JP2009223570A - Unmanned carrier, control method thereof, and traveling line for unmanned carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unmanned carrier suitable for route change due to rotation, and to provide a control method thereof and a traveling line of the unmanned carrier. <P>SOLUTION: This unmanned carrier 1 is configured by arranging driving units 4, at front and rear parts of a vehicle, each of which is provided with right and left driving wheels 8 to be independently driven by a pair of motors, a track sensor 9 for detecting a traveling line 11, and a control means 6 for controlling the rotation of the right and left driving wheels 8 by a driving means based on the detection result of the track sensor 9, to run the vehicle by the right and left driving wheels 8 of the driving unit 4, while steering the vehicle by its relative rotation. This unmanned carrier 1 is configured to rotate the vehicle by moving the front and back driving units 4 in a reverse direction along a circular track tape 11C around the intersection on the intersection of the traveling lines, and to move the front and back driving units 4 from one traveling line 11A to the other traveling line 11B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic guided vehicle that travels on a route designated in advance by a track such as a magnetic tape or a reflective tape laid on a floor surface, a control method thereof, and a traveling line of the automatic guided vehicle, and particularly suitable for a course change by turning. The present invention relates to an automatic guided vehicle, a control method thereof, and a traveling line of the automatic guided vehicle.

  Conventionally, for the purpose of automation of logistics, unmanned moving forward on the path formed by the track while correcting the left and right deviation of the vehicle with respect to the track such as magnetic tape combined with straight lines and curves laid on the floor surface by the detection sensor A conveyance vehicle is generally used (see Patent Documents 1 and 2).

This is because the spin turn steering angle φ from the distance A1 from the wheel base L of the vehicle body and the axis of the caster to the orbit after the spin turn in order to place the vehicle body on the orbit by 90 degrees without causing the vehicle body to protrude too much from the orbit. (= Tan ⁻¹ (L / A1)) is obtained, and the travel distance D (= πL / (2 sin φ)) of the spin turn is obtained from φ and L, and the steering motor and the steering motor are set so as to be the travel distance D at the steering angle φ. The spin motor is controlled to spin-turn so that it can be spin-turned without causing the vehicle body to protrude too much from the track compared to the conventional case where a caster shaft is placed on the track and spin-turned on the spot. ing.
JP-A-11-161335 Japanese Patent No. 2900484

  However, in the above conventional example, when the direction of the vehicle is turned to change the route of the automatic guided vehicle (turning on the spot), the detection range of the detection sensor is temporarily deviated from the track. A vehicle attitude angle is predicted and calculated based on the travel distance obtained by integrating the rotation speed signals from the rotary encoder, and the vehicle attitude angle is controlled based on the prediction result. For this reason, when error factors such as slip frequently occur on the wheel, there is a problem that derailment that cannot return to the target track occurs. In addition, the calculation of the travel distance and the prediction calculation of the vehicle attitude angle have a problem that the calculation steps are enormous and errors are accumulated, so that the control of the vehicle attitude angle with high accuracy cannot be performed quickly. .

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an automatic guided vehicle suitable for route change by turning, a control method thereof, and a traveling line of the automatic guided vehicle.

  The present invention relates to left and right drive wheels driven independently by a pair of drive means, a line detection means for detecting a travel line, and left and right drive wheels by the drive means based on the detection result of the line detection means. And a control unit for controlling the respective rotations of the drive unit. The drive unit is disposed in front of and behind the vehicle, and the vehicle is driven by the rotation of the left and right drive wheels of the drive unit, and the vehicle is steered by the relative rotation. An automated guided vehicle, a control method thereof, and a traveling line of the automated guided vehicle, wherein the front and rear drive units are advanced in the reverse direction along an annular traveling line centering on the intersection on the intersection of the intersecting traveling lines. Thus, the vehicle is turned to shift the front and rear drive units onto the other traveling line intersecting from one traveling line.

  Therefore, in the present invention, on the intersection of the intersecting traveling lines, the vehicle is turned by advancing the front and rear drive units in the reverse direction along the annular traveling line centering on the intersection, and on one traveling line. Since the front and rear drive units are transferred to the other travel line that intersects the vehicle, the direction of travel of the automated guided vehicle can be accurately turned in any direction in a narrow space, and the drive wheel slips during the turn. Even if such an error factor occurs, the vehicle can be turned accurately.

