JP2671297B2 - Route correction method for self-supporting unmanned vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention searches a travel route to a destination based on map data given in advance when the destination is designated, and travels on its own. The present invention relates to a self-supporting unmanned vehicle that travels to a destination while recognizing a route, and particularly relates to a route correcting method that corrects a route when the self-sustaining unmanned vehicle deviates from a regular traveling route. “Conventional technology” In recent years, with the progress of FA (Factory Automation), various types of unmanned vehicles that automatically convey parts etc. have been developed in factories, warehouses, etc. Among them, what are called self-supporting unmanned vehicles By designating a destination node, it automatically searches for an optimal route and determines which node to pass through, and automatically travels to the destination node. Here, a node is a stop point, a branch point, a work point, or the like, and is a point at which a traveling state such as a traveling speed or a traveling direction of an unmanned vehicle changes. FIG. 6 is a plan view showing a schematic configuration of the self-supporting unmanned vehicle 1 of this type. In this figure, 2L and 2R are the left and right drive wheels, and 3
L and 3R are motors that rotate the left and right drive wheels 2L and 2R respectively, and 4L and
4R is a pulse encoder that detects the rotational speed of each of the left and right drive wheels 2L and 2R, 5,5, ... is a caster type idler wheel, and 6L and 6R are ultrasonic transceivers that detect the distance to the left and right side walls W. , 7 are control devices. The control device 7 is composed of a microcomputer, and the memory thereof stores map data relating to the travel route in advance. This map data is data relating to the coordinates of each node, the distance from the planned travel route connecting each node to the left and right sidewalls W, and the like. Then, when the central station wirelessly instructs the destination node, this instruction is supplied to the control device 7 via a communication device (not shown). Then, the control device 7 searches for an optimal route based on the map data, determines a node to pass through toward the destination node, and travels along a planned route connecting these nodes in sequence. Drives motors 3L and 3R respectively. At this time, the control device 7 controls the ultrasonic transceiver 6
Measures the distance to the left and right side walls W based on the signals supplied from L and 6R respectively, and also measures the distance traveled from the immediately preceding node based on the signals supplied from the pulse encoders 4L and 4R. Then, based on these measurement results, it is determined whether or not the current traveling route deviates from the regular planned traveling route obtained based on the map data, and if it deviates, the route is corrected. . As a result, the unmanned vehicle 1 always travels on the regular planned travel route and sequentially passes on each node to reach the destination node. Here, as a method for the unmanned vehicle 1 to correct the route, two methods are conceivable: a method using traverse and a method using a combination of curves. Therefore, as shown in FIGS. 7 (a) and 7 (b), these two types of route correction methods cause the current travel route l ₁ to deviate to the left from the regular scheduled travel route l ₀ , and its deviation A case where the amount D becomes larger than a predetermined value will be described as an example. Method of Correcting Route by Traverse As shown in FIG. 7A, the unmanned vehicle 1 is temporarily stopped when the deviation amount D becomes larger than a predetermined value.
Next, after changing the directions of the driving wheels 2L and 2R by 90 degrees, the driving wheels 2L and 2R are moved in the right lateral direction, so-called traverse operation is performed, and the driving wheels 2L and 2R are moved to above the regular scheduled travel route l ₀ and stopped again. Then, after changing the direction of the drive wheels 2L, 2R to the normal running direction,
Start running again. Method for correcting route by combination of curves As shown in Fig. 7 (b), when the deviation amount D becomes larger than a predetermined value, the unmanned vehicle 1 is controlled by the two-wheel speed difference control of the driving wheels 2L, 2R. After changing the course to the right by a predetermined angle and then running a straight line for an appropriate distance, this time the course is returned to the left by a predetermined angle, thereby drawing a curve of a predetermined pattern while the unmanned vehicle 1 is in a traveling state. Then, the vehicle is returned to the regular scheduled route l ₀ . "Problems to be Solved by the Invention" By the way, in the above two route correction methods,
Each had the following drawbacks. In the traverse route correction method, the unmanned vehicle 1 must be temporarily stopped when changing the direction of the drive wheels 2L, 2R, and will be stopped twice before one correction operation is completed. As described above, when the unmanned vehicle 1 repeatedly stops and accelerates, it consumes a large amount of electric power, and the battery, which is the power source, is greatly consumed. In addition, the loss of traveling time due to two stops is large. In the route correction method by combining curves,
