JP2010013260A - Conveyance system, and traveling vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure a position and an attitude of a traveling vehicle by a single distance measuring device. <P>SOLUTION: A conveyance system 100 includes a station 110, the traveling vehicle 140 which stops at a target position in a target attitude, and a transfer means 170 for transferring load. The system includes the single distance measuring means 141 for measuring a distance between the station 110 and the traveling vehicle 140, a first distance measuring part 111 and a second distance measuring part 112 which are objects to be measured by the distance measuring means 141, a control part 151 for obtaining a first distance from the first distance measuring part 111, for making the traveling vehicle 140 travel by a predetermined distance and to a predetermined direction, and for obtaining a second distance from the second distance measuring part 112, a calculation part 152 for calculating an inclination value which is inclination of the traveling vehicle 140 from the target attitude based on the first distance and the second distance, and a transfer condition determination part 153 for determining transfer conditions of the transfer means 170 based on the inclination value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transport system including a plurality of stationary stations, a traveling vehicle that transports a load between these stations, and a transfer means that transfers the load between the station and the traveling vehicle. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport system that does not have a rail on which a vehicle travels, and transfers a load with an accurate loading position and an accurate loading posture. Moreover, it is related with the traveling vehicle used for the said conveyance system.

  For example, in the case of a transport system that loads and unloads luggage in an automatic warehouse or the like, the following processes are employed. (1) A package is placed on the station. (2) The luggage is transferred to a traveling vehicle that has arrived near the station by autonomous traveling. (3) The traveling vehicle transports the luggage to another station by autonomous traveling. (4) A traveling vehicle arrives at another station and the luggage is transferred.

  As described above, when the traveling vehicle autonomously travels in the transport system, in order for the traveling vehicle itself to recognize the position of the traveling vehicle in the entire warehouse, an index indicating the position in the warehouse may be provided in a distributed manner. When the traveling vehicle travels between the indexes, the position of the traveling vehicle is recognized using an encoder that the traveling vehicle itself has.

  Therefore, when a traveling vehicle moves from one station to another station, the traveling vehicle stops accurately in the vicinity of the other station while correcting the deviation of the encoder with the index. Then, the luggage is transferred between the other station and the traveling vehicle.

However, in the case of a transport system that transports a glass substrate or the like for a display device as a baggage, it is necessary to transfer the glass substrate between the station and the traveling vehicle at a more accurate position and more accurate posture. Therefore, the traveling vehicle employed in such a transport system is located on the traveling base with respect to the traveling base in the Y direction (the direction from the traveling vehicle toward the station) and the X direction (crossing the Y direction and within the horizontal plane. And a mounting table that moves in the θ direction (rotational direction). Further, the traveling vehicle includes measurement means that can measure the position and orientation with the station more precisely than an encoder included in the traveling vehicle. As described above, the transfer system can move the mounting table accurately based on the measurement result of the measurement system, and can transfer the glass substrate between the station and the traveling vehicle at an accurate position and an accurate posture ( Patent Document 1).
JP 2000-194418 A

  However, in the conventional transport system, it is necessary to provide a plurality of sensors in order to measure the attitude relationship between the station and the traveling vehicle. In addition, in order to measure the relative positional relationship between the station and the traveling vehicle, it is necessary to further include another sensor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a transport system that can measure the posture relationship between a station and a traveling vehicle with a single distance measuring means and realize transfer in an accurate posture. . It is another object of the present invention to provide a transport system that can measure the relative positional relationship between a station and a traveling vehicle with the distance measuring means and realize transfer at an accurate position.

