WO2019124343A1

WO2019124343A1 - Moving body

Info

Publication number: WO2019124343A1
Application number: PCT/JP2018/046500
Authority: WO
Inventors: 洋人坂原
Original assignee: 株式会社ダイヘン
Priority date: 2017-12-19
Filing date: 2018-12-18
Publication date: 2019-06-27
Also published as: JP2019109773A

Abstract

[Problem] To solve the problem that when a moving body passes through a narrow path, movement is limited due to the fact that a wall is detected as an obstacle. [Solution] A moving object 1 is provided with a distance measuring sensor 12 for measuring the distance to an object around; an obstacle detection unit 13 for detecting an obstacle using the measurement result; a movement mechanism 11; a movement control unit 17 for controlling movement so as to avoid collision against the detected obstacle; a map storage unit 15 in which a map indicating the obstacle is stored; a present position acquisition unit 14; and a determination unit 16 for determining, using the present position, whether the detected obstacle is a known obstacle in the map. Meanwhile, the movement control unit 17 exercises different control pertaining to the obstacle in accordance with the result of determination. Thus, it is possible to differentiate control with regard to a known obstacle and an unknown obstacle and reduce limitations on movement due to the fact that a known wall is detected as an obstacle, as well as prevent collision against the known obstacle.

Description

Moving body

The present invention relates to a mobile that performs obstacle detection.

In a conventional moving body, a distance measuring sensor is used to measure the distance to a surrounding object, and an obstacle is detected using the measurement result (see, for example, Patent Document 1). When an obstacle is detected in such a manner, the mobile body decelerates or stops, for example, to prevent a collision with the obstacle. As such, by performing movement control in accordance with obstacle detection in the moving body, safer movement can be realized.

JP 2017-97535 A

However, when the moving object enters a narrow passage or passes through a narrow T-junction, the moving object may become inoperable by detecting the wall as an obstacle. On the other hand, with regard to obstacles such as human beings present in the mobile environment, there is a demand for avoiding collision properly.

The present invention has been made to solve the above-described problems, and when a moving object passes through a narrow passage or the like, movement can not be restricted by obstacle detection, and a person or the like is detected as an obstacle. It is an object of the present invention to provide a mobile body whose safety can be improved by appropriately avoiding a collision.

In order to achieve the above object, a mobile according to the present invention is a mobile that moves autonomously, and uses a distance measurement sensor that measures the distance to surrounding objects in a plurality of directions, and measurement results by the distance measurement sensor Obstacle detection unit that detects an obstacle, a movement mechanism that moves a moving object, a movement control unit that controls the movement mechanism to prevent a collision with the obstacle detected by the obstacle detection unit, and world coordinates A map storage unit in which a map indicating the position of an obstacle in the system is stored, a current position acquisition unit for acquiring a current position of a moving object, and an obstacle detected by an obstacle detection unit using the current position, The movement control unit performs different control on an obstacle according to the judgment result of the judgment unit.
With such a configuration, control of movement can be made different for known obstacles shown by the map and unknown obstacles. Therefore, for example, when an unknown obstacle is detected, the vehicle stops or decelerates even if the obstacle is far, and when a known obstacle is detected, the obstacle is close. It is also possible to control so as not to stop or decelerate until it is reached. As a result, for example, it is possible to reduce the restriction of movement due to the wall being detected as an obstacle when the moving object passes through a narrow passage, etc. You will be able to slow down.

Further, in the moving object according to the present invention, the movement control unit performs control for preventing a collision when the distance to the detected obstacle is shorter than the distance threshold, and the detected known obstacle The distance threshold for may be shorter than the distance threshold for a detected unknown obstacle.
With such a configuration, for known obstacles, the range for performing control to prevent a collision is narrowed, for example, by detecting a wall as an obstacle when the moving object passes through a narrow passage or the like. It is possible to reduce the possibility of the movement of the mobile being limited.

Further, in the mobile object according to the present invention, the movement control unit may avoid the obstacle by the potential method when the detected obstacle is known.
With such a configuration, for known obstacles, using the potential method, it is possible to realize movement that bypasses obstacles, so that movement is not inhibited by known obstacles such as walls. it can.

In the mobile unit according to the present invention, the obstacle detection unit detects an obstacle in the local coordinate system of the mobile unit, and the determination unit performs local coordinate of the position of the obstacle in the world coordinate system indicated by the map. It may be transformed to the position of the system and the determination may be made in the local coordinate system.
Such a configuration makes it possible to determine whether the detected obstacle is known in the local coordinate system in which the detection result of the obstacle is included.

Further, in the mobile unit according to the present invention, the obstacle detection unit is configured to detect an obstacle in the local coordinate system of the mobile unit, and the determination unit is configured to detect the obstacle in the local coordinate system detected by the obstacle detection unit. The position may be converted to a position in the world coordinate system, and the determination may be made in the world coordinate system.
Such a configuration makes it possible to determine whether the detected obstacle is known in the same coordinate system as the map.

