JP2007219960A - Position deviation detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position deviation detection device capable of improving detection resolution of a lateral deviation amount from a travel route without increasing the number of magnetic detection elements. <P>SOLUTION: This position deviation detection device comprises: magnetic sensors 11a, 11b respectively disposed in front part and rear part center positions of an automated guided vehicle, having the large number of the magnetic detection elements 14 in a right-and-left direction perpendicular to a direction of the travel route 16; two magnetic markers 18A, 18B parallel along the travel route 16, respectively disposed front and rear positions capable of being simultaneously detected by both magnetic sensors 11a, 11b of the automated guided vehicle along the travel route 16; and a controller calculating the lateral displacement amount between the travel route 16 and the center position of the front magnetic sensor 11a, and the lateral displacement amount between the travel route 16 and the center position of the rear magnetic sensor 11b by detection data of the two magnetic markers 18A, 18B respectively detected by the magnetic detection elements 14 of the front and rear magnetic sensors 11a, 11b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a position deviation detection device, and more particularly to a position deviation detection device provided in an automatic guided vehicle capable of autonomous traveling.

An example of a position deviation detection device provided with the automatic guided vehicle capable of autonomous traveling is disclosed in Patent Document 1.
The position deviation detection device disclosed in Patent Document 1 is a device that detects an N-pole magnetic marker installed on a floor surface, and includes 48 elements (magnetic detection elements that detect an N-pole) at intervals of 10 mm. Prepare for the column. The deviation (lateral shift amount) between the magnetic marker and the center position of the position deviation detector is determined depending on which of the 48 elements has detected the N-pole magnetic marker. The element interval (10 mm) is the detection pitch, and the width that can be detected by the 48 elements in one row is the detection width.

In Patent Document 1, this position deviation detection device is attached to the front and rear portions of the automatic guided vehicle in a posture perpendicular to the magnetic marker, and the vehicle body width from the traveling path at the front and rear portions of the automatic guided vehicle. It is used as a sensor for detecting the amount of lateral displacement of the direction position, and by detecting the amount of lateral displacement before and after, the line deviation and the attitude angle deviation from the travel route (line) are obtained.
JP 2001-209429 A

  However, in the conventional position deviation detection device, since the detection pitch is 10 mm, the detection resolution of the deviation amount is 5 mm at the best. Therefore, if the distance between the magnetic sensors attached to the front and rear of the automatic guided vehicle is short, the line deviation and There was a problem that the detection resolution of the attitude angle deviation was deteriorated and the attitude angle and position of the automatic guided vehicle could not be corrected with high accuracy. If the posture angle and position cannot be corrected with high accuracy, the amount of lateral deviation with respect to the travel route increases, and stable travel along the travel route cannot be ensured.

  In order to solve such a problem, a method of increasing the number of magnetic detection elements, shortening the detection pitch, and improving the detection resolution can be considered, but if the number of magnetic detection elements increases, the cost increases. .

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a position deviation detection device that can improve the detection resolution of the amount of lateral deviation from the travel route without increasing the number of magnetic detection elements, and can secure the same detection width as in the prior art. It is what.

  In order to achieve the above-described object, the invention according to claim 1 of the present invention is an automatic guided vehicle that travels autonomously along a travel route in which a plurality of reference points are arranged. A position deviation detection device used for obtaining a posture angle of a vehicle and a distance away from the vehicle, and is disposed at a front center position and a rear center position of the automatic guided vehicle, and is perpendicular to a direction of the travel route. A magnetic sensor having a large number of magnetic detection elements at predetermined intervals in the left-right direction, and a position that can be simultaneously detected by both magnetic sensors of the automatic guided vehicle at each reference point, at a front-rear position along the travel route. And at least two magnetic markers that have a predetermined length in the front-rear direction, are parallel to each other at a predetermined distance along the travel route, and a magnetic detection element of the front magnetic sensor Detected by The amount of lateral deviation between the travel path and the center position of the front magnetic sensor is calculated from the detection data of the at least two magnetic markers, and detected by the magnetic detection element of the rear magnetic sensor, It is characterized by comprising an arithmetic unit that calculates the amount of lateral deviation between the travel route and the center position of the rear magnetic sensor based on the detection data of at least two magnetic markers.

