JP2019091148A - Unmanned carrier and control method thereof - Google Patents

Abstract

To provide an unmanned carrier capable of traveling to get over a step and its control method.SOLUTION: An unmanned carrier 100 includes four or more drive wheels 31. The unmanned carrier acquires an angle θ which should be formed between a longitudinal side of a step region 210 and a route of the unmanned carrier 100, travels along the route which forms the angle θ, and releases, about each drive wheel 31, a lock of a suspension of the drive wheel 31 or raises the position of the wheel 31 when the drive wheel 31 exists within a predetermined range with respect to the step region 210.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an automatic guided vehicle and a control method thereof.

  There is known an unmanned transfer vehicle that travels based on a transfer instruction from the outside. An example of the configuration of an automatic guided vehicle is described in Patent Document 1. In the example of Patent Document 1, the unmanned transfer vehicle includes a vehicle body having a bed, four wheels supported by the vehicle body, a plurality of traveling motors and a plurality of steering motors for driving the respective wheels, and each traveling motor and And a control unit that controls each steering motor. Such an automated guided vehicle transports containers by, for example, loading and traveling the containers in a harbor.

  In addition, although it is not a technique regarding an unmanned transfer vehicle, Patent Document 2 describes an attempt to reduce the amount of pitch by connecting driving wheels with a link in a multi-axial type vehicle.

Unexamined-Japanese-Patent No. 2010-020514 JP, 2004-161120, A

  In the conventional unmanned transfer vehicle, there is a problem that it is difficult to travel over the steps existing in the traveling route.

  FIG. 9 shows an example of such a step. A stepped region 210 is formed along the rails 200 of the gantry crane 202. The conventional unmanned conveyance vehicle 300 can not move from the land side over the step area 210 to the sea side and can not move to the sea side from the rail 200 (strictly speaking, it is more than the rail 200 closest to the land side). Work on the land side).

  Since an unmanned carrier is for carrying heavy objects, a conventional unmanned carrier has been designed on the assumption that it travels only on a flat road. Therefore, although it is possible to cope with the vibration due to the unevenness of the normal traveling road surface, the design is not made on the assumption of a short-time impact such as overcoming the step along the rail of the gantry crane.

  For example, as a method of suppressing an impact due to a step, it is conceivable to infiltrate at the slowest speed, but this may not be adopted from the aspect of operation efficiency. In addition, in the case of an unmanned transport vehicle, there may be a case where an independent drive / independent steering method in units of axles is adopted.

  The present invention has been made to solve such problems, and it is an object of the present invention to provide an unmanned transfer vehicle capable of traveling over a level difference and a control method thereof.

  A control method of an unmanned transfer vehicle according to the present invention is a control method of an unmanned transfer vehicle including four or more drive wheels, and acquires an angle between the longitudinal direction of the step area and the route of the unmanned transfer vehicle. Locking the suspension of the drive wheel when the drive wheel is within a predetermined range with respect to the step area for each drive wheel. And raising the position of the drive wheel.

  According to this configuration, for example, control of suppressing an impact when the drive wheel approaches the step area can be performed for each drive wheel.

  According to a particular aspect, the method further comprises: detecting a step feature point; and determining or updating the step region based on the step feature point.

According to a particular aspect, the angle
_{{W tc · cos (θ)} -d m} / {V · sin (θ)}> 0 and _{{L hb · sin (θ)} -W tc · cos (θ) -d m} / {V · sin ( θ)}> 0
Further, the step of determining as θ satisfying the following, where V represents the vehicle speed of the _AGV , L _hb represents the wheel base of the _AGV , W _tc represents the tread of the _AG , and d _m is a step Represents the dimension in the width direction of the area.

