JPH10105234A - Unmanned carriage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable movement to a position corresponding to a halfway point of a guide body by an autonomous travel in a short time. SOLUTION: A travel robot calculates an error quantity about a magnetic tape on the basis of the ON state of a magnetism sensor (S6) at the time of a guide travel (S4: YES) and calculates a controlled variable from the error quantity (S7) to travel on a magnetic tape. Here, when the robot moves to a halfway point of the specific magnetic tape, an autonomous travel is made (S4: NO) and a sensor output monitor process is performed to monitor whether or not the magnetism sensor turns ON (S10). To end the autonomous travel in this case (S4: YES), a virtual path having a specific distance in a specific direction is set for a magnetic tape according to the ON state of the magnetism sensor (S11) unless it is positioned on the magnetic tape, and control is so performed that its virtual error becomes zero (S12).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle configured to be able to execute a guide traveling along a guide and an autonomous traveling outside a guide along a predetermined traveling route.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No.
No. 2,783,111. This is to detect the guide line reliably by shaking the vehicle body left and right at the point where the automatic guided vehicle is to transfer to the guide line.

[0003] Japanese Patent Application Laid-Open No. 3-130806 relates to a hybrid traveling robot provided with a magnetic sensor and an encoder for detecting rotation of a driving wheel. Is corrected, the accuracy of autonomous traveling based on the detection state of the encoder at the position where the guide tape does not exist is improved, and the traveling direction is corrected by detecting the guide tape at the end of traveling.

[0004]

However, the structure disclosed in Japanese Patent Application Laid-Open No. Hei 2-278311 detects a guide line in a state where the automatic guided vehicle is stopped at a scheduled transfer point to the guide line. There is a drawback in that it takes time to detect a line and the movement time becomes longer.

Japanese Unexamined Patent Publication No. Hei 3-130806 discloses a configuration in which the vehicle runs autonomously from the end of the guide tape and moves to a predetermined end of the guide tape. There is a disadvantage that there is no correction means. In addition, there is a disadvantage that the vehicle cannot travel autonomously in the middle of the guide tape.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automatic guided vehicle that can move to a position corresponding to the middle of a vehicle by autonomous traveling in a short time.

[0007]

According to the present invention, the guide traveling means travels along the derivative based on the detection state of the derivative detection means. In addition, the autonomous traveling means travels on a predetermined traveling route outside the derivative.

[0008] The travel control means moves to a position corresponding to the middle of a predetermined guide by autonomous travel according to the travel command, and then shifts to guide travel by the guide travel means.

At this time, at the end of traveling by the traveling control means, the vehicle should be located at a position corresponding to the derivative, but depending on the traveling state, it may be located before the position corresponding to the middle of the derivative or may be located at a position corresponding to the derivative. May go too far.

In such a case, the derivative detecting means cannot detect the derivative at the end of traveling by the traveling control means. Therefore, the position shift judging means determines whether the derivative detecting means cannot detect the derivative at the end of traveling by the traveling control means. Determines the positional deviation with respect to the derivative based on whether or not the derivative detecting means detects the derivative during autonomous traveling.

The traveling correcting means corrects the traveling route so as to travel on the derivative based on the positional deviation by the positional deviation judging means, so that the traveling autonomously travels to the position corresponding to the middle of the derivative in a short time. be able to.

According to the second aspect of the present invention, even if the vehicle is displaced from the position corresponding to the derivative at the end of traveling by the traveling control means, the virtual route is set along the derivative so that the virtual route is set. By correcting the traveling route so as to match the position corresponding to the derivative, it is possible to move to the position along the derivative in a short time.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a traveling robot will be described below with reference to FIGS.
FIG. 2 schematically shows the configuration of the traveling robot. In FIG. 2, the traveling robot 1 of the present embodiment generates a traveling program on an external computer (not shown) called a base station, and then gives a traveling command to the traveling robot 1 as an unmanned carrier by wireless communication. The travel command is received by the wireless receiving unit 2. In this case, since the route until the traveling robot 1 arrives at the destination is formed by combining a plurality of sections,
A plurality of commands to the traveling robot 1 are transmitted at the same time.

The running data management unit 3 manages the running commands received by the radio receiving unit 2 in order. The command position movement processing unit 4 (corresponding to the guide traveling unit, the autonomous traveling unit, the traveling control unit, the position deviation determining unit, the traveling correction unit, and the virtual route setting unit of the present invention) is managed by the traveling data management unit. By sequentially executing the traveling commands, the traveling robot 1 travels along a predetermined traveling route.