  According to the above configuration, at least two magnetic markers are detected by the magnetic detection elements of the front and rear magnetic sensors, respectively, and front and rear from the traveling path of the front position and the rear position by the detection data of at least two magnetic markers, respectively. Is calculated. Therefore, the resolution is at least twice as compared with the case where one magnetic marker is detected by the magnetic detection elements of the front and rear magnetic sensors to determine the amount of lateral displacement, and the accuracy of the amount of lateral displacement is improved. As a result, the accuracy of the posture angle and the distance of the automatic guided vehicle from the travel route determined by the amount of lateral deviation before and after is improved.

  The invention according to claim 2 is the invention according to claim 1, wherein the predetermined distance between at least two of the magnetic markers is determined separately by the two magnetic detection elements of the magnetic sensor. It is a distance that can detect the marker.

According to the above configuration, the magnetic marker is reliably detected separately by the two magnetic detection elements of the magnetic sensor, and the amount of lateral deviation before and after is reliably determined.
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the length of each magnetic marker is the same as that of the magnetic sensor while the automatic guided vehicle is traveling at high speed. The length is set so as to be detectable by the detection element.

  According to the above configuration, even when the automatic guided vehicle is traveling at a high speed, the magnetic marker is reliably detected and the posture angle and distance of the automatic guided vehicle from the travel route are corrected when passing the reference point. Is surely done.

  The position deviation detection device of the present invention can detect the amount of lateral deviation with at least twice the detection resolution so far, and therefore, even when the distance between the front and rear magnetic sensors (mounting distance) is short, the posture angle and position are accurate. It has the effect of being able to correct well.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
First, an automatic guided vehicle that uses the position deviation detection device according to Embodiment 1 of the present invention will be described. FIG. 1 is an explanatory view of the automatic guided vehicle, and shows a bottom surface and a side surface.

  In FIG. 1, reference numeral 1 denotes an autonomous four-wheeled automatic guided vehicle having a carriage main body 2 on which a load is loaded, and is supported at the four corners of the bottom surface of the carriage main body 2 via respective rudder shafts. Traveling wheels 3 are provided. Hereinafter, the traveling direction of the automatic guided vehicle 1 is referred to as the front-rear direction X, and the direction perpendicular to the front-rear direction X on the plane is referred to as the left-right direction Y.

  Each traveling wheel 3 is provided with a traveling drive device 4 that rotationally drives the traveling wheel 3, and a steering device 5 that is driven to turn through the rudder shaft of each traveling wheel 3. A rotary encoder 6 (6a, 6b) is connected to one of the travel drive devices 4 of the two front travel wheels 3 and one of the travel drive devices 4 of the two rear travel wheels 3. Each of the four steering devices 5 is provided with a steering angle sensor 7 that detects the steering angle of the steering shaft of each traveling wheel 3.

  And the center line 10 of the trolley body 2 and the travel path 16 (described later) are respectively located at the center position in the left and right direction of the front portion of the trolley body 2 and the center position in the left and right direction (on the center line 10 of the trolley body 2). Magnetic sensors 11 (11a, 11b) that detect and output the amount of deviation are provided. Now, the distance between the center Q of the cart body 2 and the front magnetic sensor 11a is L1, and the distance between the center Q of the cart body 2 and the rear magnetic sensor 11b is L2. The centers of these magnetic sensors 11 (11a, 11b) are aligned with the center line 10 of the carriage body 2. These magnetic sensors 11 (11a, 11b) are position deviation detection devices according to Embodiment 1 of the present invention, and details will be described later.

A gyro sensor 12 is provided at the center Q of the cart body 2.
Further, as shown in FIG. 2, a travel route 16 is set as a route on which the automatic guided vehicle 1 travels on the floor surface 15 on which the automatic guided vehicle 1 travels, and a reference point is spaced along the travel route 16. 17 is set. Note that the travel route 16 has no entity like a guide line.

  Each reference point 17 has a predetermined length in the front-rear direction X at a position that can be detected at the same time in the front-rear position along the travel route 16 and in accordance with the mounting position of both magnetic sensors 11 of the automatic guided vehicle 1. A pair of left and right magnetic markers 18A and 18B having M are arranged. As shown in FIG. 4, the pair of left and right magnetic markers 18 </ b> A and 18 </ b> B are arranged parallel to the travel route 16 and at a distance of W / 2 from the center of the travel route 16. The distance W between the magnetic markers 18A and 18B will be described later.