As shown in FIG. 7 (b), the unmanned vehicle 1 travels the distance L until the correction operation is completed. For example, before the position P at which the route correction operation of the unmanned vehicle 1 is completed. If there is a node N on the side, it cannot pass above this node N. Then, for example, when it is necessary to stop at the position of the node N and perform work such as loading and unloading of conveyed goods, the device will stop at a position away from the node N. The present invention has been made in view of the above-described circumstances, and it is possible to always return an unmanned vehicle to a regular scheduled route in front of a node while minimizing the loss of power consumption and traveling time. It is intended to provide a route correction method for a self-supporting unmanned vehicle. "Means for Solving Problems" The present invention, when a destination is designated, determines a node passing through in the process of reaching the destination based on map data given in advance, and determines each of these nodes. In a self-supporting unmanned vehicle that travels while correcting the route by connecting the regular planned traveling route and the current traveling route and correcting the route to make this deviation zero, the current traveling route is the regular planned traveling route. When the vehicle deviates from the current position by a predetermined amount, the distance required to correct the route from the current position based on the combination of curves stored in a predetermined pattern is compared with the remaining travel distance from the current position to the next node to reach. However, when the remaining travel distance is larger than the required distance, the route is corrected by a combination of the curves of the predetermined patterns stored in advance, and the remaining travel distance is equal to the required distance. If it is smaller than is characterized in that to correct the path by traverse operation of moving laterally changing the direction of the drive wheels. "Operation" When the current travel route deviates from the regular planned travel route by a predetermined amount, the required distance to correct the route from the current position by a combination of the predetermined curves and the node to reach next from the current position If the remaining mileage is greater than the specified value, it is considered that the route correction is completed on the front side of the next node to reach, and the curve of the predetermined pattern stored in advance Modify the route according to the combination. On the contrary, if the remaining mileage is less than the required distance,
It is considered that the correction of the route is not completed on the front side of the next node to reach, and the route is corrected by the traverse motion of changing the direction of the driving wheels and moving to the side. As described above, according to the distance to the next node to be reached, the route correction by the combination of the curves of the predetermined pattern stored in advance and the route correction by the traverse operation are selected and used properly. We can make up for each other's drawbacks. "Example" Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the structure of a self-supporting unmanned vehicle to which a route correcting method according to an embodiment of the present invention is applied. In this figure, 10 is a side distance unit, which calculates the distance traveled from the immediately preceding node based on the pulse signals LP, RP supplied from the pulse encoders 4L, 4R, and the ultrasonic transceiver 6L. The distances to the left and right side walls W are calculated based on the signals respectively supplied from 6R and 6R. Reference numeral 11 is a map data memory in which map data is stored in advance, and 12 is a data comparison unit for comparing the side distance data output from the side distance unit 10 with the map data read from the map data memory 11. Further, 20 is a command unit, and when a destination node wirelessly instructed from the central station 23 is supplied via the communication device 24, an optimum route is searched based on map data,
Decide the node to pass when going to the destination node,
A travel command necessary for traveling along a planned travel route that connects these nodes in sequence is created and given to the travel control unit 13. The travel control unit 13 creates a speed command signal for commanding the rotational speed of each of the left and right drive wheels 2L and 2R based on the travel command supplied from the command unit 20, and controls the speed command signal to drive wheel control. Supply to the section 14, and also the data comparison section
Based on the comparison data supplied from 12, it is determined whether or not the current traveling route deviates from the regular planned traveling route obtained based on the map data by a predetermined amount d or more, and if it deviates, A speed command signal is supplied to the drive wheel control unit 14 in order to correct the route in the procedure described later, and the control mechanism 15 is driven as necessary. The drive wheel control unit 14 controls the rotation of each of the motors 3L and 3R based on the speed command signal supplied from the traveling control unit 13 and the speed feedback signal supplied from the pulse encoders 4L and 4R. . Further, the control mechanism 15 is composed of an electric cylinder, and is provided in the vicinity of two front and rear idler wheels 5, 5 located on a diagonal line of the bottom surface of the unmanned vehicle as shown in FIG. Then, the rod 15a of the electric cylinder projects downward, and the rubber member 15b provided at the tip of the rod 15a presses the floor surface, whereby the unmanned vehicle is braked. By rotating the left and right drive wheels 2L and 2R in opposite directions while the brakes are applied in this way, the left and right drive wheels 2L and 2R are changed from the normal orientation as shown in FIG. As shown in (b),
It turns 90 degrees. In this case, the left and right drive wheels 2L, 2