  Hereinafter, an automatic guided vehicle of the present invention, a control method thereof, and a traveling line of the automatic guided vehicle will be described based on an embodiment shown in FIGS. 1 is a bottom view of the automatic guided vehicle, FIG. 2 is a side view of the automatic guided vehicle, FIG. 3 is a bottom view of the automatic guided vehicle in which the position of the address sensor is changed, and FIG. 4 is a system configuration diagram of traveling control of the guided vehicle. FIG. 5 is an explanatory diagram showing the intersection of the traveling line where the automatic guided vehicle turns, FIG. 6 is an explanatory diagram of the traveling line including the intersection, and FIG. 7 is executed by the drive unit controller of the automatic guided vehicle along the normal traveling line. FIG. 8 is a flowchart of the course change control executed by the running controller at the course change at the intersection that has largely intersected.

  1 and 2, the automatic guided vehicle 1 according to the present embodiment includes two support shafts 3 provided to stand on the floor surface in front and rear of the lower portion of the vehicle body 2, and each support shaft 3. Each includes a drive unit 4 that is turnably provided, caster wheels 5 that are disposed at substantially four corners of the lower portion of the vehicle body 2, and a controller 6 that controls the drive unit 4. The caster wheel 5 supports the weight of the vehicle and is turned following the moving direction of the vehicle.

  The drive unit 4 is rotatably supported by the support shaft 3 and includes an axle 7 including a pair of drive motors (not shown), and is disposed on the left and right sides of the axle 7 and is independently driven by the pair of drive motors. A pair of drive wheels 8. In addition, the drive unit 4 includes a track sensor 9 that detects the track tape 11 that is held by brackets disposed in front of and behind the axle 7 and forms a travel line. Also, it is held by a bracket disposed in front of or behind the axle 7 and is disposed at a set position adjacent to the track tape 11, and sends an external signal (command (turn command, stop command) to the controller 6 of the automatic guided vehicle 1. A pair of left and right address sensors 10 for detecting an address mark (magnetic tape) 12 for transmitting a command (start command). In the example shown in FIG. 1, the pair of address sensors 10 are arranged from each drive unit 4 toward the center in the vehicle front-rear direction, but the installation positions of the address marks 12 are changed simultaneously. Thus, as shown in FIG. 3, the drive units 4 may be arranged in the front-rear direction of the vehicle.

  The drive unit 4 can be moved up and down by a lift mechanism 2A provided in the vehicle body 2, and the automatic guided vehicle 1 can run by bringing each drive wheel 8 into contact with the floor surface at the lowered position. In the state where it is raised by the lift mechanism 2 </ b> A, the automatic guided vehicle 1 can be freely moved by the caster wheel 5 to be detached from the track tape 11 or returned to the track tape 11. The drive unit 4 in the lifted state by the lift mechanism 2A is turned by a centering mechanism (not shown) to be in an initial state where the steering angle is zero (the central axis of the vehicle longitudinal direction and the traveling direction of the drive unit 4 coincide). The drive unit 4 can also be made to coincide with the track tape 11 only by making the vehicle direction coincide with the track tape 11 when returning to the track tape 11.

  Each drive wheel 8 is grounded on the traveling road surface and is rotationally driven by a corresponding drive motor to drive the automatic guided vehicle 1. That is, when the two drive wheels 8 are driven at the same speed by the drive motors, the axle 7 does not turn around the support shaft 3 and is orthogonal to the axle shaft connecting the left and right drive wheels 8 ( In the driving direction), the support shaft 3 is pushed through the axle 7 to move the vehicle. In this case, the combined forces in the driving direction of both drive wheels 8 are the same. As will be described later, the traveling direction of the vehicle can be changed variously according to the respective driving states (the driving direction and the driving speed of the front / rear drive unit 4) of both the drive units 4 arranged at the front and rear of the vehicle. .

  Further, when there is a difference between the driving speeds of the left and right driving wheels 8, the vehicle is driven by pushing the supporting shaft 3 according to the average speed of the both driving wheels 8 while rotating the axle 7 around the supporting shaft 3. To run. Further, when the average speed of both the drive wheels 8 becomes zero, that is, when both the drive wheels 8 are driven at the same speed in opposite directions, the axle 7 is turned around the support shaft 3 to support the The drive direction to the shaft 3 can be changed.