  The unmanned transfer vehicle according to the present invention is an unmanned transfer vehicle having four or more drive wheels, and has a function of acquiring an angle to be made between the length direction of the step area and the route of the unmanned transfer vehicle; Function of traveling along the path of the driving wheel, and for each driving wheel, when the driving wheel is within a predetermined range with respect to the step area, the suspension of the driving wheel is unlocked or the driving wheel is And a function of raising the position.

  According to the present invention, since the control for suppressing the impact is performed based on the relative position to the step area for each drive wheel, it is possible to more easily get over the step.

It is a figure which shows the example of a structure of the automatic guided vehicle which concerns on Embodiment 1 of this invention. It is a figure which shows typically the structure of the traveling unit of FIG. It is the schematic seen from the direction orthogonal to the longitudinal direction of the rail which shows the example of a peripheral structure of the automatic guided vehicle of FIG. It is an upper surface schematic diagram which shows the example of a peripheral structure of the unmanned transfer vehicle of FIG. It is a figure which shows typically the example of a structure of the level | step-difference area | region containing the rail of FIG. It is a figure which shows an example of the path | route at the time of the unmanned transfer vehicle of FIG. 1 passing a level | step difference area | region. It is a flowchart which shows the flow of a process when the unmanned transfer vehicle of FIG. 1 passes a level | step difference area | region along a path | route as shown in FIG. It is a figure which shows the specific example of the lock control in the unmanned transfer vehicle of FIG. It is a figure which shows the example of the level | step difference in which it is difficult for the conventional unmanned carrier to get over and to travel.

Hereinafter, an embodiment of the present invention will be described based on the attached drawings.
Embodiment 1
FIG. 1 shows an example of the configuration of the automatic guided vehicle 100. The unmanned carrier 100 shows an unmanned carrier for a port as an example. The unmanned carrier 100 comprises a frame 10 and at least four traveling units 30. The frame 10 is supported by the traveling unit 30 at at least four places, and the unmanned transfer vehicle 100 is moved by the operation of the traveling unit 30.

  The unmanned transfer vehicle 100 further includes a control device 20, a self position / direction recognition unit 21, and a traveling speed calculation sensor 22. The control device 20, the self position / direction recognition means 21 and the traveling speed calculation sensor 22 are mounted on the frame 10.

  The control device 20 is a calculation / command device, and includes calculation means and storage means. The controller 20 may be operable as a computer. The self position / direction recognition means 21 is a component for acquiring information representing the position and direction of the automated guided vehicle 100, and is, for example, a steering angle sensor, a gyro or the like. The traveling speed calculation sensor 22 is a component for acquiring information representing the traveling speed of the automatic guided vehicle 100, and is, for example, a servomotor rotation speed sensor or the like.

  The structure of the traveling unit 30 is schematically shown in FIG. The traveling unit 30 includes a driving wheel 31, an axle 32, a traveling motor 33, a suspension cylinder 34, and a cylinder driving device (not shown).

  The drive wheel 31 is fixed to the axle 32 and moves integrally with the axle 32. Further, a traveling motor 33 is connected to the axle 32, and when the traveling motor 33 drives and rotates the axle 32, the driving wheel 31 is rotated accordingly. Further, the axle 32 is rotatably connected to the frame 10, and is configured such that the unmanned transfer vehicle 100 moves according to the rotation of the drive wheel 31. In the present embodiment, as shown in FIG. 1, eight drive wheels 31 are provided, and each pair is attached to the axle 32 in pairs.

  A suspension cylinder 34 couples the frame 10 and the axle 32 to provide a suspension therebetween. The suspension cylinder 34 locks or unlocks the suspension in accordance with the operation of a cylinder drive (not shown). The lock of the suspension is operable, for example, by operating a valve that opens and closes a path to an accumulator containing hydraulic oil.

  When the suspension is locked, the traveling unit 30 can support the load more stably on a flat road surface. However, passing through the step while the locking is performed may cause a relatively large impact transmitted from the drive wheel 31 to the load via the frame 10.