FIG. 3 is a schematic view showing the traveling robot 1 during traveling from above. In FIG. 3, the traveling robot 1
Run on the magnetic tape 5 as a derivative. In this case, the magnetic tapes 5 are arranged in parallel, and the traveling robot 1 moves from the guide traveling on one magnetic tape 5 to the guide traveling on the other magnetic tape 5 in response to a traveling command as described later. Is set to transition to.

FIG. 4 schematically shows the lower surface of the traveling robot 1. In FIG. 4, a pair of drive wheels 6 is provided at the center of the lower surface of the traveling robot 1, and casters 7 are provided at four corners of the lower surface. in this case,
The drive wheels 6 are independently driven by a motor (indicated by reference numeral 8 in FIG. 1),
Changes its direction according to the traveling direction.

A magnetic sensor 9 for detecting the magnetic tape 5 is attached to the front and rear of the lower surface of the traveling robot 1. The magnetic sensor 9 is turned on when the magnetic sensor 9 is located at a position facing the magnetic tape 5, and the amount of displacement from the center position of the magnetic tape 5 (for example, when the width of the magnetic tape 5 is 140
mm, ± 70 mm from the center of the magnetic tape 5,
That is, a signal of a level corresponding to 0 to 140 mm from one end of the magnetic tape 5 is output.

FIG. 1 schematically shows the configuration of the command position movement processing section 4 shown in FIG. 2, which is mainly composed of a microcomputer. In FIG. 1, a map data storage unit 10 stores a map in a state where XY coordinates are set on the road surface on which the traveling robot 1 travels. The map data storage unit 10 stores the coordinates based on the coordinate position (X, Y) and the rotation angle from the Y axis. The traveling robot stops, passes,
The installation position of the guide tape for indicating the installation position and the stop position of the guide tape and the like are stored in association with the ID number.

The route generation unit 11 includes a map data storage unit 10
Based on the map data stored in the storage unit, a guide travel route that travels on the magnetic tape 5 or an autonomous travel route that includes a straight line or a branch is generated. The target value calculation unit 12 includes the route generation unit 11
A plurality of target positions are set on the route (guide travel route or autonomous travel route) set by.

The position / posture error calculator 13 calculates correction data such as a lateral error (lateral displacement) and a posture error with respect to the center position of the magnetic tape 5 based on the detection state of the magnetic sensor 9 during the guide traveling. . Current value calculation unit 14
Calculates a current value indicating the current position based on a command from the encoder 15 attached to the motor 8.

The control amount calculator 16 determines the positional relationship between the target position calculated by the target value calculator 12 and the current position calculated by the current value calculator 14, and determines the relationship between the target position and the target position. The motor 8 is driven through the motor driver 17 according to an operation pattern such as rotation, curve, sideways movement, lane change, and the like according to the target positional relationship.

Next, the operation of the above configuration will be described. FIG. 5 is a flowchart showing the operation of the command position movement processing section 4. In FIG. 5, a route generation unit 11 included in the command position movement processing unit 4 responds to a travel command from the travel data management unit 3 and outputs an ID representing a target position from map data stored in the map data storage unit 10. Necessary information is extracted on the basis of the data (S1), and a guide traveling route running on the magnetic tape 5 or an autonomous traveling route composed of straight traveling, branching, and the like is generated (S2).

The target value calculation unit 12 calculates the route (guide travel route or autonomous travel route) created by the route generation unit 11.
A target value is calculated based on the difference between the current value and the current value indicated by the current value calculation unit 14, and is provided to the control amount calculation unit 16 (S3).

When the route generator 11 has created the guide travel route for traveling on the magnetic tape 5 (S4: YES), the control amount calculator 16 determines whether the magnetic sensor 9 is on. (S5). In this case, the magnetic sensor 9 is on when it is at a position facing the magnetic tape 5 (−70 mm to +70 mm from the center of the magnetic tape 5). Means you are.

Since the magnetic sensor 9 outputs a signal of a level corresponding to the amount of displacement from the center of the magnetic tape 5, the position / posture error calculator 13 is provided before and after the traveling robot 1. Based on the signal levels of the two magnetic sensors 9, an error in the lateral direction and an attitude error (error in the traveling direction) from the center of the magnetic tape 5 can be known.

Therefore, the control amount calculation unit 16 calculates the control amount based on the calculation results of the target value calculation unit 12 and the position / posture error calculation unit 13 and drives the motor 8 through the motor driver 17. In this case, the control amount calculation unit 16
The motor 8 is controlled so that the lateral error and the posture error calculated by the position / posture error calculator 13 are both zero.

