Autonomous traveling robot and method for controlling same

Abstract

An autonomous traveling robot (1) is provided with: a sensor (50) configured to detect the presence or absence of an object within a predetermined detection range (R) in the traveling direction of the autonomous traveling robot (1); and a control unit (60) configured to, when the sensor (50) does not detect the object in the detection range (R) while the autonomous traveling robot (1) is traveling, recognize the detection range (R) as a travel permissible area (A1) where the autonomous traveling robot (1) is permitted to travel, and configured to cancel the recognition of the travel permissible area (A1) after a predetermined time (t) has elapsed from the recognition.

Description

Autonomous robot and control method thereof The present invention relates to an autonomous mobile robot and a control method thereof. For example, Patent Document 1 discloses a warehouse system. In this warehouse system, a plurality of carts are used to transport trays storing items from storage shelves on which the trays are arranged to an order preparation station for preparing the transported goods. In such a warehouse system, it is required that the plurality of carts travel efficiently. International Publication No. 2018 / 189110 An object of the present invention is to provide an autonomous mobile robot and a control method thereof that can expand the range in which the autonomous mobile robot is permitted to travel at low cost. An autonomous driving robot according to one embodiment of the present invention comprises a sensor configured to detect the presence or absence of an object within a predetermined detection range in the driving direction of the autonomous driving robot, and a control unit configured to recognize the detection range, in which the sensor does not detect an object while the autonomous driving robot is driving, as a driving-allowed area that allows the autonomous driving robot to drive, and to revoke the recognition of the driving-allowed area after a predetermined time has elapsed since the recognition. In an autonomous robot according to one embodiment of the present invention, the control unit is configured to, by canceling the certification, certify the driving-permitted area as a driving-prohibited area in which driving of the autonomous robot is prohibited. In an autonomous driving robot according to one embodiment of the present invention, the control unit is configured to recognize the detection range in which the presence of the object is detected as a no-driving area in which the autonomous driving robot is prohibited from traveling. In an autonomous robot according to one aspect of the present invention, the object includes another robot or a human worker. In an autonomous running robot according to one aspect of the present invention, the predetermined time is set based on the speed of the autonomous running robot. In an autonomous robot according to one embodiment of the present invention, the detection range is set at a predetermined distance or more from the sensor, and a warning area is set in which the speed of the autonomous robot is slowed down when the presence of the object is detected. In an autonomous robot according to one embodiment of the present invention, a danger area is set within the detection range, which is less than the specified distance, and which causes the autonomous robot to stop moving when the presence of the object is detected. In an autonomous running robot according to one aspect of the present invention, the permitted traveling area is also applied to another autonomous running robot besides the autonomous running robot. In an autonomous robot according to one aspect of the present invention, the sensor is a 3D distance measuring sensor. In an autonomous mobile robot according to one aspect of the present invention, the autonomous mobile robot is a forklift. A control method for an autonomous driving robot according to one embodiment of the present invention includes the steps of detecting the presence or absence of an object within a predetermined detection range in the driving direction of the autonomous driving robot by a sensor while the autonomous driving robot is driving, and recognizing the detection range in which the object is not detected while the autonomous driving robot is driving as a driving-allowed area that allows the autonomous driving robot to drive, and revoking the recognition of the driving-allowed area after a predetermined time has elapsed since the recognition. A program for controlling an autonomous driving robot according to one embodiment of the present invention causes a computer to execute the steps of: detecting the presence or absence of an object using a sensor within a predetermined detection range in the driving direction of the autonomous driving robot while the autonomous driving robot is driving; recognizing the detection range in which the object is not detected while the autonomous driving robot is driving as a driving-allowed area that allows the autonomous driving robot to drive, and revoking the recognition of the driving-allowed area after a predetermined time has elapsed since the recognition. FIG. 1 is a perspective view generally showing a warehouse system 100 in which an autonomous traveling robot 1 according to one embodiment of the present invention is incorporated; FIG. 2 is a perspective view generally showing a structure of a forklift 1 according to one embodiment of the present invention; FIG. 3 is a functional block diagram generally showing a configuration of a management server 140; FIG. 4 is a functional block diagram generally showing a configuration of the forklift 1; FIG. 5 is a diagram for explaining the operation of the forklift 1 when it is traveling; and FIG. 6 is a flowchart for explaining processing while the forklift 1 is traveling according to one embodiment of the present invention.

