JP7367421B2 - Autonomous running body and control method for autonomous running body - Google Patents

Description

The present invention relates to an autonomous running body and a method of controlling an autonomous running body.

Conventionally, an autonomous vehicle autonomously travels along a travel route connecting a starting point and a final destination, but if an obstacle exists on the travel route, the autonomous vehicle searches for an avoidance route. When the autonomous vehicle finds an avoidance route, it runs along the avoidance route. The autonomous running body includes a sensor that detects obstacles and a control device (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 7-64633

In Patent Document 1, when an autonomous vehicle detects an obstacle, it searches for an avoidance route and travels along this avoidance route. By the way, obstacles on the travel route can be classified into known obstacles whose existence is known in advance, such as walls and shelves, and unknown obstacles whose existence cannot be known in advance, such as people and trolleys. When the autonomous vehicle disclosed in Patent Document 1 detects an obstacle, it searches for an avoidance route without distinguishing between known obstacles and unknown obstacles. In the case of an unknown obstacle such as a person or a moving object, the autonomous mobile object can return to the original travel route from the avoidance route even if it travels on an avoidance route to avoid the unknown obstacle. However, if the known obstacle is long and large, such as a wall or shelf, there is a problem that it becomes impossible to return to the original travel route from the avoidance route.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an autonomous running body and a control method for an autonomous running body that searches for an optimal avoidance route in consideration of known obstacles.

In order to solve the above problems, the present invention includes a traveling object, a sensor mounted on the traveling object, and a search area that extends in the direction of the traveling route of the traveling object based on the detection result of the sensor. an obstacle determining section that determines whether or not a target obstacle exists; and when the obstacle determining section determines that the obstacle exists within the search area, a horizontal direction from the obstacle is determined. A known obstacle whose existence is known in advance in an autonomous running body, comprising: a search unit that searches for whether or not there is an avoidable area in which the running body can avoid in a direction intersecting the traveling direction. an area restriction unit that reduces and limits the search area so that when an object exists in the search area, the obstacle determination unit does not recognize the known obstacle as an obstacle to be avoided; When the search unit determines that the obstacle existing in the search area reduced by the area restriction unit is an unknown obstacle, the search unit determines that the avoidable area in which the traveling object can be avoided is the A search is performed to determine whether or not the search area exists in the search area that has been reduced by the area restriction unit , a changed area that is narrower than the search area is set within the search area, and the changed area is detected in the changed area. This is an area for determining whether or not to actually perform an avoidance action with respect to an unknown obstacle that has been detected, and the area limiting unit reduces and limits the changed area in accordance with the limit of the search area. However, if the unknown obstacle exists within the reduced and restricted change area and the avoidable area does not exist within the search area, the vehicle is characterized in that traveling is stopped.

In the present invention, when a known obstacle is present in the search area while the vehicle is traveling along a preset travel route, the obstacle determining section may prevent the known obstacle from being recognized as an obstacle to be avoided. The area limiting unit reduces and limits the search area. On the other hand, the search unit searches for avoidance routes for obstacles other than known obstacles. Therefore, even if a known obstacle exists within the search area, the search unit does not search for an avoidance route for the known obstacle. As a result, the traveling object will not be unable to return to the traveling route due to the traveling object avoiding a known obstacle .
Further, when reducing and limiting the search area, the area limiting unit reduces the changed area in accordance with the limit of the search area. Therefore, the change area in which obstacles need to be detected can be narrowed, and the load for detecting obstacles can be reduced.
Further, when determining that an obstacle existing within the search area is an unknown obstacle, the search unit searches whether there is an avoidable area in which the traveling object can be avoided. When the avoidable area exists, the vehicle can travel along the avoidance route to avoid the unknown obstacle, and can return to the travel route after the avoidance. The traveling object can stop when there is no avoidable area.

Further, the above autonomous running body may be configured to include a known obstacle recognition unit that recognizes the known obstacle in the search area based on the self-estimated position of the running body and a pre-stored environmental map. good.
In this case, the known obstacle recognition unit determines whether the obstacle in the search area is a known obstacle before limiting the search area based on the self-estimated position of the traveling object estimated from the sensor detection results and the pre-stored environmental map. It can be recognized that

Further, the above autonomous vehicle may be configured to include a known obstacle recognition unit that recognizes the known obstacle within the search area based on a detection result of the sensor.
In this case, by comparing the detection result of the sensor with a pre-stored environmental map, it can be recognized that the obstacle within the search area is a known obstacle before the search area is limited.

