ROUTE GENERATION DEVICE FOR AN AUTONOMOUS MOBILE BODY

Abstract

A route generation device for an autonomous mobile body (1) capable of autonomously moving to multiple destinations, the route generation device comprising: a controller (50) configured to generate a route that allows the autonomous mobile body (1) to arrive at the at least one destination within the permissible arrival time period in response to receiving an allowable arrival time period associated with at least one of the multiple destinations, inputting information related to specifics of a task to be performed at the at least one destination, and setting a required time period (T(wait,i)) according to the specifics of the task based on the required time period (T(wait,i)), wherein the controller (50) is configured to control the autonomous mobile body (1) and cause it to travel along the generated route.one of the plurality of destinations is assigned several of the tasks with different specifics, and the control unit (50) generates a route such that the required time periods (T(wait,i)) at one of the plurality of destinations do not overlap.

Description

BACKGROUND OF THE INVENTIONField of the InventionThe present invention relates to a route generation apparatus for an autonomous mobile body.Related ArtThere is a known automatic driving system for a vehicle capable of both autonomous driving and manual driving (see, for example, Japanese Unexamined Patent Application, Publication No. JP 2022-111 121 A). This automatic driving system causes a vehicle to autonomously travel along a preset route based on position information.US 2020 / 0394,922 A1 discloses a route generation apparatus for an autonomous mobile body capable of autonomously moving to a plurality of destinations, the route generation apparatus comprising a controller configured to generate, in response to obtaining an allowable arrival time range associated with at least one of the plurality of destinations, a route that allows the autonomous mobile body to arrive at the at least one destination within the allowable arrival time range.COLTIN, Brian. Multi-agent pickup and delivery planning with transfers. 2014. 2014. 2014. S. i-xiv, 1-16, 133-142 Carnegye Mellon University, USA, describes a route generation apparatus which, based on a required time period according to the specifics of a task, generates a route which allows a mobile body to arrive at a destination.SUMMARY OF THE INVENTIONIn a limited exterior area including a partial exterior area such as a construction site, a vehicle capable of autonomous driving needs to transport a load from one location to another location. In this case, since the unloading or the like is permitted at the other place within a limited scheduled period of time, the vehicle is required to arrive at the other place within the limited scheduled period of time.An object of the present invention is to provide a route generation apparatus which is designed for an autonomous mobile body and capable of causing the autonomous mobile body to arrive at a predetermined location and to perform a predetermined task within a limited scheduled period of time, thereby contributing to improvement of safety.To achieve the object, there is provided a route generating apparatus according to claim 1. Advantageous embodiments are evident from the dependent claims.In this case, it is preferable that a plurality of allowable arrival time periods can be assigned to one of the plurality of destinations, and the controller generates such a route as to satisfy one of the plurality of allowable arrival time periods. In this case, it is preferable that the required time period is set for each task type. In this case, it is preferable that the required time period is set to a value obtained by multiplying a type and / or a number of a load to be loaded on the autonomous mobile body by a time period required for a load of a single type.In this case, it is preferable that the controller generates such a route that a maximum possible number of tasks having different specifics assigned to the plurality of destinations are executed. In this case, it is preferable that the controller generates such a route that a small number of loads are loaded on the autonomous mobile body. In this case, it is preferable that the controller generates such a route that a plurality of the autonomous mobile bodies share the task.The present invention provides a route generation apparatus configured for an autonomous mobile body and capable of causing the autonomous mobile body to arrive at a predetermined location within a limited scheduled time period and executing a predetermined task, thereby contributing to improvement in safety.