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view that shows a warehouse system 100 in which an autonomous mobile robot 1 according to an embodiment of the present invention is incorporated. An example of the warehouse system 100 is established by, for example, a plurality of floors in a building. In this example, as shown in FIG. 1, the warehouse system 100 has a lower floor 101 and a floor above the lower floor 101, i.e., an upper floor 102. A travel path for the autonomous mobile robot 1 is formed on the floor surfaces of the lower floor 101 and the upper floor 102, respectively. As will be described later, the autonomous mobile robot 1 is, for example, a forklift 1 that can autonomously travel on the floor surfaces by self-location estimation on each of the lower floor 101 and the upper floor 102. In this example, a plurality of forklifts 1 are arranged on each of the lower floor 101 and the upper floor 102. In the warehouse system 100, a temporary storage area 112 is defined in a predetermined area on the floor surface of the lower floor 101 and the upper floor 102, for temporarily storing a pallet 111 on whose surface one or more cardboard boxes 110 containing a large number of identical or different items are mounted. In this example, the pallet 111 is placed directly on the floor surface. A plurality of temporary storage areas 112 may be defined on the floor surface. In the temporary storage area 112, for example, one or more pallets 111 on which one or more cardboard boxes 110 are mounted are further stacked in two layers on the cardboard box 110 mounted on the pallet 111. Note that the pallet 111 is formed, for example, in a rectangular or square flat plate shape in a plan view. A pair of insertion holes for inserting the forks of a forklift are formed on the four side surfaces of the pallet 111 that connect the front and back surfaces facing each other. The warehouse system 100 has racks 120 arranged on the floor surfaces of the lower floor 101 and the upper floor 102. The racks 120 are, for example, storage shelves for storing one or more of the above-mentioned cardboard boxes 110 placed on a pallet 111. The racks 120 are storage shelves for storing items on the pallet 111. The racks 120 have a plurality of rack units 122 formed by, for example, metal frame members 121. The racks 120 are formed by stacking the plurality of rack units 122 in the height direction while simultaneously connecting adjacent rack units 122 in the width direction and length direction parallel to the floor surface. In this example, two tiers of rack units 122 are connected to each other in the height direction and width direction, and a plurality of rack units 122 are connected to each other in the length direction. Each rack unit 122 defines one storage space 123 for storing a pallet 111 on which one or more cardboard boxes 110 are placed. Each storage space 123 can be accessed by the forks of the forklift 1 from the side of the rack 120. In this way, the forklift 1 can load the pallet 111 into the storage space 123 from the side of the rack 120, and can remove the pallet 111 to the outside of the storage space 123 from the side of the rack 120. Note that the number of rack units 122 constituting the rack 120 described above in the height direction and length direction is one example, and the rack 120 may be formed by combining other numbers of rack units 122 with each other. The warehouse system 100 has a vertical conveying device 130 capable of conveying a pallet 111 carrying one or more cardboard boxes 110 between the lower floor 101 and the upper floor 102. The vertical conveying device 130 can also convey only the pallet 111. In addition, the vertical conveying device 130 may convey, for example, a metal mesh pallet instead of the pallet 111. The vertical conveying device 130 has a conveying mechanism 131 capable of moving up and down in the vertical conveying space, and a conveyor 132 extending to the conveying mechanism 131 on the lower floor 101 and the upper floor 102, respectively. The conveyor 132 can convey the pallet 111 conveyed to the conveyor 132 by, for example, a forklift 1 to the conveying mechanism 131, and can convey the pallet 111 conveyed by the conveying mechanism 131 to the front of the forklift 1. The transport mechanism 131 can transport the pallet 111 transported by the conveyor 132 from the lower floor 101 to the upper floor 102 or from the upper floor 102 to the lower floor 101. In a plan view of the floor surfaces of the lower floor 101 and the upper floor 102, the area other than the area where the temporary storage area 112 is defined and the area where the racks 120 are arranged is defined as a movement path of the forklift 1. However, a predetermined area around the temporary storage area 112 and a predetermined area around the racks 120 are defined as buffer areas in which the intrusion of the forklift 1 is restricted. FIG. 2 is a perspective view showing a schematic structure of the forklift 1 according to an embodiment of the present invention. The forklift 1 is used to transport the cardboard boxes 110 or articles placed on the pallets 111 to various positions in the warehouse system 100. The forklift 1 can transport not only the pallets 11 on which the cardboard boxes 110 are