  The traveling direction of the vehicle is such that the driving direction of each of the drive units 4 arranged in the front and rear of the vehicle is on the same axis, that is, when the rudder angle that coincides with the longitudinal axis of the vehicle is zero, In a state where the drive unit 4 is reversed by an angle of 180 degrees (reverse position, rudder angle is 180 degrees), the vehicle can be moved straight backward. Even when the drive directions of both drive units 4 are reversed, the vehicle can be moved straight backward.

  Further, when both the drive units 4 are turned from the straight traveling position in the same direction at an angle of 90 degrees, the vehicle can be traversed in the lateral direction without changing its posture. Furthermore, when both the drive units 4 are turned in an oblique direction by an arbitrary direction and the same angle, the vehicle can be obliquely traveled in an arbitrary direction without changing its posture.

  Further, when both the drive units 4 are turned at an angle of 90 degrees in the opposite direction from the straight traveling position, the vehicle is turned on the spot without moving the center position of the vehicle (the intermediate position of the front and rear support shafts 3). be able to. Further, when the drive direction of the front drive unit 4 is turned by an arbitrary angle, the vehicle can be turned in this arbitrary direction, and the trail at that time is the axle shaft of the front drive unit 4 and the rear drive unit. A turning radius having a turning center at a point where the four axle shafts intersect is provided. When turning, the drive direction of the rear drive unit 4 (angle position around the support shaft 3) is turned to an angle opposite to the drive direction of the front drive unit 4 (angle position around the support shaft 3). Can make the vehicle turn a little by making the intersection (turning center) between the front and rear axle shafts closer to the vehicle and reducing the turning radius.

  The track sensor 9 is provided with a plurality (three in the illustrated example) of sensors along the width direction of the track tape 11 forming the travel line. Usually, the moving speed of the left and right drive wheels 8 of the drive unit 4 is adjusted by the controller 6 so that the track tape 11 is detected by all the sensors of the track sensor 9 positioned in the forward direction. The moving speed of the left and right drive wheels 8 may be adjusted so that the track tape 11 is detected by a plurality of sensors in the track sensor 9 positioned rearward in the traveling direction, and is positioned before and after the traveling direction. The moving speed of the left and right drive wheels 8 may be adjusted so that the track tape 11 is detected by all the sensors of both track sensors 9.

  FIG. 4 is a system configuration diagram of the automatic guided vehicle 1. The controller 6 includes a travel control controller 6 </ b> A that executes travel control of the automatic guided vehicle 1 and a drive unit controller 6 </ b> B that controls each drive unit 4. The travel controller 6A includes a detection signal from an address sensor 10 that detects a magnetic tape that transmits a command command and an address magnetic tape that indicates a current position, which are arranged on the side of the track tape 11 as necessary. The route / speed command from the memory circuit storing the preset travel route / vehicle speed command is inputted, and the steering angle command and speed command (start, stop, speed) of the vehicle front / rear drive unit 4 are calculated. To the drive unit controller 6B. Hereinafter, the magnetic tape for transmitting the command command and the address magnetic tape indicating the current position are collectively referred to as an address mark 12. A detection signal from the track sensor 9 is input to the drive unit controller 6B, and a steering angle command and a speed command from the travel control controller 6A are input. Based on these input signals, rotation of the left and right drive motors is performed. Calculate speed and rotational angular velocity. The rotational speed and rotational angular speed commands of the left and right drive motors are output to the motor drive circuit 13 to control each drive motor.

  The traveling line of the automatic guided vehicle 1 can be set freely along an arbitrary traveling line formed of a magnetic tape, a reflective tape, or the like, so that the automatic guided vehicle 1 can travel. By the way, when the automatic guided vehicle 1 is moved to a travel line branched from one travel line, the branched track tape 11 can be detected by the track sensor 9. At this time, the branched track tape 11 is formed so as to draw a gentle curve or the original track so that the automatic traveling of the automatic guided vehicle 1 can be performed while reliably detecting the track tape 11 by the track sensor 9. The angle between the tape 11 and the track tape 11 that branches off is set small.

  However, since the automatic guided vehicle 1 moves while detecting the track tape 11 by the track sensor 9, it is necessary to form a travel line so as to draw a gentle curve or to branch the travel line at a small angle. For this purpose, since the automatic guided vehicle 1 travels, it is not possible to change the course to a traveling line that intersects at a large angle, so the shape of the traveling line for traveling the automatic guided vehicle 1 is limited, A travel line must be formed using a large space.