  On the other hand, when the suspension is unlocked, the impact of the drive wheel 31 is more easily absorbed even if the vehicle passes through the step, which may reduce the impact transmitted to the load. However, if the road surface continues to travel with the lock released, the stability to the load may be reduced.

  In this way, if the control of the suspension can be switched appropriately between traveling on a flat road surface and climbing over a step, it is possible to achieve well-balanced stability against a load and shock absorption. There is sex.

  The traveling units 30 are each operable independently of the other traveling units 30. For example, the suspension cylinders 34 can independently perform or release the lock. Furthermore, for example, the axles 32 can be driven independently of one another and steerable independently of one another.

  The control device 20 controls the overall operation of the automated guided vehicle 100 including the self position / direction recognition means 21, the traveling speed calculation sensor 22, and the traveling units 30 in accordance with the control method described in the present specification. Further, the control device 20 has a wireless transmission device (not shown), and operates the automatic guided vehicle based on the conveyance instruction from the external computer.

  FIGS. 3 and 4 show an example of the configuration around the automated guided vehicle 100 according to the first embodiment of the present invention. FIG. 3 is a schematic view seen from the direction orthogonal to the longitudinal direction of the rail 200, and FIG. 4 is a schematic top view. The dimensional ratio of each component in the figure is not accurate.

  A gantry crane 202 is installed at a port where the unmanned transfer vehicle 100 is used. In addition, a rail 200 for moving the gantry crane 202 is disposed. In the illustrated example, two rails 200 are provided. The gantry crane 202 comprises a trolley 203, which transports containers between the container ship 201 and the AGV 100.

  The trolley 203 is capable of moving the sea side area 204, the inter-rail area 205, and the land side area 206, performs delivery work with the container ship 201 in the sea side area 204, and performs unmanned transfer in the inter-rail area 205. Carry out work with the car 100 and containers. Here, depending on the position of the AGV 100, it is possible to work with the AGV 100 not in the inter-rail area 205 but in the land side area 206. Operating time can be shortened. In particular, the gantry crane 202 often becomes a bottleneck for port transportation, and in such a case, shortening the operation time of the gantry crane 202 may improve the overall work efficiency.

  In order to reach the illustrated position, the unmanned transfer vehicle 100 needs to travel from the land side, get over one of the rails 200 present on the traveling route, and enter the inter-rail area 205. A step region 210 including the rail 200 itself is formed around the rail 200, and the step region 210 is passed to get over the rail 200.

  FIG. 5 schematically shows an example of the configuration of the step region 210 including the rail 200. As shown in FIG. This figure is a cross section perpendicular to the longitudinal direction of the rail 200. A rail groove 211 is formed on the road surface, and the rail 200 is accommodated in the rail groove 211. The structure for fixing the rail 200 is not shown. The stepped area 210 is formed by the rail 200 and the rail groove 211, and can be said to be an area discontinuous with the road surface. In the example of FIG. 5, the heights of the upper end surface of the rail 200 and the road surface are different, but the heights may be the same.

  The unmanned transfer vehicle 100 needs to cross the rail groove 211 in order to move from the land side yard to the position shown in FIGS. 3 and 4 (or vice versa). That is, each drive wheel 31 needs to pass through the step area 210.

  FIG. 6 shows an example of a route when the AGV 100 passes through the step area 210. As shown in FIG. The unmanned transfer vehicle 100 travels along a linear path passing through the position P and passes through the step area 210. The position P is separated from the step region 210 by a distance D.

  The dimensions (diameter, width, etc.) of the drive wheel 31 are designed such that the unmanned transfer vehicle 100 can pass through the step area 210 along the illustrated path. For example, the diameter of the drive wheel 31 is about the same as or larger than the width of the step region 210.

  FIG. 7 is a flowchart showing the flow of processing when the AGV 100 passes through the step area 210 along the route as shown in FIG. This process is performed by, for example, control device 20. Note that for the sake of simplicity, in FIG. 7, the step area 210 is simply expressed as "step".