Subsequently, the control amount calculating section 16 determines whether or not the vehicle has arrived at the destination calculated by the target value calculating section 12 based on the detection result of the current value calculating section 14 (S9). If not, a new target value is set by the target value calculation unit 12, and the above-described operation is repeated. By the above operation, the traveling robot 1 travels on the magnetic tape 5 during the guide traveling.

When the traveling robot 1 determines that it has reached the predetermined position, it moves from one magnetic tape 5 to the other magnetic tape arranged in parallel with the magnetic tape 5 as shown in FIG. Move to tape 5. That is, when the route generation unit 11 determines that the vehicle has reached the branch point (node) (indicated by A in the drawing) based on the map data during the guide traveling, it determines that the vehicle will shift to the autonomous traveling (S).
4: NO). In this case, as shown in FIG. 3, the traveling time can be shortened by traveling on a route (indicated by B in the drawing) in which the vehicle changes lanes.

Therefore, the target value calculating section 12 generates an autonomous traveling route shown by B in FIG. 3 by connecting curves of a predetermined curvature, and sets a plurality of target values on the autonomous traveling route thus generated. It is set (S3). As a result, the control amount calculation unit 16 controls the motor 8 so as to reach the first target value.
Control. At this time, the control amount calculation unit 16 executes the output monitoring process of the magnetic sensor 9 (S1
0), it is determined whether the traveling robot 1 has reached the magnetic tape 5 or not. By repeating the above operation, the traveling robot 1 shifts from the guide traveling, which travels the one magnetic tape 5 by the autonomous traveling, to the autonomous traveling.

When the route generator 11 determines that a node (indicated by C in FIG. 3) set on the other magnetic tape 5 has been reached, the route generator 11 determines to shift to guide travel (S4: YES), it is determined whether the magnetic sensor 9 is turned on (S5). At this time, when the traveling robot 1 is correctly positioned in the middle of the other magnetic tape 5, since the magnetic sensor 9 is on, the guide traveling is performed based on the detection state of the magnetic sensor 9 as described above. Run.

During autonomous traveling, only the signal from the encoder 15 attached to the motor 8
Since the dead reckoning traveling for controlling the rotation of the motor is performed, the correction based on the output from the magnetic sensor 9 cannot be performed during this period. For this reason, the determination of the current position during autonomous traveling may be different from the actual traveling route due to disturbance of the road surface condition or the like. Therefore, the traveling robot 1 is positioned on the magnetic tape 5 when it is determined that the current value calculated by the current value calculation unit 14 is different from the actual current value and reaches the node on the other magnetic tape 5 and shifts to guide traveling. The magnetic sensor 9 may not be turned on (S5: NO).

In such a case, the control amount calculating section 16 determines whether or not the magnetic sensor 9 has been turned on by a sensor output monitoring process during autonomous traveling. When it is determined that the magnetic tape has not reached the magnetic tape 5, and when the magnetic sensor 9 is turned on from off and turned off again, it is determined that the magnetic tape 9 has crossed the magnetic tape 5.

At this time, when the traveling robot 1 has not reached the magnetic tape, the traveling robot 1 is positioned in front of the other magnetic tape 5 as shown in FIG. 5, the traveling robot is located on the other side across the other magnetic tape 5 as shown in FIG. 7.

The control amount calculating section 16 drives the motor 8 as follows so as to move onto the magnetic tape 5 based on the above-described determination. That is, since the distance and traveling direction from the traveling robot 1 to the magnetic tape 5 are not known at the end of the autonomous traveling, regardless of the magnitude of the distance, when the magnetic sensor 9 continues to be in the OFF state during the autonomous traveling, As shown in FIG. 6, a virtual path (indicated by D in the figure) along the magnetic tape 5 is set at a position on the near side of the magnetic tape 5 (S11), and the magnetic sensor 9 is turned on from autonomous driving during autonomous traveling. When the vehicle is turned off again, a virtual path (indicated by E in the figure) along the magnetic tape 5 is set at a position across the magnetic tape 5 as shown in FIG. Assume that 1 is located.

Here, the traveling robot 1 has an angle difference (Δ) between the magnetic tape 5 and its own traveling direction during the guide traveling.
θ) and the lateral position error (Δx) are both controlled to be zero, and Δθ is determined by the outputs of the front and rear magnetic sensors 9.
Although θ and Δx are calculated, the data of the virtual route is Δθ = 0, ΔX until the magnetic sensor 9 detects the magnetic tape 5.
= L and a virtual error is set (S12),
Control is performed so that Δx becomes 0.

With the above control, the traveling robot 1 moves so as to approach the magnetic tape 5. By repeating such control, the traveling robot 1 moves until the magnetic sensor 9 detects the magnetic tape 5, and thereafter, moves. Based on Δθ and Δx obtained based on the signal level from the sensor 9, the traveling robot 1 can shift to the guide traveling moving on the magnetic tape 5.