Further, in the moving object according to the present invention, the determination unit determines that the obstacle is known when the obstacle detected by the obstacle detection unit and the obstacle shown by the map are closer than the error threshold. You may
With such a configuration, even if an error is included in the acquisition of the current position, it is possible to determine whether the obstacle is known or not, in consideration of the error.

According to the mobile according to the present invention, the control of movement can be made different for known and unknown obstacles indicated by the map, for example, when the mobile passes through a narrow passage etc. While being able to reduce the restriction of movement by detecting a known obstacle such as a wall, it becomes possible to appropriately stop and decelerate an unknown obstacle such as a human.

Block diagram showing the configuration of a mobile according to an embodiment of the present invention Flow chart showing operation of mobile according to the same embodiment A diagram showing an example of a map in the embodiment The figure which shows an example of the detection result of the obstacle in the embodiment. The figure which shows an example of the local coordinate system which shows the detected obstacle and the obstacle on a map in the same embodiment. The figure which shows an example of the local coordinate system which shows the detected obstacle and the obstacle on a map in the same embodiment. The figure which shows an example of the detection result of the obstacle in the embodiment. The figure which shows an example of the local coordinate system which shows the detected obstacle and the obstacle on a map in the same embodiment. The figure which shows an example of the world coordinate system which shows the detected obstacle and the obstacle on a map in the embodiment. Diagram for explaining movement control in the embodiment Diagram for explaining movement of mobile in the same embodiment

Hereinafter, the mobile unit according to the present invention will be described using the embodiment. In the following embodiments, components and steps denoted by the same reference numerals are the same or correspond to each other, and the description thereof may not be repeated. The moving body according to the present embodiment is controlled with respect to movement performed when an obstacle is detected with respect to a known obstacle shown by a map and an unknown obstacle such as a human present in the moving environment of the moving body. It is different.

FIG. 1 is a block diagram showing the configuration of a mobile unit 1 according to the present embodiment. The mobile unit 1 according to the present embodiment moves autonomously, and includes the moving mechanism 11, the distance measurement sensor 12, the obstacle detection unit 13, the current position acquisition unit 14, and the map storage unit 15. A determination unit 16 and a movement control unit 17 are provided. Note that moving the mobile unit 1 autonomously may be moving to a destination based on its own judgment instead of moving according to an operation instruction that the mobile unit 1 receives from a user or the like. The destination may be, for example, manually determined or automatically determined. Also, the movement to the destination may or may not be performed, for example, along the movement path. Further, to move to the destination based on its own judgment may be, for example, moving to the destination by the moving body 1 determining itself by the traveling direction, movement, stop, and the like. Also, for example, the mobile unit 1 may move so as not to collide with an obstacle. The moving body 1 may be, for example, a carriage or a moving robot. The robot may be, for example, an entertainment robot, a monitoring robot, a transfer robot, a cleaning robot, or a robot for capturing a moving image or a still image. , May be other robots.

The moving mechanism 11 moves the moving body 1. For example, the moving mechanism 11 may or may not be capable of moving the moving body 1 in all directions. To be able to move in all directions means to be able to move in any direction. The moving mechanism 11 may have, for example, a traveling unit (for example, a wheel or the like) and a driving unit (for example, a motor or an engine) for driving the traveling unit. When the moving mechanism 11 can move the moving body 1 in all directions, the traveling part may be an all-direction moving wheel (for example, an omni wheel, a mecanum wheel, or the like). For a movable body having an omnidirectionally moving wheel and movable in all directions, see, for example, JP-A-2017-128187. A known mechanism can be used as the moving mechanism 11, and thus the detailed description thereof is omitted.

The ranging sensor 12 measures the distances to surrounding objects in a plurality of directions. The distance measurement sensor 12 may be, for example, a laser sensor, an ultrasonic sensor, a distance sensor using a microwave, a distance sensor using a stereo image captured by a stereo camera, or the like. The laser sensor may be a laser range sensor (laser range scanner). Note that these distance measuring sensors are already known, and the description thereof will be omitted. In the present embodiment, the case where the distance measuring sensor 12 is a laser range sensor will be mainly described. In addition, the moving body 1 may have one laser range sensor, or may have two or more laser range sensors. In the latter case, all directions may be covered by two or more laser range sensors. Further, when the distance measuring sensor 12 is an ultrasonic sensor, a distance sensor using microwaves, etc., the distances in multiple directions may be measured by rotating the distance measuring direction of the distance measuring sensor 12. A plurality of distance measurement sensors 12 arranged for each direction may be used to measure the distance in a plurality of directions. The distance measuring sensor 12 may measure the distance in the direction of the predetermined range, or may measure the distance in all directions. For example, the distance measuring sensor 12 may measure distances in a plurality of directions with respect to the range only in front of the moving body 1. Further, for example, the distance measurement sensor 12 may measure distances in a plurality of directions at predetermined angular intervals for the entire circumference (360 degrees). The angular interval may be constant, such as, for example, an interval of 1 degree, an interval of 2 degrees, or an interval of 5 degrees. The information obtained from the distance measurement sensor 12 may be, for example, distances to surrounding objects with respect to each of a plurality of azimuth angles based on a certain direction of the mobile body 1. By using the distance, it becomes possible to know what kind of object exists around the moving body 1 in the local coordinate system of the moving body 1.