placed, but also one or more pallets 111 on which the cardboard boxes 110 are not placed. As described above, the forklift 1 can autonomously travel based on its own position estimation in the warehouse system 100, but can also travel manually by an operator's operation. In the following description, in the longitudinal direction of the forklift 1, the direction toward the front of the forklift 1 is defined as the forward direction FD, while the direction toward the rear of the forklift 1 opposite to the forward direction FD is defined as the rearward direction BD. Similarly, in the height direction of the forklift 1, the direction toward the top of the forklift 1 is defined as the upward direction UD, while the direction toward the bottom of the forklift 1 opposite to the upward direction UD is defined as the downward direction DD. Furthermore, in the lateral direction of the forklift 1, the direction toward the left of the forklift 1 is defined as the leftward direction LD, while the direction toward the right of the forklift 1 opposite to the leftward direction LD is defined as the rightward direction RD. The forklift 1 includes a vehicle body 10 and a load handling assembly 20 disposed at the front end of the vehicle body 10. The vehicle body 10 includes a main body 11, a pair of straddle legs 12, 12 extending parallel to each other in a forward direction FD from the front end of the main body 11, and a head guard 13 attached to the upper end of the main body 11. The main body 11 includes, for example, at its rear end, a driver's seat 14 on which an operator can stand, and an operation unit 15 on its upper surface for the operator to operate the forklift 1. The load handling assembly 20 is disposed between the straddle legs 12, 12. The head guard 13 prevents luggage or objects from falling toward the operator from above. The vehicle body 10 includes a pair of front wheels 16 disposed at the lower part of each of the straddle legs 12, 12, and, for example, one rear wheel (not shown) disposed at the lower part of the main body 11. A drive motor (not shown) mounted in the main body 11 is connected to the rear wheels. The drive motor is supplied with power from, for example, a battery (not shown) similarly mounted in the main body 11. That is, the rear wheels are drive wheels, while the front wheels 16 are driven wheels. The rear wheels are disposed, for example, offset to the left in the LD direction from the center of the forklift 1 in the left-right direction. The rear wheels are driven in the forward direction and change their angle in the left-right direction, so that the forklift 1 can move forward, backward, left and right. When the forklift 1 transports the pallet 111, it travels facing backward in the BD direction. The load handling assembly 20 is an assembly capable of lifting and lowering the pallet 111. The load handling assembly 20 has a mast assembly 30 and a fork assembly 40. The mast assembly 30 is supported between a pair of straddle legs 12, 12 so as to be movable in a forward direction FD and a rearward direction BD. The fork assembly 40 is supported at the front end of the mast assembly 30 so as to be movable in an upward direction UD and a downward direction DD. In the state shown in Fig. 1, the mast assembly 30 is disposed at a position where it is maximally advanced in the forward direction FD. Also, the fork assembly 40 is disposed at a position raised in the upward direction UD from the lowest position. The mast assembly 30 has a base 31 disposed between the pair of straddle legs 12, a pair of outer masts 32 standing upright in the upward direction UD from the base 31, and a pair of inner masts 33 disposed inside the pair of outer masts 32 in the left direction LD and right direction RD, respectively. The outer masts 32 are formed integrally with the front end of the base 31, for example. The outer masts 32 are disposed spaced apart from each other at a predetermined interval in the left-right direction. The base 31, the outer masts 32 and the inner masts 33 are supported between the pair of straddle legs 12 so as to be movable in the forward direction FD and the rearward direction BD. The inner masts 33, 33 stand upright in the height direction adjacent to the inner sides of the outer masts 32, 32 in the left-right direction. The inner masts 33, 33 are supported by the outer masts 32, 32 so as to be able to move in the height direction relative to the outer masts 32, 32. The fork assembly 40 is supported by the inner masts 33, 33 so as to be able to move in the height direction relative to the inner masts 33, 33. Since the fork assembly 40 is supported by the outer masts 32 via the inner masts 33, 33, it can move in the forward direction FD and the rearward direction BD together with the brackets 41, the outer masts 32 and the inner masts 33. The fork assembly 40 has a bracket 41, a pair of forks 42, 42, and a backrest 43. The bracket 41 is supported by the inner masts 33, 33 so as to be movable in the height direction relative to the inner masts 33, 33. The pair of forks 42, 42 are attached to the front surface of the bracket 41. Each of the pair of forks 42, 42 extends in the forward direction FD from the bracket 41 at a position where, for example, one outer mast 32 and one inner mast 33 