Control method for unmanned carrier vehicle

Abstract

To accurately return an unmanned carrier vehicle onto a guide line after the unmanned carrier vehicle is temporarily removed from the guide line.SOLUTION: While a second unmanned carrier vehicle 3 is made to travel autonomously, a guide line 20 is detected by a camera 10. Based on this detection result, the second unmanned carrier vehicle 3 acquires a position of the guide line 20 (virtual guide line 20'). The second unmanned carrier vehicle 3 is made to perform an autonomous travel so that a deviation between the position of the guide line 20 (virtual guide line 20') and a self position P2 of the second unmanned carrier vehicle 3 is within a predetermined range.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a method for controlling an automated guided vehicle. [Background technology]

[0002] In the assembly process of a vehicle body, various parts are often assembled from both sides of the vehicle body in the width direction while the vehicle body is being transported by a transport device. For example, the following Patent Document 1 shows a method of sequentially assembling various parts to the vehicle body while the vehicle body is being transported by an unmanned guided vehicle that can travel along a guide line (track line). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-207225 A [Patent Document 2] Japanese Patent Application Publication No. 7-5912 Summary of the Invention [Problem to be solved by the invention]

[0004] In an assembly line using automated guided vehicles as described above, workers and parts are arranged on both sides of the transport path of the vehicle body. In contrast, for example, as shown in FIG. 17, if a cart 103 carrying a vehicle body W is transported by two automated guided vehicles 101 and 102, the orientation of the vehicle body W can be freely changed. For example, in the first working area Q1 in FIG. 17, the first automated guided vehicle 101 is the leading side and the second automated guided vehicle 102 is the trailing side, and parts are assembled from the left side of the vehicle body W while the vehicle body W is transported with the front side facing forward. On the other hand, in the second working area Q2, the second automated guided vehicle 102 is the leading side and the first automated guided vehicle 101 is the trailing side, and parts are assembled from the right side of the vehicle body W while the vehicle body W is transported with the rear side facing forward. In this case, since workers and parts need to be arranged only on one side of the transport path of the vehicle body W in the width direction (the upper side in the figure), the width dimension of the assembly line can be reduced.

[0005] As described above, when changing the direction of the vehicle body W, it is necessary to change the order of the first and second unmanned guided vehicles 101 and 102. For example, as shown in FIG. 18, the second unmanned guided vehicle 102 is removed from the guide line 110 and rotated 180° around the first unmanned guided vehicle 101, thereby changing the order of the two unmanned guided vehicles 101 and 102, and the direction of the vehicle body W can be reversed. However, while the second unmanned guided vehicle 102 is removed from the guide line 110 and rotates, the direction of the first unmanned guided vehicle 101, which is the reference for the rotation angle, may be slightly shifted. In addition, the guide line 110 is usually laid manually by an operator, and therefore may not be a perfect straight line. In these cases, even if the second unmanned guided vehicle 102 is rotated 180° relative to the first unmanned guided vehicle 101, the second unmanned guided vehicle 102 may not be accurately positioned on the guide line 110.

[0006] For example, the above-mentioned Patent Document 2 discloses a method for returning an automated guided vehicle to a second guided travel section by calculating a travel distance, travel time, and steering speed required for the automated guided vehicle to reach the second guided travel section accurately and in a correct posture based on the posture of the automated guided vehicle at the time of transition from the first guided travel section to the autonomous travel section, when the travel route of the automated guided vehicle has an autonomous travel section sandwiched between a first guided travel section and a second guided travel section. However, in this case, the longer the distance of the autonomous travel section, the more errors are accumulated, making it difficult to return the automated guided travel section accurately.