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a diagram illustrating an autonomous mobile body according to an embodiment of the present invention; FIG. 2 is a block diagram illustrating a controller constituting a part of an autonomous mobile body route generation apparatus according to an embodiment of the present invention; FIG. 3 is a diagram illustrating a detection range in which an obstacle can be detected by an autonomous mobile body according to an embodiment of the present invention; FIG. 4 is a diagram illustrating a plurality of detection areas in which an obstacle can be detected by an autonomous mobile body according to an embodiment of the present invention; FIG. 5 is a diagram illustrating a manner in which an autonomous mobile body determines an obstacle according to an embodiment of the present invention; FIG. 6 is a diagram illustrating a time window indicating a scheduled period of time in which an autonomous mobile body route generation apparatus according to an embodiment of the present invention can perform a task at a predetermined location; FIG. 7 is a diagram illustrating a plurality of time slots indicating scheduled periods in which an autonomous mobile body route generation apparatus according to an embodiment of the present invention can perform tasks at a predetermined location; FIG. 8 is a diagram corresponding to a case where two autonomous mobile bodies perform tasks at a predetermined location, and illustrates a task start hour and an autonomous mobile body waiting period during the task as determined by an autonomous mobile body route generation apparatus according to an embodiment of the present invention; FIG. 9 is a diagram corresponding to a case where two autonomous mobile bodies perform tasks at a predetermined location, and illustrates that a task start hour and a waiting period during the task of one of the autonomous mobile bodies do not overlap with those of the other as determined by an autonomous mobile body route generation apparatus according to an embodiment of the present invention; and FIG. 10 is a diagram illustrating locations where an autonomous mobile body performs tasks and routes connecting the locations as determined by a route generation apparatus according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE INVENTIONHereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. An autonomous mobile body 1 according to the present embodiment is a vehicle configured as an unmanned car or the like provided with a loading platform, for example. The autonomous mobile body 1 autonomously travels along a road without a driver on board in a limited outdoor work area including a partial outdoor area such as a construction site, and transports a load from one location to another location. If an obstacle OB or the like is located on a travel route where the autonomous mobile body 1 travels, the autonomous mobile body 1 itself detects the obstacle OB or the like, generates and updates therein a cost map regarding a route along which the autonomous mobile body 1 is to travel instead of being switched for guidance by communication with an external device, and thereby travels while avoiding the obstacle OB.As illustrated in FIGS. 1 and 2, the autonomous mobile body 1 includes a vehicle body 10 having a rectangular shape in plan view, a controller 50 provided on the vehicle body 10, an input unit (not shown) such as a touch panel electrically connected to the controller 50, and a communication device (not shown) electrically connected to the controller 50 and capable of transmitting and receiving information to and from another autonomous mobile body 1. The information exchanged between the autonomous mobile bodies 1 refers to, for example, an allowable arrival time period set for each of the sites, tasks having different specifics (for example, loading, unloading, etc.) to be performed at each site, a required time period according to the specifics of each task, and a task start hour of each task. In FIG. 1, a front end portion and a rear end portion of the vehicle body 10 are shown as right end portion and left end portion, respectively. The front end portion and the rear end portion of the vehicle body 10 are both provided with cameras 11, LIDARe (light detection and scanning) 12, and radars 13 that function as external detection devices for detecting and detecting an external environment of the vehicle body 10. The vehicle body 10 further includes a GPS device (not shown).The vehicle body 10 includes, for example, a frame constituting a skeleton of the autonomous mobile body 1, and an outer shell covering a space defined by the frame.A travel unit has a function of causing the autonomous mobile body 1 to travel according to a cost map with respect to a route generated and updated by a route generator 512 described later. The traveling unit is mounted on the vehicle body and includes wheels (not shown) and an engine (not shown). The wheels are rotatably supported at right and left ends of front and rear portions of the autonomous mobile body 1, and include driving wheels and running wheels. The motor drives the drive wheels.The cameras 11 include two cameras 11 installed at the right and left ends of the front portion, two cameras 11 installed at positions near the center of the front portion of the vehicle body 10 (i.e., four cameras 11 in total at the front portion), and a camera 11 installed at the center of the rear portion of the vehicle body 10, and detect an object OB located in the directions C shown in FIG. 1.The LIDARs 12 include LIDARs 12 respectively installed at the right and left ends and at the center of the front portion of the vehicle body 10 (i.e., a total of three LIDARs 12 at the front portion), and LIDARs 12 respectively installed at the right and left ends and at the center of the rear portion of the vehicle body 10 (i.e., a total of three LIDARs 12 at the rear portion), and detect an object OB located in the directions L shown in FIG. 1.The radars 13 include radars 13 respectively installed at the right and left ends of the front portion of the vehicle body 10 (i.e., a total of two radars 13) at the front portion and radars 13 respectively installed at the right and left ends of the rear portion of the vehicle body 10 (i.e., a total of two radars 13) at the rear portion, and detect an object