are disposed in the left-right direction. The backrest 43 is attached, for example, to the upper end of the bracket 41. The backrest 43 prevents cargo on a pallet being lifted by the forks 42 from falling backward of the fork assembly 40. In this example, the forklift 1 has a distance measurement sensor 50 attached on the head guard 13 along the rear end of the head guard 13. The distance measurement sensor 50 is disposed, for example, at the center in the left-right direction of the forklift 1. The distance measurement sensor 50 is a 3D LiDAR (light detection and ranging) sensor that can detect the presence or absence of an object (if an object exists, its shape) within a predetermined three-dimensional detection range in the rear direction BD of the forklift 1. Specifically, the distance measurement sensor 50 obtains 3D point cloud data of objects within the detection range by irradiating this detection range with laser light. The 3D point cloud data is a collection of points having three-dimensional coordinates in the three-dimensional detection range. The 3D point cloud data is composed of the coordinates and color information of each point, and the presence or absence of an object within the detection range is detected by measuring the distance from the distance measurement sensor 50 to each point. The three-dimensional detection range of the distance measuring sensor 50 is, for example, a predetermined irradiation distance from the forklift 1 toward the rear direction BD, a predetermined angular range in the left-right direction of the forklift 1, and a predetermined angular range in the height direction of the forklift 1. In one example of the distance measuring sensor 50, the irradiation distance is set to 3 m, the angular range in the left-right direction is set to 145 degrees, and the angular range in the height direction is set to 60 degrees. The frequency of the laser light of the distance measuring sensor 50 is set to, for example, 5 to 10 Hz. These values ​​of the distance measuring sensor 50 are merely examples, and other values ​​may be set. Although the distance measuring sensor 50 is attached on the head guard 13, it may be attached, for example, to the rear end of the main body 11 of the vehicle body 10 of the forklift 1 as long as it can irradiate the laser light in the rear direction BD. The forklift 1 may further include three distance measurement sensors (not shown) for detecting the presence or absence of an object in the detection ranges of the forward direction FD and the right direction RD, the detection ranges of the forward direction FD and the left direction LD, and the detection range of the backward direction BD. These distance measurement sensors may be, for example, 2D LiDAR sensors. For example, one distance measurement sensor may be attached to the front end of each straddle leg 12, and one distance measurement sensor may be attached to the rear end and lower end position of the main body 11. These three distance measurement sensors are arranged at the same height from the floor surface. These distance measurement sensors can detect the presence or absence of an object in a two-dimensional detection range over 360 degrees horizontally at the height of the distance measurement sensors. These distance measurement sensors may be used to generate a two-dimensional map of the layout of the temporary storage area 112 and the racks 120 by mapping the lower floor 101 and the upper floor 102 of the warehouse system 100. It is to be noted that a three-dimensional map of the layout may be generated by using 3D LiDAR for the distance measurement sensors. As shown in Fig. 3, the warehouse system 100 has a management server 140 that manages the operation of the forklift 1 with respect to the entry, storage, and retrieval of goods, the storage status of goods in the temporary storage area 112 and the racks 120, and the like. This management is realized by the control unit (computer) executing a program stored in the storage unit, as described below. Specifically, these processes are executed according to the information processing described in the program. In other words, the information processing described in the program functions as a concrete means in which the software related to the program and various hardware resources of the warehouse system 100 work together, by reading the program into the control unit. The management server 140 includes a control unit 150 and a storage unit 160. The control unit 150 includes a communication control unit 151, an inventory management unit 152, and a transport control unit 153. The storage unit 160 stores a program 161 for controlling the process of warehousing, storage, and retrieval of items in the warehouse system 100. In addition to the program 161, the storage unit 160 stores information about items stored in the temporary storage area 112 and the rack 120 (e.g., information for managing which items are stored in which locations) and a two-dimensional map showing the layout of the temporary storage area 112 and the rack 120 in the warehouse system 100. The control unit 150 manages the warehouse system 100 by executing the program 161 stored in the storage unit 160. The management server 140 may be realized, for example, by a physical server installed