JPS63150709A - Collision evading method in autonomous unmanned vehicle system - Google Patents

Abstract

PURPOSE:To avoid collision without decreasing the processing capability of a central station by reporting it to the central station via a communication means if each unmanned vehicle detects the access of other unmanned vehicle and executing the collision evading based on the information given from the central station. CONSTITUTION:When unmanned vehicles 1A, 1B detect the access of other unmanned vehicle by other vehicle detector 7A(7B), a command section 4 gives a traveling control command directly to a traveling section 5 to stop the vehicle 1A(1B) once. Then the detection of the other vehicle is reported to the central station 2 via a communication equipment 3 together with its own identification code, the present position and the node number reaching next. Moreover, the operation to evade collision is executed based on the collision evading information given from the central station 2 is executed. Thus the collision of the unmanned vehicles is evaded in advance without reducing the processing capability of the central station.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention enables a plurality of self-contained unmanned vehicles to recognize their current positions and use built-in map information to locate work points designated by a central station. The present invention relates to a collision avoidance method that can prevent collisions between autonomous unmanned vehicles in an autonomous unmanned vehicle system that moves around.

[Conventional technology] Currently, autonomous unmanned vehicles are being actively developed.
As shown in Fig. 7, this type of unmanned vehicle system includes a plurality of unmanned vehicles A, B, ... and these unmanned vehicles A, B.
A typical example is one consisting of one central station C that centrally controls , . . . Then, each unmanned vehicle A, B,... follows the instructions from the central station C, travels via each node (passing point) Nl-N9 to the work point where the work request has occurred, and performs the required work. . Central station C manages map information of the movement area of unmanned vehicles A, B, etc., and also manages all unmanned vehicles A.
, B, etc., and monitors the status of each unmanned vehicle A, B, etc., such as their current position and whether or not they are working, and communicates with each unmanned vehicle A, B, etc. using communication means such as wireless.
・Gives work instructions while communicating with.

For example, as shown in FIG. 7, when a work request occurs at a work point located at node N9, the central station C selects the best unmanned vehicle to go to node N9 from among the unmanned vehicles that are not currently performing work. Search for. Here, unmanned vehicle A is at node Nl
If the unmanned vehicle A is waiting between node N2 and N2, a command is given to the unmanned vehicle A to go to node N9. Then,
Unmanned vehicle A selects node N based on its own built-in map information.
9, for example, node N2-N3→N
Determine 6 = N 9 routes. The vehicle then travels along this route to node N9 while recognizing its current location and relying on the built-in map information.

[Problems to be solved by the invention] By the way, in the above-mentioned autonomous unmanned vehicle system, the central station C only specifies the node to which each unmanned vehicle A, B, etc. should go. As for the travel route, each unmanned vehicle A, B, . . . independently determines the travel route. The reason is that all unmanned vehicles A, B,... that are not currently working.
If the central station C was searching for a route to the node to which it should go, then the unmanned vehicles A, B,
This is because the search time becomes longer in proportion to the number of devices, and rapid processing becomes impossible. However, the central station C does not manage the driving routes of each unmanned vehicle A, B, etc.
Each unmanned car A.

In the method determined independently by B,..., collisions between unmanned vehicles must be avoided in some way. For example, as shown in FIG.
If there is an unmanned vehicle B traveling on route No. 3 and unmanned vehicle A starts traveling on the route of nodes N2 → N5 → N6 → N9, the two will collide between nodes N2 and N5. This will result in

This invention was made against this background, and an object of the present invention is to provide a collision avoidance method in a self-sustaining unmanned vehicle system that can avoid the above-mentioned collision between self-sustaining unmanned vehicles. do.

Means for Solving the ε Problem] In order to solve the above problem, the present invention provides for each unmanned vehicle to
A communication means for exchanging information with the central station and a detection means for detecting the approach of another unmanned vehicle are provided, and when each unmanned vehicle detects the approach of another unmanned vehicle by the detection means, The apparatus is characterized in that it reports this to the central station via the communication means, and at the same time executes actions to avoid the collision based on information provided from the central station.

[Operations] According to the above configuration, each unmanned vehicle reports the possibility of a collision to the central station. Based on this information, the relevant unmanned vehicle takes action to avoid a collision. In this case, if there is no risk of a collision occurring, the central station can perform other processing, so that the processing capacity of the central station is not reduced.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. In this embodiment, in order to simplify the explanation, a self-contained unmanned vehicle consisting of two unmanned vehicles 1, 8, and IB (hereinafter abbreviated as vehicle A and vehicle B) and a central station 2 will be described. This will be explained using a system as an example.