OB located in the directions R shown in FIG. 1. The cameras 11, the LIDARs 12, and the radars 13 are electrically connected to the controller 50, and output a detection signal to the controller 50 when detecting the obstacle OB.As illustrated in FIG. 2, the controller 50 is an electronic control unit (ECU) including a central processing unit (CPU) 51, a memory 52, and a memory 53. The CPU 51 controls various components of the autonomous mobile body 1 by executing a program stored in the memory 53 in the memory 52, and executes the program. The functions of the controller 50 may be implemented by a semiconductor integrated circuit such as a programmable logic device (PLD) or an application specific integrated circuit (ASIC), or may be implemented by software. In other words, the functions of the controller 50 may be implemented by either hardware or software.The CPU 51 functions as a travel controller 511 and a route generator 512. For example, when functioning as the route generator 512, the CPU 51 generates and updates a cost map regarding a route along which the autonomous mobile body 1 is to travel based on information regarding an obstacle OB or the like detected by the cameras 11, the LIDARs 12, and the radars 13. Further, the CPU 51 functions as the travel control device 511 to control the travel unit, and thereby causes the autonomous mobile body 1 to travel according to the cost map generated and updated with respect to the route. Thus, the function of autonomous driving along a road without a driver on board while avoiding an obstacle OB and transporting a load from one location to another location in a work area is achieved.The storage 53 stores in advance a map of a route in the work area and a cost map corresponding to the map. As illustrated in FIG. 3, the map includes a road RD in which a broken line CE is drawn on the center of a driving lane for driving the autonomous mobile body 1. When the position of the autonomous mobile body 1 is specified by the GPS device (not shown), the obstacle OB on the route is not detected, and the driving controller 511 controls the driving unit to cause the autonomous mobile body 1 to travel on the line CE indicated by the broken line along the route in the map. For example, as shown in FIG. 5, the cost map corresponding to the map includes a plurality of square grid cells M 1 to M 9 arranged in a grid pattern and into which the cost map is divided. The cost map is stored in the memory 53. In FIG. 3, in order to indicate the traveling direction of the autonomous mobile body 1, the autonomous mobile body 1 is illustrated as a pentagonal shape corresponding to the original rectangular shape whose short side ahead in the traveling direction is deformed in a protruding manner.Detection of an obstacle OB by the controller 50 will now be described. As illustrated in FIG. 3, the autonomous mobile body 1 detects an obstacle OB within a detection area DA that is an area along the line CE in the map. If an obstacle OB is present on the route along which the autonomous mobile body 1 travels, an operation of detecting an obstacle OB is performed while a long distance detection range GR shown in FIG. 4 is set as the detection range DA. The long distance detection area GR extends along the line CE and is an area where the detection operation is performed to a far position in front of the autonomous mobile body 1. If it is detected that an obstacle OB is present in the long distance detection area GR, an operation for detecting the obstacle OB is performed while setting a short distance detection area YE as the detection area DA. The short distance detection area YE extends along the line CE and is an area in which the detection operation is performed up to a relatively close position in front of the autonomous mobile body 1.Simultaneously with the operation for detecting the obstacle OB in the long distance detection area GR or the short distance detection area YE, an operation for detecting the obstacle OB is performed while setting a short distance detection area RE as the detection area DA. The short distance detection area RE extends in a direction in which the autonomous mobile body 1 is oriented, and is an area in which the detection operation is performed to a relatively close position in front of the autonomous mobile body 1. The short distance detection area RE is set as the detection area DA to stop the autonomous mobile body 1 if a dynamic obstacle OB suddenly appears immediately in front of the autonomous mobile body 1.In other words, the long distance detection area GR and the short distance detection area YE both have the line CE at their center, while the short distance detection area RE is alignable in a direction deviating from the line CE but along a direction in which the autonomous mobile body 1 is oriented. In the above-described detection area DA, the obstacle OB occupying one or some of the grid cells M 1 to M 9 of the cost map is detected as described later. In each of these detection areas, the detection operation is performed by the cameras 11, the LIDARs 12, and the radars 13.When it is detected that one or some of the grid cells M 1 to M 9 of the cost map are occupied, the controller 50 determines whether or not the occupying object is an obstacle OB in the following manner. When, in any one of the long distance detection area GR, the short distance detection area YE, and the short distance detection area RE shown in FIG. 4, during traveling of the autonomous mobile body 1, one of the occupied