[0007] Therefore, an object of the present invention is to allow an unmanned guided vehicle to once leave a guide line and then return accurately to the guide line. [Means for solving the problem]

[0008] In order to solve the above problem, the present invention provides a method for returning an unmanned guided vehicle having a line detection unit that detects a guide line provided on a travel path to the guide line after the unmanned guided vehicle is caused to leave the guide line and travel autonomously, the method comprising: detecting the guide line by the line detection unit while causing the automated guided vehicle to travel autonomously; The automated guided vehicle acquires a position of the guide line based on a detection result of the line detection unit; The present invention provides a method for controlling an unmanned guided vehicle, the method comprising the step of autonomously driving the unmanned guided vehicle so that the deviation between the position of the guide line stored by the unmanned guided vehicle and the self-position of the unmanned guided vehicle falls within a predetermined range.

[0009] When an automated guided vehicle is caused to leave the guide line and travel autonomously, the line detection unit does not usually detect the guide line. In the present invention, as described above, while the automated guided vehicle is caused to leave the guide line and travel autonomously, the line detection unit detects the guide line, and the automated guided vehicle acquires the position of the guide line based on the detection result. In this way, the automated guided vehicle is caused to travel autonomously so that the deviation amount between the guide line position acquired by the automated guided vehicle device and the self-position of the automated guided vehicle is within a predetermined range, thereby making it possible to accurately return the automated guided vehicle to the guide line.

[0010] As described above, by acquiring the position of the guide line when the line detection unit detects the guide line, even if the guide line subsequently moves out of the detectable range of the line detection unit, the unmanned guided vehicle can be accurately positioned on the guide line by autonomously driving the unmanned guided vehicle so that the deviation between the position of the guide line already acquired by the unmanned guided vehicle device and the unmanned guided vehicle's own position is within a specified range.

[0011] The above control method can also be applied to a control method for an automated guided vehicle having a plurality of automated guided vehicles. That is, the present invention provides a method for controlling an automated guided vehicle having a first automated guided vehicle and a second automated guided vehicle each having a line detection unit for detecting a guide line provided on a travel path, and a connection unit for connecting the first automated guided vehicle and the second automated guided vehicle, the method comprising the steps of: In a state where the first unmanned guided vehicle is disposed on the guide line, the second unmanned guided vehicle is caused to depart from the guide line and autonomously travel so as to rotate around the first unmanned guided vehicle, and is caused to return to the guide line, detecting the guide line by the line detection unit of the second automated guided vehicle while autonomously traveling the second automated guided vehicle; The second automated guided vehicle acquires a position of the guide line based on a detection result of the line detection unit; and causing the second unmanned guided vehicle to travel autonomously so that the deviation between the position of the guide line acquired by the second unmanned guided vehicle and the self-position of the second unmanned guided vehicle falls within a predetermined range. Effect of the Invention

[0012] As described above, according to the present invention, after an automatic guided vehicle is temporarily removed from a guide line, it can be accurately returned to the guide line. [Brief description of the drawings]

[0013] [Figure 1] FIG. [Diagram 2] FIG. 2 is a side view of the unmanned transport device. [Diagram 3] FIG. 4 is a plan view showing a state in which the above-mentioned unmanned transport device travels along a guide line. [Figure 4] 11 is a plan view showing a state in which the unmanned transport device is stopped and the second unmanned transport vehicle is rotated by 90°. FIG. [Diagram 5] FIG. 11 is a plan view showing a state in which the second unmanned guided vehicle has been rotated 90° around the first unmanned guided vehicle. [Figure 6] FIG. 2 is a plan view showing the state in which both unmanned transport vehicles of the unmanned transport device are traveling side by side. [Figure 7] FIG. 11 is a plan view showing a state in which the second automated guided vehicle has been further rotated. [Figure 8] 8 is a plan view showing information acquired by a control unit of the second automatic guided vehicle in the state shown in FIG. 7. FIG. [Figure 9] 13 is a plan view showing a state in which the second automatic guided vehicle is further rotated and the guide line is detected by the line detection unit of the second automatic guided vehicle. FIG. [Figure 10]10 is a plan view showing information acquired by a control unit of the second automated guided vehicle in the state shown in FIG. 9. FIG. [Figure 11] FIG. 13 is a plan view showing a state in which the second unmanned guided vehicle has been further rotated and is disposed on the guide line. [Figure 12] 12 is a plan view showing information acquired by a control unit of the second automatic guided vehicle in the state shown in FIG. 11. FIG. [Figure 13] FIG. 13 is a plan view showing a state in which the second automatic guided vehicle has been rotated by 90° so that both automatic guided vehicles face the same direction. [Figure 14] 11 is a flow chart showing a control method for causing the second automated guided vehicle to travel autonomously. FIG. [Figure 15] FIG. 15 is a flow chart showing detailed steps of step S1 in FIG. [Figure 16] FIG. 15 is a flow chart showing detailed processes of step S2 in FIG. [Figure 17] FIG. 1 is a plan view of an automobile assembly line using an automated guided vehicle having two automated guided vehicles. [Figure 18] 18 is a plan view showing a state in which the automatic guided vehicle in FIG. 17 is turned over. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] 1 and 2 includes a first automated guided vehicle 2, a second automated guided vehicle 3, and a carriage 4 as a connector that connects these vehicles. Each of the automated guided vehicles 2, 3 and the carriage 4 are connected via a vertical rotation shaft 5. This allows each of the automated guided vehicles 2, 3 to rotate freely around the rotation shaft 5 relative to the carriage 4. The rotation shaft 5 is fixed to the carriage 4 via a bracket 6, and is rotatably supported by bearings (not shown) provided on the automated guided vehicles 2, 3.