  The traveling line shown in FIG. 5 shows the form of the traveling line at the intersection used when the course is surely changed to the traveling line intersecting at a large angle. In other words, a circular running line is formed by the circular track tape 11C so as to surround the intersection where one track tape 11A and the other track tape 11B intersect. The circular track tape 11C is formed in a circular shape centering on the center of the intersection, and the tape width is set to the same width as the normal track tapes 11A and 11B. Further, since the track sensor 9 for detecting the circular track tape 11C is arranged to be offset forward and backward with respect to the support shaft 3 of the drive unit 4, the track sensor 9 is orthogonal to the circular track tape 11C. Face each other in an inclined state. The diameter of the circular track tape 11 </ b> C is set to the same dimension as the distance between the support shafts 3 of the drive unit 4 before and after the automatic guided vehicle 1.

  In addition, in order to stop the automatic guided vehicle 1 with the center being coincident with the center of the intersection, an address mark 12A for a stop / turn command is provided. For example, in the case where the automatic guided vehicle 1 enters the intersection along the first track tape 11A from the direction of the arrow in the drawing and moves out of the intersection and proceeds in the direction of the arrow along the second track tape 11B, the automatic guided vehicle When the center of 1 coincides with the center of the intersection, an address mark 12A for a stop / turn command is installed at a portion where the address sensor 10 installed in the front drive unit 4 is located.

  At the time point described above, the support shafts 3 of the front and rear drive units 4 are stopped at positions where the first track tape 11A and the circular track tape 11C intersect each other. Then, as will be described later, each drive unit 4 is turned by 90 degrees around the support shaft 3 to advance each drive unit 4 along the circular track tape 11C, and the automatic guided vehicle 1 moves to the second track tape 11B. In order to stop the traveling on the circular track tape 11C, the stop instruction address mark 12B is installed in the vicinity of the second track tape 11B. This stop command address mark 12B is provided for each drive unit 4 in order to stop each drive unit 4 at the normal position.

  In the above description, the installation position of the address mark 12B indicates a case where the first track tape 11A is changed from the direction indicated by the arrow to the second track tape 11B and then moved in the direction indicated by the arrow. When the course is changed and the process proceeds to the first track tape 11A, it is necessary to install an address mark 12B different from that described above for the purpose.

  FIG. 6 shows an example of travel lines that the automatic guided vehicle 1 intersects greatly. A circular track tape 11C and a necessary address mark 12B (not shown) are installed at each intersection. And the automatic guided vehicle 1 can be made to turn in the 1st intersection from the A direction, and advance to the B direction, for example, and can turn and drive in the C direction or the D direction at the 2nd intersection.

  The turning method of the automatic guided vehicle 1 having the above configuration and the operation of the turning device will be described below based on the flowcharts shown in FIGS. FIG. 7 shows a flowchart of travel control executed by the drive unit controller when the automatic guided vehicle 1 travels along the normal travel line, that is, when the automatic guided vehicle 1 travels normally. FIG. 8 shows a flowchart of the route change control executed by the travel controller in the route change at the intersection that greatly intersects.

  The control for normal travel shown in FIG. 7 is executed for each of the front and rear drive units 4, and each drive unit 4 has its traveling direction substantially directed to the traveling direction of the automatic guided vehicle 1 (the steering angle is substantially 0). )), The rotational speeds of the left and right drive wheels 8 are adjusted based on the detection result of the track sensor 9 while rotating the left and right drive wheels 8 at substantially the same speed. Thus, the automatic guided vehicle 1 travels while being steered along the travel line.

  In the first step S1 of this flowchart, feedback control of the drive motor is performed, and the left and right drive wheels 8 are driven to rotate at the same speed. On the other hand, in the next step S2 and step S3, it is confirmed from the detection result of the track sensor 9 whether or not all the sensors provided along the width direction of the track tape 11 are in the detected state of the track tape 11. Yes. Here, if any of the sensors on both sides in the width direction is in the non-detection state of the track tape 11, that is, if the sensor is displaced from the track tape 11, a negative determination is made in step S2 or step S3.

