JP5126298B2 - Transport vehicle and transport vehicle system - Google Patents

Description

  The present invention relates to a transport vehicle and a transport vehicle system, and more particularly, to a transport vehicle and a transport vehicle system in which motors are separately provided on left and right wheels and the wheels can be driven independently.

  2. Description of the Related Art A transport vehicle for transporting a large glass substrate or a cassette in which a plurality of glass substrates are stored is known. The transport vehicle automatically travels in a clean room in the factory and transports articles between processing devices.

  The track on which the transport vehicle travels is, for example, a rail suspended from the ceiling. The space in which the rail and the transport vehicle travel is a clean room that is blocked from the outside.

  The conveyance vehicle has wheels on both the left and right sides. A motor is connected to one wheel to form a driving wheel, and the other wheel serves as a driven wheel. The transport vehicle further includes guide rollers that contact the left and right guide rails (see, for example, Patent Document 1).

JP 2007-4374 A

  When the transport vehicle travels a curve, it is necessary to generate an appropriate speed difference between the left and right wheels. However, when the left and right wheels are independently driven as the drive wheels by providing separate motors for the left and right wheels, it is difficult to appropriately drive the left and right wheels. Therefore, in patent document 1, a drive wheel is arrange | positioned and the conveyance vehicle is made to drive | work.

  An object of the present invention is to stabilize traveling behavior in a transport vehicle in which motors are separately provided on left and right wheels and the wheels can be driven independently.

  Hereinafter, a plurality of modes will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.

A transport vehicle according to an aspect of the present invention is a transport vehicle that travels along a track including a curved portion, and includes a vehicle body, a first travel wheel and a second travel wheel, a first motor and a second motor, And a travel controller. The first traveling wheel and the second traveling wheel are provided on the left and right sides of the vehicle body. The first motor and the second motor are connected to the first traveling wheel and the second traveling wheel, respectively. The travel controller controls the first motor and the second motor. The travel controller controls the first motor and the second motor by converting the speed command pattern into different speed commands using the left and right wheel speed ratio table when the transport vehicle travels the curved portion. The left and right wheel speed ratio table includes a curve travel start table, a curve travel continuation table, and a curve travel end table.
In this transport vehicle, the travel controller controls the first motor and the second motor, whereby the left and right first travel wheels and the second travel wheels are driven independently. More specifically, the travel controller converts the speed command pattern into a different speed command using the left and right wheel speed ratio table when the transport vehicle travels on the curved portion, so that the first motor and the second motor are changed. I have control. Therefore, the transport vehicle travels on the curved portion in a state where the first traveling wheel and the second traveling wheel are given an appropriate speed difference.
Moreover, since the left and right wheel speed conversion table includes a curve travel start table, a curve travel continuation table, and a curve travel end table, these tables can be used properly. That is, it is not necessary to prepare a speed pattern or table that matches the length of the curved portion.

The traveling controller may convert the speed command pattern using the curve travel end table when the end of the curve is grasped while the speed command pattern is converted using the curve travel start table. The curve travel end table is used from a part having the same speed ratio as the speed ratio of the curve travel start table when grasping the curve end.
In this case, the curve travel end table can be used while the curve travel start table is being used. That is, it is possible to cope with curved portions having different lengths.

The travel controller may convert the speed command pattern using the curve travel start table when it recognizes the start of the curve while converting the speed command pattern using the curve travel end table. The curve travel start table is used from a position having the same speed ratio as the speed ratio of the curve travel end table when grasping the curve start.
In this case, the curve travel start table can be used while the curve travel end table is being used. That is, it is possible to cope with curved portions having different lengths.

A transport vehicle system according to another aspect of the present invention includes a track, the transport vehicle described above, a detected member, a detector, and a determination unit. The member to be detected is provided from the curve start position to the curve end position in the curved portion of the track. The detector is provided on the vehicle body and can detect the member to be detected. The determination unit determines the position of the vehicle body based on the detection result from the detector.
In this system, since the determination unit determines the position of the vehicle body based on the detection result from the detector, an accurate position of the transport vehicle can be obtained. Thereby, the traveling controller can convert the speed command pattern into different speed commands with high accuracy using the left and right wheel speed ratio table.

The start part of the member to be detected may be provided before the curve start position of the curved part in the traveling direction.
In this case, since the start portion of the detected member is provided before the curve start position of the curved portion, the speed command pattern can be converted into a different speed command using the left and right wheel speed ratio table. It starts before the transport vehicle reaches the curved section. Therefore, the traveling on the curved portion of the transport vehicle is stabilized, and as a result, the problem that the guide roller comes into strong contact with the guide is less likely to occur.