[0016] Each of the automated guided vehicles 2 and 3 has left and right wheels 8, a motor 9 that rotates and drives each wheel 8, a rotation speed detection unit (not shown) that detects the rotation speed of each wheel 8, a camera 10 as a line detection unit, an angle detection unit 11 that detects the rotation angle of the rotating shaft 5, a control unit 12 that controls the motor 9, and a battery (not shown) that supplies power to the motor 9, the rotation speed detection unit, the camera 10, the angle detection unit 11, and the control unit 12. The control unit 12 is connected to the motor 9, the rotation speed detection unit, the camera 10, and the angle detection unit 11.

[0017] The left and right wheels 8 are each independently controlled by a motor 9. The traveling speed of the automated guided vehicles 2, 3 can be controlled by adjusting the rotational speed of both wheels 8. In addition, the steering angle of each automated guided vehicle 2, 3, i.e., the rotation angle of each automated guided vehicle 2, 3 around the rotation axis 5 relative to the carriage 4, can be controlled by adjusting the difference in rotational speed between the left and right wheels 8 of each automated guided vehicle 2, 3.

[0018] The camera 10 detects the position of the guide line 20 (see FIG. 3) laid on the floor surface of the travel path. In this embodiment, the image captured by the camera 10 is transmitted to the control unit 12, and the position and posture of the guide line 20 are obtained from this image. The guide line 20 is made of a material that can be identified when captured in the image of the camera 10, for example, light-reflective tape. Alternatively, the guide line 20 may be made of magnetic tape, and the line detection unit that detects it may be composed of a magnetic detector. Note that it is preferable for the line detection unit to be capable of detecting the position and posture of the guide line 20, but it is sufficient if it is capable of at least detecting the position of the guide line 20.

[0019] The angle detection unit 11 detects the rotation angle of each of the automated guided vehicles 2, 3 relative to the cart 4. In this embodiment, the angle detection unit 11 detects the rotation angle of the rotation shaft 5 relative to the automated guided vehicles 2, 3. This detection result is transmitted to the control unit 12, whereby the attitude (steering angle) of the automated guided vehicles 2, 3 relative to the cart 4 can be obtained.

[0020] The control unit 12 of the first automated guided vehicle 2 and the control unit 12 of the second automated guided vehicle 3 are connected to each other so that they can communicate with each other. Therefore, for example, information detected by the camera 10 of the first automated guided vehicle 2 (for example, information on an event display unit installed on the floor surface) is transmitted not only to the control unit 12 of the first automated guided vehicle 2 but also to the control unit 12 of the second automated guided vehicle 3.

