JPH0760344B2 - How to drive an automated guided vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a traveling method of an automated guided vehicle.

[Conventional technology]

In the running method of the automatic guided vehicle, a guiding tape is attached to the floor as a predetermined main runway, and the guiding travel is performed by this, and at a branch point, a turning part, a crossing point, etc., a predetermined route is set. There is a thing which makes it run autonomously and carries out the combination of this guidance running and autonomous running.

[Problems to be Solved by the Invention]

Thus, in the traveling method by the combination of autonomous traveling and guided traveling, when shifting from autonomous traveling to guided traveling,
If the vehicle body of the automated guided vehicle does not exactly follow the guiding element at the end point of autonomous driving, the sensor installed on the vehicle side cannot detect the guiding element on the floor side and the vehicle may shift to guided driving. It will be impossible. In order to prevent this, conventionally, it is necessary to widen the effective range of the sensor and detect the inductive element even if the vehicle body is slightly displaced from the inductive element, or to perform highly accurate autonomous traveling so that the vehicle body follows the inductive element. is there.

If the effective range of the sensor is widened in this way, the power consumption by the sensor also increases, which is a disadvantageous condition for the battery-driven automatic guided vehicle. In addition, highly accurate autonomous driving requires expensive equipment.

It is an object of the present invention to set the effective range of the sensor to the minimum allowable range required for guide traveling on a straight road, and to surely shift from autonomous traveling to guided traveling without departing from the traveling route.

[Means for Solving the Problems]

The present invention has been made to achieve the above-mentioned object, and is an unmanned guided vehicle which is guided by a guiding element and autonomously runs on a curved road such as a branch point, a crossing point, a turning point of a traveling route. When moving from autonomous driving to guided driving, the vehicle is allowed to pass through the guided road during autonomous driving, and the vehicle body position with respect to the guiding element is measured based on the measured azimuth angle of the vehicle body and the sensor's guiding element detection information. When the azimuth and displacement of the vehicle body with respect to the guideway are within the predetermined allowable range, the vehicle body position measurement value for autonomous traveling is corrected, and the vehicle is switched to the guideway with the guide element to reliably guide the vehicle to the guide element on the guideway. .

〔Example〕

 The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 shows a main part of an automated guided vehicle according to the present invention. The vehicle body 1 is provided with steered wheels 2 having a steering motor M1 and left and right drive shafts 4 and 5 which are driven to travel by a traveling motor M2 through a differential gear 3, and the vehicle body 1 is steered. A control device 6 for controlling the wheels 2, a position measuring device 7, and a traveling mode switching device 8 are provided, and a signal from a signal plate sensor 9 is transmitted to the traveling mode switching device 8 and a signal from an inductive element sensor 10 provided on the vehicle body 1 is positioned. They are electrically connected to the measuring device 7 so as to be input respectively.

Further, the left drive wheel 4 is provided with a left rotation amount sensor 11, and the right drive wheel 5 is provided with a right rotation amount sensor 12, which are connected to input signals from the both sensors 11, 12 to the position measuring device 7. It

Further, on the floor surface F, guiding elements 20, 21 for guiding an unmanned guided vehicle through a predetermined guiding route (traveling route) are arranged, and the guiding elements 20, 21 are arranged to cross each other. None, signal plates 23, 24 for catching a signal that the guided vehicle shifts from one induction element 20 to the other induction element 21.
Is provided at the optimum position of each element 20, 21. The inductive elements 20 and 21 and the signal plates 23 and 24 shown in the present embodiment are tape-shaped in this embodiment, but are not limited to them.

Therefore, the vehicle body 1 of the automatic guided vehicle is the guide route 20 or 21.
When traveling along, the inductive elements 20 and 21 are detected by the inductive element sensor 10 and travel along the elements. When moving from one inductive element 20 to the other inductive element 21 intersecting with this, the vehicle body travels autonomously from the signal plates 23 to 24, and this inductive travel and autonomous travel are provided on routes 20 and 21. The signal plate sensor 9 detects the signal plates 23 and 24 to switch the traveling mode between the guidance by the inductive element and the autonomous traveling. This is performed by the traveling mode switching device 8 and the position measuring device 7 is operated by this switching signal. To instruct.