  The distance between the center of the front magnetic markers 18A and 18B and the reference point 17 is the distance L1 between the center Q of the cart body 2 and the front magnetic sensor 11a, and the center and reference point of the rear magnetic markers 18A and 18B. The distance to 17 is the distance L2 between the center Q of the cart body 2 and the rear magnetic sensor 11b.

  As shown in FIG. 1, the cart body 2 is provided with a control device 20 that controls the travel drive device 4 and the steering device 5. As shown in FIG. 3, the control device 20 includes the left and right shift amounts detected by the two magnetic sensors 11 a and 11 b, the angular velocity detected by the gyro sensor 12 (the angle moved in one second), Pulses output from the two rotary encoders 6a and 6b, the absolute angle of the rudder shaft detected by the four steering angle sensors 7 with the central line 10 of the cart body 2 as 0 degrees are input, and the control device 20 Accordingly, a drive command is output to the four travel drive devices 4, and a turn command is output to the four steering devices 5.

The control device 20 includes an arithmetic processing unit 25, a storage unit 26, and a vehicle control unit 27. The arithmetic processing unit 25 includes an attitude angle deviation / line deviation calculation unit 31, an attitude angle calculation unit 32, and a travel distance calculation unit 33. The vehicle position calculation unit 34 and the autonomous guidance processing unit 35, and the vehicle control unit 27 includes a travel control unit 41 and a steering control unit 42.
[Storage unit 26]
The storage unit 26 stores coordinates such as a start point and an end point for each route of the travel route 16 divided into several blocks, and absolute coordinates of each reference point 17. Thereby, the travel route information and the absolute coordinates of the destination are obtained.
[Attitude angle deviation / line deviation calculation unit 31]
The posture angle deviation / line deviation calculation unit 31 of the calculation processing unit 25 is the front of the center of the travel route 16 calculated when the two magnetic sensors 11a and 11b detect the magnetic markers 18A and 18B. From the deviation amount df and the rear deviation amount dr (calculation will be described later), the attitude angle deviation φ and the line deviation ε from the travel route 16 are calculated by equations (1) and (2), and the attitude angle deviation φ is calculated by the attitude angle. The position angle deviation φ and the line deviation ε are output to the vehicle position calculation unit 34 (see FIG. 5).

φ = tan ⁻¹ {(df−dr) / L} (1)
ε = (df + dr) / 2 (2)
Note that L is a span (L1 + L2) between the magnetic sensors 11a and 11b.
[Attitude angle calculation unit 32]
The attitude angle calculation unit 32 integrates the angular velocities detected by the gyro sensor 12 (the initial value is 0 degree with respect to the travel route 16) to obtain the posture angle θ from the travel route 16. Also, when the posture angle deviation φ is input from the posture angle deviation / line deviation calculation unit 31, the posture angle θ is set as the posture angle deviation φ (corrected) (θ = φ), and thereafter, the angular velocity is integrated from the posture angle θ. . Further, the obtained attitude angle θ is output to the vehicle position calculation unit 34.

The travel distance calculation unit 33 separately counts the pulses input from the rotary encoders 6a and 6b, and multiplies the counted value by the travel amount per pulse to determine the travel distance. And the travel distance s is output to the vehicle position calculation unit 34.
[Vehicle position calculation unit 34]
The vehicle position calculation unit 34 is a calculation unit that obtains absolute vehicle position information (x, y, θ) {(x, y) is a plane coordinate, θ is an attitude angle} of the center Q of the automatic guided vehicle 1, The posture angle θ obtained by the posture angle calculation unit 32 and the travel distance s obtained by the travel distance calculation unit 33 are input, the posture angle θ is updated, and the change amount Δθ of the posture angle and the travel distance per unit time. The amount of change Δs is obtained, the amount of change (Δx, Δy) of the position per unit time is obtained, and the current coordinates (x, y) are updated by adding to the previous coordinates (x, y). Further, when the vehicle position calculation unit 34 receives an arrival signal (described later) from the autonomous guidance processing unit 35 to the reference point 17, the vehicle position calculation unit 34 obtains the posture angle deviation φ and the line deviation ε from the posture angle deviation / line deviation calculation unit 31. The absolute vehicle position information (x, y, θ) is corrected using the absolute coordinates of the reference point 17 stored in the storage unit 26. That is, the posture angle θ is set as the posture angle deviation φ, and the plane coordinates (x, y) are corrected by the equations (3) and (4) based on the posture angle deviation φ and the line deviation ε.