  In the transport vehicle or the transport vehicle system according to the present invention, the left and right wheel speed conversion table includes a curve travel start table, a curve travel continuation table, and a curve travel end table, so that it matches the length of the curved portion. There is no need to prepare a speed pattern or table.

The schematic diagram of the conveyance vehicle system by which one Embodiment of this invention was employ | adopted. The partial top view of a conveyance vehicle system. The block block diagram which shows the control structure of a conveyance vehicle system. The block block diagram which shows the traveling control part of a conveyance vehicle. Speed ratio table when driving on a curve. Speed ratio table at the time of curve driving, graph of speed command when driving wheel is assumed to be centered at the time of curve driving, and speed of left and right wheels when speed command is converted to left and right wheel speed using speed ratio table Chart. The flowchart which shows operation | movement of the traveling control part at the time of curve part traveling. A speed ratio table that is actually used when a curve ends during conversion using the curve travel start table. A speed ratio table that is actually used when a curve starts during conversion using the curve travel end table.

(1) Transportation vehicle system The conveyance vehicle system 1 by which one Embodiment of this invention was employ | adopted is demonstrated using FIG. FIG. 1 is a schematic diagram of a transport vehicle system in which an embodiment of the present invention is adopted.

  The transport vehicle system 1 includes a track 2 and a transport vehicle 3 that travels on the track 2. In this embodiment, the track 2 is suspended from the ceiling, and the periphery of the track 2 is a clean room.

  The track 2 has a traveling rail 4 and a guide rail 6. The traveling rail 4 is composed of left and right first traveling rails 4a and second traveling rails 4b. The first traveling rail 4a and the second traveling rail 4b have flat traveling surfaces.

  The guide rail 6 has a first guide rail 6a and a second guide rail 6b. The first guide rail 6a and the second guide rail 6b are provided at the outer ends of the first travel rail 4a and the second travel rail 4b, respectively. The first guide rail 6a and the second guide rail 6b extend upward.

  A power supply line (not shown) is provided along the first traveling rail 4a and the second traveling rail 4b.

  As shown in FIG. 2, the track 2 includes a first straight part 201, a branch part 206 at the tip of the first straight part 201, a curved part 203 that turns to the right from the branch part 206, and a straight line from the branch part 206. And a second linear portion 202 extending in a shape.

  The first traveling rail 4 a and the second traveling rail 4 b extend from the first straight portion 201 through the branching portion 206 into both the second straight portion 202 and the curved portion 203.

  The first guide rail 6 a is not provided at the branching portion 206 in the portion of the first traveling rail 4 a from the first straight portion 201 toward the second straight portion 202. Furthermore, the second guide rail 6 b is not provided at the branching portion 206 in the portion of the second traveling rail 4 b from the first straight portion 201 toward the curved portion 203.

(2) Transport Vehicle The transport vehicle 3 includes a transport vehicle main body 15, a drive travel unit 18, and a driven travel unit 19. Since the structure of the transport vehicle body 15 is the same as the conventional one, the description thereof is omitted. The drive travel unit 18 and the driven travel unit 19 are bogies that are rotatably attached to the transport vehicle body 15.

  The drive travel unit 18 will be described with reference to FIG. The drive travel unit 18 mainly includes a main body frame 20, a first drive wheel unit 21, a second drive wheel unit 22, a fixed guide roller mechanism (31, 32), and a branch guide roller mechanism (33, 34, 35).

  The first drive wheel unit 21 is attached to the right end portion of the main body frame 20 and has a first traveling wheel 25, a first motor 26, and a first encoder 27. The first traveling wheel 25 is placed on the traveling surface of the first traveling rail 4a. The first motor 26 is connected to the first traveling wheel 25. The first encoder 27 measures the rotation of the first motor 26 and transmits a pulse signal. Thereby, the rotation speed and the number of rotations of the first motor 26 can be obtained.

  The second drive wheel unit 22 is attached to the left end portion of the main body frame 20, and includes a second traveling wheel 28, a second motor 29, and a second encoder 30. The second traveling wheel 28 is placed on the traveling surface of the second traveling rail 4b. The second motor 29 is connected to the second traveling wheel 28. The second encoder 30 measures the rotation of the second motor 29 and transmits a pulse signal. Thereby, the rotation speed and the number of rotations of the second motor 29 can be obtained.