[0021] Next, a control method for transporting a vehicle body by the above-mentioned automated guided transport device 1 in an automobile assembly line will be described with reference to Figures 3 to 13. Note that in Figure 3 and other figures, the carriage 4 of the automated guided transport device 1 is simplified, and the vehicle body mounted thereon is omitted.

[0022] The guide line 20 is laid on the floor surface of the travel path of the automatic guided vehicle 1 (see FIG. 3). In the illustrated example, the guide line 20 is linear. Event display units 31, 32 are provided near the guide line 20. The event display units 31, 32 are provided within the detectable range of the camera 10 that detects the guide line 20. The event display units 31, 32 are formed of, for example, two-dimensional barcodes.

[0023] As shown in FIG. 3, when both the automated guided vehicles 2 and 3 travel along the guide line 20, the automated guided vehicles 2 and 3 are controlled in a trace travel mode. In the trace travel mode, the automated guided vehicles 2 and 3 are controlled to follow the guide line 20 while traveling at a predetermined speed. Specifically, the control unit 12 (see FIG. 1) acquires the position of the width direction center of the guide line 20 from the image of the camera 10, and calculates the amount of deviation in the width direction (direction perpendicular to the guide line 20) between the width direction center of the guide line 20 and the self positions P1 and P2 (for example, the axis of the rotation shaft 5) of the automated guided vehicles 2 and 3. By controlling each motor 9 to adjust the difference in the number of revolutions of the left and right wheels 8 so as to reduce the amount of deviation, the automated guided vehicles 2 and 3 can be made to travel along the guide line 20. At this time, the vehicle body mounted on the cart 4 is transported with its front facing forward in the direction of travel of the unmanned transport device 1 (to the right in the figure), and various parts are assembled to this vehicle body from one side in the width direction (for example, the left side of the vehicle body) (a state similar to that of the first work area Q1 in Figure 17).

[0024] Then, when the camera 10 of the first AGV 2 detects the event display unit 31, this detection result is transmitted to the control units 12 of both AGVs 2, 3, which stop the motors 9 of both AGVs 2, 3 (see FIG. 4). After that, with the first AGV 2 stopped, the second AGV 3 is rotated 90° on the spot (see arrow A in FIG. 4).

[0025] Thereafter, the second unmanned guided vehicle 3 is caused to leave the guide line 20 and travel autonomously. In this embodiment, as shown by arrow B in Fig. 5, the second unmanned guided vehicle 3 is caused to turn around the first unmanned guided vehicle 2. Specifically, the angle detection unit 11 of the second unmanned guided vehicle 3 detects the angle θ2 between the traveling direction N of the second unmanned guided vehicle 3 (a horizontal direction perpendicular to the axis of the wheels 8, 8 of the second unmanned guided vehicle 3) and the center line L of the carriage 4 (a straight line connecting the axis of the rotating shafts 5, 5 connecting the carriage 4 and the unmanned guided vehicles 2, 3), and the control unit 12 of the second unmanned guided vehicle 3 controls the rotation speed of the left and right wheels 8 so that the angle θ2 is maintained at 90°. Then, the angle detection unit 11 of the first AGV 2 detects the angle θ1 between the traveling direction M of the first AGV 2 (the horizontal direction perpendicular to the axis of the wheels 8, 8 of the first AGV 2) and the center line L of the carriage 4, and when this angle θ1 reaches 90°, the second AGV 3 is stopped. As a result, the traveling directions M, N of both AGVs 2, 3 are made parallel, as shown in Fig. 5.

[0026] Thereafter, the first and second automated guided vehicles 2 and 3 are caused to travel parallel to each other side by side (see arrow C in FIG. 5). Specifically, the first automated guided vehicle 2 is caused to travel forward along the guide line 20 in the trace control mode. The second automated guided vehicle 3 is controlled so that the angles θ1 and θ2 between the travel directions M and N of both automated guided vehicles 2 and 3 and the center line L of the carriage 4 are both maintained at 90°. At this time, the vehicle body mounted on the carriage 4 is transported with its width direction parallel to the travel direction of the automated guided device 1, and various parts are assembled from one side in the front-rear direction of the vehicle body (for example, the front side of the vehicle body).