x = xm−εsin θ (3)
y = ym−εcos θ (4)
Thus, accurate absolute vehicle position information (x, y, θ) is obtained at each reference point 17.
[Autonomous guidance processing unit 35]
The autonomous guidance processing unit 35 travels the automatic guided vehicle 1 along the travel route 16 to a predetermined reference point 17 based on the current vehicle coordinates obtained by the vehicle position calculation unit 34 and the route information stored in the storage unit 26. The steering angle of the steering device 5 is calculated so that the target steering angle θm is determined, and the traveling speed v is obtained to start traveling. When the reference point 17 is reached, the arrival signal is output to the vehicle position calculation unit 34.
[Running control unit 41]
When the travel control unit 41 of the vehicle control unit 27 inputs a travel start command from the autonomous guidance processing unit 35, it drives the four travel drive devices 4 so as to achieve the travel speed v, and inputs a travel stop command. The four travel drive devices 4 are stopped.
[Steering control unit 41]
When the target steering angle θm is input from the autonomous guidance processing unit 35, the steering control unit 42 of the vehicle control unit 27 feeds back the absolute angle of the rudder shaft detected by the four steering angle sensors 7 using this value as a target value. However, the four steering devices 5 are controlled.

  With the configuration of the control device 20, when a destination instruction is input from a setting display (not shown), the current position {coordinate (x, y)} to the destination reference point 17 {coordinate (xm, ym)}. In this case, the center line 10 of the automatic guided vehicle 1 is controlled so as to coincide with the travel route 16.

As described above, the vehicle is obtained from the front shift amount df and the rear shift amount dr detected by the two magnetic sensors 11a and 11b positioned at the front and rear at each reference point 17 and the absolute information (x, y, θ) of the reference point 17. Since the position is corrected and traveling along the travel route 16 is performed based on the vehicle position, if the accuracy of the front displacement amount df and the rear displacement amount dr detected by the magnetic sensors 11a and 11b is poor, the vehicle position is corrected. There is a risk that the accuracy may deteriorate and the vehicle cannot travel along the travel route 16.
[Magnetic sensor and calculation of front shift amount df and rear shift amount dr]
Hereinafter, when both the front and rear magnetic sensors 11a and 11b detect the pair of left and right magnetic markers 18A and 18B, a calculation method for calculating the front shift amount df and the rear shift amount dr from the center of the travel route 16 is described. Will be described. This calculation is executed in a posture angle deviation / line deviation calculation unit (an example of a calculation device) 31. The position deviation detection device includes magnetic sensors 11a and 11b, magnetic markers 18A and 18B, and a posture angle deviation / line deviation calculation unit. (An example of an arithmetic unit)

  As shown in FIG. 4B, the magnetic sensors 11a and 11b according to the first embodiment include a plurality of (for example, 48 same as the conventional ones) arranged at a pitch P in the left-right direction perpendicular to the center line 10 of the carriage body 2. ), And the height direction distance H from the magnetic markers 18A and 18B is determined by at least two (three in the figure) magnetic detection elements 14 positioned vertically above the magnetic markers 18A and 18B. The distance is detectable. And the position of the magnetic detection element 14 which detected each of the magnetic markers 18A and 18B with the highest sensitivity is specified, and the distance from the center of the magnetic sensors 11a and 11b (the center line 10 of the cart body 2) is output.

  The length M of the magnetic markers 18A and 18B is set by a length that can be detected even when the automatic guided vehicle 1 travels at a high speed. Further, the minimum distance W (predetermined distance) between the right magnetic marker 18A and the left magnetic marker 18B is at least one magnetism by the three magnetic detection elements 14, as shown in FIG. 4B. The distance is set such that the magnetic markers 18A and 18B can be detected separately and reliably with the detection element 14 in between, and (multiple of the pitch p of the magnetic detection element 14 + p / 2).