  The fixed guide roller mechanism (31, 32) has a pair of first fixed guide rollers 31 and a pair of second fixed guide rollers 32. The pair of first fixed guide rollers 31 are disposed at the right end portion of the main body frame 20 so as to be separated from each other in the traveling direction. More specifically, the first fixed guide roller 31 is disposed away from both the front and rear sides of the first traveling wheel 25 in the traveling direction, and is always in contact with or close to the inner side of the first guide rail 6a. The pair of second fixed guide rollers 32 are disposed at the left end portion of the main body frame 20 so as to be separated from each other in the traveling direction. More specifically, the second fixed guide roller 32 is disposed away from both the front and rear sides of the second traveling wheel 28 in the traveling direction, and is always in contact with or close to the inner side of the second guide rail 6b.

  The branch guide roller mechanism (33, 34, 35) is a mechanism for performing a branch operation in the branch portion 206, and includes a pair of first branch guide rollers 33, a second branch guide roller 34, and a first branch guide roller. And a drive unit 35 (FIG. 3).

  The first branch guide roller 33 is disposed corresponding to the first fixed guide roller 31. The second branch guide roller 34 is disposed corresponding to the second fixed guide roller 32. The first branch guide roller driving unit 35 (FIG. 3) is a mechanism for changing the positions of the first branch guide roller 33 and the second branch guide roller 34.

  With the above structure, the first branch guide roller 33 and the second branch guide roller 34 are in contact with or close to the outside of the first guide rail 6a by the first branch guide roller driving unit 35 (FIG. 3), It moves between a non-guide position away from the first guide rail 6a.

The driven traveling unit 19 mainly includes a main body frame 23, a first driven wheel 36, a second driven wheel 37, a second fixed guide roller mechanism (40, 41), and a second branch guide roller mechanism (42, 43, 44).
The first driven wheel 36 is placed on the first traveling rail 4 a of the traveling rail 4. The second driven wheel 37 is placed on the second traveling rail 4 b of the traveling rail 4.

  The second fixed guide roller mechanism (40, 41) has a pair of third fixed guide rollers 40 and a pair of fourth fixed guide rollers 41. The third fixed guide roller 40 is disposed at the right end of the main body frame 23 so as to be separated in the traveling direction. More specifically, the third fixed guide roller 40 is disposed away from both the front and rear sides in the traveling direction of the first driven wheel 36, and is always in contact with or close to the inner side of the first guide rail 6a. The fourth fixed guide roller 41 is arranged at the left end of the main body frame 23 so as to be separated in the traveling direction. More specifically, the fourth fixed guide roller 41 is disposed away from both the front and rear sides of the second driven wheel 37 in the traveling direction, and is always in contact with or close to the inner side of the second guide rail 6b.

  The second branch guide roller mechanism (42, 43, 44) is a mechanism for performing a branch operation in the branch portion 206, and includes a pair of third branch guide rollers 42, a fourth branch guide roller 43, and a second branch. And a guide roller driving unit 44 (FIG. 3).

  The first branch guide roller 33 is disposed corresponding to the first fixed guide roller 31. The second branch guide roller 34 is disposed corresponding to the second fixed guide roller 32. The second branch guide roller drive unit 44 (FIG. 3) is a mechanism for changing the positions of the first branch guide roller 33 and the second branch guide roller 34.

  With the above structure, the second branch guide roller driving unit 44 (FIG. 3) causes the third branch guide roller 42 and the fourth branch guide roller 43 to abut or approach the outside of the first guide rail 6a; It moves between a non-guide position away from the first guide rail 6a.

(3) Detected part and sensor A plurality of types of detected parts provided along the traveling rail 4 will be described with reference to FIG. The detected part includes a reflective tape 11, a barcode 13, and a magnetic mark 14. In FIG. 2, the reflective tape 11, the barcode 13, and the magnetic mark 14 are illustrated inside the traveling rail 4, but actually are provided on the traveling rail 4 or the upper surface of the guide rail.
The reflective tape 11 is a member for detecting the position of the transport vehicle 3 in the curved portion 203 and is disposed in the curved portion 203. The start end 11a of the reflective tape 11 is disposed in front of the running direction from the actual start position 203a of the curved portion 203. Further, the end (not shown) of the reflective tape 11 is arranged in front of the actual end of the curved portion (not shown).
The bar code 13 functions as an origin mark and a plurality of reference marks of the traveling rail 4.
The magnetic mark 14 is a member that indicates the stop position of the transport vehicle 3. The magnetic mark 14 is made of a magnetic material such as steel or a non-magnetic material such as copper or aluminum. In this embodiment, the magnetic mark 14 is disposed on the first straight portion 201, and the stop position 80 is in the middle of the magnetic mark 14.