Moreover, in the above-mentioned autonomous running body, the area limiting section may be configured to limit the search area in the width direction of the traveling route to a position closest to the known obstacle from the running body.
In this case, the area limiter limits the search area in the width direction of the travel route to the position closest to the known obstacle from the traveling object, so the known obstacle deviates from the restricted search area and the obstacle determination unit It is not determined that there is a known obstacle to be avoided within the area.

Further, the present invention allows a traveling object to travel, and determines whether or not an obstacle exists within a search area that extends in the direction of a route traveled by the traveling object based on a detection result of a sensor mounted on the traveling object. If it is determined that the obstacle exists within the search area, there is an avoidable area from the obstacle in a horizontal direction that intersects with the traveling direction, in which the traveling object can avoid it. In the control method for an autonomous running body that searches for whether This is an area for determining whether or not to actually perform an avoidance action, and when a known obstacle whose existence is known in advance based on the detection result of the sensor exists in the search area, the known obstacle is The search area is reduced and restricted so that the obstacle is not recognized as an obstacle to be avoided, and the obstacle existing within the reduced search area so that the known obstacle is not recognized as an obstacle to be avoided. When it is determined that an object is an unknown obstacle, a search is performed to determine whether an avoidable area in which the traveling object can be avoided exists in the search area, and the change area is a limit of the search area. If the unknown obstacle exists within the reduced and limited change area and the avoidable area does not exist within the search area, the traveling object It is characterized by stopping .

In the present invention, even if a known obstacle exists within the search area, the search unit does not search for an avoidance route for the known obstacle. As a result, the traveling object will not be unable to return to the traveling route due to the traveling object avoiding a known obstacle.

According to the present invention, it is possible to provide an autonomous running body and a method for controlling an autonomous running body that searches for an optimal avoidance route in consideration of known obstacles.

FIG. 1 is a plan view of an autonomous running body according to an embodiment of the present invention. FIG. 1 is a block configuration diagram of an autonomous running body according to an embodiment of the present invention. FIG. 2 is a flow diagram showing a procedure for controlling an autonomous running body. FIG. 3 is a plan view showing a search area restricted by the presence of a known obstacle. FIG. 2 is a plan view showing a restricted search area where an unknown obstacle exists. FIG. 3 is a plan view showing the movement of a traveling object that performs an evasive action. FIG. 3 is a plan view showing an unrestricted search area in which an unknown obstacle exists.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An autonomous running body according to an embodiment of the present invention will be described below with reference to the drawings. This embodiment is an example in which the present invention is applied to an autonomous traveling body for transporting loads, which is equipped with omnidirectional wheels and a loading platform that allow movement in all directions.

As shown in FIG. 1 , the autonomous running body 10 includes a running body 11 having a main body 12 and a plurality of wheels 13 . A loading platform (not shown) is provided at the top of the main body 12. Wheel 13 is an omnidirectional moving wheel. An omnidirectional moving wheel is a wheel that not only rotates integrally with an axle (not shown) but also can move in the axial direction of the axle. In this embodiment, the main body 12 is provided with four wheels 13. By controlling the rotation speed and rotation direction of the wheels 13, the traveling body 11 can move in all directions while maintaining the orientation of the main body 12. Further, the traveling body 11 can move while changing the direction of the main body 12, and can also change the direction of the main body 12 while not moving. Note that "omnidirectional" herein refers to the direction of movement of the traveling body 11 on the road surface or floor surface in which it travels.

As shown in FIG. 2, the autonomous running body 10 includes a drive mechanism 14 that drives wheels 13. The drive mechanism 14 includes a drive motor 15 for rotating the wheels 13 and a motor driver 16 for driving the drive motor 15. A drive motor 15 and a motor driver 16 are provided for each wheel 13. Therefore, the number of drive motors 15 and motor drivers 16 is the same as the number of wheels 13. The motor driver 16 controls the rotation speed of the drive motor 15 in accordance with commands from the control device 17 . The control device 17 can control the traveling direction of the main body 12 by controlling the rotation speed of the drive motor 15 via the motor driver 16 .