  Among the plurality of sensors of the track sensor 9 arranged in the width direction of the track tape 11 forming the travel line, when the right end sensor is removed from the track tape 11 and becomes a non-detection state, a negative determination is made in step S2. The process proceeds to step S4. In step S4, the rotational speed of the left drive wheel 8 of the left and right drive wheels 8 of the drive unit 4 is reduced. That is, when the right sensor is not detected, it is determined that the drive unit 4 is shifted to the right side of the track tape 11 and the left drive wheel 8 is decelerated. As a result, the drive unit 4 gradually turns to the left, and the deviation from the travel line is corrected.

  When it is determined that the drive unit 4 is shifted to the left with respect to the track tape 11, a negative determination is made in step S3, and the process proceeds to step S5. In step S5, on the contrary, the rotational speed of the right drive wheel 8 is decelerated and the drive unit 4 is gradually turned to the right to correct the deviation of the drive unit 4 from the travel line.

  Thus, the correction of the deviation of the drive unit 4 with respect to the travel line is performed based on the detection result of the track sensor 9, and in a state where all the sensors of the track sensor 9 detect the track tape 11, the step is performed. Affirmative determination is made at each of S2 and S3, and the left and right drive wheels 8 are driven at the same speed to travel (step S1). As a result, the automatic guided vehicle 1 can travel while being steered along the travel line while the deviation from the travel line is corrected.

  The course change control executed by the travel control controller of the automatic guided vehicle 1 shown in FIG. 8 is executed when it is determined whether or not the course change is performed based on the travel program, and the course change is determined. The In the traveling program, an address mark 12 for changing the course and a traveling direction are set. That is, whether to travel to the right or to the left from the original track tape 11A (hereinafter referred to as one track tape 11A) that has traveled is set.

  In step S10, the vehicle travels while detecting the address mark 12A indicating the course change position by the address sensor 10, and when the address mark 12A is detected, the vehicle is temporarily stopped (step S11).

  Next, in step S12, the left and right drive wheels 8 of the front and rear drive units 4 are rotationally driven in opposite directions to rotate the drive unit 4 about the support shaft 3 with respect to the vehicle body 2 of the automatic guided vehicle 1. . At this time, the drive unit 4 is rotated such that the traveling directions of the drive units 4 provided before and after the automatic guided vehicle 1 are directed in different directions.

  That is, as shown in FIG. 9, when the automatic guided vehicle 1 detects the address mark 12A and stops, the drive unit 4 on the front side is moved with respect to the traveling direction (direction of arrow A1) along one track tape 11A. The drive unit 4 on the rear side is rotated so as to be directed to the front side in the direction of travel perpendicular to the direction of the arrow A2, and the rear drive unit 4 is rearward in the direction of travel (arrow A3) orthogonal to the direction of travel along one track tape 11A. Direction).

  The rotation of the drive unit 4 about the support shaft 3 is continued, and when the circular track tape 11C is detected by all the sensors of the track sensor 9 provided in each drive unit 4, as shown in FIG. The rotation around is stopped (step S13). As a result, the rotation angle of the front drive unit 4 and the rotation angle of the rear drive unit 4 are each approximately 90 degrees.

  Next, the process proceeds to step S14, and the track sensor 9 provided in the front and rear drive units 4 is moved forward while the circular track tape 11C is detected. Each drive unit 4 is driven to rotate while controlling the drive speed of the left and right drive wheels 8 in order to follow the circular track tape 11C. In this case, the driving speed of the left and right driving wheels 8 is such that the speed of the inner driving wheel 8 near the center point of the automatic guided vehicle 1 is lower than the speed of the outer driving wheel 8 far from the central point of the automatic guided vehicle 1. It is controlled with the wheel difference. As a result, as shown in FIG. 11, the front and rear drive units 4 and the automatic guided vehicle 1 turn around the central point of the automatic guided vehicle 1.

  Next, the process proceeds to step S15, where the address sensor 10 of any one of the front and rear drive units 4 is disposed close to the other track tape 11B in order to stop the drive unit 4, and is a stop command address mark. It is confirmed whether 12B is detected. When the address mark 12B is detected, the process proceeds to step S16, where one of the drive units 4 before and after detecting the address mark 12B is stopped, and the other drive unit that does not detect the stop instruction address mark 12B. 4 continues traveling and proceeds to step S17.