  In order to solve the above-described problems, a transport system according to the present invention includes a station, a traveling vehicle that stops at a target position near the station in a target posture, and a transfer means that transfers a load between the station and the traveling vehicle. A distance measuring means for measuring a distance between the station and the traveling vehicle, and provided on the other of the station and the traveling vehicle. A first distance between the first distance measuring section and the second distance measuring section and the first distance measuring section to be measured by the distance measuring means is acquired from the distance measuring means, and the traveling vehicle Based on the acquired first distance and second distance, and a controller that acquires a second distance from the second distance measuring unit from the distance measuring means. By tilting the car from the target posture A calculation unit for calculating an inclination value that, characterized in that it comprises a transfer condition determination unit determining a transfer condition of said transferring means based on the calculated gradient value.

  According to this, it is possible to acquire an inclination value that is an inclination from the target posture of the traveling vehicle that has reached the target position by a single distance measuring means. Then, it becomes possible to transfer between the station and the traveling vehicle in an accurate posture.

  And a third distance measuring unit provided on the other of the station and the traveling vehicle, wherein the distance from the distance measuring means gradually changes when the traveling vehicle is moved in the predetermined direction. The unit further obtains a third distance with the third distance measuring unit from the distance measuring means, and the calculation unit is further based on the measured first distance or the second distance and the third distance. It is preferable that a shift value that is a shift from the target position is calculated, and the transfer condition determination unit determines a transfer condition of the transfer means based on the calculated shift value.

  According to this, it is possible to acquire the posture and position of the traveling vehicle with respect to the station with a single distance measuring means, and it is possible to transfer the load more accurately.

  Moreover, it is preferable that the said control part acquires said 1st distance and said 2nd distance, running the said traveling vehicle.

  As a result, the movement of the traveling vehicle and the acquisition of the inclination value can be performed at the same time, and the time for transporting the luggage can be shortened. Further, since there is no need to repeat deceleration and acceleration, there is no error in travel distance due to inertia, and errors due to backlash can be suppressed.

  Furthermore, the control unit is configured such that a line connecting the first distance measuring unit and the second distance measuring unit and a line connecting the traveling vehicle and the target position are parallel, and the traveling vehicle and the target position are When the distance reaches a threshold value, the traveling vehicle is decelerated, and the first distance measuring unit and the second distance measuring unit are preferably disposed between a position where the traveling vehicle decelerates and a target position. .

  According to this, since distance measurement is performed at a low speed, it is possible to ensure high transfer accuracy.

  According to the present invention, it is possible to measure the posture and position of the traveling vehicle with respect to the station with a single distance measuring means, and transfer the load between the station and the traveling vehicle in an accurate posture and accurate position. It becomes possible.

  Next, an embodiment according to the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view schematically showing a part of the transport system according to the embodiment.

  As shown in the figure, the transport system 100 transports a glass substrate 200 as a load using a traveling vehicle 140, and transfers the load between the station 110 and the traveling vehicle 140 using a transfer means 170. This system includes a distance measuring means (not shown), a first distance measuring section 111, a second distance measuring section 112, and a third distance measuring section 113. An index 101 is attached to the floor on which the traveling vehicle 140 travels. In the case of the present embodiment, the transfer means 170 is provided separately for the station 110 and the traveling vehicle 140.

  2A and 2B are diagrams showing a traveling vehicle, in which FIG. 2A is a top view and FIG. 2B is a bottom view.

  As shown in FIG. 5A, the traveling vehicle 140 is provided with a mounting table 171 as a part of the transfer means 170 on the upper side, and autonomously moves the glass substrate 200 mounted on the mounting table 171. It is an apparatus for carrying, and an electronic computer 150 is mounted. A distance measuring means 141 is attached to a corner of the traveling vehicle 140. Further, as shown in FIG. 4B, the traveling vehicle 140 has two drive wheels 142 and four auxiliary wheels 143 attached to the bottom surface.