  As shown in FIG. 6, when the right magnetic marker 18A is detected by the front magnetic sensor 11a, the distance from the center line 10 (the center of the magnetic sensor 11a) of the carriage main body 2 is dfR, and the left magnetic marker is The distance from the center line 10 (the center of the magnetic sensor 11a) of the cart body 2 when 18B is detected is assumed to be dfL. Further, when the right magnetic marker 18A is detected by the rear magnetic sensor 11b, the distance from the center line 10 (the center of the magnetic sensor 11b) of the carriage main body 2 is drR, and the carriage main body when the left magnetic marker 18B is detected. The distance from the center line 10 of 2 (the center of the magnetic sensor 11b) is assumed to be drL.

The front shift amount df and the rear shift amount dr are calculated by equations (5) and (6).
df = (dfR + dfL) / 2 (5)
dr = (drR + drL) / 2 (6)
As described above, the front shift amount df and the rear shift amount dr are respectively determined by the two shift amounts dfR and dfL detected by the front magnetic sensor 11a and the two shift amounts drR and drL detected by the rear magnetic sensor 11b. As a result, the front displacement amount df and the rear displacement amount dr are detected with a detection resolution twice as high as when a magnetic sensor having the same configuration is used. As a result, the accuracy of the attitude angle deviation φ and the line deviation ε from the travel route 16 of the automatic guided vehicle 1 obtained by the front deviation amount df and the rear deviation amount dr is improved, and the absolute vehicle position information (x, y, θ) is improved. Improves accuracy.

  As described above, according to the first embodiment, the front displacement amount df and the rear displacement amount dr can be detected with twice the resolution even when the same magnetic sensor as the conventional one is used. Even when the distance (mounting distance) L between 11a and 11b is short, the posture angle and the position can be accurately corrected.

  Further, according to the first embodiment, since the same magnetic sensor as the conventional one is used, the pitch p of the magnetic detection elements 14 is halved and the number of the magnetic detection elements 14 is doubled while maintaining the detection width. It is not necessary to use an expensive magnetic sensor, and an increase in cost can be suppressed.

  According to the first embodiment, the distance W between the magnetic markers 18A and 18B is set to a distance at which the magnetic markers 18A and 18B can be separately detected by at least two magnetic detection elements 14 of the magnetic sensors 11a and 11b. Therefore, the magnetic markers 18A and 18B can be detected separately by the magnetic detection elements 14 of the magnetic sensors 11a and 11b, and the front displacement amount df and the rear displacement amount dr can be reliably obtained.

According to the first embodiment, the length M of the magnetic markers 18A and 18B is set to a length that can be detected by the magnetic detection element 14 of the magnetic sensors 11a and 11b while the automatic guided vehicle 1 is traveling at a high speed. Even when the automatic guided vehicle 1 is traveling at high speed, when the magnetic markers 18A and 18B are reliably detected and pass the reference point 17, the posture angle θ of the automatic guided vehicle 1 from the traveling path 16 The line deviation ε can be reliably corrected, and the setting accuracy of the target posture angle θm of the automatic guided vehicle 1 can be improved.
[Embodiment 2]
In the first embodiment, a pair of left and right magnetic markers 18A and 18B are arranged at the front and rear positions of each reference point 17, but in the second embodiment, as shown in FIGS. In addition, three magnetic markers 19 (19A, 19B, 19C) are arranged on the travel path 16 at the left and right positions parallel to the travel path 16 and taking a distance W. In the second embodiment, the position deviation detection device includes magnetic sensors 11a and 11b, magnetic markers 19A, 19B, and 19C, and an attitude angle deviation / line deviation calculation unit 31.

  Now, the length of the central magnetic marker 19B in the front-rear direction X is M1, the length of the right magnetic marker 19A and the left magnetic marker 19C in the front-rear direction X is M2 (M1> M2), and the center positions are aligned. . Note that the length M1 of the central magnetic marker 19B is longer than the length M2 of the other magnetic markers 19A and 19C, so that it is possible to detect early that the automatic guided vehicle 1 has reached the reference point 17 during traveling. I am doing so.