  First, the unmanned transfer vehicle 100 acquires position information of the unmanned transfer vehicle 100 (step S1). The position information is obtained, for example, through the self position / direction recognition means 21. More specifically, it may be acquired, for example, via a GPS system or a transponder, or in the case where a camera or the like is mounted on the automated guided vehicle 100, it may be acquired by analyzing a photographed image. Good.

  Next, the unmanned transfer vehicle 100 acquires information representing a range (passable range) through which the unmanned transfer vehicle 100 can pass in the step area 210 (step S2). This range may be received, for example, from an external computer or the like via wireless communication, or when the camera or the like is mounted on the automated guided vehicle 100, it is acquired by analyzing the captured image. It is also possible to acquire one stored in advance in the storage means of the control device 20.

  Although the form of the information representing the passable range can be arbitrarily designed, for example, it can be in the form of representing the longitudinal direction and the positions of both ends of the step region 210. More specifically, if the coordinates of two points are specified in a two-dimensional coordinate system or a three-dimensional coordinate system, the direction of the straight line connecting the two points represents the longitudinal direction of the step region 210, and the two points are It represents both ends of the step region 210.

  Next, the unmanned transfer vehicle 100 determines the position (pass target position) when passing through the step area 210 (step S3). The determination method can be arbitrarily designed, but can be, for example, the center of the passable range.

  Next, the unmanned transfer vehicle 100 determines the position (start target position) at which the traveling operation for passing through the step area 210 is started (step S4). The determination method can be arbitrarily designed, but for example, assuming a straight traveling route as shown in FIG. 6, a position (position P) at which the distance to the step area 210 is D on that route is the target position It may be

  In the present embodiment, the traveling path when passing through the step area 210 is linear, and the longitudinal direction of the step area 210 forms a constant angle θ. Although the method of determining this θ is arbitrary, for example, it may be determined that a plurality of traveling units 30 do not exist simultaneously in the step area 210 at the same time (more strictly, included in different traveling units 30) It may be determined that the driven wheels 31 do not simultaneously exist in the step region 210). For example, if θ is too small, the right front wheel and the right rear wheel may simultaneously cover the step area 210. If θ is too large, the left and right front wheels may simultaneously cover the step area 210. Is selected. In this way, the AGV 100 acquires the angle between the longitudinal direction of the step area 210 and the path of the AGV 100.

  For example, it is assumed that four traveling units 30 in the unmanned transfer vehicle 100 are arranged to form a rectangular apex. The four traveling units 30 are respectively referred to as a front right wheel, a front left wheel, a rear right wheel and a rear left wheel. When passing through the step area 210 in the order of the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel, a non-zero time from when the right front wheel leaves the step area 210 until the left front wheel enters the step area 210 If there is a non-zero time from when the left front wheel leaves the step area 210 to when the right rear wheel enters the step area 210, two traveling units 30 do not simultaneously cover the step area 210.

As a concrete formula,
_{{W tc · cos (θ)} -d m} / {V · sin (θ)}> 0 and _{{L hb · sin (θ)} -W tc · cos (θ) -d m} / {V · sin ( θ)}> 0
It may be determined as θ that satisfies

However, V represents the vehicle speed (m / s) of the automatic guided vehicle 100, and can be acquired using the traveling speed calculation sensor 22 or the like. L _hb represents the wheel base (m) of the _AGV 100, and W _tc represents the tread (m) of the _AGV 100. The unit is an example. The values of “Wheel base” and “Tread” are appropriately set in consideration of the size (body size) of the automated guided vehicle 100 and the difference in the contact surface of the drive wheels 31 (tires) due to the difference in the maximum load weight. Ru.

  As an example, the wheel base means the distance between the front and rear drive wheels 31 or the axle 32, and more strictly, the drive wheel 31 (or axle 32) at the front end of the traveling direction of the AGV 100 and the rear end It means the distance between the wheel 31 (or the axle 32).