  The distance measuring unit 141 is a device that measures the distance from the first distance measuring unit 111, the second distance measuring unit 112, and the third distance measuring unit 113. In the case of the present embodiment, a reflection type laser distance sensor using a laser beam is employed as the distance measuring means 141. Since the laser distance sensor has high directivity, by fixing the laser distance sensor to the traveling vehicle 140, the distance between an object in a predetermined direction with respect to the traveling vehicle 140 and the laser distance sensor is accurately measured. be able to. Further, the time required for the distance measurement is short enough that the part for measuring the distance to the laser distance sensor can be regarded as one point even when the measurement is performed while the traveling vehicle 140 is traveling. Therefore, in order to accurately measure the posture and position of the traveling vehicle 140, a laser distance measuring sensor can be suitably employed as the distance measuring means 141. A broken line arrow in the figure represents the distance measuring direction of the distance measuring means 141.

  The distance measuring means 141 may be not only a laser distance measuring sensor but also an apparatus that measures the distance by extending the arm and bringing it into contact with the first distance measuring unit 111 or the like. In addition, there is no particular limitation on the distance measurement method such as distance measurement using ultrasonic waves. In the case where two separated devices are used to measure the distance between the devices, the method of transmitting data related to the distance is the distance measuring means 141 in the present invention.

  The drive wheels 142 are wheels that are connected to a drive source (not shown) to drive the traveling vehicle 140 and are driven to rotate about a horizontal axis, and are provided at both ends of the traveling vehicle 140 in the width direction. . Further, the drive wheel 142 is attached to the traveling vehicle 140 by turning a turntable 144 for turning the drive wheel 142 about a vertical axis. Further, the two drive wheels 142 can rotate around the vertical axis independently of each other. As described above, it is possible to make the traveling vehicle 140 go straight in a desired direction by making the two driving wheels 142 the same straight line or parallel. Further, by arranging the two drive wheels 142 in the intersecting direction, it is possible to travel on a line having a desired curvature.

  Moreover, the drive wheel 142 and the turntable 144 are provided with an encoder, and the encoder can output the moving distance and moving direction of the traveling vehicle 140.

  The auxiliary wheels 143 are wheels for keeping the traveling vehicle 140 horizontal while allowing the traveling vehicle 140 to travel, and are attached to the vicinity of the four corners of the lower surface of the traveling vehicle 140. The auxiliary wheel 143 is a wheel that is not connected to the drive source and rotates following the traveling state of the traveling vehicle 140.

  The mounting table 171 is one of the elements constituting the transfer means 170 and is a table on which the glass substrate 200 is mounted. Further, the mounting table 171 is rotatably attached to the traveling vehicle 140 and can be rotated with respect to the traveling vehicle 140 at an angle based on the acquired signal.

  FIG. 3 is a block diagram showing a functional configuration of the electronic computer.

  As shown in the figure, the electronic computer 150 is a computer that includes an arithmetic device, a storage device, and an interface, and that can perform calculations and control of equipment based on programs and data stored in the storage device. As processing functions, a control unit 151, a calculation unit 152, a transfer condition determination unit 153, and a transmission unit 154 are provided.

  The control unit 151 is a processing unit that can acquire a signal from an external device and control the external device. In the case of the present embodiment, the control unit 151 can acquire data related to the distance from the distance measuring unit 141. In addition, the control unit 151 can drive the traveling vehicle 140 by controlling the driving wheel 142 and can acquire the traveling distance of the traveling vehicle 140 based on a signal from the driving wheel encoder 145. In addition, the control unit 151 can drive the turntable 144 and feed back a signal from the turntable encoder 146 to control the turning angle of the drive wheel 142 so that the traveling vehicle 140 is directed in a predetermined direction. It is.

  In addition, the control unit 151 obtains the distance-related data (first distance) from the distance measuring means 141, causes the traveling vehicle 140 to travel in a predetermined distance and in a predetermined direction, and then again from the distance measuring means 141. It is possible to execute the step of acquiring data on the distance (second distance) in the order described above. Furthermore, after acquiring the second distance, the control unit 151 causes the traveling vehicle 140 to travel in a predetermined distance and in a predetermined direction, and acquires distance data (third distance) from the distance measuring unit 141. Can be executed in the order described above.