  The lengths M1 and M2 of the magnetic markers 19C, 19A, and 19B are set according to the lengths that can be detected by distinguishing them from each other and that can be detected even when the automatic guided vehicle 1 is traveling at a high speed. The minimum distance W between the magnetic marker 19B and the minimum distance W between the central magnetic marker 19B and the left magnetic marker 19C is, as shown in FIG. 8B, a minimum of two magnetic detection elements 14 Thus, the magnetic markers 19A, 19B, and 19C are set at distances that can detect the magnetic markers 19A, 19B, and 19C separately and securely with at least one (two in the figure) magnetic detection element 14 interposed therebetween.

  Now, as shown in FIG. 9, when the right magnetic marker 19A is detected by the front magnetic sensor 11a, the distance from the center line 10 (the center of the magnetic sensor 11a) of the carriage body 2 is dfR, and the central magnetic marker is The distance from the center line 10 (the center of the magnetic sensor 11a) of the cart body 2 when 19B is detected is dfC, and the center line 10 (the center of the magnetic sensor 11a) of the cart body 2 when the left magnetic marker 19C is detected. The distance to is dfL. Further, when the right magnetic marker 19A is detected by the rear magnetic sensor 11b, the distance from the center line 10 (the center of the magnetic sensor 11b) of the cart body 2 is drR, and the cart body when the center magnetic marker 19C is detected. The distance from the center line 10 of 2 (the center of the magnetic sensor 11b) is dfC, and the distance from the center line 10 (the center of the magnetic sensor 11b) of the cart body 2 when the left magnetic marker 19B is detected is drL.

  Depending on whether the magnetic sensors 11a, 11b are detecting three magnetic markers 19A, 19B, 19C or two magnetic markers 19A, 19B or 19B, 19C are detected, the amount of forward displacement df and the amount of backward displacement are determined. The quantity dr is calculated as follows. This calculation is executed in a posture angle deviation / line deviation calculation unit (an example of a calculation device) 31.

When three magnetic markers 19A, 19B, and 19C are detected {see FIG. 10 (a)}.
df = (dfR + dfC + dfL) ÷ 3 (7)
dr = (drR + drC + drL) ÷ 3 (8)
When two magnetic markers 19B and 19C are detected {see FIG. 10B}.

df = W ÷ 2 + (dfC + dfL) ÷ 2 (9)
dr = W ÷ 2 + (drC + drL) ÷ 2 (10)
When two magnetic markers 19A and 19B are detected {see FIG. 10 (c)}.

df = W ÷ 2 + (dfR + dfC) ÷ 2 (11)
dr = W ÷ 2 + (drR + drC) ÷ 2 (12)
As described above, the front shift amount df and the rear shift amount dr are respectively the three shift amounts dfR, dfC, dfL detected by the front magnetic sensor 11a, and the three shift amounts drR, detected by the rear magnetic sensor 11b. By obtaining using drC and drL, the front displacement amount df and the rear displacement amount dr are detected with a detection resolution approximately twice that when the magnetic sensor having the same configuration is used. As a result, the accuracy of the attitude angle deviation φ and the line deviation ε from the travel route 16 of the automatic guided vehicle 1 obtained by the front deviation amount df and the rear deviation amount dr is improved, and the absolute vehicle position information (x, y, θ) is improved. Improves accuracy. In addition, since the three magnetic markers 19 (19A, 19B, 19C) are arranged in parallel at the distance W, the detection range is doubled compared to the case where only the two magnetic markers 19 are arranged. Yes.

  As described above, according to the second embodiment, the front shift amount df and the rear shift amount dr can be detected with about twice the detection resolution even when the same magnetic sensor as the conventional one is used. Even when the distance (mounting distance) L between 11a and 11b is short, the posture angle and the position can be accurately corrected.

  Further, according to the second embodiment, since the same magnetic sensor as the conventional one is used, it is not necessary to use an expensive magnetic sensor in which the pitch of the magnetic detection elements is halved, and an increase in cost can be suppressed.

  According to the second embodiment, the distance W between the magnetic markers 19A, 19B, and 19C can be detected separately by at least two magnetic detection elements 14 of the magnetic sensors 11a and 11b. By setting the distance, it is possible to reliably detect the magnetic markers 19A, 19B, and 19C separately by the magnetic detection elements 14 of the magnetic sensors 11a and 11b, and to reliably obtain the front displacement amount df and the rear displacement amount dr. it can.