Further, the traveling motor M2 divides the output into two by the differential gear 3, rotates the left and right driving wheels 4 and 5 to drive the vehicle body 1, and at the same time, the rotation amount of each of the rotation amount sensors 11 and 1.
The signal is detected at 2 and the signal is sent to the position measuring device 7.

The steering motor M1 rotates the steered wheels based on a command from the control device 6, determines the traveling direction of the vehicle body 1, guides a predetermined route along the guiding element, or preliminarily travels autonomously. It is controlled so as to travel on a predetermined route.

When the inductive element sensor 10 detects the inductive element 20 or 21, the inductive element sensor 10 sends the detection information to the position measuring device 7 and outputs it.

When the signal board sensor 9 detects the signal board 23 or 24 on the route, the signal board sensor 9 sends the detection information to the traveling mode switching device and outputs it. Then, the traveling mode switching device 8 and the position measuring device 7
Are connected to each other, and their operation is changed by the changeover switch SW according to a command from the traveling mode changeover device.

Therefore, when the vehicle body 1 guides on the guide route by the guide element 20 or 21, the guide element sensor 10 causes the guide element 20 or
Based on the information detected by 21, the deviation between the vehicle body and the guidance element is measured, the steering angle is calculated so that the deviation goes to zero, the steering information is sent to the control device, and the vehicle body travels along the route. The steered wheels are steered so that the vehicle runs. Then, the control device controls the rotation amount of the steering motor so that the steering information output from the position measuring device and the actual steering angle match, and thus the vehicle body follows the target element along the guiding element or as will be described later. It is driven by.

In the case of autonomous traveling, when the signal board sensor 9 detects the signal board while the vehicle is guided on the route, the vehicle body is switched from the guided travel to the autonomous travel by the traveling mode switching device. This is the traveling distance of the vehicle body based on the average amount of rotation of the left and right driving wheels 4 and 5 sent from the rotation amount sensors 11 and 12 provided on the left and right driving wheels 4 and 5, and the azimuth angle of the vehicle body based on the difference in the amount of rotation of both wheels. Is calculated and steering information is output so that the deviation from the target route stored in advance as position information becomes zero. In this way, when the inductive element sensor detects the inductive element during autonomous traveling, the vehicle body position measurement value with respect to the inductive element is corrected from this detection information and the vehicle body azimuth angle obtained by position measurement during autonomous traveling.

The traveling during the autonomous traveling is shown in FIG.

The position from the signal plate 23 to the point a at which the inductive element of the target path is detected is measured with the center position of the vehicle body on the signal plate 23 as a base point, and the position measurement value is corrected at the point a. From point a to point b, the guiding element cannot be detected again, so the vehicle body is guided autonomously by using position corrected point a. At point b, the induction element is detected again and the position is corrected. From point b to c
Up to the point, position measurement is performed with the point b as the base point, and the vehicle travels autonomously. From the point c to the signal plate 24, the inductive element can be constantly detected, so that the position is always corrected and the vehicle autonomously travels according to the result. When the signal board 24 is detected, the mode is switched to the guide running.
The signal plate 24 is for confirming whether or not the azimuth and the deviation of the vehicle body with respect to the guideway are within predetermined allowable ranges.

FIG. 4 (B) shows traveling during autonomous traveling in the conventional method for comparison with the method of the present invention. In the conventional method, the vehicle travels autonomously from the signal board 23 to the signal board 24. During this time, the position of the signal board 24 is measured from the center position of the vehicle body when the signal board 23 is detected to the signal board 24 for autonomous traveling, and the position is not corrected.

Next, a method of traveling the automatic guided vehicle according to the present invention will be described with reference to the flowchart shown in FIG.