Also, as an example, the tread means the distance between the left and right drive wheels 31 or the axle 32, and more strictly, between the plurality of drive wheels 31 provided at the same position in the traveling direction of the automated guided vehicle 100 (or Means the distance between a plurality of axles 32). When three or more drive wheels 31 are disposed at the same position in the traveling direction, it means the distance between those at both ends in the left-right direction.
The values of “wheel base” and “tread” are set in consideration of the size (body size) of the automated guided vehicle 100 and the difference in the contact surface of the drive wheels 31 (tires) due to the difference in the maximum load weight. It is also good.

Further, d _m represents the dimension (m) in the width direction of the step region 210. The dimension in the width direction of the step area 210 may be stored in advance in the storage means of the control device 20, may be received from an external computer or the like via wireless communication, or may be obtained by other means It is also good.

If such θ is not determined to be a specific value, a specific value may be selected on the basis of any reference from the range of the corresponding θ. Although the range of the applicable θ varies depending on the configuration of the automatic guided vehicle 100 and the like, for example, θ ≧ 17 °. Of such a corresponding range of θ, the smallest value may be selected, or the largest value may be selected. Alternatively, the time from when the right front wheel leaves the step area 210 to when the left front wheel enters the step area 210 is equal to the time from when the left front wheel leaves the step area 210 to when the right rear wheel enters the step area 210. May be selected. In other words, { _Wtc · cos (θ) −d _m } / {V · sin (θ)} = {L _hb · sin (θ) −W _tc · cos (θ) −d _m } / {V · sin (Θ)} may be selected. Although such θ varies depending on the configuration of the automated guided vehicle 100 and the like, for example, θ = 23 °.

  Such a value of θ may be calculated or determined by the control device 20 using the above-mentioned equation, or may be stored in advance in the storage means of the control device 20, or from an external computer or the like. It may be received via wireless communication or may be obtained by other means.

  Next, the unmanned transfer vehicle 100 determines whether or not the start target position (position P) has been reached (step S5). If not reached, the unmanned transfer vehicle 100 repeats the determination of step S5 while continuing traveling toward the start target position. If it has arrived, the unmanned transfer vehicle 100 performs steering and speed adjustment, and enters a path forming an angle θ with the step area 210 (step S6). In the example of FIG. 6, although the steering operation is completed at only one point, the steering operation may be performed while traveling with a distance other than 0 (in this case, traveling along a curved route during the steering operation) Will be After step S6, the automated guided vehicle 100 travels along a path forming an angle θ with the longitudinal direction of the step area 210. In other words, the control device 20 causes the automatic guided vehicle 100 to travel along a path forming an angle θ with the longitudinal direction of the step region 210. Note that step S6 corresponds to the start time of the traveling operation, and the traveling operation itself continues from step S6.

  Next, the unmanned transfer vehicle 100 determines whether or not the step area 210 is detected (step S7). For example, the unmanned transfer vehicle 100 may include a camera for photographing the step area 210, and the control device 20 may detect the step area 210 based on the image photographed by the camera. More specifically, the control device 20 may detect the step feature point 212 corresponding to the step region 210, and determine the step region 210 based on the detected step feature point 212 (more strictly, The position of the step area 210 may be updated from the position acquired in step S2 or S3 to the position determined in step S7). Alternatively, the control device 20 detects the step characteristic point 213 corresponding to the rail 200, and based on the detected step characteristic point 213 and the known width information (for example, adding the width of the rail groove 211) Region 210 may be determined. When the level difference region 210 is not detected, the AGV 100 repeats the determination of step S7 while continuing the traveling.

  Next, the unmanned transfer vehicle 100 unlocks the suspension of the drive wheel 31 when the drive wheel 31 is within a predetermined range with respect to the step region 210 for each drive wheel 31. In addition, when the drive wheel 31 is not present within a predetermined range with respect to the step area 210, the suspension of the drive wheel 31 may be locked. Such control can be realized, for example, as in steps S8 and S9 described later.