In FIG. 1, the central station 2 is a CPU (central processing unit)
It consists of , memory, communication equipment, etc.
The status of the car and Car B is always known, such as the current location and whether or not work is underway. It is also connected to each work point, accepts work requests from the work points, and transmits this information to Car A and Car B by radio.

Car A and car B are composed of a communication device 3, a command section 4, a running section 5, a map memory 6, and an other vehicle detector 7A (7B). Further, the running unit 5 includes a running control unit 8,
Left and right drive wheels 9L and 9R, and a motor lOL that rotationally drives the left and right drive wheels 9L and 9R, respectively.

+OR, pulse encoders 11L and 11R that detect the rotational speed of the left and right drive wheels 9L and 9R, respectively, and transmitter/receivers 12L and I2R that emit ultrasonic waves toward the left and right and receive the ultrasonic waves reflected from the left and right side walls. , an ultrasonic distance measuring section 13 that measures the distance to the left and right side walls based on the ultrasonic propagation time, and a trajectory correction section 14.

The map memory 6 stores in advance map data regarding the coordinates of each node, the distance from the travel route connecting each node to the left and right side walls, and the like.

In addition, the trajectory correction unit 14- compares the distance measurement data obtained from the ultrasonic distance measurement unit 13 and the map data read from the map memory 6 point by point, and adjusts the correction data based on the comparison result. The signal is supplied to the control section 8.

The travel control unit 8 normally creates a travel pattern suitable for the configuration of its own travel device based on a travel command (consisting of travel distance, speed, rotation angle, node number to be reached after travel, etc.) instructed by the command unit 4. (Trajectory patterns such as straight travel, curves, etc. and speed turns) are created, and the rotations of the left and right drive wheels 9L and 9R are controlled respectively based on the travel patterns and correction data. Furthermore, when a travel control command is directly supplied from the command unit 4 during a collision avoidance operation to be described later, the travel control unit 8 executes this command with priority. In this case, unlike usual, the driving control unit 8 controls the rotation of the drive wheels 9L and 9R as instructed by the command unit 4, so that the command unit 4 directly controls the driving. Become.

Other vehicle detectors 7A and 7B mounted on cars A and B respectively include a transmitter that emits omnidirectional identification radio waves of a predetermined frequency (for example, about 100 kHz), and a transmitter that emits omnidirectional identification radio waves of a predetermined frequency (for example, about 100 kHz), and a transmitter that emits omnidirectional identification radio waves of a predetermined frequency (for example, about 100 kHz), and a transmitter that emits omnidirectional identification radio waves of a predetermined frequency (for example, about 100 kHz), and a transmitter that emits omnidirectional identification radio waves of a predetermined frequency (for example, about 100 kHz). As shown in Figure 3, the transmitter and receiver are operated alternately, and the receiver or receiver receives the identification radio waves emitted from the transmitter of the other party within the range of and a detection circuit that outputs a detection signal when detected. In this case, the transmission period TA during which the transmitter on the other vehicle detector 7A side operates and the reception period RA during which the receiver operates are the same as the transmission period TB during which the transmitter on the other vehicle detector 7B side operates and the receiver operates. Reception period RB
and are appropriately set to be different from each other. As a result, as shown in FIG. 2, when vehicle A and vehicle B approach within the detection range of radius ra or rb, other vehicle detectors 7A and
B detects identification radio waves emitted by the other side and supplies a detection signal to the command section 4. and,
The detection range of the radii ra and rb above varies slightly depending on the output of each transmitter and the sensitivity adjustment of each receiver, but is approximately 3.
It is set to about m.

On the other hand, the command unit 4 is wirelessly connected to the central station 2 via the communication device 3, and performs polling/serenoti.

Various information is exchanged with the central office 2 using the communication method. When the command unit 4 is instructed from the central station 2 to the node of the work point where the work request has occurred, the command unit 4 searches for the optimal travel route by referring to the map data stored in the map memory 6, and searches for the optimal travel route to reach the target node. Determine which nodes to pass through when heading to . Further, travel commands are sequentially created and given to the travel unit 5 so that the robot moves along the travel route connecting each determined node.

Second, when a detection signal is supplied from the other vehicle detector 7A (7B), the command unit 4 starts a collision avoidance operation to be described later, gives a direct travel control command to the travel unit 5, and controls the drive wheels 9.
Directly controls the rotation of L and 9R.

Next, an explanation will be given of the operation in the above-described first embodiment when cars A and B approach each other between nodes N2 and N5 while facing each other, as shown in FIG.