  As shown in FIG. 3, the driving traveling unit 18 and the driven traveling unit 19 are further provided with a photoelectric sensor 47, a linear scale 49, and a barcode reader 50. The photoelectric sensor 47 is for detecting the reflective tape 11. Note that the photoelectric sensor 47 in the figure is a sensor for detecting a position during traveling on a curved portion that is bent to the right, and a sensor (not shown) for the curved portion that is bent to the left is provided separately. The linear scale 49 is for detecting the magnetic mark 14. The linear scale 49 obtains the absolute position of the transport vehicle 3 with respect to the magnetic mark 14, in other words, the position based on the magnetic mark 14. The barcode reader 50 is for detecting the barcode 13.

(4) Control Configuration The control configuration of the transport vehicle system 1 will be described with reference to FIG. FIG. 3 is a block diagram showing a control configuration of the transport vehicle system.

  The transport vehicle system 1 includes a transport vehicle controller 52. The transport vehicle controller 52 is a controller for managing the traveling of the plurality of transport vehicles 3. The transport vehicle controller 52 and the transport vehicle 3 can communicate with each other. The transport vehicle controller 52 includes a controller main body 54 and a memory 55. The controller body 54 is a computer that includes a CPU, a RAM, a ROM, and the like and executes a program. A route map is stored in the memory 55.

  The route map is a map that describes the arrangement of the travel route, the position of the origin, the reference position based on the origin, and the coordinates of the transfer position. The coordinates are obtained by converting the travel distance from the origin into the number of output pulses of the encoder of the transport vehicle.

  The transport vehicle 3 has a travel control unit 59. The travel control unit 59 can transmit a drive signal to the first motor 26 and the second motor 29 based on a command from the transport vehicle controller 52. The travel control unit 59 is further connected to the branch control unit 60. The branch control unit 60 can transmit a drive signal to the first branch guide roller driving unit 35 and the second branch guide roller driving unit 44 (FIG. 3) based on a command from the transport vehicle controller 52.

(5) Travel control system of conveyance vehicle The travel control unit 59 will be described with reference to FIG. FIG. 4 is a block diagram illustrating a travel control unit of the transport vehicle.
The travel control unit 59 is a computer that includes a CPU, a RAM, a ROM, and the like, and executes a program. The route map 61, a speed pattern generation unit 62, a first motor control unit 63, a second motor control unit 64, a speed And a ratio table 300.

Furthermore, the first encoder 27, the second encoder 30, the photoelectric sensor 47, the linear scale 49, and the barcode reader 50 are connected to the travel control unit 59.
The route map 61 is stored in a memory in the travel control unit 59. The speed pattern generation unit 62 can communicate with the transport vehicle controller 52.

  When the travel control unit 59 receives a transport command from the transport vehicle controller 52, the travel control unit 59 obtains a distance from the current position to the stop position based on the route map 61 and inputs the distance to the speed pattern generation unit 62. The speed pattern generation unit 62 calculates a travel distance from the difference between the coordinates of the current position on the route map 61 and the coordinates of the target position, thereby generating a pattern of travel speed to the stop position.

  The first motor control unit 63 mainly includes a first error amplification unit 65A, a first PID control unit 66A, and a first amplifier 67A. The first error amplifier 65A amplifies the error. The first PID control unit 66A performs PID control based on the error obtained by the first error amplification unit 65A. The first amplifier 67A performs current amplification for the first motor 26 and the like. The first encoder 27 detects the rotational speed of the rotating shaft of the first motor 26, and the current position and speed of the first traveling wheel 25 obtained thereby are input to the speed pattern generator 62 and the first error amplifier 65A. . In addition, the structure of the 1st motor control part 63 is one Example, Comprising: This invention is not limited to this.

The second motor control unit 64 mainly includes a second error amplification unit 65B, a second PID control unit 66B, a second amplifier 67B, and a PI control unit 68. The second error amplifying unit 65B amplifies the error. The second PID control unit 66B performs PID control based on the error obtained by the second error amplification unit 65B. The PI control unit 68 is arranged in parallel with the second PID control unit 66B, and performs PI control based on the error obtained by the second error amplification unit 65B. The second amplifier 67B performs current amplification for the second motor 29 and the like. The second encoder 30 detects the rotational speed of the rotation shaft of the second motor 29, and the current position and speed of the second traveling wheel 28 obtained thereby are input to the speed pattern generator 62 and the second error amplifier 65B. . In addition, the structure of the 2nd motor control part 64 is one Example, Comprising: This invention is not limited to this.
With the configuration described above, the transport vehicle 3 continues traveling while comparing the coordinates described in the route map 61 with the internal coordinates of the own machine (coordinates obtained by the encoder).