  In step S17, it is determined whether or not the address sensor 10 of the other drive unit 4 has detected a stop command address mark 12B installed in the vicinity of the other track tape 11B for stopping the drive unit 4. Check. When the address sensor 10 of the other drive unit 4 has not detected the stop address mark 12B installed for the stop, the process proceeds to step S18, and the address sensor of the other drive unit 4 within a predetermined time set in advance. It is confirmed whether or not the address mark 12B of the stop command 10 installed for the stop is detected. When the address sensor 10 of the other drive unit 4 detects the stop instruction address mark 12B installed close to the other track tape 11B for stopping the drive unit 4, the process proceeds to step S19.

  In step S19, the other drive unit 4 is stopped and the process proceeds to step S19. As shown in FIG. 12, the drive units 4 before and after the automatic guided vehicle 1 are stopped with their traveling directions orthogonal to the other track tape 11 of interest.

  The stop address mark 12B is installed at the position where the left and right drive wheels 8 of the drive units 4 that have traveled on the circular circular track tape 11C together form the other track. It is installed on the floor corresponding to the position of the address sensor 10 at the time. When the address sensor 10 generates a detection signal when it passes through the address mark 12B, the address sensor 10 is installed considering the time when the detection signal is generated.

  As described above, since the stop address mark 12B for the drive unit 4 is installed at each of the two intersections between the circular circular track tape 11C and the other track tape 11B, at the time when each drive unit 4 arrives. Even if a difference occurs, each drive unit 4 can be accurately stopped on the other travel line.

  In step S20, as shown in FIG. 13, the relative rotation direction of the left and right drive wheels 8 is rotated so as to be opposite to the rotation direction on one track tape 11A, and each drive unit 4 is rotated on the other side. The drive unit 4 is rotated back toward the traveling direction of the automatic guided vehicle 1 of the track tape 11B. Then, it is confirmed whether or not the track sensor 9 of the drive unit 4 has detected the other track tape 11B. When this return rotation causes the track sensor 9 of the drive unit 4 to detect the other track tape 11B and travel along the other track tape 11B based on the detection result of the track sensor 9 becomes possible, the process proceeds to step S21. Then, execution of the next command, for example, normal running based on the detection result of the track sensor 9 is started.

  Note that the address sensor 10 of the other drive unit 4 in step S17 confirms the detection of the stop instruction address mark 12B installed close to the other track tape 11B for stopping the drive unit 4. If it is not possible even after the elapse of the predetermined time set in step S18, the process proceeds to step S22, it is determined that the other drive unit 4 is derailed, and the automatic guided vehicle 1 is stopped.

  As described above, after the drive unit 4 is turned at a predetermined angle of 90 degrees with respect to the automatic guided vehicle 1, the front and rear drive units 4 are placed on the circular arc tape 11 </ b> C having the same point as the rotation center. By running along, the automatic guided vehicle 1 can be turned in the narrow space by turning the automatic guided vehicle 1 around the rotation center.

  Moreover, since the front and rear drive units 4 are in a state of being coincident at a predetermined angle, the drive unit 4 can be accurately rotated around a desired center point.

  In addition, since the rotation angle of the drive unit 4 is set to a substantially right angle and is rotated on an arc around the center point on the plane of the automatic guided vehicle 1, a small and stable rotation is possible in a narrow space. Thereby, for example, it is possible to prevent the load on the upper surface of the automatic guided vehicle 1 from being greatly shaken by the rotation of the automatic guided vehicle 1 and causing collapse of the cargo.

  In the present embodiment, the following effects can be achieved.

  (A) Left and right drive wheels 8 driven independently by a pair of drive means, a track sensor 9 as line detection means for detecting a travel line 11, and the drive based on the detection result of the line detection means And a control unit 6 for controlling the rotation of the left and right drive wheels 8 by the means, and a drive unit 4 provided on the support shaft 3 arranged at the front and rear of the vehicle so as to be turnable. This is an automatic guided vehicle 1 in which a vehicle is driven by the rotation of a wheel 8 and the drive unit 4 is turned by the relative rotation of the vehicle 8 and the control method thereof. The vehicle is turned by moving the front and rear drive units 4 in the opposite direction along a circular orbit tape 11C as an annular traveling line as a center. And to the front and rear of the drive unit 4 is respectively transferred onto the other of the operating line 11B crossing from the line 11A. For this reason, the advancing direction of the automatic guided vehicle 1 can be turned in an arbitrary direction in a narrow space, and even if an error factor such as slip of the drive wheels 8 occurs during the turning, the vehicle is turned accurately. be able to.