When an unmanned guided vehicle traveling along a guiding element reaches a route change point such as a turning point, a branch point, or a crossing point, a signal board sensor detects the signal board on the traveling path and outputs the information to the traveling mode. Output to the switching device. The traveling mode switching device outputs a command for switching the traveling mode to autonomous traveling to the position measuring device based on this output. The position measuring device extracts the distance and azimuth angle data of the vehicle body center and the target route at the time of detecting the signal plate from a pre-stored data table, sets them as position information of the target route, and starts the position measurement of the vehicle body. When the guidance element on the target route cannot be detected, the deviation from the target route is calculated based on the position information of the target route and the vehicle body position and azimuth angle by position measurement, and the vehicle autonomously travels on the target route. When the guidance element on the target route is detected, the position measurement device determines the vehicle body azimuth θ by the position measurement, the position Ds at which the guidance element sensor detects the guidance element, and the vehicle body position relative to the target route from the distance Ws between the body center and the sensor center. Is calculated by the following formula,
Correct the position measurement value.

x = L−Ds cos θ−Ws sin θ where L: target route coordinates Then, based on the corrected accurate position measurement value, the vehicle autonomously travels to the guiding element on the target route side. After that, when the inductive element cannot be detected, autonomous traveling based on the position measurement value, autonomous traveling based on the corrected position measurement value that can be detected,
Guide the vehicle body onto the guidance element on the target route side. When the signal board sensor detects the signal board that means the autonomous traveling end point, the traveling mode switching device outputs a command to switch the traveling mode to guided traveling, and the position measuring device also switches the operation to guided traveling and travels along the guiding element. To do.

FIG. 7 is a flowchart showing a conventional traveling method for comparison with the traveling method according to the present invention. As shown in FIG. 3 (A), the autonomous traveling route is set so that the vehicle body obliquely enters the target route at a shallow angle, whereby the target route side guiding element can be reliably detected.

In addition, in the conventional method, the traveling path of autonomous traveling is shown in FIG.
As shown in (1), the target path detection point was set to the point where the vehicle body became the same as the angle of the target path. Therefore, if an error occurred in the autonomous traveling path, the target path could not be detected. In order to prevent this, the effective range of the inductive sensor had to be widened in consideration of the path error.

〔The invention's effect〕

 The traveling method of the present invention has the following effects.

Even when the vehicle is traveling autonomously, if an inductive element on the target route side is detected, the error in the information on autonomous traveling is corrected based on that information, so a large allowable range for the error in autonomous traveling route information and position measurement information can be taken. It eliminates the need for expensive equipment such as gyros.

After detecting the inductive element and correcting the position, the vehicle body is guided onto the inductive element by autonomous traveling, so that the effective range of the inductive element sensor can be reduced. (1 pole theory, however, since straight running is a guide, the sensor can be reduced to the minimum range required for straight running.) By setting the autonomous running route so that the vehicle body diagonally enters the target route, Even if the effective range of the element sensor is small, the inductive element can be reliably detected and the position can be corrected.

[Brief description of drawings]

FIG. 1 is a schematic view of a vehicle body of an automated guided vehicle, FIG. 2 is an explanatory view of vehicle body position correction, and FIG. 3 is an explanatory view of setting an autonomous traveling path.
(A) shows the present invention, (B) a conventional example, FIG. 4 is an explanatory view during autonomous traveling, (A) shows the present invention, (B) shows a conventional example, and FIG. 5 shows 6 is a block diagram of the control device, and FIG. 7 is a flowchart of a conventional running method. 1 is a vehicle body, 2 is steered wheels, 4 and 5 are drive wheels, 6 is a control device,
7 is a position measuring device, 8 is a driving mode switching device, 9 is a signal plate sensor, 10 is an inductive element sensor, 11 and 12 are rotation amount sensors, 20 and 21 are inductive elements, 23 and 24 are signal plates, and M1 is steering. Motor, M2 is a traveling motor.

Claims (1)

[Claims] 1. A traveling method of an unmanned guided vehicle in which a guiding element is used to indicate a traveling route, and an unmanned guided vehicle is guided along the traveling route, the method being autonomous at a branch point, a crossing point, a turning point, etc. of the route. In a combination of traveling, when shifting from autonomous traveling of an unmanned guided vehicle to guided traveling, the guided traveling path is passed during autonomous traveling, and the azimuth measurement value of the vehicle body at the time of passage and the guidance element detection information of the sensor The vehicle position is measured, the measured value of the vehicle position for autonomous traveling is corrected based on the result, and when the azimuth and deviation of the vehicle body with respect to the guideway are within the predetermined permissible range, the guide element is switched to guide traveling. A method for driving an automated guided vehicle, which is characterized in that