The obstacle detection unit 13 detects an obstacle using the distance measured by the distance measurement sensor 12. For example, when it is found that an object is present in a predetermined area near the moving body 1 by the distance measured by the distance measurement sensor 12, the obstacle detection unit 13 detects the object as an obstacle. It is also good. For example, when the distance to the surrounding object measured by the distance measurement sensor 12 becomes equal to or less than a predetermined threshold, the obstacle detection unit 13 may detect the object as an obstacle. The distance to the surrounding object may be, for example, the distance from the distance measurement sensor 12 or the distance from the outer edge of the moving body 1, and the outer edge of the moving body 1 is virtually expanded It may be a distance from a position or a distance from another reference. In addition, the number of areas where an obstacle is detected may be one, or two or more. The area may include, for example, all directions of the mobile unit 1 or may include only the traveling direction of the mobile unit 1. In order to detect an obstacle using the distance measurement result, the obstacle detection unit 13 detects an obstacle in the local coordinate system of the moving object 1. The local coordinate system of the mobile unit 1 is a coordinate system set in the mobile unit 1. When the obstacle detection unit 13 detects an obstacle, it is preferable that the obstacle detection unit 13 acquires a position (e.g., a coordinate value or the like) in the local coordinate system regarding the detected obstacle. The position may, for example, be indicated by one or more points or by a line. The point may be, for example, a measurement point by the distance measurement sensor 12.

The current position acquisition unit 14 acquires the current position of the mobile unit 1. The acquisition of the current position may be performed, for example, using wireless communication, may be performed using a measurement result of the distance to the surrounding object, or may be performed by capturing an image of the surrounding , And other means capable of obtaining the current position may be used. As a method of acquiring the current position using wireless communication, for example, a method using GPS (Global Positioning System), a method using indoor GPS, a method using a nearest wireless base station, and the like are known. Also, for example, as a method of acquiring the current position by using the measurement result of the distance to the surrounding object or photographing the surrounding image, for example, known by SLAM (Simultaneous Localization and Mapping) or the like. Any method may be used. As a measurement result of the distance to the surrounding object, for example, the measurement result of the distance measurement sensor 12 may be used. In addition, when a map (for example, a measurement result of the distance to a surrounding object, a map having a photographed image, etc.) created in advance is stored, the current position acquisition unit 14 uses the map to The current position may be obtained by specifying the position corresponding to the measurement result of the distance to the object, and the surrounding image is taken and the map is used to specify the position corresponding to the photographing result. The position may be acquired. Also, the current position acquisition unit 14 may acquire the current position using, for example, an autonomous navigation device. Further, it is preferable that the current position acquisition unit 14 acquire the current position including the direction (direction) of the mobile body 1. The direction may be indicated by an azimuth angle measured clockwise, for example, with 0 degrees to the north, and may be indicated by information indicating other directions. The orientation may be obtained by an electronic compass or a geomagnetic sensor. It is assumed that the position of the mobile object 1 on the map stored in the map storage unit 15 can be specified by the current position acquired by the current position acquisition unit 14. As described later, since the map of the world coordinate system (global coordinate system) is stored in the map storage unit 15, the current position acquired by the current position acquiring unit 14 may also be a position in the world coordinate system. . Further, when the current position acquired by the current position acquisition unit 14 is not a position in the world coordinate system, it is preferable that the current position can be converted to a position in the world coordinate system.

The map storage unit 15 stores a map indicating the position of the obstacle in the world coordinate system. The obstacle may indicate, for example, a wall or a column in a mobile environment, or a machine or device installed on a floor surface. For example, when the mobile unit 1 moves in the factory, the map may be a map showing obstacles in the factory. For example, the map may be as shown in FIG. In FIG. 3, obstacles B1 to B4 are shown. Those obstacles may be, for example, a surrounding wall in the moving space of the moving body 1, a facility installed, or the like. The process of storing the map in the map storage unit 15 does not matter. For example, a map may be stored in the map storage unit 15 via a recording medium, or a map transmitted via a communication line or the like may be stored in the map storage unit 15. The storage in the map storage unit 15 may be temporary storage in a RAM or the like, or may be long-term storage. The map storage unit 15 can be realized by a predetermined recording medium (for example, a semiconductor memory, a magnetic disk, an optical disk, etc.).

The determination unit 16 uses the current position acquired by the current position acquisition unit 14 to determine whether the obstacle detected by the obstacle detection unit 13 is a known one indicated by the map stored in the map storage unit 15 Determine if. Hereinafter, an obstacle indicated by a map may be referred to as a "known obstacle", and an obstacle not indicated by the map may be referred to as an "unknown obstacle". The determination unit 16 determines whether the obstacle detected by the obstacle detection unit 13 is a known obstacle or an unknown obstacle. The determination unit 16 can specify the positional relationship between the mobile unit 1 and the obstacle on the map by using the current position of the mobile unit 1 and the map. Then, when the obstacle detected by the obstacle detection unit 13 corresponds to any obstacle on the map, it can be determined that the detected obstacle is known, and the obstacle is detected. If the obstacle does not correspond to any obstacle on the map, it can be determined that the detected obstacle is unknown. This determination may be made in (1) the local coordinate system or (2) in the world coordinate system, as described below. In the present embodiment, in order to simplify the description, the local coordinate system and the world coordinate system are each assumed to be a two-dimensional orthogonal coordinate system. Further, the local coordinate system is an xy coordinate system, and the world coordinate system is an xy coordinate system.