(6) General Description of Travel Control Operation Generally, the transport vehicle 3 has a required travel distance obtained from the route map 61 along the track 2, a current position obtained from the first encoder 27 and the second encoder 30, and Travel control is performed according to the current speed.

  A control operation when the transport vehicle 3 travels along the curved portion 203 will be described. When traveling on the curved section 203, generally, the left and right motors cannot be perfectly synchronized, so that the travel locus does not match the actual curve rail and the traveling wheel collides with the guide rail. There is a problem that the behavior becomes unstable. The present invention uses the following means for solving the problem.

  The speed pattern generator 62 confirms the current position of the transport vehicle 3 by collating the detection results from the photoelectric sensor 47 and the detection results from the first encoder 27 and the second encoder 30. The speed pattern generation unit 62 uses the current position information and the speed ratio table 300 (described later) to generate a target speed signal from the first error amplification unit 65A and the second error amplification unit 65B so that an appropriate left-right speed difference is generated. Send to.

  When entering the curved portion 203, the speed pattern generator 62 decelerates the inner wheel and accelerates the outer wheel, thereby causing the center speed of the transport vehicle 3 to run in accordance with a specified speed (for example, 60 m / min). The speed pattern generation unit 62 uses the speed ratio table 300 calculated in advance to improve calculation efficiency and reduce processing load.

(7) Speed Ratio Table A speed ratio table (wheel speed conversion table) 300 at the time of curve traveling used by the speed pattern generation unit 62 will be described with reference to FIG. The speed ratio table 300 is a table that defines the speed ratio of the left and right drive wheels with respect to the curve travel time, and includes an outer wheel speed ratio 301 and an inner wheel speed ratio 302.

As is clear from the figure, when the speed ratio between the inner ring and the outer ring is 100% when entering the curve, the inner ring speed ratio 302 decreases as the outer ring speed ratio 301 increases. When the outer wheel speed ratio 301 becomes 100 + α% (for example, a total of 115%) and the inner wheel speed ratio 302 becomes 100−α% (for example, a total of 85%), this state continues in a predetermined travel section. Finally, the outer ring speed ratio 301 becomes smaller, and the inner ring speed ratio 302 becomes larger along with it, and finally both become 100%.
The value of α is set to be different according to the distance between the left and right drive wheels and the curve curvature.

  In summary, in the speed ratio table 300, the curve travel start table 304 in which the speed ratio is separated, the curve travel continuation table 305 in which the speed ratio is constant, and the curve travel end table 306 in which the speed ratio approaches. Is set. More specifically, in the curve travel start table 304, the outer ring speed ratio 301 increases in proportion to time, and the inner ring speed ratio 302 decreases in proportion to time. In the curve travel end table 306, the outer wheel speed ratio 301 decreases in proportion to time, and the inner wheel speed ratio 302 increases in proportion to time.

(8) Detailed Description of Curved Section Travel Control Speed control when the transport vehicle 3 travels the curved section 203 will be described with reference to FIGS. 6 and 7. FIG. 6 shows a speed ratio table at the time of curve traveling, a graph of speed commands when it is assumed that there is a drive wheel at the center of the aircraft during curve traveling, and a graph of speeds of left and right wheels converted from the speed commands using the speed ratio table. It is. FIG. 7 is a flowchart showing the operation of the traveling control unit during traveling on the curved portion.

  The upper part of FIG. 6 is the speed ratio table 300 described above. The middle part of FIG. 6 is a turning center speed 307 assuming that the driving wheel is at the center of the body during curve traveling. The turning center speed 307 is divided into an acceleration period 308, a constant speed period 309, and a deceleration period 310. The lower part of FIG. 6 is an inner / outer wheel speed diagram when the transport vehicle 3 accelerates at a predetermined acceleration from before the curve and stops after the curve.

Hereinafter, the control operation of the speed pattern generator 62 will be described with reference to FIG. The speed pattern generation unit 62 generates a speed command before entering the curve unit 203 and gives the speed command to the first motor 26 and the second motor 29.
In step S <b> 1, the speed pattern generation unit 62 waits to reach the curve unit 203. The fact that the curve portion 203 has been reached is grasped by the photoelectric sensor 47 detecting the start end 11 a of the reflective tape 11.