in a building in which the warehouse system 100 is established, or may be realized, for example, by a cloud server built on the Internet. The communication control unit 151 controls communication between the management server 140 and the forklift 1. The communication method may be, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), or the like. The inventory management unit 152 manages the inventory status of the warehouse system 100. Specifically, the inventory management unit 152 manages information (SKU) for identifying each item, information on the inventory number of each item specified by the SKU, information (ID) for identifying the location where the item is stored, and the like, in association with each other. The transport control unit 153 manages and controls the operation of the forklift 1. Specifically, the transport control unit 153 generates a transport instruction for instructing the forklift 1 on which item from which location to transport to which location in the warehouse system 100. To specifically explain the generation of transport instructions in the transport control unit 153, the transport control unit 153 generates transport instructions for a specified forklift 1 for each warehousing or unloading process in the warehouse system 100. The case of an instruction to transport goods only on the lower floor 101 or the upper floor 102 is as follows. The transport instruction in this case includes, for example, a) a first movement path from the current position of the forklift 1 to the specified pallet 111, b) an instruction regarding a pick operation to pick up the specified pallet 111, c) a second movement path to a specified location to which the specified pallet 111 is transported, and d) an instruction regarding a drop operation to drop the specified pallet 111 at the specified location. On the other hand, a transport instruction from the lower floor 101 to the upper floor 102, or from the upper floor 102 to the lower floor 101, is as follows. Specifically, the transport instruction includes a first transport instruction to the forklift 1 arranged on one floor and a second transport instruction to the forklift 1 arranged on the other floor. The first transport instruction includes a) a first movement path from the current position of the forklift 1 to the designated pallet 111, b) an instruction regarding a pick operation to pick the designated pallet 111, c) a second movement path to the conveyor 132 of the vertical transport device 130, and d) an instruction regarding a drop operation to drop the designated pallet 111 onto the conveyor 132. On the other hand, the second transport instruction includes a) a first movement path from the current position of the forklift 1 to the conveyor 132 of the vertical transport device 130, b) an instruction for a pick operation to pick the specified pallet 111, c) a second movement path to a specified location to transport the specified pallet 111, and d) an instruction for a drop operation to drop the specified pallet 111 at the specified location. In this way, in the case of a transport instruction from the lower floor 101 to the upper floor 102, or a transport instruction from the upper floor 102 to the lower floor 101, a transport instruction is transmitted to each of the forklifts 1. Note that the first movement path and the second movement path do not need to be the shortest path, and may be a rough path along which the forklift 1 can move on the map of the warehouse system 100. That is, the movement path is a path on which no object that obstructs the travel of the forklift 1 exists. That is, there is no reference object (e.g., rack 120, wall, etc.) that the forklift 1 refers to for self-location estimation on the movement path. FIG. 4 is a functional block diagram showing a schematic configuration of the forklift 1. The forklift 1 has a control unit 60 and a storage unit 70. The control unit 60 has a communication control unit 61 and an equipment control unit 62. The storage unit 70 stores a program 71 for controlling the operation of the forklift 1. In addition to the program 71, the storage unit 70 stores a two-dimensional map showing the layout of the temporary storage area 112 and the racks 120 in the warehouse system 100. This map is shared with the management server 140. As described above, the map is generated by, for example, the forklift 1 mapping the lower floor 101 and the upper floor 102 using a ranging (2D LiDAR) sensor. The control unit 60 controls the operation of the forklift 1 by executing the program 71 stored in the storage unit 70. The communication control unit 61 controls communication between the management server 140 and the forklift 1. The equipment control unit 62 controls the operation of the forklift 1. Specifically, the equipment control unit 62 can control the forward movement, backward movement, and left and right turning of the forklift 1 by driving the rear wheels, and the operation of picking and dropping the pallet 111 by driving the mast assembly 30 and the fork assembly 40 of the loading assembly 20. In addition, as described later, the equipment control unit 62 further manages a travel-permitted area in which the forklift 1 is permitted to travel while the forklift 1 is traveling on the lower floor 