[0027] Thereafter, when the first AGV 2 detects the event display unit 32, the first AGV 2 is stopped (see FIG. 6). Then, the second AGV 3 again turns around the first AGV 2 (see arrow D). At this time, the control unit 12 of the second AGV 3 controls the rotation speed of the left and right wheels 8 so that the angle θ2 between the traveling direction N of the second AGV 3 and the center line L of the carriage 4 is maintained at 90°, similar to the turning travel indicated by arrow B in FIG. 5.

[0028] As described above, the second unmanned guided vehicle 3 is caused to turn and when the second unmanned guided vehicle 3 returns to the guide line 20, the second unmanned guided vehicle 3 is stopped. The stopping position of the second unmanned guided vehicle 3 at this time is set based on the position of the guide line 20 acquired by the second unmanned guided vehicle 3. The control during the autonomous travel (turning travel) of the second unmanned guided vehicle 3 will be described in detail below. This control is repeatedly performed at short time intervals while the second unmanned guided vehicle 3 is autonomously traveling.

[0029] When the second automated guided vehicle 3 leaves the guide line 20 and starts autonomous traveling (turning traveling), as shown in FIG. 14, the control unit 12 of the second automated guided vehicle 3 updates its own position (step S1). Specifically, as shown in FIG. 15, it is confirmed whether the odometry information (radius and rotation number of the wheel 8) of the left and right wheels 8 of the second automated guided vehicle 3 and the angle θ1 of the center line L of the carriage 4 with respect to the traveling direction M of the first automated guided vehicle 2 (hereinafter, also referred to as the turning angle θ1 of the second automated guided vehicle 3) have been updated (step S11). If these pieces of information have been updated, the odometry information and turning angle θ1 of the wheel 8 at this time are obtained (step S12), and the self-position of the second automated guided vehicle 3 is calculated from these pieces of information (step S13). On the other hand, if the odometry information and turning angle θ1 of the wheel 8 of the second automated guided vehicle 3 have not been updated, this process is terminated.

[0030] Next, the position and posture of the guide line 20 are updated (step S2). Specifically, as shown in Fig. 16, first, it is confirmed whether the image of the camera 10 of the second automated guided vehicle 3 has been updated (step S21). If the image has not been updated, this process is terminated. If the image has been updated, the image is acquired (step S22), and it is confirmed whether the guide line 20 is captured in the acquired image (step S23).

[0031] For example, in the state shown in Fig. 7, the guide line 20 is not within the detectable range of the camera 10 of the second automated guided vehicle 3, and the guide line 20 is not captured on the image of the camera 10, so this step ends. In this case, the control unit 12 of the second automated guided vehicle 3 does not acquire the position of the guide line 20. Therefore, as shown in Fig. 8, the guide line 20 does not appear in the coordinate system set by the control unit 12 of the second automated guided vehicle 3, and the self-positions P1, P2 and traveling directions M, N of both automated guided vehicles 2, 3 appear.

[0032] Then, as shown in FIG. 9, when the guide line 20 enters the detectable range of the camera 10 of the second automated guided vehicle 3 and is captured in the image of the camera 10, the width direction center position and orientation of the guide line 20 on the image are calculated (step S24 in FIG. 16). Then, in step S3 in FIG. 14, it is confirmed whether the position and orientation of the guide line 20 have been updated, and if the position and orientation of the guide line 20 have been updated as described above, the position and orientation of the guide line 20 as seen from the second automated guided vehicle 3 are calculated (step S4 in FIG. 14). That is, the position and orientation of the guide line 20 on the image of the camera 10 are converted into a coordinate system set by the control unit 12 of the second automated guided vehicle 3. As a result, as shown in FIG. 10, the guide line 20 converted into the coordinate system (this is called a "virtual guide line 20'") appears in the coordinate system set by the control unit 12 of the second automated guided vehicle 3.