  In step S <b> 2, the speed pattern generation unit 62 determines whether or not the position of the transport vehicle 3 obtained from the detection results from the first encoder 27 and the second encoder 30 in the curved portion 203 is accurate. Judgment based on. If so, the process skips step S3 and moves to step S4. If not, the process moves to step S3.

  In step S3, the speed pattern generator 62 updates the output values from the first encoder 27 and the second encoder 30 to correct values.

  In step S <b> 4, the speed pattern generation unit 62 generates a speed command based on the turning center speed 307.

  In step S <b> 5, the speed pattern generation unit 62 converts the speed command into a left / right speed difference command 311 using the speed ratio table 300. Specifically, the multiplication factor of the corresponding position is obtained from the position of the conveyance vehicle 3 in the curved portion 203 and the speed ratio table 300, and the inner ring speed and the outer ring speed at the corresponding position are obtained by multiplying the current speed by the multiplication factor. calculate. That is, the outer ring speed command 312 is accumulated by adding the value of the outer ring speed ratio 301 to the turning center speed 307, and the inner ring speed command 302 is added by adding the value of the inner ring speed ratio 302 to the turning center speed 307. 313 is created.

  In step S <b> 6, the speed pattern generation unit 62 outputs the left / right speed difference command 311 to the first motor control unit 63 and the second motor control unit 64, respectively.

  In step S <b> 7, the speed pattern generation unit 62 determines whether the transport vehicle 3 has left the curved portion 203. If not, the process returns to step S2. If it leaves, the process ends. Whether or not the curved portion 203 has been removed is determined based on the detection result from the photoelectric sensor 47, for example.

  The above steps S1 to S7 are executed continuously, and as a result, the speeds of the left and right drive wheels shown in the lower part of FIG. 6 are realized. For example, in FIG. 6, it is as follows.

Time t0 to t1: Conversion by the speed ratio table 300 is not performed. Therefore, the speed command value in the acceleration period 308 of the turning center speed 307 is directly given to the left and right drive wheels.
Time t1 to t2: The speed command value in the acceleration period 308 of the turning center speed 307 is converted into a left / right speed difference command using the curve travel start table 304 of the speed ratio table 300.
Time t2 to t3: The speed command value in the acceleration period 308 of the turning center speed 307 is converted into a left / right speed difference command using the curve travel continuation table 305 of the speed ratio table 300.
Time t3 to t4: The speed command value in the constant speed period 309 of the turning center speed 307 is converted into a left / right speed difference command using the curve travel continuation table 305 of the speed ratio table 300.
Time t4 to t5: The speed command value in the constant speed period 309 of the turning center speed 307 is converted into a left / right speed difference command using the curve travel end table 306 of the speed ratio table 300.
Time t5 to t6: Conversion by the speed ratio table 300 is not performed. Therefore, the left and right drive wheels are given the speed command value for the constant speed period 309 of the turning center speed 307 as it is.
Time t6 to t7: Conversion by the speed ratio table 300 is not performed. Therefore, the speed command value of the deceleration period 310 of the turning center speed 307 is directly given to the left and right drive wheels.

As described above, by appropriately changing the rotational speeds of the first motor 26 and the second motor 29 when traveling along the curved portion 203, the transport vehicle 3 can travel along the curve appropriately. Therefore, a large load does not act on the guide rail.
(9) Speed ratio table shift operation

The speed pattern generation unit 62 can appropriately shift the conversion part of the speed ratio table 300 according to the change in the state of the trajectory 2 during the left-right speed conversion using the speed ratio table 300. Thereby, it can respond also to the some curve part from which distance differs. For example, all curves including a 180 degree curve, a 90 degree curve, and a 45 degree curve can be handled with one speed ratio table.
1) When the curve detection suddenly turns off while the curve continues For example, when the curve detection suddenly turns off while the curve continues, the speed pattern generation unit 62 switches from the curve travel continuation table 305 to the curve travel end table 306, The speed command pattern is converted into left and right wheel speeds.

2) When the curve detection is suddenly turned off during the start of the curve The speed pattern generator 62 grasps the end of the curve during the conversion of the speed command pattern using the curve travel start table 304 as shown in FIG. In the case (time t9), the speed command pattern is converted using the curve travel end table 306. The curve travel end table 306 is used from a portion (speed ratio at time t12) having the same speed ratio as the speed ratio of the curve travel start table 304 when grasping the curve end. Therefore, the outer ring speed ratio 301 ′ and the inner ring speed ratio 302 ′ that are actually used have a diamond shape as shown in FIG.
In this case, the curve travel end table 306 can be used even while the curve travel start table 304 is being used. That is, it is possible to cope with curved portions having different lengths.