A sensor 18 and a control device 17 are mounted on the main body 12 of the traveling body 11. As the sensor 18, a sensor capable of causing the control device 17 to detect an obstacle is used. The sensor 18 of this embodiment is a laser range finder (LRF). A laser range finder is a rangefinder that measures distance by emitting a laser to the surrounding area and receiving the reflected light from the area hit by the laser. In this embodiment, a two-dimensional laser range finder is used that irradiates laser while changing the irradiation angle in the horizontal direction.

If the portion hit by the laser is defined as the irradiation point, the sensor 18 measures the distance to the irradiation point in association with the irradiation angle. That is, the sensor 18 can measure relative coordinates indicating the distance between the traveling object 11 and the irradiation point. In this embodiment, the angle at which the sensor 18 can be irradiated with the laser in the horizontal direction is 270°.

As shown in FIG. 1, assuming that the center of the irradiation possible angle is the reference axis G, the irradiation possible angle is in the range of ±135 degrees of the reference axis G. The relative coordinates measured by the sensor 31 are coordinates of an orthogonal coordinate system in which the direction in which the reference axis G extends is the Y axis, and the direction perpendicular to the Y axis is the X axis.

As shown in FIG. 2, the control device 17 includes a CPU 20 and a storage section 21 including a RAM, a ROM, and the like. The control device 17 may include dedicated hardware that executes at least some of the various processes, such as an application specific integrated circuit (ASIC). The controller 17 may be configured as a circuit including one or more processors operating according to a computer program, one or more dedicated hardware circuits such as an ASIC, or a combination thereof. The processor includes a CPU and memory such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to perform processes. Memory, or computer readable media, includes anything that can be accessed by a general purpose or special purpose computer.

The storage unit 21 stores various programs for controlling the traveling body 11, as well as an environmental map related to the movement space in which the traveling body 11 moves. The environmental map is a map that is created while the traveling object 11 moves in a moving space. A technique for simultaneously estimating the self-position of the traveling object 11 and constructing an environmental map is called SLAM (Simultaneous Localization and Mapping).

As shown in FIG. 1, when the traveling body 11 travels, the control device 17 generates a traveling route R. The traveling route R is a route from the current position, which is the starting point, of the traveling object 11 to the final destination. Note that when the main body 12 is traveling straight, the traveling route R and the reference axis G face in the same direction. In FIG. 1, the traveling route R and the reference axis G overlap. As a method for generating the travel route R, a method of generating a route by creating a grid map of possible travel routes, a potential method using a potential field, etc. can be used. The control device 17 functions as a route generation section.

The control device 17 sets a position on the traveling route R that is a predetermined distance away from the traveling object 11 as a target point P1, and controls the drive mechanism 14 to travel toward the target point P1. The control device 17 causes the traveling body 11 to travel such that the reference axis G of the sensor 18 faces the traveling direction of the traveling body 11. The control device 17 sets a search area A and a change area B while the traveling body 11 is traveling in order to avoid contact between the traveling body 11 and an obstacle.

As shown in FIG. 1, the search area A is a rectangular area divided by two long sides S1 and S2 extending in the X-axis direction and two short sides S3 and S4 extending in the Y-axis direction. Ru. The search area A is an area that extends from the traveling body 11 in the direction of the route along which the traveling body 11 travels. Here, "the direction of the route in which the traveling body 11 travels" refers to the direction in which the traveling body 11 travels on the set traveling route R.

Of the two long sides S1 and S2 extending in the X-axis direction, one long side S1 passes through a predetermined position P2 of the traveling body 11, and the other long side S2 is located further in the traveling direction than the traveling body 11. The dimension of the search area A in the X-axis direction is determined by how far the search for obstacles is to be performed in a direction intersecting the direction of the route along which the traveling object 11 travels. The dimension of the search area A in the X-axis direction varies depending on the location where the traveling object 11 is expected to travel, and varies depending on the layout of the room, the width of the road, and the like.

The predetermined position P2 is an arbitrary position on the traveling body 11, and is a predetermined fixed position. In this embodiment, the predetermined position P2 is the center of the main body 12 in the Y-axis direction and the center of the vehicle body in the X-axis direction. The search area A is an area that is symmetrical about the reference axis G.