[0033] Then, when the control unit 12 of the second automated guided vehicle 3 acquires the virtual guide line 20' as described above, it calculates the amount of deviation between the widthwise center of the virtual guide line 20' and the self-position P2 of the second automated guided vehicle, and judges whether or not this amount is within a predetermined range (step S5 in FIG. 14). In the state shown in FIGS. 9 and 10, since the amount of deviation is outside the predetermined range, it is judged that the second automated guided vehicle 3 is not disposed on the guide line 20, and the process shown in FIG. 14 is terminated.

[0034] After that, when the second automated guided vehicle 3 is further rotated, the guide line 20 goes out of the detectable range of the camera 10 (see FIG. 11). At this time, the guide line 20 is not captured in the image of the camera 10, so the position of the guide line 20 cannot be acquired in real time. However, since the control unit 12 has already acquired the virtual guide line 20', it calculates the deviation between the widthwise center of the virtual guide line 20' and the updated self-position P2, and judges whether the deviation is within a predetermined range. Then, as shown in FIG. 12, when the deviation between the widthwise center of the virtual guide line 20' and the self-position P2 of the second automated guided vehicle 3 falls within a predetermined range, it is judged that the second automated guided vehicle 3 is disposed on the guide line 20 (step S6 in FIG. 14), and the second automated guided vehicle 3 is stopped.

[0035] When an automated guided vehicle is made to leave the guide line and travel autonomously, the guide line is not usually detected by a camera or the like, but in the above control method, the second automated guided vehicle 3 travels autonomously while detecting the guide line 20 by the camera 10, and the stopping position of the second automated guided vehicle 3 is set based on the virtual guide line 20' acquired from the detection result. This allows the second automated guided vehicle 3 to return accurately to the guide line 20.

[0036] After that, as shown by the arrow E in Fig. 13, the second unmanned guided vehicle 3 is rotated 90° on the spot to face the same direction as the first unmanned guided vehicle 2. As a result, the order of the first unmanned guided vehicle 2 and the second unmanned guided vehicle 3 is swapped on the guide line 20. In this state, both unmanned guided vehicles 2 and 3 are caused to travel along the guide line 20 in the trace control mode. At this time, the vehicle body mounted on the cart 4 is transported with its rear side facing forward in the traveling direction of the unmanned guided device 1 (facing right in the figure), and various parts are assembled to this vehicle body from the other side in the width direction (for example, the right side of the vehicle body) (the same state as the second work area Q2 in Fig. 17).

[0037] The present invention is not limited to the above embodiment. Other embodiments of the present invention will be described below, but redundant description of points similar to the above embodiment will be omitted.

[0038] In the above embodiment, when the second unmanned guided vehicle 3 is autonomously driven to return to the guide line 20, the self-position P2 of the second unmanned guided vehicle 3 is acquired based on the odometry information of the wheels 9 and the turning angle θ1. In this case, if the wheels 9 slip or the posture of the first unmanned guided vehicle 2 shifts during autonomous driving, the acquired self-position P2 will shift from the actual position. Therefore, when the position of the guide line 20 (virtual guide line 20') is acquired based on the image of the camera 10, the self-position P2 of the second unmanned guided vehicle 3 relative to the virtual guide line 20' may be calculated using the previously acquired self-position P2 and the relative position of the camera 10. In this case, regardless of the previous running state of the second unmanned guided vehicle 3 (slip of the wheels 9, posture shift of the first unmanned guided vehicle 2, etc.), the self-position P2 of the second unmanned guided vehicle 3 when the camera 10 photographs the guide line 20 can be accurately acquired. By subsequently controlling the number of rotations of the wheels 8 of the second unmanned guided vehicle 3 so that the deviation between the thus obtained self-position P2 and the virtual guide line 20' falls within a specified range, the self-position P2 of the second unmanned guided vehicle 3 can be positioned on the guide line 20.

[0039] In the above embodiment, the first unmanned guided vehicle 2 and the second unmanned guided vehicle 3 are arranged side by side and run parallel to each other (see arrow C in Figure 5), but this step may be omitted and the second unmanned guided vehicle 3 may be made to continuously rotate 180° around the first unmanned guided vehicle 2.

