a second rotary encoder that measures rotation of the power transmission mechanism at any position. The moving body according to claim 4, wherein the first rotary encoder and the second rotary encoder measure rotations of the first wheel and the second wheel, respectively. The second positioning device measures a relative displacement amount from a given initial position by using the second sensor data output from each of the first rotary encoder and the second rotary encoder, The moving body according to claim 4 or 5, wherein the position moved by the displacement amount from the position is estimated as the position of the moving body. The mobile body according to claim 6, wherein the arithmetic circuit updates the initial position with a position estimated by the first positioning device. The moving body according to claim 6, wherein the arithmetic circuit updates the initial position at a predetermined cycle. The mobile body according to claim 3, wherein the first positioning device outputs data indicating a degree of coincidence between the first sensor data and the map data as first reliability data. When the value of the first reliability data becomes equal to or lower than the switching threshold value while the estimation result by the first positioning device is selected as the position of the moving body, the arithmetic circuit outputs the estimation result by the second positioning device. The moving body according to claim 9, which is selected as the position of the moving body. The arithmetic circuit outputs, as second reliability data, a difference between a position obtained as an estimation result by the first positioning device and a position obtained as an estimation result by the second positioning device. The mobile object described in. When the calculation circuit is selecting the estimation result by the first positioning device as the position of the moving body, and the value of the second reliability data becomes equal to or greater than a predetermined allowable value, the second positioning device. The moving body according to claim 11, wherein the estimation result according to is selected as the position of the moving body. The arithmetic circuit, when the estimation result by the second positioning device is selected as the position of the moving body, the value of the first reliability data becomes equal to or greater than a predetermined return threshold, and The mobile body according to claim 11 or 12, wherein when the value of the 2 reliability data becomes less than the predetermined allowable value, the estimation result by the first positioning device is selected as the position of the mobile body. When the arithmetic circuit selects the estimation result by the second positioning device, the drive unit moves at a slower speed than when the arithmetic circuit selects the estimation result by the first positioning device. The moving body according to any one of claims 9 to 13, which moves the body. When the arithmetic circuit selects the estimation result by the second positioning device, the first positioning device uses the first sensor data and the estimation result by the second positioning device to perform the first estimation. The mobile object according to claim 14, which performs a calculation. When the value of the first reliability data output by the first positioning device by performing the first estimation calculation is equal to or greater than a predetermined return threshold,
The drive device further reduces the speed of the moving body,
The mobile body according to claim 15, wherein the first positioning device performs the first estimation calculation again. When the value of the first reliability data output by the first positioning device again by performing the first estimation calculation again is equal to or more than the return threshold,
The moving body according to claim 16, wherein the driving device increases a speed of the moving body. When the value of the first reliability data output by the first positioning device again by performing the first estimation calculation again does not maintain the return threshold value or more,
The driving device increases the speed of the moving body,
The mobile body according to claim 16 or 17, wherein the first positioning device performs the first estimation calculation again after a predetermined time has elapsed. The arithmetic circuit is
A moving distance of the moving body within a fixed time estimated based on an estimation result by the first positioning apparatus, and a moving distance of the moving body within the fixed time estimated based on an estimation result by the second positioning apparatus Is greater than a first threshold, or
Angle change amount of the moving body within the certain time period estimated based on the estimation result by the first positioning device, and angle of the moving body within the certain time period estimated based on the estimation result by the second positioning device When the difference from the change amount is larger than the second threshold value,
The moving body according to any one of claims 1 to 18, wherein the estimation result by the second positioning device is selected as the position of the moving body. 20. The arithmetic circuit receives an instruction of a destination from the outside, controls the drive device by utilizing the selected position of the moving body, and moves the moving body toward the destination. The mobile object described in. The arithmetic circuit outputs a signal indicating which of the estimation result by the first positioning device and the estimation result by the second positioning device is selected when the moving body is moved. The mobile body according to any one of 20. Further equipped with a display,
The arithmetic circuit outputs the signal to the display,
The display receives the signal and displays information indicating which one of the first positioning device and the second positioning device is selected.
The moving body according to claim 21. The arithmetic circuit transmits the signal to a device external to the moving body,
The external device receives the signal and presents which of the first positioning device and the second positioning device is selected as light, sound, or character information.
The moving body according to claim 21. A computer program executed by an arithmetic circuit in a mobile, comprising:
The moving body is
At least one motor,
A drive device that controls the at least one motor to move the moving body;
A first sensor that outputs first sensor data indicating a sensing result obtained according to the movement of the moving body by a first sensing method;
A second sensor that outputs second sensor data indicating a sensing result obtained according to the movement of the moving body by a second sensing method different from the first sensing method;
A first positioning device that estimates the position of the moving body by performing a first estimation calculation using the first sensor data;
A second positioning device that estimates a position of the moving body by performing a second estimation calculation different from the first estimation calculation using the second sensor data;
The arithmetic circuit;
Equipped with
The computer program, the arithmetic circuit,
One of the estimation result by the first positioning device and the estimation result by the second positioning device depending on whether or not the reliability data indicating the certainty of the estimation result by the first positioning device matches a predetermined condition. Is selected as the position of the moving body,
Computer program.

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