(1) Determination in Local Coordinate System In this case, the determination unit 16 converts the position of the obstacle in the world coordinate system indicated by the map stored in the map storage unit 15 into the position in the local coordinate system, Make a decision in the coordinate system.

For example, as shown in FIG. 4A, it is assumed that the obstacle D1 is detected by the obstacle detection unit 13. In addition, the obstacle detection shall be performed in area | region R11 using a ranging result. The region R11 may be, for example, a region in the traveling direction of the mobile body 1. Since the ranging result is, for example, information of a pair of angle and distance as described above, the result of plotting the result on the local coordinate system of the moving body 1 is a set of points, but in FIG. 4A, In order to simplify the explanation, it is indicated by an outline like an obstacle D1. Therefore, the contour may be considered strictly as a set of one or more measurement points. The same applies to other obstacles.

Further, it is assumed that the current position in the world coordinate system at that time is (X1, Y1, Θ1). Note that (X1, Y1) is a coordinate value indicating a position in the world coordinate system, and Θ1 is an angle indicating a direction in the world coordinate system. The angle may be, for example, an angle based on the X axis or Y axis of the world coordinate system. By specifying the position and direction on the map corresponding to the current position, the determination unit 16 can specify the position of the obstacle on the map in the local coordinate system. The identification may be performed, for example, by transforming the position of an obstacle in the world coordinate system into the local coordinate system using a transformation matrix from the world coordinate system to the local coordinate system (for example, simultaneous transformation matrix etc.) Good. When the scale of the world coordinate system and that of the local coordinate system are different, the difference in scale should be taken into account in the transformation. Then, when the position in the local coordinate system with respect to the obstacle B4 on the map shown in FIG. 3 is specified, if it is as shown in FIG. 4B, the position and shape of the outline of the obstacle B4 is an obstacle In order to coincide with the position and the shape of the obstacle D1 detected by the object detection unit 13, the determination unit 16 determines that the obstacle D1 is a known obstacle. The determination as to whether the obstacle on the map matches the detected obstacle may be made, for example, depending on whether the feature points extracted from each match. A method of determining whether two figures match is already known, and the detailed description thereof is omitted.

In addition, for example, when the acquisition of the current position is performed by self-positioning using the measurement result of the distance to the surrounding object, a certain degree of error exists in the current position. Therefore, when the position of the obstacle is converted from the world coordinate system to the local coordinate system using its current position, as shown in FIG. 4C, the error in the position between the obstacle B4 and the obstacle D1 becomes the distance E1. Can be In that case, for example, when the distance E1 is smaller than the error threshold E _TH , that is, the obstacle D1 detected by the obstacle detection unit 13 and the obstacle B4 indicated by the map are the error threshold E _TH. When it is closer, the determination unit 16 may determine that the obstacle D1 is known. The error threshold value E _TH may be set to be larger than the error of the current position, the error of the detected position of the obstacle, and the like, for example.

Also, for example, as illustrated in FIG. 5A, it is assumed that the obstacle detection unit 13 detects the obstacle D2. Further, it is assumed that the position of the obstacle on the map in the world coordinate system is converted to the position of the local coordinate system using the current position at that time, and the result is the position of the obstacle B4 shown in FIG. 5B. Then, in the local coordinate system shown in FIG. 5B, since the obstacle B4 and the obstacle D2 have different contour positions and shapes, the determination unit 16 determines that the obstacle D2 is an unknown obstacle. It is also good.

(2) Determination in the world coordinate system In this case, the determination unit 16 converts the position of the obstacle in the local coordinate system detected by the obstacle detection unit 13 into the position in the world coordinate system, and determines in the world coordinate system I do. The determination is substantially performed in the same manner as the above (1) except that the coordinate system in which the determination is made is different.

For example, as illustrated in FIG. 4A, when the obstacle detection unit 13 detects the obstacle D1, the determination unit 16 uses the current position (X1, Y1, Θ1) at that time to determine the local coordinate system. The position of the obstacle D1 at is converted to the world coordinate system. The transformation may be performed, for example, using a transformation matrix (eg, simultaneous transformation matrix) from the local coordinate system to the world coordinate system. It is assumed that the obstacle D1 is at the position shown in FIG. 6 in the world coordinate system due to the conversion. It is assumed that the point P1 on the map and the direction of the arrow extending from the point P1 indicate the current position (X1, Y1, Θ1) of the mobile unit 1. As shown in FIG. 6, the position and the shape of the obstacle D1 detected by the obstacle detection unit 13 match the position and the shape of the obstacle B4 shown on the map of the world coordinate system. Determines that the obstacle D1 is a known obstacle. In the same manner as the above description, even if the obstacle B4 on the map and the detected obstacle D1 are separated from each other, if both are close to the error threshold, the determination unit 16 determines the obstacle D1. It may be determined that is known.