grid cells M 1 to M 9 comes to be included, the controller 50 first calculates, for a plurality of upper portions (Za, Zb, etc.) of the occupying object, position differences from the lowermost end portion (Zmin) of the occupying object. When an average value of the position differences exceeds a predetermined threshold value, the controller 50 determines the occupying object as the obstacle OB.Generation of a route for the autonomous mobile body 1 by the route generator 512 of the controller 50 will now be described. A case where a plurality of autonomous mobile bodies 1 each configured to transport a load from one location to a plurality of other locations execute their tasks simultaneously will be described below.First, an allowable arrival time margin (time window) is input and allocated for each location via an input unit (not shown) such as a touch panel. Specifically, as illustrated in FIG. 6, if a first allowable arrival time period in which autonomous mobile body 1 is to arrive at a predetermined location is from 7:00 to 10:00, a start hour e 1i and an end hour I 1i of the allowable arrival time period are respectively set to 7:00 and 10:00 by the input unit (not shown). If two or more allowed arrival periods can be assigned, e 1i, e 2i,..., e Lii, and I 1i, I 2i,..., and I Lii are respectively input and set as shown in FIG. 7.Further, information regarding the tasks having different specifics (for example, loading, unloading, etc.) to be performed at the locations, a starting hour is input for each type of the task, etc., and also, a required time period is input for each type of task or according to the specifics of the task. Specifically, as illustrated in FIG. 8, the task start sounds pi, the required time period T(wait,i), and the like for the i-th autonomous mobile body 1 are input and set. If the task is unloading, the required time period T(wait,i) is set to a value obtained by multiplying the type number of loads or the number of loads to be loaded on the autonomous mobile body 1 by a time period required for a load of a single type.Based on the required time period T(wait,i) calculated as described above, the route generator 512 generates such a route that the autonomous mobile body 1 arrives at the location within the allowable arrival time period of e 1i to I 1i. If two or more allowed arrival time periods can be assigned, the route generator 512 generates such a route that one of the allowed arrival time periods is satisfied. That is, the route is generated so as to satisfy the following condition.If two or more tasks having different specifics, such as loading and unloading of multiple loads, are assigned to the site, the generated route is adjusted such that the required time periods for the two or more tasks at the site do not overlap each other. Incidentally, as described later, during input of two or more tasks to a node, the required periods may overlap each other because the calculation is made such that the finally generated route prevents the required periods from overlapping each other.Specifically, a travel time of the autonomous mobile body 1 between nodes, i.e., between locations, is set to a value obtained by dividing a distance between the locations defined as an edge by an upper limit speed along the edge. When a task start hour and a required time period for the i-th autonomous mobile body 1 are respectively defined as pi and T(wait,i), and a task start time and a required time period for the j-th autonomous mobile body 1 are respectively defined as pj and T(wait,j), a route satisfying the following condition is generated. FIG. 9 illustrates a result obtained by satisfying the above condition. In FIG. 9, the hatched portions represent scheduled periods corresponding to the required periods during which the i-th autonomous mobile body 1 and the j-th autonomous mobile body 1 perform their tasks. With respect to the area surrounded by the broken line, the required periods do not temporarily overlap each other with respect to the vertical axis representing the time axis. That is, the route is designed such that the required periods for the i-th autonomous mobile body 1 and the j-th autonomous mobile body 1 to perform their tasks do not overlap each other at the site.The route generated is designed such that a maximum possible number of tasks with different specifics, such as loading, unloading, etc., can be carried out in multiple places. On the other hand, the route is generated such that the number of loads to be loaded on the autonomous mobile body 1 is as small as possible. The travel controller 511 controls and causes the autonomous mobile body 1 to travel along the generated route.Now, with reference to FIG. 10, a more specific example will be described in which the loading and unloading among the locations A to N are performed at the locations B, E, G, and I. [Table 1] Table 1] [Table 1] Table 1]1Iron Material· 1B. B9:00-10:00G.9:45-10:302Wood material ·· 1E. E9:00-9:15I.9:30-11:00As shown in Table 1, an iron material of task number 1 is to be charged at the location B, while a wood material of task number 2 is to be charged at the location E. The one material of task number 1 is to be unloaded at location G, while the one material of task number 2 is to be unloaded at location I. In this way, for each task, the type and the number of loads, the name of the place where the load is to be made, the name of the place where the load is to be made, and an allowable task period (allowable load period in which the load is