In this embodiment, the distance in the Y-axis direction from the predetermined position P2 to the target point P1 is the dimension of the search area A in the Y-axis direction, that is, the dimension of the short sides S3 and S4 of the search area A. The dimension of the search area A in the Y-axis direction is set depending on, for example, the time required to move the traveling object 11 from detection of an obstacle to a position where the obstacle can be avoided. Note that the target point P1 for avoiding obstacles does not necessarily need to be provided on the long side S2, and may be set at an appropriately shifted position in consideration of the agility and target followability of the traveling object 11 when avoiding the obstacle. .

A change area B is set within the search area A. The change area B is a rectangular area defined by two long sides S5 and S6 extending in the X-axis direction and two short sides S7 and S8 extending in the Y-axis direction. Of the two long sides S5 and S6 extending in the X-axis direction, one long side S6 passes through the predetermined position P2, and the other long side S5 is located further in the traveling direction than the traveling body 11. The change area B can be said to be an area that extends from the traveling body 11 in the direction of the traveling route R along which the traveling body 11 travels. The change area B is an area that is symmetrical about the reference axis G.

Change area B is narrower than search area A. Note that "narrow" means that the area of the change area B on the XY plane is smaller than the search area A. The dimension of the change area B in the Y-axis direction is shorter than the dimension of the search area A in the Y-axis direction. The dimension of the change area B in the X-axis direction is shorter than the dimension of the search area A in the X-axis direction.

The dimension of the change area B in the Y-axis direction, that is, the dimensions of the short sides S7 and S8 of the change area B, determines the avoidance start distance when the traveling object 11 starts the avoidance action. The control device 17 starts the avoidance action when the distance between the traveling object 11 and the obstacle in the Y-axis direction becomes less than the dimension of the change area B in the Y-axis direction.

The dimension of the change area B in the X-axis direction determines the avoidance distance when performing the avoidance action. The avoidance distance is the distance between the traveling object 11 and the obstacle in the X-axis direction. The dimension of the changed region B in the X-axis direction is longer than the longest dimension of the traveling body 11 in the X-axis direction, and the difference between the dimension of the traveling body 11 in the X-axis direction and the dimension of the modified region B in the X-axis direction The avoidance distance is determined from

The control device 17 performs obstacle avoidance processing to maintain the distance between the running object 11 and the obstacle at a predetermined value or more so that the moving object 11 and the obstacle do not come into contact with each other. Hereinafter, the obstacle avoidance process performed by the control device 17 will be explained along with its operation. The obstacle avoidance process is repeatedly performed while the traveling body 11 is traveling.

As shown in FIGS. 3 and 4, the control device 17 first determines whether a known obstacle H1 exists within the search area A (see step S01). The known obstacle H1 is an obstacle whose existence is known in advance, and is an obstacle that is distinguished from an unknown obstacle whose existence is unpredictable. For example, FIG. 4 shows an example in which a known obstacle H1 exists in the search area A. The known obstacle H1 is, for example, a wall forming a passage or a shelf installed on the floor.

In step S01, when the control device 17 determines that the known obstacle H1 exists within the search area A, the control device 17 reduces and limits the search area A. The control device 17 recognizes the existence of the known obstacle H1 based on the self-estimated position of the traveling object 11 based on the detection result of the sensor 18 and a pre-stored environmental map. The control device 17 obtains the self-estimated position from the detection results of the sensor 18 and the environmental map while the traveling object 11 is traveling. As shown in FIG. 4, when the traveling object 11 travels and a known obstacle H1 is included in the search area A, the control device 17 compares the obtained self-estimated position with the known obstacle H1 included in the environmental map. The presence of the known obstacle H1 can be recognized by comparing the position with the known obstacle H1. Therefore, the control device 17 corresponds to a known obstacle recognition section.