The R, the motors 3L and 3R, the pulse encoders 4L and 4R, and the like are attached to the same frame (not shown), and this frame is rotatably supported about a point R. On the other hand, reference numeral 21 denotes a memory in which curve data for route correction, which the traveling control unit 13 refers to when a route is corrected by a combination of curves of a predetermined pattern, is stored in advance. The following two types of curve data are stored in this memory 21. The first curve data is control data for changing the traveling direction of the unmanned vehicle to the right by a predetermined angle so as to draw a curve of a predetermined pattern, and the second curve data is of a predetermined pattern. It is control data for changing the traveling direction of the unmanned vehicle to the left by a predetermined angle so as to draw a curve. The first curve data is control data necessary to control the unmanned vehicle so that the unmanned vehicle traveling from the lower side to the upper side in FIG. 3 can draw the curve C1 in the figure. . By drawing this curve C1, the traveling direction of the unmanned vehicle will be converted to the right by a predetermined angle θ, and
In the meantime, the unmanned vehicle will move to the right in the figure by a predetermined distance d / 2. On the other hand, the second curve data is control data for controlling the unmanned vehicle so that the curve C2 opposite to the first curve data can be drawn. So that curve
By drawing C2, the traveling direction of the unmanned vehicle
However, the unmanned vehicle will move to the right in the figure by the predetermined distance d / 2. Further, the traveling control unit 13 has a function of controlling the unmanned vehicle so as to maintain the current traveling state without changing the traveling method and speed of the unmanned vehicle, that is, a function of causing the unmanned vehicle to travel at a constant speed straight line. There is. Furthermore, the traveling control unit 13 is provided with a function of selecting and executing a route correction by a combination of curves of a predetermined pattern and a route correction by a traverse operation according to the distance to the next node to reach. There is. That is, when the current travel route deviates from the regular planned travel route by a predetermined amount d or more, a predetermined distance L required to correct the route from the current position by a combination of curves of a predetermined pattern, and the next from the current position. comparing the remaining travel distance L ₁ to the arrival to the node N, if the remaining traveling distance L ₁ was larger than the predetermined distance L, to modify a path by a combination of curves having a predetermined pattern, the remaining traveling distance L _{If 1} is less than or equal to the predetermined distance L, the path is corrected by a traverse motion in which the directions of the left and right drive wheels 2L and 2R are changed by 90 degrees and the vehicle moves laterally. Next, the operation of the above-described embodiment will be described with reference to the flowchart shown in FIG. The unmanned vehicle travels while comparing the side distance data and the map data (step SP1) and obtaining the deviation amount D which is the difference between them as in the above-mentioned conventional example. Then, the deviation amount D and the predetermined amount d are compared at each short predetermined time interval (step
S2). In this case, the predetermined amount d is the distance d / 2 to the right in FIG. 3 when the unmanned vehicle draws the curve C1 and the distance d / 2 when the unmanned vehicle draws the curve C2 in FIG. Distance to the left d /
It is the total distance of 2 and. Until the deviation amount D exceeds the predetermined amount d, the correction control is not particularly performed, and the traveling control unit 13 continues the traveling of the unmanned vehicle. Now, for example, as shown in FIGS. 5 (a) and 5 (b), an unmanned vehicle travels on a travel route l ₁ that is largely deviated to the left in the drawing from a regular travel route l0, and the deviation is caused. When the amount D exceeds the predetermined amount d, the process proceeds to step SP3. In this step SP3, the traveling control unit 13 has a predetermined distance L required to complete the correction of the route from the current position on the traveling route l ₁ by the combination of the curves of the predetermined pattern, and the node to be reached next from the current position. Compare with the remaining travel distance L ₁ to N. Then, in the case as shown in FIG. 5 (a), it is determined in step SP3 that (remaining travel distance L ₁ )> (required distance L), and the route on the front side of the node N to reach next is determined. It is considered that the correction is completed, and the process proceeds to step SP4.
After that, the route is corrected by the combination of the curves of the predetermined pattern in the procedure shown in steps SP4 to SP6. That is, the travel route unit 13 controls the travel of the unmanned vehicle based on the first curve data stored in the memory 21 and causes the curve C1 to be drawn. In this case, while the unmanned vehicle is still traveling, change its traveling direction to the right by a predetermined angle θ,
Proceed a distance d / 2 to the right from travel route l ₁ (step SP
Four). Then, when the curve C1 has been drawn, the process proceeds to step SP5, and the unmanned vehicle is driven at a constant speed straight line. As shown in FIG. 3, the travel distance in this case is a distance to the right by a distance (D−d) obtained by subtracting a predetermined value d from the deviation amount D. Then, when the unmanned vehicle travels to the right by the distance (D-d), the process proceeds to step SP6, and the traveling control unit 13 travels the unmanned vehicle based on the second curve data stored in the memory 21. Control and draw curve C2. Therefore, while the unmanned vehicle is traveling, the traveling direction of the unmanned vehicle is changed to the left by the predetermined angle θ, and the vehicle travels to the right by the distance d / 2. As a result, the unmanned vehicle returns to the regular scheduled travel route l ₀ on the front side of the next node N, and thereafter travels on the regular scheduled travel route l ₀ toward the node N. On the other hand, in the case as shown in FIG.