  Further, according to the second embodiment, the lengths M1, M2 of the magnetic markers 19A, 19B, 19C can be detected by the magnetic detection elements 14 of the magnetic sensors 11a, 11b while the automatic guided vehicle 1 is traveling at a high speed. By doing so, even when the automatic guided vehicle 1 is traveling at high speed, the magnetic markers 19A, 19B, 19C are reliably detected, and when the automatic marker 1 passes through the reference point 17, the automatic guided vehicle from the traveling route 16 is used. The posture angle θ 1 and the line deviation ε can be reliably corrected.

  In the first and second embodiments, two or three magnetic markers are used, but more magnetic markers may be installed. At this time, the interval between the magnetic markers needs to be an interval that can be reliably detected by at least two magnetic detection elements 14.

  In the second embodiment, the length M1 of the central magnetic marker 19B is longer than the length M2 of the other magnetic markers 19A and 19C, but the length is the same (M1 = M2) or longer. It is also possible to make the length M2 longer than the length M1 (M1 <M2).

  In the first and second embodiments, the automatic guided vehicle 1 uses the rotary encoder 6 and the gyro sensor 12 to estimate the self position (coordinates). In this way, the rotary encoder 6 and the gyro sensor are used. 12 is not limited to use, and other devices, for example, a device that measures a position by measuring a distance from three fixed points and a GPS device are used to estimate the self-position. Also good.

It is explanatory drawing of the automatic guided vehicle which uses the position deviation detection apparatus in Embodiment 1 of this invention, (a) is a bottom view, (b) is a side view. In the same position deviation detection apparatus, it is an arrangement view of a reference point and a magnetic marker installed on the floor surface. It is a control block diagram of the same position deviation detection apparatus. It is explanatory drawing which showed a response | compatibility with the magnetic sensor and magnetic marker of the same position deviation detection apparatus. It is a figure explaining the gap | deviation amount from the driving | running route of the automatic guided vehicle of the position deviation detection apparatus. It is detection explanatory drawing of the amount of horizontal shift of the position deviation detection apparatus. In the position deviation detection apparatus in Embodiment 2 of this invention, it is an arrangement | positioning drawing of the reference point installed on a floor surface, and a magnetic marker. It is explanatory drawing which showed a response | compatibility with the magnetic sensor and magnetic marker of the same position deviation detection apparatus. It is detection explanatory drawing of the amount of horizontal shift of the position deviation detection apparatus. It is detection explanatory drawing of the amount of horizontal shift of the position deviation detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic guided vehicle 2 Bogie main body 3 Traveling wheel 4 Travel drive device 5 Steering device 6 Rotary encoder 7 Steering angle sensor 10 Center line of bogie main body 11a, 11b Magnetic sensor 12 Gyro sensor 14 Magnetic detection element 16 Travel path 17 Reference point 18A, 18B, 19A, 19B, 19C Magnetic marker 20 Controller 21 Setting indicator

Claims (3)

In an automatic guided vehicle that autonomously travels along a travel route on which a plurality of reference points are arranged, a position deviation detection device used to obtain an attitude angle of the automatic guided vehicle from the travel route and a distance away from the travel route. ,
A magnetic sensor having a large number of magnetic detection elements arranged in the left-right direction perpendicular to the direction of the travel path, each disposed at a front center position and a rear center position of the automatic guided vehicle;
For each of the reference points, each of the reference points is arranged at a position along the travel route and at a position that can be simultaneously detected by both magnetic sensors of the automatic guided vehicle, and has a predetermined length in the front-rear direction, At least two magnetic markers parallel to each other at a predetermined distance along the travel route;
Based on the detection data of at least two magnetic markers detected by the magnetic detection element of the front magnetic sensor, a lateral shift amount between the travel route and the center position of the front magnetic sensor is calculated, and the rear And an arithmetic unit that calculates a lateral shift amount between the travel route and the center position of the rear magnetic sensor based on detection data of at least two magnetic markers detected by the magnetic detection element of the magnetic sensor. A position deviation detection device characterized by comprising: 2. The positional deviation according to claim 1, wherein the predetermined distance between at least two of the magnetic markers is a distance at which the magnetic markers can be separately detected by two magnetic detection elements of the magnetic sensor. Detection device. 3. The length of each magnetic marker is set to a length that can be detected by a magnetic detection element of the magnetic sensor while the automatic guided vehicle is traveling at a high speed. The position deviation detection apparatus described in 1.

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