The movement control unit 17 controls the movement of the movable body 1 by controlling the movement mechanism 11. The control of movement may be control of the direction of movement of the mobile body 1 or start / stop of movement. For example, when the movement path is set, the movement control unit 17 may control the movement mechanism 11 so that the moving body 1 moves along the movement path. More specifically, the movement control unit 17 may control the movement mechanism 11 so that the current position acquired by the current position acquisition unit 14 is along the movement path. In addition, the movement control unit 17 may control movement using a map. In that case, the mobile unit 1 may use the map stored in the map storage unit 15.

In addition, the movement control unit 17 controls the movement mechanism 11 so as to prevent the collision with the obstacle detected by the obstacle detection unit 13. The movement control unit 17 performs different control on the obstacle in accordance with the determination result of the determination unit 16. That is, the movement control unit 17 performs different control depending on whether the detected obstacle is known or unknown. When the detected obstacle is known, the movement control unit 17 performs weaker control to prevent a collision as compared with the case where the detected obstacle is unknown. It may be Weaker control may be considered to be control in which the change from normal movement control becomes smaller. For example, deceleration is weaker control than stop and bypass control is weaker than stop. The movement control when the detected obstacle is unknown may be considered to be normal movement control when the obstacle is detected. Note that different control means that the method of movement control is different, and does not mean whether the result of the control is different. For example, as described later, even when using different distance threshold values for a known obstacle and an unknown obstacle, if the detected obstacle is present in the vicinity of the mobile body 1, This is because the mobile unit 1 is stopped regardless of any obstacle. In addition, the movement control unit 17 does not necessarily perform control for preventing a collision for all detected obstacles. When the movement control unit 17 satisfies a predetermined condition (for example, the distance to the obstacle may be shorter than a distance threshold described later) for the detected obstacle, the movement control unit 17 Control such as deceleration or stop for preventing a collision may be performed, and when a predetermined condition is not satisfied for a detected obstacle, control for preventing a collision may not be performed. Here, following (A) and (B) can be mentioned as an example of the different control regarding a known obstacle and an unknown obstacle.

(A) In the case of using a different distance threshold to prevent a collision with an obstacle In this case, the movement control unit 17 prevents the collision when the distance to the detected obstacle is shorter than the distance threshold. Control is performed, and when the distance to the detected obstacle is longer than the distance threshold, the control for preventing the collision is not performed. In addition, when the distance to the detected obstacle is the same as the distance threshold, the movement control unit 17 may or may not perform control for preventing a collision. The distance threshold is different for known and unknown obstacles. That is, it is assumed that the distance threshold for the detected known obstacle is shorter than the distance threshold for the detected unknown obstacle. Therefore, even if a certain obstacle is detected, if the obstacle is known, the moving body 1 does not stop or decelerate, whereas if the obstacle is unknown, the moving body 1 stops. And there will be situations where it will slow down. Here, this movement control will be described using the specific example shown in FIG. FIG. 7 is a diagram showing an example of two distance thresholds. In FIG. 7, it is assumed that the region R <b> 11 is a region within the radius L <b> 1 from the position of the distance measurement sensor 12. Then, the distance threshold for the unknown obstacle is set to L1, and the distance threshold for the known obstacle is set to L2. L2 is a real number smaller than L1. Further, in this specific example, when an obstacle within the distance threshold is detected, the movement control unit 17 stops the moving body 1. Then, when the obstacle D3 shown in FIG. 7 is detected by the obstacle detection unit 13 (in this case, the obstacle D4 in FIG. 7 is not detected), the obstacle D3 is known. If the object is an obstacle, the movement control unit 17 does not stop the moving body 1 because the obstacle is farther than the distance threshold L2. On the other hand, if the obstacle D3 is unknown, it is an obstacle closer than the distance threshold L1, so the movement control unit 17 stops the moving body 1. Further, when the obstacle D4 shown in FIG. 7 is detected by the obstacle detection unit 13, it is closer than the distance threshold L1, L2 regardless of whether the obstacle is known or unknown. Since the obstacle is an obstacle, the movement control unit 17 stops the moving body 1. In the case where no obstacle is detected in the region R11, the movement control unit 17 does not stop the moving body 1.

In addition, although the case where the distance from the ranging sensor 12 was used as a distance to an obstacle was demonstrated here, it may not be so. As the distance to the obstacle, for example, the distance from the outer edge of the mobile body 1 or another place may be used. Since the position of the obstacle in the local coordinate system can be specified by the distance measurement result, the position can be used to obtain the distance from the arbitrary position of the mobile body 1 to the obstacle. The movement control unit 17 may perform the above-described movement control using the thus obtained distance.

Also, the distance threshold may be the same for all directions or may be different for each direction. In the latter case, for example, a large distance threshold may be used for the traveling direction, and the distance may be shorter as the traveling direction is away.