101 and the upper floor 102, and a travel-prohibited area in which the forklift 1 is not permitted to travel, i.e., the forklift 1 is prohibited from traveling. FIG. 5 is a diagram for explaining the operation of the forklift 1 when traveling. In this example, a scene is assumed in which the forklift 1 travels in the backward direction BD. At time t0, the forklift 1 is stopped at a position x0. The distance measuring sensor 50 acquires 3D point cloud data of the detection range R by irradiating a three-dimensional detection range R in the backward direction BD with a laser beam. In the detection range R, an area that is a predetermined distance or more from the distance measuring sensor 50 is defined as a warning area R1, and an area that is less than a predetermined distance from the distance measuring sensor 50 is defined as a danger area R2. When an object is detected in the warning area R1 based on the 3D point cloud data, the forklift 1 decelerates its speed. On the other hand, when an object is detected in the danger area R2, the forklift 1 stops. The object includes, for example, another robot, a human worker, some obstacle, etc. The forklift 1 can travel on the floor surface at a speed of, for example, 1.4 m per second. Here, the forklift 1 starts traveling from position x0. The forklift 1 reaches position x1 at time t1 and stops without detecting an object within the detection range R during traveling. In this case, the detection range R detected at a predetermined time interval from time t0 to time t1 is recognized as a traveling allowable area A1 in which the forklift 1 is permitted to travel. For example, the forklift 1 can travel freely within the recognized traveling allowable area A1. Here, if the forklift 1 is stopped at position x1 from time t1 to time t2, the recognition of the predetermined traveling allowable area A1 is canceled as the time elapses from time t1 to time t2. Specifically, the traveling allowable area A1 in which a predetermined threshold time has elapsed since the recognition is recognized as a traveling prohibited area A2 in which the forklift 1 is not permitted to travel. The travel-allowed area A1 and the travel-prohibited area A2 thus determined may be generated as a cost map by being superimposed on a map possessed by the forklift 1. That is, in the cost map, the areas defined as the travel-allowed area A1 and the travel-prohibited area A2 are displayed on the map. This cost map may be stored only in the forklift 1, but may also be transmitted to the management server 140 and stored in the storage unit 160 of the management server 140. The cost map may also be shared with other forklifts 1 via the management server 140. In this way, the travel-allowed area A1 and the travel-prohibited area A2 determined by the forklift 1 can be applied to other forklifts 1. Specifically, for example, when setting a travel route of another forklift 1, the travel-allowed area A1 and the travel-prohibited area A2 determined by the forklift 1 can be referred to, thereby setting a travel route that avoids the travel-prohibited area A2. When considering a group of forklifts 1, for example, when a person is near a destination that cannot be seen by other forklifts 1, information from a certain forklift 1 can be used to set a travel route of the other forklifts 1. Such information sharing helps to coordinate the fleet of forklifts 1, reducing costs and improving system efficiency. In addition, the predetermined time until the travel permitted area A1 is cancelled and the travel prohibited area A2 is determined is determined taking into consideration various factors. For example, the predetermined time may be determined according to the speed of the forklift 1, the time when another object (e.g., another robot, a human worker, etc.) is expected to enter the travel permitted area A1, etc. FIG. 6 is a flowchart for explaining the processing of the forklift 1 according to an embodiment of the present invention. A transport instruction is sent from the transport control unit 153 of the management server 140 to a specified forklift 1. The forklift 1 that receives the transport instruction moves from its current position to a specified pick position according to the transport instruction. During travel for moving, the distance measurement sensor 50 detects the presence or absence of an object in the detection range R at time t based on the 3D point cloud data of the detection range R acquired at a predetermined time interval (step S1). If no object is detected (step S1, NO), the detection range R at that time t is recognized as a travel allowable area A1 (step S2). The recognized travel allowable area A1 is reflected in the cost map of the storage unit 70 based on, for example, coordinate values ​​that define a two-dimensional area obtained by viewing the three-dimensional space of the detection range R in a planar view (step S3). After that, the processing returns to step S1. On the other hand, on the cost map, the passage of time from the recognition of the travel-allowed area A1 is observed (step S4). If the predetermined time has not passed since the recognition of the travel-allowed area A1 (step S4, NO), the process returns to step S4. On the other hand, when the predetermined time has passed since the