[0040] The coupling part of the automated guided vehicle 1 is not limited to the cart 4. For example, the automated guided vehicles 2, 3 may be coupled by a coupling part that does not have wheels. Alternatively, each automated guided vehicle 2, 3 may be provided with a turntable that can rotate via a rotation shaft 5, and a transported object may be loaded so as to straddle the turntables provided on both automated guided vehicles 2, 3. In this case, the turntables of both automated guided vehicles 2, 3 and the transported object loaded on them serve as coupling parts.

[0041] In the above embodiment, while the second automated guided vehicle 3 is autonomously traveling, the line detection unit (camera 10) detects the guide line 20 at short intervals. In this case, there is a risk that the camera 10 may mistakenly detect a foreign object lying on the floor as the guide line 20. Therefore, it may be determined whether or not to adopt the detection result of the camera 10 in combination with the rotation angle θ1 of the second automated guided vehicle. Specifically, only when the rotation angle θ1 of the second automated guided vehicle 3 is within a predetermined range (for example, 150 to 180°), the position of the guide line 20 may be acquired from the detection result of the camera 10, and the detection result of the camera 10 may be ignored in other angle ranges. This increases the reliability of the detection result of the position of the guide line 20 by the line detection unit.

[0042] The present invention is not limited to an unmanned transport device in which multiple unmanned transport vehicles are connected together, but can also be applied to a case in which a single unmanned transport vehicle capable of traveling along a guide line 20 is temporarily removed from the guide line 20 and then returned to the guide line 20.

[0043] The present invention can also be applied to the case where an object other than a vehicle body is transported by an unmanned guided vehicle. [Explanation of symbols]

[0044] 1. Unmanned transport device 2. First automated guided vehicle 3. 2nd automated guided vehicle 4 Bogie (connecting part) 5 Rotation Axis 6 Bracket 8 wheels 9 Motor 10 Camera (line detection unit) 11 Angle detection unit 12 Control section 20 Guidance Line 20' Virtual Guiding Line 31 Event display section 32 Event display section L Center line of joint M Direction of travel of the first automated guided vehicle N Direction of travel of the second automated guided vehicle P1 Self-position of the first automated guided vehicle P2 Self-position of the second automated guided vehicle

Claims

1. When an unmanned guided vehicle having a line detection unit that detects a guide line provided on a travel path is returned to the guide line after being caused to leave the guide line and travel autonomously, detecting the guide line by the line detection unit while causing the automated guided vehicle to travel autonomously; The automated guided vehicle acquires a position of the guide line based on a detection result of the line detection unit; A method for controlling an unmanned guided vehicle, comprising a step of autonomously driving the unmanned guided vehicle so that a deviation between the position of the guide line acquired by the unmanned guided vehicle and the unmanned guided vehicle's own position falls within a predetermined range.

2. 2. The control method for an automated guided vehicle according to claim 1, wherein after the line detection unit detects the guide line, when the guide line is out of the detectable range of the line detection unit, the automated guided vehicle is caused to autonomously travel so that a deviation between the position of the guide line acquired by the automated guided vehicle and the automated guided vehicle's own position falls within a predetermined range.

3. In controlling an automated guided vehicle having a first automated guided vehicle and a second automated guided vehicle each having a line detection unit that detects a guide line provided on a travel path, and a connection unit that connects the first automated guided vehicle and the second automated guided vehicle, In a state where the first unmanned guided vehicle is disposed on the guide line, the second unmanned guided vehicle is caused to leave the guide line and autonomously travel so as to rotate around the first unmanned guided vehicle, and is caused to return to the guide line, detecting the guide line by the line detection unit of the second automated guided vehicle while autonomously traveling the second automated guided vehicle; The second automated guided vehicle acquires a position of the guide line based on a detection result of the line detection unit; A method for controlling an unmanned guided vehicle, comprising the step of autonomously driving the second unmanned guided vehicle so that the deviation between the position of the guide line acquired by the second unmanned guided vehicle and the self-position of the second unmanned guided vehicle is within a predetermined range.

Images