When the control device 17 recognizes the known obstacle H1, it reduces the search area A by setting the short side of the search area A that is close to the known obstacle H1 to a position that does not include the known obstacle H1. (See step S02). In the example shown in FIG. 4, the short side S4 is set at the position closest to the traveling object 11 (X1 in the X-axis direction) in the known obstacle H1. Specifically, the control device 17 changes the position of the short side S4 so that it follows the plane closest to the travel route R of the known obstacle H1 in the X-axis direction. Therefore, the known obstacle H1 is no longer included in the search area Ar after the search area A is reduced. Therefore, the control device 17 corresponds to an area limiting section. In this embodiment, in addition to the restriction due to the reduction of the search area A, the change area B, which is an area within the search area A, is reduced and restricted, and becomes the changed area Br after being reduced.

When the control device 17 determines in step S01 that the known obstacle H1 does not exist within the search area A, the control device 17 proceeds to step S03. In other words, the control device 17 does not reduce or limit the search area A and the change area B. Note that the control device 17 releases the restrictions on the reduced and restricted search area Ar and change area Br when the known obstacle H1 is located behind the long side S1 of the search area Ar due to the travel of the traveling object 11. Then, the search area A and the change area B are returned to those before the restriction. The control device 17 can recognize that the known obstacle H1 is located behind the long side S1 of the search area Ar based on the self-estimated position and the position of the known obstacle H1 included in the environmental map.

As shown in FIG. 3, in step S03, the control device 17 determines whether an unknown obstacle H2 exists within the search area A (or Ar). First, the control device 17 detects an unknown obstacle H2 existing in the direction of movement of the main body 12. The unknown obstacle H2 is detected based on the detection result of the sensor 18. If the X and Y coordinates of the irradiation point of the sensor 18 are within the search area A (Ar), the control device 17 identifies the irradiation point as an unknown obstacle H2, and determines that the unknown obstacle H2 exists. to decide.

In step S03, if the unknown obstacle H2 does not exist within the search area A (Ar), the control device 17 ends the process. On the other hand, if the unknown obstacle H2 exists within the search area A (Ar), the control device 17 performs the process of step S04. The control device 17 functions as an obstacle determination section. Therefore, the control device 17 corresponds to an obstacle determination section, and also functions as a known obstacle recognition section and an unknown obstacle determination section.

In step S04, the control device 17 determines whether the avoidable area As exists within the search area A (Ar). First, the control device 17 searches for an avoidable area As within the search area A (Ar). The search for the avoidable area As is performed by, for example, searching the search area Ar clockwise around the reference axis G as shown by the arrow Y1 in FIG. 5, and then searching the search area counterclockwise as shown by the arrow Y2. This is done by searching inside Ar.

The avoidable area As is a space in which the traveling object 11 can proceed in the Y-axis direction while maintaining the distance from the unknown obstacle H2 to a predetermined value or more when it is lined up with the unknown obstacle H2 in the X-axis direction. shows. That is, it is a space in which the vehicle can pass by the unknown obstacle H2 while keeping the distance to the unknown obstacle H2 at a predetermined value or more. Note that the predetermined value is set to prevent contact between the unknown obstacle H2 and the traveling object 11, taking into consideration the detection accuracy of the sensor 18 and the possibility that the unknown obstacle H2 is a moving object. There is.

The control device 17 determines a space within the search area A (Ar) whose dimension from the unknown obstacle H2 in the X-axis direction is equal to or greater than a threshold value as an avoidable area As. Note that the threshold value is set based on a dimension that allows the traveling object 11 to travel while maintaining the distance between the traveling object 11 and the obstacle at a predetermined value or more. In the example shown in FIG. 5, one unknown obstacle H2 exists within the search area Ar. The space between the unknown obstacle H2 and the short side S3 of the search area Ar becomes an avoidable area As whose dimension in the X-axis direction is equal to or larger than the threshold value. Since the space between the unknown obstacle H2 and the short side S4 of the search area Ar is less than the threshold value, it is not an avoidable area As.

As shown in FIG. 3, if the avoidable area As does not exist within the search area A (Ar), the control device 17 performs the process of step S09. On the other hand, if the avoidable area As exists within the search area A (Ar), the control device 17 performs the process of step S05. The control device 17 searches for whether there is an avoidable region As in which the traveling object 11 can be avoided in a horizontal direction intersecting the traveling direction (Y-axis direction) from the unknown obstacle H2. It functions as an exploration department.