  (A) On one traveling line 11A at the intersection, the left and right drive wheels 8 of the front and rear drive units 4 are reversed to turn the front and rear drive units 4 in opposite directions with respect to the vehicle. The front and rear drive units 4 are directed to the vehicle by turning the left and right drive wheels 8 of the front and rear drive units 4 on the other travel line 11B on the other travel line 11B. On the other hand, in order to turn in the opposite direction and return the traveling direction to the front and rear direction of the vehicle so as to be separated from the annular traveling line 11C, the transition to the annular traveling line 11C and the separation from the annular traveling line 11C are accurate. Can be executed well.

  (C) During the turning of the vehicle in which the drive unit 4 travels along the annular travel line 11C, the drive speed of the inner drive wheel 8 near the center of the intersection is reduced relative to the drive speed of the outer drive wheel 8. Therefore, an inner / outer wheel difference is generated with respect to the left and right drive wheels 8 of the drive unit 4, and derailment from the annular traveling line 11C can be suppressed.

  (D) The front and rear drive units 4 include an address sensor 10 that detects an address mark 12 disposed along the travel line 11B, and the control means 6 is disposed adjacent to one travel line 11A at the intersection. When the detected address mark 12B is detected, it is determined that the center of the intersection coincides with the intermediate point of the front and rear drive units 4, and the traveling along one traveling line 11A is stopped, and the other traveling line at the intersection is stopped. When the address mark 12B arranged adjacent to the intersection of 11B and the annular traveling line 11C is detected, it is determined that each drive unit 4 has reached the other traveling line 11B, and the annular traveling line 11C. In order to stop traveling along the vehicle, the vehicle is accurately stopped at the intersection as compared with traveling using only the traveling lines 11A to 11C, and others. It can reach high precision with respect to the traveling line 11B. Further, even if a difference occurs at the arrival time of each drive unit 4, each drive unit 4 can be accurately stopped on the other travel line 11B.

The bottom view of the automatic guided vehicle which shows one Embodiment of this invention. A side view of the automatic guided vehicle. The bottom view of the automatic guided vehicle which changed the arrangement position of an address sensor. The system block diagram of traveling control of a conveyance vehicle. Explanatory drawing which shows the intersection of the travel line which an automatic guided vehicle turns. Explanatory drawing of the travel line containing an intersection. The flowchart of the traveling control performed by the drive unit controller of the automatic guided vehicle along a normal traveling line. The flowchart of the course change control performed by the traveling control controller in the course change in the intersection which cross | intersected largely. Explanatory drawing which shows the operation state of the automatic guided vehicle stopped at the intersection. Explanatory drawing explaining operation | movement of the automatic guided vehicle following FIG. Explanatory drawing explaining the turning operation | movement of the automatic guided vehicle following FIG. Explanatory drawing explaining the completion | finish state of the turning operation | movement of the automatic guided vehicle following FIG. Explanatory drawing explaining operation | movement of the automatic guided vehicle following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic guided vehicle 2 Car body 3 Support shaft 4 Drive unit 5 Caster wheel 6 Controller 7 Axle 8 Drive wheel 9 Track sensor 10 Address sensor 11, 11A, 11B Track tape which comprises a travel line 11C Circular track tape 12, 12A, 12B Address mark

Claims (11)