3) When the curve detection is suddenly turned on during the end of the curve As shown in FIG. 9, the speed pattern generation unit 62 grasps the start of the curve while converting the speed command pattern using the curve travel end table 306. In the case (time t18), the speed command pattern is converted using the curve travel start table 304. The curve travel start table 304 is used from a portion (speed ratio at time t15) having the same speed ratio as the speed ratio of the curve travel end table when the curve start is grasped. Accordingly, use of the next outer ring speed ratio 301 ′ ″ and inner ring speed ratio 302 ′ ″ is started in the middle of the outer ring speed ratio 301 ″ and the inner ring speed ratio 302 ″.
In this case, the curve travel start table 304 can be used even while the curve travel end table 306 is being used. That is, it is possible to cope with curved portions having different lengths.

4) When curve detection is already turned on at the start of travel (when the speed is 0) The speed pattern generator 62 starts the speed conversion control using the curve travel continuation table 305.

  As described above, since the running control of the curved portion depends on the detection result by the photoelectric sensor 47, the failure check of the photoelectric sensor 47 is highly important. Therefore, the sensor operation is also registered in the route map 61, and the input of the route map 61 and the photoelectric sensor 47 is always checked. As a result, for example, when both the right curve detection and the left curve detection are turned on, it is determined to be abnormal, and it is further determined to be abnormal when curve detection is turned on at the straight line portion.

(10) Features The above embodiment can be expressed as follows. The transport vehicle 3 is a transport vehicle that travels along the track 2 including the curved portion 203, and includes the transport vehicle body 15 and the first travel wheel. 25, the second traveling wheel 28, the first motor 26 and the second motor 29, and a speed pattern generator 62. The first traveling wheel 25 and the second traveling wheel 28 are provided on the left and right of the transport vehicle body 15. The first motor 26 and the second motor 29 are connected to the first traveling wheel 25 and the second traveling wheel 28, respectively. The speed pattern generator 62 controls the first motor 26 and the second motor 29. The speed pattern generation unit 62 converts the speed command pattern into different speed commands using the speed ratio table 300 when the transport vehicle 3 travels the curved portion 203, thereby causing the first motor 26 and the second motor 29 to move. I have control. The speed ratio table 300 includes a curve travel start table 304, a curve travel continuation table 305, and a curve travel end table 306.
In this transport vehicle 3, the speed pattern generator 62 controls the first motor 26 and the second motor 29, whereby the left and right first traveling wheels 25 and the second traveling wheels 28 are driven independently. More specifically, the speed pattern generation unit 62 converts the speed command pattern into a different speed command using the speed ratio table 300 when the transport vehicle 3 travels the curved portion 203, thereby the first motor 26. The second motor 29 is controlled. Therefore, the transport vehicle 3 travels on the curved portion 203 in a state where the first traveling wheel 25 and the second traveling wheel 28 are given an appropriate speed difference.
Further, since the speed ratio table 300 includes a curve travel start table 304, a curve travel continuation table 305, and a curve travel end table 306, each of these tables can be used properly. There is no need to prepare a speed pattern or a table that matches the speed.

The transport vehicle system 1 includes a track 2, a transport vehicle 3, a reflective tape 11, a photoelectric sensor 47, and a speed pattern generation unit 62. The reflective tape 11 is provided from the curve start position to the curve end position in the curved portion 203 of the track 2. The photoelectric sensor 47 is provided in the carrier body 15 and can detect the reflective tape 11. The speed pattern generation unit 62 determines the position of the transport vehicle body 15 based on the detection result from the photoelectric sensor 47.
In this system, since the speed pattern generation unit 62 determines the position of the transport vehicle body 15 based on the detection result from the photoelectric sensor 47, the accurate position of the transport vehicle 3 can be obtained. Thereby, the speed pattern generation unit 62 can convert the speed command pattern into different speed commands with high accuracy using the speed ratio table 300.

The start end 11 a of the reflective tape 11 is provided in front of the running direction with respect to the curve start position 203 a of the curved portion 203.
In this case, since the start end 11a of the reflective tape 11 is provided before the curve start position 203a of the curved portion 203, the speed command pattern is converted into a different speed command using the speed ratio table 300. Is started before the transport vehicle 3 actually reaches the curved portion 203. Therefore, the traveling in the curved portion 203 of the transport vehicle 3 is stabilized, and as a result, the problem that the guide roller strongly contacts the guide is less likely to occur.