recognition (step S4, YES), the recognition of the travel-allowed area A1 is cancelled. That is, the travel-allowed area A1 is recognized as a travel-prohibited area A2 (step S5). The recognized travel-prohibited area A2 is reflected in the cost map of the storage unit 70 based on, for example, coordinate values ​​that define a two-dimensional area in which the three-dimensional space of the detection range R is viewed in a plane (step S6). After that, the process returns to step S1. In this way, the areas that constitute the travel-allowed area A1 and the travel-prohibited area A2 are dynamically updated on the cost map. On the other hand, if an object is detected in the detection range R at a certain time t while the forklift 1 is traveling (step S1, YES), the detection range R at that time t is recognized as a travel-prohibited area A2 (step S7). The recognized travel-prohibited area A2 is reflected on the cost map of the storage unit 70 (step S8). Then, the process returns to step S1. At the same time as step S7, the process of step S9 is executed. Specifically, since the object first enters the warning area R1 of the detection range R, the forklift 1 decelerates its speed (step S9). Furthermore, if the object enters the danger area R2 due to the traveling of the forklift 1, the forklift 1 stops at that time t (step S10). Then, it is observed whether the object has been removed from the danger area R2 (step S11), and if it has not been removed (step S11, NO), the transport process of the forklift 1 ends due to an error. Thereafter, for example, 1) the object is removed from the danger area R2, 2) the error is cleared by operating a switch provided on the forklift 1 or the like, and 3) the error on the program 71 is cleared, whereby the work based on the transport instruction of the forklift 1 is resumed. Note that the work 2) may be omitted. On the other hand, if the object is removed from the danger area R2 (step S11, YES), the process returns to step S1. The above process is executed while the forklift 1 is traveling. Specifically, the process may be executed between the current position of the forklift 1 and the pick position of the designated pallet 111, and between the pick position and the designated drop position of the pallet 111. When the forklift 1 stops traveling, the above process is temporarily stopped. In this example, the process of determining the travel permitted area A1 and the travel prohibited area A2 during the transport process of the pallet 111 has been described, but these processes may also be executed while the forklift 1 is traveling in a situation other than the transport process. In addition, the above process may also determine whether the pick operation or the drop operation is permitted depending on whether an object is detected during the pick operation of the pallet 111 at the pick position and during the drop operation of the pallet 111 at the drop position. For example, if an object is detected within the detection range R during a pick or drop operation, the object may be removed, and the error may be cleared by operating a switch or on the program 71, as described above, and then the forklift 1 may resume operation. In the warehouse system 100 as described above, while the forklift 1 is traveling during the transport process of the pallet 111 carrying one or more cardboard boxes 110, the distance measuring sensor 50 of the forklift 1 can detect the presence or absence of an object within the detection range R in the rear direction BD. The detection range R in which no object is detected is recognized as the travel allowable area A1. In this way, the travel allowable area A1 increases over time while the forklift 1 is traveling. On the other hand, when a predetermined time has passed since the recognition, the travel allowable area A1 is recognized as the travel prohibited area A2. That is, the travel allowable area A1 decreases over time. In this way, the travel allowable area A1 that dynamically changes while the forklift 1 is traveling defines the range in which the forklift 1 can travel safely. By incorporating the distance measuring sensor 50 in the forklift 1, such a range in which the forklift 1 can travel safely can be generated at low cost. Note that the above embodiment has been described using the forklift 1 as an example of an autonomous traveling robot, but the autonomous traveling robot may be applied to robots other than the forklift 1. In addition, the forklift 1 may incorporate a fork assembly having a pair of clamps, instead of the pair of forks 42, 42, that clamps the cardboard box 110 or the like from both sides. The same reference numbers are used throughout the drawings to refer to the same or similar components. The following embodiments are not intended to limit the invention as set forth in the claims. Features of the invention are described herein, but changes and modifications can be made without departing from the spirit and scope of the disclosed embodiments. Furthermore, particular features, structures or characteristics can be combined in any suitable manner in one or more embodiments. It is intended that the following detailed description be considered as exemplary only, with a true scope and spirit being indicated by the following claims.