allowed and an allowable load period in which the load is allowed) are input as a set. This type of input allows an increase in the number of tasks and allows a plurality of autonomous mobile bodies 1 to share a task for transporting loads. For convenience, the following description is based on an assumption that, in FIG. 10, a travel time along a vertical line between the points A and B and a travel time along a horizontal line between the points A and B are each 5 minutes, and a travel time along a diagonal line (oblique line) between the points A and F is 10 minutes. Further, assume that a time required for loading at a place is 1 minute, and assume that a time required for unloading at a place is 2 minutes. The departure point is placed at the location A.According to a shortest route starting from the location A, the charging of the task number 2 should be done at the location E, the charging with task number 1 should be done at the location B, the discharging of the task number 1 should be done at the location G, and the discharging of the task number 2 should be done at the location I via the location H.However, as shown in Table 1, the "allowable loading period" and the "allowable unloading period", which are specific examples of the above-described "allowable arrival time period", are set at each location. Accordingly, in order for the autonomous mobile body 1 to arrive at the locations within these scheduled periods, a route is set as follows.Departure from location A at 9:00 AM.Arrival at location E at 9:05, charge task number 2, exit from location E at 9:06.Arrival at location B at 9:16, charge task number 1, exit from location B at 9:71 (via locations C and D)Arrival at the I location at 9:37, unload task number 2, exit from the I location at 9:39 (via location H)Arrival at the point G at 9:49, unload task number 1, exit from the point G at 9:51The present embodiment achieves the following effects. The present embodiment includes the controller 50 that: in response to obtaining an allowable arrival time period assigned to at least one of a plurality of locations as a destination, generates input information regarding the specifics of a task to be executed at the at least one location, and sets a required time period according to the specifics of the task, based on the required time period, generates a route that allows the autonomous mobile body to arrive at the at least one location as the destination within the allowable arrival time period. The controller 50 controls and causes the autonomous mobile body 1 to travel along the generated route. This feature further makes it possible to generate a route in consideration of the allowable arrival time margin, the specifics of the task, and the required time period under conditions that the autonomous mobile body 1 has a limited battery capacity and a limited payload. This feature enables the autonomous mobile body 1 to arrive at a predetermined location within a limited scheduled time period to execute a task, and enables generation of a route that allows the autonomous mobile body 1 to execute a task more safely.According to the present embodiment, a plurality of allowable arrival time periods may be assigned to one of the plurality of locations, and the controller 50 generates such a route that one of the plurality of allowable arrival time periods is satisfied. This feature enables the autonomous mobile body 1 to perform a task without accepting an unnecessary waiting time in the site.According to the present embodiment, the required time period is set for each task type. This feature makes it possible to set different time periods for different types of tasks, one of which requires a great deal of time and another of which requires a small amount of time. Thus, an appropriate required time period can be set for each task.According to the present embodiment, the required time period is set to a value obtained by multiplying the type and / or the number of loads to be loaded on the autonomous mobile body 1 by a time period required for the load of a single type. This feature makes it possible to set the required time period in consideration of the type and / or the number of loads, thereby enabling generation of a more suitable route.According to the present embodiment, a plurality of tasks having different specifics are assigned to one of the plurality of locations as the destinations, and the controller 50 generates a route such that the required periods of time at the one of the plurality of locations do not overlap each other. This feature makes it possible to avoid a situation in which a plurality of autonomous mobile bodies 1 arrive at a location simultaneously and one or more of the plurality of autonomous mobile bodies 1 are required to wait while preventing the tasks from being performed.According to the present embodiment, the controller 50 generates such a route that a maximum possible number of tasks having different specifics assigned to the plurality of locations as the destinations are executed. This makes it possible to carry out the tasks with improved efficiency.According to the present embodiment, the controller 50 generates such a route that a small number of loads are loaded on the autonomous mobile body 1. Due to this feature, the load on the autonomous mobile body 1 can be reduced, thereby making it possible to improve the consumption efficiency of the battery that supplies electric power for driving the wheels of the autonomous mobile body 1 while the autonomous mobile body 