  The calculation unit 152 obtains the first distance, the second distance, and the travel distance of the traveling vehicle 140 from when the first distance is acquired until the second distance is acquired (predetermined). Is a processing unit that calculates an inclination value that is an inclination from a target posture (described later) of the traveling vehicle 140 based on the above.

  The calculation unit 152 is a processing unit that can also calculate a deviation value that is a deviation from a target position (described later) based on the first distance or the second distance and the third distance.

  Based on the result calculated by the calculation unit 152, the transfer condition determination unit 153 moves the transfer unit 170 (for example, how many times the mounting table 171 is rotated around the carriage 140, or the transfer claw is moved). This is a processing unit that determines how many millimeters 172 (to be described later) is moved and how many millimeters the transfer claw 172 is projected.

  The transmission unit 154 is a processing unit that transmits the transfer condition determined by the transfer condition determination unit 153 to the transfer unit 170.

  FIG. 4 is a top view showing the station.

  As shown in FIG. 5A, the station 110 is provided with a transfer claw 172 which is a part of the transfer means 170 on the upper side, and a glass substrate 200 placed on the transfer claw 172 is placed thereon. Equipment. In the station 110, a target plate 114 including a first distance measuring unit 111, a second distance measuring unit, and a third distance measuring unit 113 is attached to a side surface. A rail 115 is laid on the upper surface of the station 110 in parallel with the side surface to which the target plate 114 is attached.

  The station 110 is an area or place where the glass substrate 200 is temporarily stored (placed) in order to transfer the traveling vehicle 140 and the glass substrate that is a load, and the specific shape and the like are particularly It is not limited.

The target plate 114 is a plate-like member in which one end portion is cut off obliquely to form the third distance measuring unit 113, and is a member to be a distance measurement target of the distance measuring unit 141. The target plate 114 has a surface that can sufficiently reflect the laser beam emitted from the distance measuring means 141. The portions of the target plate 114 other than the third distance measuring unit 113 are opposed to each other in parallel, and intersecting surfaces intersect perpendicularly. Therefore, when one surface of the target plate 114 (hereinafter referred to as “attachment surface”) is attached along the side surface of the station 110, a surface parallel to the attachment surface (hereinafter referred to as “reflection surface”) is Parallel to the side.

  In addition, although the 1st ranging part 111 and the 2nd ranging part 112 are provided in the reflective surface of the target plate 114, the position of the 1st ranging part 111 and the 2nd ranging part 112 is a ranging means. Since the position is a distance measured by 141 and is determined by software by the control unit 151, the area cannot be specifically limited.

  The transfer claw 172 is one of the elements constituting the transfer means 170 and is a device on which the glass substrate 200 is placed. The transfer claw 172 is attached to the rail 115 laid on the upper surface of the station 110 and can move along the rail 115 to a position based on the acquired signal. In addition, the transfer claw 172 can move vertically with respect to the rail 115 with the glass substrate 200 placed thereon, and the uppermost surface portion can be moved up and down with the transfer claw 172 protruding. ing. Accordingly, the transfer claw 172 is projected in a state where the glass substrate 200 is mounted, the glass substrate 200 is disposed above the mounting table 171 on the traveling vehicle 140 side, and the uppermost surface portion of the transfer claw 172 is lowered, It becomes possible to transfer the glass substrate 200 from the station 110 side to the traveling vehicle 140 side. Moreover, if the reverse process is performed, the glass substrate 200 can be transferred from the traveling vehicle 140 side to the station 110 side.

  FIG. 5 is a diagram illustrating a process of measuring the position and posture of the traveling vehicle in the transport system, and (a) to (e) are illustrated in the order of passage of time.

  In addition, the rectangle drawn with the broken line shown to the same figure has shown the target position and the target attitude | position which the traveling vehicle 140 should arrive.