First, at time T1 shown in FIG. 3, the other vehicle detector 7A of vehicle A detects the other vehicle (in this case, since there are two systems, the other vehicle is inevitably vehicle B). In the case of three or more vehicles, it is assumed that an identification radio wave of an unspecified vehicle is detected and a detection signal is output to the command unit 4. Then, the command unit 4 of car A starts collision avoidance operation.

Hereinafter, with reference to the flowchart shown in FIG. 4, the collision avoidance operation of car A will be explained in relation to the collision avoidance operation of car B and the operation of the central station.

First, when car A detects the approach of another car, step SAI
Then, the process proceeds to step SA2, and the command unit 4 of car A communicates with the traveling unit 5
A direct travel control command is given to the vehicle A to stop, and as a result, vehicle A temporarily stops. Next, the detection of another vehicle is reported to the central station 2 via the communication device 3 along with the identification code (vehicle number) of its own force, the current position, and the next node number to arrive at (step 5A3).

Upon receiving this report, the central station 2 determines whether or not there is a report indicating that another vehicle has been detected from a vehicle other than vehicle A (step 5C).
I) If there is a report, proceed to step SC2; if there is no report, proceed to step SC3. This step 5-
At C3, the central office 2 requests all vehicles to report their current location and the next node number they will arrive at. Next, based on the reports from all the cars, it is determined whether or not there are other cars near car A. Step 5C4
), if it exists, it is assumed that there is a risk of a collision and the process proceeds to step SC5; if it does not exist, it is assumed that there is no risk of a collision and the process proceeds to step S06. In step SC5, ・B who is at risk of colliding with car A
Command the car to stop.

After receiving this command, car B temporarily stops (step 5Bl)
, and then reports the vehicle's identification code, current position, and next arriving node number to the central station 2 (step 5B2).
).

On the other hand, the central office 2 performs steps SC5 to SC2.
In step SC2, an action to avoid a collision between cars A and B is determined based on the reports from cars A and B and the path situation, and this collision avoidance action is carried out by cars A and B.
Give instructions to each car.

In this case, as shown in FIG. 5, the central office 2
If the vehicles are facing each other, the action of avoiding each other to the right and passing each other is determined as a collision avoidance action. Further, for example, when car A and car B are heading in the same direction, the overtaking operation is determined as the collision avoidance operation. Thereafter, in step SC7, car A instructs car B to restart.

Now, after stopping at step SA2, car A executes the process of step SA3 described above, and then performs the process of step SA4.
In step SA4, it is determined whether there has been an instruction from the central station 2 to permit relaunch. If there is an instruction, the process proceeds to step SA8; if there is no instruction, the process proceeds to step SA5. . In step SA5, it is determined whether or not there is an instruction for collision avoidance operation from the central station 2. If there is an instruction, the process proceeds to the next step SA6, and the collision avoidance operation is performed as instructed by the central station 2. perform an action. In the next step SA7, it is determined whether there is an instruction to restart from the central station 2, and if there is an instruction,
Proceed to step SA8 and start again.

In parallel with the above-mentioned operation of car A, car B performs step SB.
After stopping at I, the process of step SR2 described above is executed, and then the process proceeds to step SB3.
, it is determined whether there is an instruction for collision avoidance operation from the central station 2, and if there is an instruction, the next step SB
4 and perform collision avoidance operations as instructed by the central station 2. In the next step SB5, it is determined whether or not there is an instruction from the central station 2 to restart the vehicle. If there is an instruction, the process proceeds to step SB6 and the vehicle restarts.

As a result of the above, as shown in FIG. 5, cars A and B move to the right side of each other and pass each other, and then start again and return to the original travel route, completing the collision avoidance operation.

Here, for example, as shown within the frame of the two-dot chain line in FIG.
If car A detects the approach of car B while moving away from the node N6, the central station 2 determines in step SC4 that there is no risk of collision and proceeds to step SC6. Instructs vehicle A to allow it to start again. As a result, car A proceeds from step SA4 to step SA8 and starts moving again.

Next, the operation of the second embodiment of the present invention will be explained with reference to the flowchart shown in FIG.

In this figure, the same reference numerals are given to the same processing parts as in the first embodiment, and the explanation thereof will be omitted.

In this second embodiment, the central office 2 performs step SC+
In this case, if it is determined that there is a report from another vehicle, or if the process in step SC5 is executed, step 5C is executed.
Proceed to IO.

In this step 5 CIO, the information received from car A, that is, the identification code of car A, the current position, and the node number to arrive next, is transferred to car B, and the information received from car B, that is, car B The identification code, current location, and next arriving node number are transferred to car A.

Next, in step 5CII, the instruction regarding the collision avoidance operation received from car B is transferred to car A.