Left and right drive wheels that are independently driven by a pair of drive means, line detection means for detecting a travel line, and rotation of the left and right drive wheels by the drive means based on the detection result of the line detection means A drive unit having a control means for controlling the front and rear of the vehicle, the vehicle is driven by rotation of the left and right drive wheels of the drive unit, and the vehicle is steered by its relative rotation. Control method,
On the intersection of the intersecting traveling lines, the vehicle is turned by advancing the front and rear drive units in a reverse direction along an annular traveling line centering on the intersection, and the other intersecting from one traveling line A control method for an automatic guided vehicle, characterized in that front and rear drive units are moved on a travel line, respectively.   The front and rear drive units are arranged so as to be able to turn on support shafts arranged in front and rear of the vehicle, respectively, and the front and rear drive units are turned in opposite directions with respect to the vehicle, respectively, so as to advance in the opposite direction. The method for controlling an automatic guided vehicle according to claim 1.   On one travel line at the intersection, the left and right drive wheels of the front and rear drive units are reversed to turn the front and rear drive units in opposite directions with respect to the vehicle, and the traveling direction is set as the lateral direction of the vehicle. Facing the annular travel line, on the other travel line, the left and right drive wheels of the front and rear drive units are reversed to turn the front and rear drive units in opposite directions with respect to the vehicle. The method for controlling an automatic guided vehicle according to claim 1 or 2, wherein the vehicle is returned to the front-rear direction of the vehicle and separated from the annular traveling line.   The driving speed of the inner driving wheel near the center of the intersection is reduced with respect to the driving speed of the outer driving wheel during turning of the vehicle in which the driving unit travels along an annular traveling line. The control method of the automatic guided vehicle according to any one of claims 1 to 3.   When an address mark arranged adjacent to one of the travel lines at the intersection is detected, it is determined that the center of the intersection coincides with the midpoint of the front and rear drive units, and travel along one of the travel lines is stopped. And determining that each drive unit has reached the other travel line when the address mark arranged adjacent to the intersection between the other travel line and the annular travel line is detected. 5. The automatic guided vehicle control method according to claim 1, wherein the traveling along the traveling line is stopped. Left and right drive wheels that are independently driven by a pair of drive means, line detection means for detecting a travel line, and rotation of the left and right drive wheels by the drive means based on the detection result of the line detection means A control unit for controlling the vehicle, and a drive unit disposed on the support shaft arranged at the front and rear of the vehicle so as to be able to turn, and the vehicle is driven by the rotation of the left and right drive wheels of the drive unit and driven by the relative rotation An automated guided vehicle in which the vehicle is steered by turning the unit;
The control means turns the vehicle by turning the front and rear drive units in a reverse direction with respect to the vehicle along an annular traveling line centering on the intersection on the intersection of the intersecting traveling lines, An automatic guided vehicle is characterized in that the front and rear drive units are respectively transferred to the other traveling line intersecting from the other traveling line.   The control means rotates the front and rear drive units in opposite directions with respect to the vehicle by reversing the left and right drive wheels of the front and rear drive units on one travel line at the intersection, and the traveling direction thereof is determined by the vehicle. The front and rear drive units are turned in opposite directions with respect to the vehicle by reversing the left and right drive wheels of the front and rear drive units on the other travel line. The automatic guided vehicle according to claim 6, wherein the advancing direction is returned to the front-rear direction of the vehicle and separated from the annular traveling line.   The control means decelerates the driving speed of the inner driving wheel close to the center of the intersection with respect to the driving speed of the outer driving wheel during turning of the vehicle that causes the driving unit to travel along the annular traveling line. The automatic guided vehicle according to claim 6 or 7, characterized in that.   The front and rear drive units include an address sensor that detects an address mark disposed along a traveling line, and the control unit detects an address mark disposed adjacent to one traveling line at the intersection. At the time, it is determined that the center of the intersection coincides with the intermediate point of the front and rear drive units, and the traveling along one traveling line is stopped, and at the intersection of the other traveling line of the intersection and the annular traveling line, respectively. 7. The traveling along the annular traveling line is stopped by determining that each drive unit has reached the other traveling line when the adjacent address mark is detected. The automatic guided vehicle according to any one of 8. Left and right drive wheels that are independently driven by a pair of drive means, line detection means for detecting a travel line, and rotation of the left and right drive wheels by the drive means based on the detection result of the line detection means A drive unit having a control means for controlling the front and rear of the vehicle, the vehicle is driven by rotation of the left and right drive wheels of the drive unit, and the vehicle is steered by its relative rotation. Traveling line,
A travel line for an automatic guided vehicle comprising an annular travel line for causing the front and rear drive units to travel in opposite directions around an intersection of intersecting travel lines. An address mark that is arranged adjacent to one of the traveling lines of the intersection, determines that the center of the intersection and the middle point of the front and rear drive units coincide with each other, and stops traveling along one of the traveling lines,
An address mark that is arranged adjacent to the intersection of the other traveling line and the annular traveling line at the intersection and determines that each drive unit has reached the other traveling line and stops traveling along the annular traveling line. The travel line of the automatic guided vehicle according to claim 10, comprising:

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