In SP3, it is determined that (remaining travel distance L ₁ ) ≦ (required distance L), it is considered that the route correction is not completed on the front side of the node N that arrives next, the process proceeds to step SP7, and thereafter, step SP7. ~ By the procedure shown in SP9, the route is corrected by the traverse motion of changing the direction of the driving wheels and moving to the side. That is, the traveling control unit 13 temporarily stops the unmanned vehicle (step SP7), and then shifts to the traverse operation of step SP8.
In this step SP8, the braking mechanism 15 is driven,
The rod 15a is projected downward, the rubber member 15b provided at the tip of the rod 15a is pressed against the floor surface, and the unmanned vehicle is braked. By rotating the left and right drive wheels 2L and 2R in opposite directions with the brakes applied in this manner, the left and right drive wheels 2L and 2R can be moved from the normal direction to the position shown in FIG. 2 as shown in FIG. As shown in (b), the direction is rotated by 90 degrees about the point R. Then, the drive wheels 2L, 2R are rotated in the same direction, the unmanned vehicle is moved to above the regular scheduled travel route l ₀ , and then stopped again. Next, the drive wheels 2L, 2R are changed to the original normal traveling direction, and the traverse operation is completed. Then, it progresses to step SP9 and it accelerates and it restarts until it reaches a predetermined traveling speed. As a result, the unmanned vehicle returns to the regular scheduled travel route l ₀ on the front side of the node N, and thereafter travels on the regular scheduled travel route l ₀ toward the node N. Contrary to the case shown in FIGS. 5 (a) and 5 (b), the unmanned vehicle largely deviates to the right from the regular planned travel route l ₀ , and the deviation amount D exceeds the predetermined amount d. Also in the case, the unmanned vehicle is returned to the regular scheduled travel route l _{0 in the same} manner as the above-described operation. In this way, the remaining travel distance to the next node N
Depending on L ₁ , a route correction by a combination of curves of a predetermined pattern and a route correction by a traversing motion are selected, and an unmanned vehicle is always on the regular scheduled route l _{0 in} front of the node N. Return to. [Advantages of the Invention] As described above, according to the present invention, according to the distance to the next node to reach, the route correction by the combination of the curves and the route correction by the traverse are used properly, and the drawbacks of both are eliminated. Since we want to make up for each other, we can minimize the loss of power consumption and traveling time to the minimum necessary compared with the case where the route was corrected only by traverse in the past.
Further, there is an effect that the unmanned vehicle can always be returned on the regular scheduled travel route in front of the node.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the structure of a self-supporting unmanned vehicle to which a route correcting method according to an embodiment of the present invention is applied, and FIGS. 2 (a) and 2 (b) are according to the same embodiment. FIG. 4 is a bottom view showing the structure of the self-supporting unmanned vehicle, FIG. 3 is a view for explaining a traveling pattern when the route is corrected by a combination of curves of a predetermined pattern in the same embodiment, and FIG. 4 is a route in the same embodiment. A flow chart for explaining the correction operation,
FIGS. 5 (a) and 5 (b) are plan views for explaining the route correcting operation according to the embodiment, FIG. 6 is a plan view showing a schematic configuration of a conventional self-standing unmanned vehicle, and FIG. 7 (a). And (b)
FIG. 6 is a diagram for explaining a conventional route correction operation. 2L, 2R …… Drive wheel, 3L, 3R …… Motor, 4L, 4R …… Pulse encoder, 6L, 6R …… Ultrasonic transmitter / receiver, 10 …… side distance part, 11 …… Map data memory, 12 …… Data comparison section, 13
...... Traveling control unit, 14 ...... Drive wheel control unit, 15 …… Brake mechanism, 20 …… Command unit, 21 …… Route correction curve data memory.

Claims (1)

(57) [Claims] When the destination is specified, the nodes to pass through in the process of heading to the destination are determined based on the map data given in advance, and the regular planned route connecting each of these nodes and the current traveling route are determined. In a self-supporting unmanned vehicle that travels while comparing and obtaining a deviation and correcting the path so that this deviation becomes zero, when the current travel path deviates from the regular scheduled travel path by a predetermined amount, a predetermined value stored in advance is stored. Compare the required distance required to correct the route by the combination of the curve of the pattern and the remaining travel distance from the current position to the next node to reach, and if the remaining travel distance is greater than the required distance, , The route is corrected by the combination of the curves of the predetermined pattern stored in advance, and when the remaining travel distance is smaller than the required distance, the direction of the drive wheel is changed to move to the side. A route correction method for a self-supporting unmanned vehicle, which is characterized by correcting a route by a traversing motion.