On the other hand, when Car B receives information about Car A's identification code, current position, and next arriving node number from the central station 2, it receives (Car A's identification code) < ( Since it is the identification number 1 code of the own army, it recognizes that the own army is the master side. Then, the collision avoidance behavior of both the own army and vehicle A is determined, and the collision avoidance behavior of vehicle A is determined via the central station 2.
Instruct car A (step 5 BIO).

Thereafter, in step 5BII, the vehicle executes the self-determined collision avoidance operation and restarts the vehicle (step 5B6).

On the other hand, when Car A receives information about Car B's identification code, current position, and next arriving node number from the central station 2, it receives the information (Identification code of Car B)〉( It recognizes that the opponent's B car is the master side and its own army is the slave side. Then, the vehicle B executes the collision avoidance operation instructed via the central station 2 (step 5ALO), and then restarts (step 5A).
8).

In this way, in the second embodiment, when cars A and B approach each other and there is a risk of collision, the one with the larger identification code always becomes the master side, and collision avoidance on both the master side and the slave side is performed. It is designed to determine the behavior.

Therefore, compared to the first embodiment described above, the central office 2
The burden of processing can be reduced.

In addition, in the embodiment described above, the other vehicle detector 7A,
7B is configured to emit mutual identification radio waves and have a detection gap configuration, but it may be configured to detect other vehicles using ultrasonic waves having a different frequency from the ultrasonic waves for distance measurement, for example. Further, as a communication method between the central office 2 and cars A and B, a boring/serenting method may be used, or, of course, a token babbling method may be used.

[Effects of the Invention] As explained above, according to the present invention, a self-contained unmanned vehicle comprising a central station and a plurality of self-contained unmanned vehicles that move to a work point designated by the central station and perform required work. In an unmanned vehicle system, each unmanned vehicle is provided with a communication means for exchanging information with a central station and a detection means for detecting that another unmanned vehicle is approaching, and each unmanned vehicle is configured to detect other unmanned vehicles by the detection means. When detecting the approach of an unmanned vehicle, the system reports this to the central station via the communication means, and executes actions to avoid a collision based on information provided from the central station. Therefore, collisions between autonomous unmanned vehicles can be avoided. In addition, only when there is a risk of a collision, the central station only needs to provide the necessary information to the unmanned area in order to deal with this collision, which reduces the processing capacity of the central station. There's nothing to do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of a self-supporting unmanned vehicle system according to a first embodiment of the present invention, FIG. 2 is a plan view showing a general external configuration of an unmanned vehicle in the same embodiment, and FIG. A timing chart for explaining the operation of the other vehicle detector provided in the unmanned vehicle in the same embodiment, FIG. 4 is a flowchart for explaining the operation of the same embodiment, and FIG. 5 is a collision avoidance according to the same embodiment. A plan view to explain the operation,
FIG. 6 is a flowchart for explaining the operation of the second embodiment of the present invention, and FIG. 7 is a plan view for explaining the operation of the conventional autonomous unmanned vehicle system. l A, I B...Unmanned vehicle (Car A, Car B), 2
...Central station, 3...Communication device, 4...
...Command section, 5...Traveling section, 6...
Map memory, 7A, 7B...Other vehicle detector

Claims (1)

[Scope of Claims] 1) A central station and a plurality of unmanned vehicles that recognize their current positions and move to work points designated by the central station to perform required work, relying on built-in map information. In the autonomous unmanned vehicle system, each of the unmanned vehicles is provided with a communication means for exchanging information with the central station and a detection means for detecting the approach of another unmanned vehicle, When the vehicle detects the approach of another unmanned vehicle by the detection means, the vehicle reports this to the central station via the communication means, and avoids a collision based on information provided from the central station. A collision avoidance method in an autonomous unmanned vehicle system characterized by performing actions for 2) If any of the unmanned vehicles detects the approach of another unmanned vehicle and reports this to the central station, the central station will report the positional relationships and movement directions of all unmanned vehicles. A collision avoidance method in a self-contained unmanned vehicle system according to claim 1, characterized in that a collision avoidance method in a self-contained unmanned vehicle system is characterized in that the collision is recognized and, based on the recognition result, an operation instruction for avoiding the collision is given to the corresponding unmanned vehicle. . 3) When any of the unmanned vehicles detects the approach of another unmanned vehicle and reports this to the central station, the central station receives information regarding the positional relationship and movement direction of each unmanned vehicle. is transmitted to the relevant unmanned vehicle, and the relevant unmanned vehicles determine actions to avoid a collision based on the information transmitted from the central station, and mutually execute the actions. A collision avoidance method in a self-supporting unmanned vehicle system according to claim 1.