1 is traveling. Further, in the present embodiment, the controller 50 generates such a route that a plurality of autonomous mobile bodies share the task. This feature makes it possible to avoid a situation in which, at a target location, a period during which one of the plurality of autonomous mobile bodies 1 performs its task overlaps a period during which another one of the plurality of autonomous mobile bodies 1 performs its task, to enable the tasks to be performed with high efficiency.The present invention is not limited to the above embodiment, and various structural changes can be made without departing from the principle of the present invention. For example, the configuration of the autonomous mobile body 1 according to the above embodiment is a non-limiting example. In the above embodiment, the autonomous mobile body serves to transport a load from one location to another while autonomously driving along a road without a driver on board, and executes loading and unloading in a limited outdoor work area including a partial outdoor area such as a construction site. However, this is a non-limiting example. For example, it is also possible to perform, as the tasks, maintenance tasks to be performed preferably at least once a day for the autonomous mobile body, specific examples of which are replacement of a battery in the case of an autonomous mobile body equipped with a detachable battery, refueling with fuel such as gasoline in the case of an autonomous mobile body running with an internal combustion engine, pneumatic pressure inspection of tires, and inspection of contamination of sensors.Further, in the above embodiment, the route is generated such that a maximum possible number of tasks having different specifics assigned to the plurality of locations as the destinations are executed. However, this is a non-limiting example. For example, it is also possible to generate such a route that an essential condition is satisfied that the autonomous mobile body 1 is not overcharged in weight or the battery charge level is equal to or higher than a predetermined level.There is provided a route generation device that is adapted for an autonomous mobile body and capable of causing the autonomous mobile body to arrive at a predetermined location within a limited scheduled period of time and performs a predetermined task, thereby contributing to improvement in safety. The route generation apparatus includes a controller configured to, in response to obtaining an allowable arrival time period associated with at least one of the plurality of destinations, generate an input of information regarding specifics of a task to be executed on the at least one destination, and set a required time period according to the specifics of the task, based on the required time period, generate a route that allows the autonomous mobile body to arrive at the at least one destination within the allowable arrival time period. The controller is configured to control the autonomous mobile body and cause it to travel along the generated route.EXPLANATION OF THE REFERENCE NUMERALS1 Autonomous mobile body 50 Controller pi Task Start Hour T(wait,i) Required Time Period

Claims

A route generation apparatus for an autonomous mobile body (1) capable of autonomously moving to a plurality of destinations, the route generation apparatus comprising: a controller (50) configured to, in response to obtaining an allowable arrival time period associated with at least one of the plurality of destinations, generate input of information regarding specifics of a task to be executed on the at least one destination, and set a required time period (T(wait,i )) according to the specifics of the task based on the required time period (T(wait,i )), generate a route that allows the autonomous mobile body (1) to arrive at the at least one destination within the allowable arrival time period, wherein the controller (50) is configured to:, to control and cause the autonomous mobile body (1) to travel along the generated route, a plurality of the tasks having different specifics are associated with one of the plurality of targets, and the controller (50) generates such a route that the required periods (T(wait,i)) of the one of the plurality of targets do not overlap each other.The route generation apparatus according to claim 1, wherein a plurality of allowable arrival time periods can be assigned to one of the plurality of destinations, and the controller (50) generates a route so as to satisfy one of the plurality of allowable arrival time periods.The route generating apparatus according to claim 1, wherein the required time period (T(wait,i)) is set for each task type.The route generation apparatus according to claim 1, wherein the required time period (T(wait,i)) is set to a value obtained by multiplying a type and / or a number of a load to be loaded on the autonomous mobile body (1).The route generation apparatus according to claim 1, wherein the controller (50) generates a route such that a maximum possible number of tasks having different specifics associated with the plurality of destinations are executed.The route generation apparatus according to claim 1, wherein the controller (50) generates a route such that a small number of loads are loaded on the autonomous mobile body (1).The route generation apparatus according to claim 1, wherein the controller (50) generates a route such that a plurality of the autonomous mobile bodies share the task.

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