As shown in FIGS. 3 and 5, in step S05, the control device 17 selects one avoidable area As to be used when performing avoidance action. Hereinafter, the avoidable area As used when performing an avoidance action will be referred to as an avoidance area At. When a plurality of avoidable areas As exist within the search area A (Ar), the control device 17 calculates the distance from the sensor 18 to the center of the avoidable area As in the X-axis direction. The control device 17 selects the avoidable area As having the shortest distance from the sensor 18 to the center, that is, the avoidable area As closest to the traveling object 11, as the avoidable area At.

On the other hand, as shown in FIG. 5, when there is one avoidable area As, the control device 17 selects this avoidable area As as the avoidable area At. The control device 17 then performs the process of step S06. The control device 17 functions as a calculation section.

In step S06, the control device 17 determines whether or not an obstacle exists within the change area B. If an obstacle exists within the change area B, the control device 17 performs the process of step S07.

As shown in FIG. 3, in step S07, the control device 17 controls the traveling object 11 to move toward the avoidance area At. If the unknown obstacle H2 exists within the change area B, the traveling object 11 will travel to avoid the unknown obstacle H2. The change area B can be said to be an area for determining whether or not to actually perform an avoidance action with respect to the detected unknown obstacle H2. Even if the unknown obstacle H2 exists in the search area A (Ar), if the unknown obstacle H2 does not exist in the changed area B, no avoidance action will be taken, and the unknown obstacle H2 in the changed area B will not be taken. Avoidance action is performed when the obstacle H2 exists.

The dimension of the change area B in the Y-axis direction, that is, the dimensions of the short sides S7 and S8 of the change area B, determines the avoidance start distance when the traveling object 11 starts the avoidance action. The control device 17 starts an avoidance action when the distance between the traveling object 11 and the unknown obstacle H2 in the Y-axis direction becomes less than the dimension of the change area B in the Y-axis direction.

The dimension of the change area B in the X-axis direction determines the avoidance distance when performing the avoidance action. The avoidance distance is the distance between the traveling object 11 and the obstacle in the X-axis direction. The dimension of the changed region B in the X-axis direction is longer than the longest dimension of the traveling body 11 in the X-axis direction, and the difference between the dimension of the traveling body 11 in the X-axis direction and the dimension of the modified region B in the X-axis direction The avoidance distance is determined from

As shown in FIG. 6, the avoidance action is performed by causing the traveling body 11 to travel diagonally with respect to the traveling route R toward the avoidance area At from the traveling route R. When the avoidance action is performed, the X coordinate of the traveling object 11 will move away from the X coordinate of the traveling route R, and the traveling object 11 will deviate from the traveling route R. The traveling route R can be said to be the route on which the traveling object 11 travels when no avoidance action is taken.

As shown in FIG. 3, after completing the process in step S07, the control device 17 performs the process in step S06. That is, while it is determined in step S06 that the unknown obstacle H2 exists, avoidance action is performed in step S07.

As shown in FIG. 3, when it is determined in step S06 that the unknown obstacle H2 does not exist within the change area B, the control device 17 performs the process of step S08. Specifically, if the unknown obstacle H2 exists within the change area B, it is determined in step S06 that the unknown obstacle H2 continues to exist, and the avoidance action in step S07 continues. It will be done. When the avoidance action is completed, the unknown obstacle H2 no longer exists within the change area B, and the process of step S08 is performed.

In step S08, the control device 17 returns the traveling object 11 to the traveling route R, and ends the process. Specifically, if the avoidance action is being performed in step S07, the control device 17 controls the drive mechanism 14 so that the traveling object 11 returns to the traveling route R. As a result, the X coordinate of the traveling body 11 approaches the X coordinate of the traveling route R, and the traveling body 11 returns to the traveling route R. Moreover, when the avoidance action is not performed, the state in which the traveling object 11 is traveling on the traveling route R is maintained.

On the other hand, if the avoidable area As does not exist within the search area A (Ar), in step S09, the control device 17 determines whether or not the unknown obstacle H2 exists within the change area B (or Br). . The control device 17 performs the process of step S10 when the unknown obstacle H2 exists within the change area B (or Br). On the other hand, if the unknown obstacle H2 does not exist within the change area B (or Br), the control device 17 ends the process. The control device 17 stops the traveling body 11 in step S10. That is, the control device 17 stops the traveling object 11 when the unknown obstacle H2 exists within the change area B and the avoidable area As does not exist within the search area A (or Ar).