  As shown in FIG. 5A, the line connecting the first distance measuring unit 111 and the second distance measuring unit 112 is parallel to the line connecting the traveling vehicle 140 and the target position, and the traveling vehicle 140 and the target When the distance to the position becomes a threshold value, the control unit 151 decelerates the traveling vehicle 140 to a predetermined speed (creep speed) and causes the traveling vehicle 140 to travel straight toward the target position. However, due to the accuracy of the drive wheel encoder 145 and the turntable encoder 146, it is difficult for the traveling vehicle 140 to travel in an accurate distance and in an accurate direction so that the desired transfer accuracy is satisfied.

  Next, as shown in FIG. 5B, when the control unit 151 determines that the traveling vehicle 140 has reached a predetermined position, the control unit 151 acquires the first distance from the distance measuring unit 141.

  Next, as shown in FIG. 3C, the control unit 151 causes the traveling vehicle 140 to travel in the same direction as before by a predetermined distance. Thereafter, the control unit 151 acquires the second distance from the distance measuring unit 141. Note that the distance traveled by the traveling vehicle 140 may be acquired from the drive wheel encoder 145, the speed of the traveling vehicle 140 is statistically calculated based on the data from the drive wheel encoder 145, and the second distance from the first distance acquisition. It may be specified by the time until the distance acquisition.

  As described above, based on the first distance, the second distance, and the travel distance of the travel vehicle 140 between them, the posture value of the travel vehicle 140 with respect to the reflecting surface of the target plate 114, that is, the tilt value that is the tilt from the target posture is obtained. Calculated by the calculation unit 152.

  Although a specific calculation method is not limited, for example, if it is assumed that the traveling direction of the traveling vehicle 140 and the ranging direction of the ranging means 141 are perpendicular, the traveling distance of the traveling vehicle 140 is calculated. If the difference between the first distance and the second distance is the numerator, the slope value can be calculated.

  Next, as shown in FIG. 4D, the control unit 151 causes the traveling vehicle 140 to travel in the same direction as before for a predetermined distance. Thereafter, the control unit 151 acquires the third distance from the distance measuring unit 141.

  The third distance acquired by the control unit 151 is the distance between the third distance measuring unit 113 and the distance measuring means 141, and is the distance between the surface oblique to the reflecting surface and the distance measuring means 141. Therefore, based on the difference between the second distance (or the first distance) and the third distance and the angle of the oblique surface with respect to the reflective surface, the direction parallel to the reflective surface with respect to the target plate 114 of the traveling vehicle 140 (FIG. e) The positional relationship in the middle x direction), that is, a deviation value from the target position is calculated by the calculation unit 152.

  Next, the inclination value and the deviation value calculated by the calculation unit 152 are acquired, and the transfer condition determination unit 153 determines the transfer condition. This transfer condition includes a distance for moving the transfer claw 172 along the rail 115, a distance for protruding the transfer claw 172 (in the y direction in the figure), and rotating the mounting table 171 with respect to the traveling vehicle 140. This is the turning angle.

  Then, the transmission unit 154 transmits the transfer condition to the transfer claw 172 and the mounting table 171.

  The transfer claw 172 and the mounting table 171 that have acquired the transfer condition slide along the rail 115 so as to match the transfer condition as shown in FIG. Move.

  Then, the glass substrate 200 is transferred according to the transfer conditions.

  According to the configuration and the process as described above, the inclination value with respect to the target posture of the traveling vehicle 140 and the deviation value with respect to the target position can be calculated using the single distance measuring unit 141, and the transport system 100. Cost, in particular, the cost of the traveling vehicle 140 can be reduced.

  In the above-described embodiment, the first distance and the second distance are acquired while the traveling vehicle 140 is traveling. However, the present invention stops the traveling vehicle 140 and acquires the first distance and the second distance. This includes cases where

  Moreover, although the 1st ranging part 111 and the 2nd ranging part 112 existed in the same surface, it is not necessarily limited to this. If the positional relationship between the first distance measuring unit 111 and the second distance measuring unit 112 can be grasped in advance, the posture of the traveling vehicle 140 can be calculated using the positional relationship.