(11) Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.

  In the said embodiment, although the conveyance vehicle detected the start and the end of the curved part with the sensor, this invention is not limited to this. For example, the conveyance vehicle may make a software determination using an encoder.

In the said embodiment, although the reflective tape was provided continuously along the curve part, this invention is not limited to this. The reflective tape may be provided intermittently.
In the embodiment described above, the transport vehicle travels on a track suspended from the ceiling, but the present invention is not limited to this. The track may be provided on the ground, or the transport vehicle may be suspended from the track.

  In the embodiment, the encoder measures the rotation of the motor, but the present invention is not limited to this. The encoder may measure the rotation of the driving wheel or the driven wheel.

The combination type and detection purpose of the detected portion and the sensor are not limited to the above embodiment.
The installation position and number of the detection target parts are not limited to the above embodiment.

  The present invention can be widely applied to a transport vehicle in which motors are separately provided on the left and right wheels and the wheels can be driven independently.

DESCRIPTION OF SYMBOLS 1 Transportation vehicle system 2 Track 3 Transportation vehicle 4 Traveling rail 4a 1st traveling rail 4b 2nd traveling rail 6 Guide rail 6a 1st guide rail 6b 2nd guide rail 11 Reflective tape (detected member)
11a Start end 13 Bar code 14 Magnetic mark 15 Carrier body (vehicle body)
18 Drive Traveling Section 19 Followed Traveling Section 20 Main Body Frame 21 First Drive Wheel Unit 22 Second Drive Wheel Unit 23 Main Body Frame 25 First Travel Wheel 26 First Motor 27 First Encoder 28 Second Travel Wheel 29 Second Motor 30 First 2 Encoder 31 1st fixed guide roller 32 2nd fixed guide roller 33 1st branch guide roller 34 2nd branch guide roller 35 1st branch guide roller drive part 36 1st driven wheel 37 2nd driven wheel 40 3rd fixed guide roller 41 4th fixed guide roller 42 3rd branch guide roller 43 4th branch guide roller 44 2nd branch guide roller drive part 47 Photoelectric sensor (detector)
49 Linear scale 50 Bar code reader 52 Car carrier controller 54 Controller main body 55 Memory 59 Travel control unit 60 Branch control unit 61 Route map 62 Speed pattern generation unit (travel controller, determination unit)
63 1st motor control part 64 2nd motor control part 80 Stop position 201 1st straight line part 202 2nd straight line part 203 Curved part 203a Start position 206 Branching part 300 Speed ratio table (left and right wheel speed conversion table)
301 Outer wheel speed ratio 302 Inner ring speed ratio 304 Curve travel start table 305 Curve travel continuation table 306 Curve travel end table 307 Turning center speed 308 Acceleration period 309 Constant speed period 310 Deceleration period 311 Left and right speed difference command 312 Outer ring speed command 313 Inner ring speed command 313

Claims (5)

A transport vehicle that travels along a track including a curved portion,
The car body,
A first traveling wheel and a second traveling wheel provided on the left and right of the vehicle body;
A first motor and a second motor respectively connected to the first traveling wheel and the second traveling wheel;
A travel controller for controlling the first motor and the second motor;
The travel controller controls the first motor and the second motor by converting a speed command pattern into different speed commands using a left and right wheel speed conversion table when the transport vehicle travels the curved portion. And
The left and right wheel speed conversion table has a curve travel start table, a curve travel continuation table, and a curve travel end table.
Transport vehicle. When the travel controller grasps the end of the curve while converting the speed command pattern using the curve travel start table, the travel controller converts the speed command pattern using the curve travel end table,
2. The transport vehicle according to claim 1, wherein the curve travel end table is used from a location having the same speed ratio as the speed ratio of the curve travel start table when the curve end is grasped. When the travel controller grasps the start of the curve while converting the speed command pattern using the curve travel end table, the travel controller converts the speed command pattern using the curve travel start table,
The conveyance vehicle according to claim 1 or 2, wherein the curve travel start table is used from a position having the same speed ratio as the speed ratio of the curve travel end table when the curve start is grasped. A trajectory including a curved portion,
The transport vehicle according to any one of claims 1 to 3,
A detected member provided from a curve start position to a curve end position in the curved portion of the trajectory;
A detector provided on the vehicle body and capable of detecting the detected member;
A determination unit for determining a position of the vehicle body based on a detection result from the detector;
Transportation vehicle system equipped with.   The transport vehicle system according to claim 4, wherein a start portion of the detected member is provided in a traveling direction before a curve start position of the curved portion.

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