Note that FIG. 7 shows a case where the known obstacle H1 does not exist in the search area A and the unknown obstacle H2 exists in the search area A. In FIG. 7, since the known obstacle H1 does not exist in the search area A, the search area A is not reduced. The control device 17 performs avoidance processing for the unknown obstacle H2 through a series of steps starting from step S03 shown in FIG. In this way, the autonomous mobile body 10 and the control method for the autonomous mobile body 10 in this embodiment search for an optimal avoidance route in consideration of the known obstacle H1.

This embodiment has the following effects.
(1) When a known obstacle H1 exists within the search area A while the traveling object 11 is traveling on a preset travel route R, control is performed so that the known obstacle H1 is not recognized as an obstacle to be avoided. The device 17 reduces and limits the search area A. On the other hand, the control device 17 searches for an avoidance route for the unknown obstacle H2, which is an obstacle other than the known obstacle H1, in the restricted search area Ar. Therefore, even if the known obstacle H1 exists within the search area A, the control device 17 does not search for an avoidance route for the known obstacle H1. As a result, the traveling object 11 will not be unable to return to the traveling route R due to the traveling object 11 avoiding the known obstacle H1.

(2) The control device 17 as a known obstacle recognition unit determines the search area before limiting the search area A based on the self-estimated position of the traveling object 11 estimated based on the detection result of the sensor 18 and the environmental map stored in advance. It can be recognized that the obstacle in A is the known obstacle H1.

(3) The control device 17 serving as an area limiting unit limits the search area A in the width direction of the traveling route R from the traveling object 11 to the position closest to the known obstacle H1. For this reason, the known obstacle H1 does not deviate from the restricted search area Ar, and the control device 17 does not determine that the known obstacle H1 to be avoided exists within the search area Ar.

(4) The control device 17 as an area restriction unit reduces and limits a change area B, which is set within the search area A and is narrower than the search area A, in accordance with the restrictions of the search area A. Therefore, the change region B in which the unknown obstacle H2 needs to be detected can be narrowed, and the load for detecting the unknown obstacle H2 can be reduced.

(5) When the control device 17 as an obstacle determination section determines that an obstacle present in the search area A (or Ar) is an unknown obstacle H2, the control device 17 as a search section It is searched whether there is an avoidable area As that can be avoided. Therefore, when the avoidable area As exists, the traveling object 11 can travel along the avoidance route to avoid the unknown obstacle H2, and can return to the travel route R after the avoidance. When the avoidable area As does not exist, the traveling body 11 can stop.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention. For example, the following modifications may be made.

○ In the above embodiment, the known obstacle recognition unit recognizes that the obstacle in the search area is a known obstacle before limiting the search area based on the self-estimated position of the traveling object and the pre-stored environmental map. I recognized this, but it is not limited to this. For example, the known obstacle recognition unit may recognize that an obstacle within the search area is a known obstacle before limiting the search area by comparing the detection result of the sensor with a pre-stored environmental map.
In the above embodiment, the sensor is a laser range finder (LRF), but the sensor is not limited to this. The sensor may be any means that can measure relative coordinates indicating the distance between the traveling object 11 and the obstacle, and may be, for example, a stereo camera or the like.
In the above embodiment, the case where one unknown obstacle exists in the restricted search area has been described, but the present invention is not limited to this. A plurality of unknown obstacles may exist in the limited search area. For example, when a first obstacle and a second obstacle exist in a restricted search area, an avoidable area in the X-axis direction may be determined. When a plurality of avoidable areas exist, any one of the avoidable areas may be selected.
In the above embodiment, in step S06 of FIG. 3, if the unknown obstacle H2 is present in the change area B, the control device 17 continues in step S06 to determine whether the unknown obstacle H2 exists. Although an example has been shown in which it is determined that the vehicle is present and the avoidance action in step S07 is continued, the invention is not limited to this. For example, after it is continuously determined in step S06 that the unknown obstacle H2 exists, the avoidance action in step S07 may be performed and the process may be terminated. In this case, after the process ends, control is executed again from step S01.
In the above embodiment, the traveling body 11 is stopped in step S10, but this may be changed. If an obstacle exists in the change area B (Br) and the avoidable area As does not exist in the search area A (Ar), the control device 17 may change the process of step S10 as appropriate. For example, a travel route other than the travel route R may be generated, and the traveling object 11 may be made to travel along this travel route.
In the embodiment described above, the traveling body is provided with omnidirectional wheels, but the traveling body is not limited to this. For example, the traveling direction of the vehicle may be changed by two-wheel speed difference control in which two wheels are used and the rotational speeds of the two wheels are made different to perform steering. Alternatively, the traveling direction may be changed by providing an individual steering mechanism for each wheel and performing individual steering for each wheel.
In the embodiments described above, the autonomous running body for transporting loads is provided with a loading platform, but the autonomous running body is not limited to transporting loads. The autonomous running body may be any running body that can autonomously run, and may be, for example, an autonomous vacuum cleaner.