  Further, as shown in FIG. 6, the transfer means 170 may be provided on one of the station 110 or the traveling vehicle 140. The transfer means 170 shown in the figure suspends and holds the glass substrate 200 by suction, can move the glass substrate 200 in a horizontal plane, and can also rotate the glass substrate 200.

  The present invention can be used in automatic warehouses, semiconductor manufacturing factories, display manufacturing factories, and the like.

It is a perspective view showing typically a part of conveyance system which is an embodiment. It is a figure which shows a traveling vehicle, (a) is a top view, (b) is a bottom view. It is a block diagram which shows the function structure of an electronic computer. It is a top view which shows a station. It is a figure which shows the measurement process of the position and attitude | position of a traveling vehicle in a conveyance system, (a)-(e) is shown in order of passage of time. It is a figure which shows other embodiment of a conveyance system.

Explanation of symbols

100 transport system 101 index 110 station 111 first distance measuring unit 112 second distance measuring unit 113 third distance measuring unit 114 target plate 115 rail 140 traveling vehicle 141 distance measuring means 142 driving wheel 143 auxiliary wheel 144 rotating table 145 driving wheel Encoder 146 Turntable encoder 150 Electronic computer 151 Control unit 152 Calculation unit 153 Transfer condition determination unit 154 Transmitter 170 Transfer means 171 Mounting table 172 Transfer claw 200 Glass substrate

Claims (5)

A transport system comprising a station, a traveling vehicle that stops at a target position in the vicinity of the station in a target posture, and a transfer means that transfers a load between the station and the traveling vehicle,
Ranging means provided on one of the station and the traveling vehicle, and measuring a distance between the station and the traveling vehicle;
A first distance measuring unit that is provided on the other of the station and the traveling vehicle and is a distance measuring object of the distance measuring means; and a second distance measuring unit;
The first distance to the first distance measuring unit is acquired from the distance measuring means, the traveling vehicle is traveled in a predetermined distance and in a predetermined direction, and the second distance to the second distance measuring section is determined from the distance measuring means. A control unit to obtain;
A calculation unit that calculates an inclination value that is an inclination from the target posture of the traveling vehicle based on the acquired first distance and the second distance;
A transfer system comprising: a transfer condition determining unit that determines a transfer condition of the transfer means based on the calculated inclination value. further,
A third distance measuring unit provided on the other of the station and the traveling vehicle, wherein the distance to the distance measuring means gradually changes when the traveling vehicle is moved in the predetermined direction;
The control unit further acquires a third distance from the third ranging unit from the ranging unit,
The calculation unit further calculates a deviation value that is a deviation from the target position based on the measured first distance or the second distance and the third distance,
The transfer system according to claim 1, wherein the transfer condition determining unit determines a transfer condition of the transfer means based on the calculated deviation value.   The transport system according to claim 1, wherein the control unit acquires the first distance and the second distance while driving the traveling vehicle. The control unit has a parallel line connecting the first distance measuring unit and the second distance measuring unit and a line connecting the traveling vehicle and the target position, and the distance between the traveling vehicle and the target position is When the threshold is reached, the vehicle is decelerated,
The transport system according to claim 3, wherein the first distance measuring unit and the second distance measuring unit are disposed between a position where the traveling vehicle decelerates and a target position. A traveling vehicle that stops in a target position near the station,
Ranging means for measuring the distance to the station;
The first distance from the first distance measuring unit possessed by the station is acquired from the distance measuring means, the traveling vehicle is traveled in a predetermined distance and in a predetermined direction, and the second distance from the second distance measuring unit possessed by the station. A control unit that acquires the distance measuring means;
A calculation unit that calculates an inclination value that is an inclination from the target posture of the traveling vehicle with respect to the station based on the acquired first distance and the second distance;
A traveling vehicle comprising: a transmission unit that transmits the calculated slope value to a transfer means for transferring a load between the station and the traveling vehicle.

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