Claims

1. An autonomous driving robot comprising: a sensor configured to detect the presence or absence of an object within a specified detection range in the driving direction of the autonomous driving robot; and a control unit configured to recognize the detection range, in which the sensor does not detect an object while the autonomous driving robot is driving, as a driving-permitted area that allows the autonomous driving robot to drive, and to revoke the recognition of the driving-permitted area after a specified time has elapsed since the recognition.

2. The autonomous mobile robot of claim 1, wherein the control unit is configured to, upon cancellation of the certification, certify the driving-permitted area as a driving-prohibited area in which driving of the autonomous mobile robot is prohibited.

3. The autonomous mobile robot of claim 1, wherein the control unit is configured to recognize the detection range in which the presence of the object is detected as a no-travel area in which the autonomous mobile robot is prohibited from traveling.

4. The autonomous mobile robot of claim 1, wherein the object includes another robot or a human worker.

5. The autonomous mobile robot of claim 1, wherein the predetermined time is set based on the speed of the autonomous mobile robot.

6. An autonomous mobile robot as described in claim 1, wherein the detection range is set at a predetermined distance or more from the sensor, and a warning area is set in which the speed of the autonomous mobile robot is slowed down when the presence of the object is detected.

7. The autonomous mobile robot of claim 6, wherein the detection range is set to a danger area less than the predetermined distance, and the autonomous mobile robot is caused to stop moving when the presence of the object is detected.

8. The autonomous mobile robot according to claim 1, wherein the allowable travel area is also applied to another autonomous mobile robot besides the autonomous mobile robot itself.

9. The autonomous mobile robot according to claim 1, wherein the sensor is a 3D distance sensor.

10. The autonomous mobile robot according to claim 1, wherein the autonomous mobile robot is a forklift.

11. A method for controlling an autonomous running robot comprising the steps of: detecting the presence or absence of an object within a predetermined detection range in the running direction of the autonomous running robot by a sensor while the autonomous running robot is running; and recognizing the detection range in which the object is not detected while the autonomous running robot is running as a running allowable area that allows the autonomous running robot to run, and revoking the recognition of the running allowable area after a predetermined time has elapsed since the recognition.

12. A program for controlling an autonomous driving robot, the program causing a computer to execute the steps of: detecting the presence or absence of an object using a sensor within a predetermined detection range in the driving direction of the autonomous driving robot while the autonomous driving robot is driving; and recognizing the detection range in which the object is not detected while the autonomous driving robot is driving as a driving-permitted area that allows the autonomous driving robot to drive, and revoking the recognition of the driving-permitted area after a predetermined time has elapsed since the recognition.

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