In addition, control in the case where detection of an obstacle is performed may be performed stepwise according to the distance between the obstacle and the moving object 1. For example, when a distant obstacle is detected, the movement control unit 17 decelerates the moving body 1, and when a nearby obstacle is detected, the movement control unit 17 stops the moving body 1 You may Such may be the case when a known obstacle is detected and when an unknown obstacle is detected. Further, in the local coordinate system of the mobile unit 1, the stop area and the deceleration area for the unknown obstacle may be set, and the stop area and the deceleration area for the known obstacle may be set. The stop area of the known obstacle is set closer to the mobile body 1 than the stop area of the unknown obstacle, and the deceleration area of the known obstacle is the deceleration area of the unknown obstacle. It is preferable that the position closer to the mobile unit 1 be set than that. Then, when an unknown obstacle exists in the stop area of the unknown obstacle, the movement control unit 17 stops the mobile body 1, and the unknown obstacle exists in the deceleration area of the unknown obstacle. In this case, the movement control unit 17 may decelerate the moving body 1. Also, when a known obstacle exists in the stop area of the known obstacle, the movement control unit 17 stops the mobile body 1, and a known obstacle exists in the deceleration area of the known obstacle. In this case, the movement control unit 17 may decelerate the moving body 1. In addition, when the moving body 1 is decelerated, the speed after the deceleration may be fixed or not. In the latter case, for example, deceleration may be performed so as to be a speed determined relative to the current speed (e.g., 50% speed, etc.).

Moreover, although the case where the mobile body 1 may stop or decelerate in response to detection of a known obstacle has been described, this may not be the case. When a known obstacle is detected, the movement control unit 17 may not perform control for preventing a collision with the obstacle. Specifically, in the above description, the distance threshold for the known obstacle may be set to the lowest value, ie, a value that is not to be subjected to control for preventing a collision against the known obstacle. . In the case of FIG. 7, for example, the distance threshold for known obstacles may be set to “0”. Since known obstacles are known in advance, the movement route etc. is usually searched or set so as to avoid the obstacles, and stop and deceleration are performed for known obstacles. Even if not, it is considered that there is no possibility that the mobile body 1 collides with a known obstacle if movement control is properly performed. Therefore, even if control to prevent a collision is not performed for a known obstacle, it is considered that the possibility of becoming a problem is low.

(B) In the case where collision with an obstacle is prevented by a different method In this case, for example, when the detected obstacle is known, the movement control unit 17 avoids the obstacle by the potential method. As described above, the moving mechanism 11 may be controlled to control the moving mechanism 11 so as to decelerate or stop when the detected obstacle is unknown. To avoid the obstacle may be to pass other than the position of the obstacle. In the potential method, since the path generation is performed assuming that each obstacle generates a repulsive force, the mobile body 1 is not stopped, and bypasses each obstacle or does not approach each obstacle and goes to the destination . Therefore, the mobile object 1 can be prevented from decelerating or stopping by detection of a known obstacle, and priority can be given to reaching the destination. On the other hand, since an unknown obstacle may be a human or the like, in order to ensure safety, it is preferable to give priority to the prevention of the collision. Therefore, the movement control unit 17 performs avoidance using the potential method when a known obstacle is detected, and performs deceleration or stop when an unknown obstacle is detected by appropriate control. It is believed that there is. Also, for example, when the acquisition of the current position is performed by self-positioning using the measurement result of the distance to the surrounding object, a certain degree of error exists in the current position. On the other hand, when the potential method is used, a path as far as possible from the obstacle is generated, so even if such an error exists at the current position, the mobile body 1 collides with the known obstacle at the time of actual movement. The possibility of doing so is considered to be low. Therefore, also from this point of view, it is considered preferable to use the potential method to avoid known obstacles. In addition, methods other than the potential method may be used as a detour method of a known obstacle. For example, when a known obstacle is detected, the movement control unit 17 detects the position of the known obstacle detected using Rapidly exploring Random Trees (RRT), the Dijkstra method, the A * algorithm, or the like. A route to be avoided may be obtained, and the moving mechanism 11 may be controlled so that the mobile unit 1 moves along the route.

In the above description, when the detected obstacle is known, the collision with the obstacle is prevented by the bypass of the obstacle using the potential method or RRT, etc., and the detected obstacle is unknown. Although the case where a collision with an obstacle is prevented by decelerating or stopping when it is a thing was described, it may not be so. For example, when the detected obstacle is known, the collision with the obstacle is prevented by avoiding the obstacle using the potential method, and the potential is detected when the detected obstacle is unknown. The collision with the obstacle is prevented by the acquisition of the route that bypasses the obstacle using non-legal RRT, Dijkstra method, A * algorithm, etc., and the movement along the route (that is, the movement to bypass the obstacle) It may be done.

Next, the operation of the mobile unit 1 will be described using the flowchart of FIG.
(Step S101) The movement control unit 17 controls the movement of the movable body 1. The control of the movement may be, for example, control of the movement toward the destination. The mobile unit 1 may reach the destination from the departure place by repeatedly performing the control of the movement in step S101.

(Step S102) The obstacle detection unit 13 determines whether an obstacle has been detected. And when an obstruction is detected, it progresses to step S103, and when that is not right, it returns to step S101.