  In step S <b> 8, the AGV 100 calculates the timing at which the lock of the suspension is switched for each drive wheel 31. The calculation method of this timing can be designed arbitrarily. For example, the timing may be such that the lock is released at the time when the drive wheel 31 enters the step area 210 and the lock is implemented again at the time when the drive wheel 31 leaves the step area 210. Alternatively, a predetermined margin time is provided, and the lock is released at a time obtained by subtracting the margin time from the time when the drive wheel 31 enters the step area 210, and the margin time is added to the time when the drive wheel 31 escapes from the step area 210 The timing may be such that locking is performed again at time. The allowance time may be a fixed value, or may be determined based on the vehicle speed of the AGV 100 (eg, in proportion to the vehicle speed).

In step S9, the AGV 100 switches the suspension lock according to the determined timing.
FIG. 8 shows a specific example of lock control in the AGV 100. The unmanned transfer vehicle 100 is about to pass through the step area 210 at the speed V. At a point prior to FIG. 8 (a), locking has been performed for all drive wheels 31 (ON). At the time shown in FIG. 8A, the lock on the right front wheel is released (OFF). When the right front wheel passes through the step area 210, at the time of FIG. 8 (b), the locking of the right front wheel is implemented again (or later) while the locking of the left front wheel is released. When the left front wheel passes through the step area 210, at the time of FIG. 8C, the locking of the left front wheel is implemented again (or later), and the locking of the right rear wheel is released. When the right rear wheel passes through the step area 210, at the time of FIG. 8 (d), the locking of the right rear wheel is implemented again (or later) while the locking of the left rear wheel is released. Thereafter, although not shown, when the left rear wheel passes through the step area 210, locking of the left rear wheel is implemented again.

  As described above, according to the automatic guided vehicle 100 and the control method thereof according to the first embodiment of the present invention, the control is performed to suppress the impact based on the relative position to the step area 210 for each drive wheel 31. You can get over the step more easily.

  Further, since it becomes possible to pass through the step area 210, delivery of a container or the like is not performed at the position of the unmanned transfer vehicle 100 shown in FIGS. 3 and 4 instead of the position of the unmanned transfer vehicle 300 shown in FIG. Work can be done. For this reason, the moving distance of the trolley 203 of the gantry crane 202 can be reduced. In particular, in a situation where the operating speed of the trolley 203 becomes a bottleneck for port transportation, the overall work efficiency can be dramatically improved.

  In addition, the impact on the load when passing through the step area 210 can be reduced. Furthermore, a relatively high speed can be maintained when passing through the step region 210, and the transport efficiency of the container or the like is improved.

In the first embodiment, the following modifications can be made.
In the first embodiment, the control for releasing the lock of the suspension is performed as the control for suppressing the impact, but the control for suppressing the impact is not limited to this. Instead of or in addition to the control for releasing the suspension lock, control for raising the position of the drive wheel 31 may be performed. For example, the suspension cylinder 34 may be operable to raise or lower the position of the drive wheel 31 depending on the operation of the cylinder drive. The position of the drive wheel 31 can be changed, for example, by manipulating the amount of oil injected into the upper space and the lower space of the suspension cylinder 34, respectively. In such a configuration, the unmanned transfer vehicle 100 causes the position of the drive wheel 31 to be higher than the predetermined position when the drive wheel 31 is within a predetermined range with respect to the step region 210 for each drive wheel 31. . Further, when the drive wheel 31 does not exist within the predetermined range with respect to the step area 210, the position of the drive wheel 31 is lowered (that is, returned to the predetermined position).

  Although eight drive wheels 31 are provided in the first embodiment, four or more drive wheels may be provided. In that case, for example, one drive wheel may be attached to each axle.