According to the above configuration, when the vehicle travels to the position corresponding to the middle of the magnetic tape 5 by the autonomous traveling and then shifts to the guide traveling, when the autonomous traveling is terminated. The position deviation with respect to the magnetic tape 5 is determined based on the output state of the magnetic sensor 9, and the movement is controlled so as to approach the magnetic tape 5 based on the determination result of the position deviation, so that the derivative cannot be detected. Sometimes, compared to a configuration in which the operation is simply interrupted by a detection error, the robot is stopped, and the robot is slowed down, the traveling robot 1 is stopped in a short time without stopping the traveling robot 1 while searching for the derivative in the work flow. It is possible to move to the position corresponding to the middle of the tape 1 in a short time and shift to the guide traveling.

In this case, the virtual path is set based on the result of the determination of the positional deviation with respect to the magnetic tape 5 determined at the end of the autonomous traveling, and control is performed so as to move onto the magnetic tape 5 based on the virtual path. It can be moved on the magnetic tape 5 in a short time with a simple control.

FIG. 8 shows a second embodiment of the present invention.
The second embodiment is characterized in that a wall surface or a facility in a factory is used as a derivative. That is, in FIG. 8, the traveling robot 1 is provided with infrared distance sensors 17 as derivative detecting means at four corners, calculates a shift amount and a shift angle of the infrared distance sensor 17 from a wall surface or the like, and calculates an error of the error. Are set to be zero, thereby setting a target travel line at the time of guide travel at a position at a fixed distance from the wall surface. In this case, since the sum of the distance from the wall surface to the infrared distance sensor 17 and the distance from the infrared distance sensor 17 to the center of the traveling robot 1 corresponds to the current actual traveling line, the actual traveling with respect to the target traveling line is performed. By calculating the shift amount and the shift angle of the line, the first
As in the embodiment, the guide travel can be performed along the wall surface or the like.

Here, when the traveling robot 1 moves from one target traveling line to the other target traveling line by autonomous traveling, if the traveling robot 1 gets too close to or away from the wall surface from the other target traveling line, the infrared distance Since the displacement is out of the detection range of the sensor 17 and the displacement amount and the displacement angle with respect to the wall surface are unknown, in such a case, virtual routes are set on both sides of the other target travel line in the same manner as in the first embodiment. By executing the control, it is possible to move in a short time in the middle of the target travel line. Incidentally, a reflecting plate for making the reflected light of the infrared distance sensor 17 uniform may be provided on the wall surface.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. A guide tape may be provided as a derivative, and the optical sensor may detect the guide tape. It is also possible to use a device that controls to move from the end of the magnetic tape to the middle of the magnetic tape. In this case, the magnetic tapes may be arranged to be orthogonal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a command position movement processing unit according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing the overall configuration.

FIG. 3 is a plan view of the traveling robot showing a normal traveling locus.

FIG. 4 is a bottom view of the traveling robot.

FIG. 5 is a flowchart illustrating an operation of a command position movement processing unit;

FIG. 6 is a view corresponding to FIG.

FIG. 7 is a view corresponding to FIG.

FIG. 8 is a view corresponding to FIG. 3, showing a second embodiment of the present invention.

[Explanation of symbols]

1 is a traveling robot (automated guided vehicle), 4 is a commanded position movement processing unit (guide traveling means, autonomous traveling means, traveling control means,
5 is a magnetic tape (derivative), 9 is a magnetic sensor (derivative detection means), and 17 is an infrared distance sensor (derivative detection means).

Claims (2)

[Claims] 1. A derivative detecting means for detecting a derivative set along a traveling route, a guide traveling means for traveling along the derivative based on a detection state of the derivative detecting means, Autonomous traveling means traveling on the set traveling route, and moving to a position corresponding to the middle of a predetermined derivative by autonomous traveling by the autonomous traveling means in response to a traveling command,
Travel control means for shifting to guide travel by the guide travel means; and when the derivative detection means has failed to detect the derivative at the end of travel by the travel control means, the derivative detection means detects the derivative during autonomous travel. A displacement determining means for determining a displacement with respect to the derivative based on whether or not the displacement is detected; and when the displacement determining means detects the displacement, the vehicle travels along the derivative based on the displacement. An automatic guided vehicle provided with travel correction means for correcting a route. 2. A virtual route setting device for setting a virtual route deviated by a predetermined distance in a predetermined direction with respect to the derivative based on a result of the determination by the position deviation determining device, 2. The automatic guided vehicle according to claim 1, wherein the traveling route is corrected based on the virtual route set by the means.