(Step S103) The determination unit 16 performs conversion between the world coordinate system and the local coordinate system. As described above, for example, the position of the obstacle on the map of the world coordinate system may be converted to the position of the local coordinate system of the mobile 1, and the position of the obstacle detected in the local coordinate system of the mobile 1 The position may be converted to a position on the map of the world coordinate system.

(Step S104) The determination unit 16 determines whether the detected obstacle is known or unknown, using the position of the obstacle after conversion in step S103. Then, if a known obstacle is detected, the process proceeds to step S105, and if an unknown obstacle is detected, the process proceeds to step S106.

(Step S105) The movement control unit 17 performs movement control according to detection of a known obstacle. Then, the process returns to step S101. As described above, this movement control may be, for example, deceleration or stop of the moving body 1 or bypassing of an obstacle using the potential method or the like. In addition, when the distance to the detected known obstacle is larger than the distance threshold, the movement control unit 17 may not perform control according to the detection of the obstacle. When the moving object 1 is decelerated according to the detection of a known obstacle, the movement control unit 17 restricts the upper limit of the movement speed to one after decelerating, and then returns to step S101 to perform movement. You may continue. In that case, when the obstacle is not detected (when it is determined NO in step S102), the upper limit of the moving speed may be released. In addition, when the moving object 1 is stopped in response to the detection of a known obstacle, the movement control unit 17 continues the stop until the obstacle is not detected, and after the obstacle is not detected, the step is performed. It may return to S101 and resume movement.

(Step S106) The movement control unit 17 performs movement control according to the detection of an unknown obstacle. Then, the process returns to step S101. This movement control may be, for example, deceleration or stop of the moving body 1 as described above. In addition, when the distance to the detected unknown obstacle is larger than the distance threshold, the movement control unit 17 may not perform control according to the detection of the obstacle. When the moving object 1 is decelerated in response to the detection of an unknown obstacle, the movement control unit 17 restricts the upper limit of the movement speed to one after deceleration, and then returns to step S101 to move. You may continue. In that case, when the obstacle is not detected (when it is determined NO in step S102), the upper limit of the moving speed may be released. In addition, when the moving object 1 is stopped in response to the detection of an unknown obstacle, the movement control unit 17 continues the stop until the obstacle is not detected, and after the obstacle is not detected, the step is performed. It may return to S101 and resume movement.

In addition, although the case where one obstacle was detected in obstacle detection was explained in the flow chart of Drawing 2, two or more obstacles may be detected simultaneously in obstacle detection. In that case, for example, for each detected obstacle, as in steps S104 to S106, it may be determined whether it is known or not and movement control may be specified according to the determination result. In this case, the movement control unit 17 specifies movement control corresponding to each obstacle for each obstacle, selects the safest movement control from among the plurality of movement controls thus specified, The moving mechanism 11 may be controlled to perform the movement control. The safest movement control is movement control that is the least likely to collide with an obstacle. For example, if the identified movement control is the deceleration of the moving body 1, the stopping of the moving body 1, and the detouring of the detected obstacle, the movement control unit 17 determines that the moving body with the highest degree of safety. The stop of 1 may be selected, and the moving mechanism 11 may be controlled to stop the moving body 1. In addition, the movement control unit 17 may combine them instead of selecting any one of the plurality of movement controls identified. For example, if the identified movement control is deceleration of the moving body 1 and detouring of the detected obstacle, the movement control unit 17 decelerates the moving body 1 and detects the detected obstacle. The movement mechanism 11 may be controlled to bypass the Moreover, the order of the process in the flowchart of FIG. 2 is an example, and the order of each step may be changed as long as the same result can be obtained. Although not included in the flowchart of FIG. 2, distance measurement by the distance measurement sensor 12 and acquisition of the current position by the current position acquisition unit 14 are assumed to be repeatedly performed. Further, in the flowchart of FIG. 2, the processing is ended by the arrival of the moving object 1 at the destination, or the interruption of the power-off or the processing end.

FIG. 8 is a diagram for describing a specific example of movement of the mobile unit 1 according to the present embodiment. Referring to FIG. 8, mobile unit 1 starts from the position of mobile unit 1-0 and sequentially moves each position of mobile units 1-1, 1-2, and 1-3 (step S101). ). In the movement, when passing through the passage between the obstacles B2 and B3 or passing through the passage between the obstacles B1 and B3, the obstacle detection unit 13 detects the obstacles B1 to B3 as obstacles respectively. However, the determining unit 16 determines that the obstacles B1 to B3 are known (steps S103 and S104). As a result, the mobile unit 1 can continue to move as shown in FIG. 8 by using a short distance threshold or bypassing an obstacle according to the potential method (step S105). . In addition, when an unknown obstacle such as a human being is detected in the middle of the movement (steps S102 to S104), safety is also ensured by performing deceleration or stop of the mobile body 1 accordingly. It will be.