10 Autonomous running body 11 Running body 17 Control device (obstacle determination unit, known obstacle determination unit, area restriction unit, search unit, traveling direction change unit, calculation unit)
18 Sensor A Search area Ar Search area (after reduction limit)
As Avoidable area At Avoidable area B Change area Br Change area (after reduction change)
H1 Known obstacle H2 Unknown obstacle R Travel route

Claims (5)

A running body,
a sensor mounted on the traveling body;
an obstacle determination unit that determines whether an obstacle to be avoided exists within a search area that extends in the direction of a traveling route of the traveling object based on the detection result of the sensor;
When the obstacle determination unit determines that the obstacle exists within the search area, avoidance that allows the traveling object to avoid the obstacle in a horizontal direction that intersects with the traveling direction. An autonomous running body comprising: a search unit that searches whether a possible region exists;
When a known obstacle whose existence is known in advance exists in the search area, an area where the search area is reduced and restricted so that the obstacle determination unit does not recognize the known obstacle as an obstacle to be avoided. Equipped with a restriction part,
When the obstacle determination unit determines that the obstacle existing in the search area reduced by the area restriction unit is an unknown obstacle, the search unit determines that the obstacle exists in the search area reduced by the area restriction unit. searching whether a possible area exists in the search area reduced by the area limiting unit ;
A change area that is narrower than the search area is set within the search area,
The change area is an area for determining whether or not to actually take avoidance action with respect to the unknown obstacle detected in the change area,
The area restriction section is
reducing and limiting the change area in accordance with the limit of the search area;
An autonomous mobile body, characterized in that when the unknown obstacle exists within the reduced and restricted change area and the avoidable area does not exist within the search area, the autonomous mobile body stops running. The autonomous driving system according to claim 1, further comprising a known obstacle recognition unit that recognizes the known obstacle in the search area based on a self-estimated position of the traveling object and a pre-stored environmental map. body. The autonomous vehicle according to claim 1, further comprising a known obstacle recognition unit that recognizes the known obstacle within the search area based on a detection result of the sensor. The autonomous vehicle according to any one of claims 1 to 3, wherein the area limiting unit limits the search area in the width direction of the traveling route to a position closest to the known obstacle from the traveling object. Running body. Run the running body,
Determining whether or not an obstacle exists within a search area extending in the direction of the route traveled by the traveling body based on the detection result of a sensor mounted on the traveling body;
If it is determined that the obstacle exists within the search area, whether there is an avoidable area from the obstacle in a horizontal direction that intersects with the traveling direction, in which the traveling object can be avoided. In a method for controlling an autonomous running body that searches for whether
A change area that is narrower than the search area is set within the search area,
The change area is an area for determining whether or not to actually take avoidance action with respect to the unknown obstacle detected in the change area,
When a known obstacle whose existence is known in advance based on the detection result of the sensor exists in the search area, the search area is reduced and restricted so that the known obstacle is not recognized as an obstacle to be avoided. death,
When it is determined that the obstacle existing in the search area, which is reduced so as not to recognize the known obstacle as an obstacle to be avoided, is an unknown obstacle, the traveling object can be caused to avoid it. searching whether an avoidable area exists in the reduced search area;
the modification area is reduced and restricted in accordance with the restriction of the search area;
Autonomous running characterized in that when the unknown obstacle exists within the reduced and restricted change area and the avoidable area does not exist within the search area, the traveling of the running object is stopped. How to control your body.

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