  Although four traveling units 30 (two pairs) are provided in the first embodiment, five or more traveling units may be provided. For example, six (three pairs) or eight (four pairs) may be used. In the case of using five or more traveling units, relatively stable traveling is possible even when the center of gravity of the unmanned transfer vehicle 100 is biased due to loading of a container or the like.

  Further, in the case of using five or more traveling units, it is also possible to simultaneously unlock the suspension for a plurality of traveling units. For example, if the lock is implemented for at least three drive wheels and control is made so that the projected point of the gravity center of the AGV is present inside the polygon formed by the drive wheels, a plurality of drives can be performed simultaneously. Even when the wheel lock is released, it is possible to stabilize the unmanned transfer vehicle and mitigate the impact.

  In the first embodiment, the suspension cylinder 34 is a hydraulic cylinder, but the method of suspension can be arbitrarily changed. For example, an electric cylinder or a pneumatic cylinder may be used. By using a cylinder other than the hydraulic cylinder, oil leakage measures become unnecessary.

  In the first embodiment, the step area 210 is configured of the rail 200 and the rail groove 211. However, if the configuration of the step area 210 is one that can be defined in the longitudinal direction (an object having a certain distance in the longitudinal direction) Not limited to. It may be a groove other than the rail groove 211, for example, a groove for flowing rain water or the like. On the other hand, it may be a rail that is not provided with a groove and protrudes from the road surface.

  In the first embodiment, the position of the drive wheel 31 and the position of the axle 32 are not distinguished, but they may be distinguished. For example, the positional relationship between the drive wheel 31 and the axle 32 may be stored in advance in the storage means of the control device 20, and the suspension may be controlled based on the position of the drive wheel 31 instead of the position of the axle 32. Also, the position of the drive wheel 31 may be treated as a range rather than a point. For example, the area (grounding area) where the driving wheel 31 contacts the ground may be obtained or calculated, and the locking may be released when the grounding area and the step area 210 at least partially overlap.

  In the first embodiment, after the passable range of the step area 210 is obtained in step S2, the process of detecting the step area 210 is performed in step S7. In this way, the position of the step area 210 can be recognized more accurately, but it is also possible to omit step S7 if it is possible to acquire position information with sufficient accuracy in step S2. In that case, the timing control of steps S8 and S9 is performed based on the information acquired in step S2.

  31 driving wheel, 100 unmanned transfer vehicle, 210 step area, θ angle (angle to be made between the longitudinal direction of the step area and the route of the unmanned transfer vehicle).

Claims (4)

A control method of an automatic guided vehicle, comprising four or more drive wheels, comprising:
Acquiring an angle between the longitudinal direction of the step area and the route of the unmanned transfer vehicle;
Running the AGV along the angled path;
And releasing the lock of the suspension of the drive wheel or raising the position of the drive wheel when the drive wheel is within a predetermined range with respect to the step area for each of the drive wheels. Method. Detecting step feature points;
The method according to claim 1, further comprising: determining or updating the stepped region based on the stepped feature point. Said angle,
_{{W tc · cos (θ)} -d m} / {V · sin (θ)}> 0 and _{{L hb · sin (θ)} -W tc · cos (θ) -d m} / {V · sin ( θ)}> 0
Further comprising the step of determining as θ satisfying
Where V represents the speed of the unmanned transport vehicle,
L _hb represents the wheelbase of the _AGV ;
W _tc represents the tread of the unmanned carrier;
d _m represents the dimension in the width direction of the step region,
A method according to claim 1 or 2. It is an unmanned carrier equipped with four or more drive wheels,
A function of acquiring an angle between the longitudinal direction of the step area and the route of the AGV;
The function of traveling along the angled path;
Each of the drive wheels has a function of unlocking the suspension of the drive wheels or raising the position of the drive wheels when the drive wheels are within a predetermined range with respect to the step region. Unmanned carrier.

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