As described above, according to the mobile object 1 of the present embodiment, the known obstacle is obtained by performing different movement control in the case where the detected obstacle is known and the case where the detected obstacle is unknown. And appropriate obstacles can be made for unknown obstacles. Specifically, the possibility that the moving body 1 is decelerated or stopped in response to detection of a known obstacle can be reduced, and even if a known obstacle is detected, the moving body Smoother movement of 1 will be able to be continued. In addition, when an unknown obstacle is detected, safety can be ensured by decelerating or stopping the moving body 1 according to the detection.

In the present embodiment, determination unit 16 determines whether the detected obstacle is known or unknown in the local coordinate system of mobile unit 1 or the world coordinate system corresponding to the map. Although the case has been described, it does not have to be. The determination unit 16 may make the determination in a third coordinate system that is neither the local coordinate system of the mobile body 1 nor the world coordinate system of the map. In that case, the position of the obstacle detected in the local coordinate system is converted to the third coordinate system, the position of the obstacle on the map is also converted to the third coordinate system, and the conversion results are used. The judgment may be made.

Moreover, although the case where only the obstacle detection using the measurement result by the distance measurement sensor 12 is performed is described in the present embodiment, obstacle detection other than that may be performed. For example, obstacle detection may be performed using a contact sensor. In that case, when an obstacle is detected by the contact sensor, the movement control unit 17 may perform movement control such as stopping the moving body 1.

Also, in the above embodiment, each processing or each function may be realized by centralized processing by a single device or a single system, or distributed processing by a plurality of devices or a plurality of systems. It may be realized by

Further, in the above embodiment, the transfer of information performed between the components is performed by, for example, one of the components if the two components performing the transfer of information are physically different. It may be performed by the output of the information and the reception of the information by the other component, or if the two components that exchange the information are physically the same, one of the components It may be performed by moving from the phase of processing corresponding to to the phase of processing corresponding to the other component.

Further, in the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component Also, information such as threshold values, mathematical expressions, addresses and the like used by each component in processing may be held temporarily or for a long time in a recording medium (not shown), even if not specified in the above description. Further, each component or a storage unit (not shown) may store information in the recording medium (not shown). Each component or a reading unit (not shown) may read information from the recording medium (not shown).

Further, in the above embodiment, when the information used in each component or the like, for example, information such as a threshold or an address used in processing by each component or various setting values may be changed by the user, Although not explicitly stated in the description, the user may or may not be able to change the information as appropriate. When the user can change such information, the change is realized, for example, by a receiving unit (not shown) that receives a change instruction from the user and a change unit (not shown) that changes the information according to the change instruction. May be The acceptance of the change instruction by the acceptance unit (not shown) may be, for example, acceptance from an input device, reception of information transmitted via a communication line, or acceptance of information read from a predetermined recording medium .

Further, in the above embodiment, when two or more components included in the mobile unit 1 have a communication device, an input device, etc., the two or more components may have a physically single device. Or may have separate devices.

Further, in the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of the execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. The program may be executed by being downloaded from a server or the like, or may be executed by being read out of a program recorded on a predetermined recording medium (for example, an optical disc, a magnetic disc, a semiconductor memory, etc.) Good. Also, this program may be used as a program that constitutes a program product. Also, the computer that executes the program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

Further, it is needless to say that the present invention is not limited to the above embodiments, and various modifications are possible, which are also included in the scope of the present invention.

As mentioned above, according to the mobile by this invention, the effect that it can respond appropriately also to an unknown obstacle and a known obstacle is acquired, and it is useful as a mobile which moves autonomously.

Claims

It is a mobile that moves autonomously,
A distance measuring sensor that measures the distance to surrounding objects in multiple directions;
An obstacle detection unit that detects an obstacle using the measurement result of the distance measurement sensor;
A moving mechanism for moving the moving body;
A movement control unit that controls the movement mechanism to prevent a collision with an obstacle detected by the obstacle detection unit;
A map storage unit in which a map indicating the position of the obstacle in the world coordinate system is stored;
A current position acquisition unit that acquires a current position of the mobile object;
A determination unit that determines whether an obstacle detected by the obstacle detection unit is a known one indicated by the map using the current position;
The mobile control unit performs different control on an obstacle according to the determination result of the determination unit.
The movement control unit performs control for preventing a collision when the distance to the detected obstacle is shorter than the distance threshold,
The mobile according to claim 1, wherein the distance threshold for the detected known obstacle is shorter than the distance threshold for the detected unknown obstacle.
The mobile unit according to claim 1, wherein the movement control unit performs avoidance of the obstacle by the potential method when the detected obstacle is known.
The obstacle detection unit detects an obstacle in a local coordinate system of the moving body,
The movement according to any one of claims 1 to 3, wherein the determination unit converts the position of the obstacle in the world coordinate system indicated by the map into the position of the local coordinate system, and performs the determination in the local coordinate system. body.
The obstacle detection unit detects an obstacle in a local coordinate system of the moving body,
The said judgment part converts the position of the obstacle in the local coordinate system detected by the said obstacle detection part into the position of a world coordinate system, and performs the said judgment in a world coordinate system. Or mobile listed.
The judgment unit judges that the obstacle is known when the obstacle detected by the obstacle detection unit and the obstacle shown by the map are closer than an error threshold. The mobile according to any one of claims 5 to 10.