JP6950629B2 - Transport vehicle - Google Patents

Description

The present invention relates to a transport vehicle.

As a conventional transport vehicle, the one described in Patent Document 1 is known. This transport vehicle is a self-propelled transport vehicle that loads and unloads luggage inside a container such as a truck container. Inside the housing, a plurality of reflectors for reflecting the laser beam are provided. The transport vehicle grasps its position by detecting the laser beam reflected by the reflector.

Japanese Unexamined Patent Publication No. 7-101554

However, in the above-mentioned transport vehicle, reflectors must be provided at a plurality of places inside the housing. In this case, every time the traveling environment of the transport vehicle, that is, the housing to be worked on changes, it is necessary to newly install the reflector, which requires a great deal of time and effort. Therefore, there has been a demand for a transport vehicle capable of performing accurate automatic control regardless of the traveling environment.

Therefore, an object of the present invention is to provide a transport vehicle capable of performing accurate automatic control regardless of the traveling environment.

The transport vehicle according to one aspect of the present invention is a self-propelled transport vehicle that loads and unloads luggage inside the housing, and is arranged at a vehicle body for traveling and a reference position of the vehicle body outside the housing. A first distance acquisition unit and a second distance acquisition unit for acquiring information on the distance between the vehicle body and the reference position setting member are provided, and the first distance acquisition unit and the first distance acquisition unit are provided. The second distance acquisition unit acquires information on the distance between different points in the width direction of the vehicle body and the reference position setting member.

The transport vehicle according to one aspect of the present invention is the first to acquire information on a distance between a reference position setting member arranged outside the housing and setting a reference position of a vehicle body and a distance between the vehicle body and the reference position setting member. A distance acquisition unit and a second distance acquisition unit are provided. For example, when the vehicle body is tilted from the straight traveling state, the distance between the portion on one end side and the portion on the other end side in the width direction of the vehicle body with respect to the reference position setting member occurs. On the other hand, the first distance acquisition unit and the second distance acquisition unit acquire information on the distance between different points in the width direction of the vehicle body and the reference position setting member, respectively. Therefore, by comparing the distance information acquired by the first distance acquisition unit with the distance information acquired by the second distance acquisition unit, the traveling state of the vehicle body can be accurately grasped. As a result, it is possible to accurately automatically control the transport vehicle. Since the reference position setting member used for acquiring the distance information is arranged outside the housing, even if the traveling environment changes due to the change of the housing, it is not necessary to install it again. Can be. As described above, accurate automatic control can be performed regardless of the traveling environment.

The transport vehicle further includes a traveling state acquisition unit that acquires the traveling state of the vehicle body, and the traveling state acquisition unit is acquired by the first distance information acquired by the first distance acquisition unit and the second distance acquisition unit. The abnormality of the traveling state of the vehicle body may be determined based on the deviation from the second distance information. In this way, it is possible to easily grasp the abnormality of the traveling state by using the deviation between the first distance information and the second distance information.

The transport vehicle further includes a first drive unit and a second drive unit provided at different positions in the width direction of the vehicle body, and a drive control unit that controls the first drive unit and the second drive unit. The drive control unit may correct the deviation between the first distance information and the second distance information by setting the first drive unit and the second drive unit to different rotation speeds. As a result, the drive control unit can return the vehicle body to the normal traveling state.

Each of the first distance acquisition unit and the second distance acquisition unit is provided on a line encoder for detecting the length of the drawn line and a reference position setting member, and is positioned to fix and position the end of the line. It may be equipped with a part. As described above, the first distance acquisition unit and the second distance acquisition unit can accurately acquire the distance by using the line encoder.

According to the present invention, it is possible to provide a transport vehicle capable of accurately performing automatic control regardless of the traveling environment.

It is a schematic diagram which shows the state that the transport vehicle which concerns on this embodiment carries out loading and unloading of cargo. It is a schematic block diagram which shows the schematic structure of the transport vehicle which concerns on this embodiment. It is a conceptual diagram which shows each running state. It is a flowchart which shows the processing content of a control part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing a state in which the transport vehicle 1 according to the present embodiment is loading and unloading the cargo W. The transport vehicle 1 loads and unloads the luggage W inside the housing body C such as the loading platform and the container of the truck T. In the example shown in FIG. 1, the transport vehicle 1 works as the housing C inside the loading platform of the truck T. The truck T is stopped at the parking space P. On the rear side (building side) of the parking space P, a step portion S rising upward from the parking space P is formed. The truck T stops with the door at the rear end of the housing body C open with respect to the step portion S. The transport vehicle 1 travels so as to enter the inside of the housing body C from the step portion S. Further, the transport vehicle 1 travels so as to go out from the inside of the housing body C to the outside and return to the step portion S.

The transport vehicle 1 is a self-propelled vehicle that automatically travels and automatically loads and unloads the cargo W. The transport vehicle 1 includes a vehicle body 2 for traveling and a cargo handling unit 3 for loading and unloading the luggage W. The vehicle body 2 is provided with a plurality of wheels, and by driving the wheels, the vehicle body 2 travels in the front-rear direction. The cargo handling unit 3 includes a holding unit 6 for holding the cargo W and an arm unit 7 for moving the holding unit 6. One end of the arm portion 7 is fixed to the vehicle body 2, and the holding portion 6 is fixed to the other end. The arm portion 7 is composed of a plurality of joint portions and a plurality of link portions.

Next, the configuration of the transport vehicle 1 will be described in more detail with reference to FIG. FIG. 2 is a schematic configuration diagram showing a schematic configuration of the transport vehicle 1 according to the present embodiment. The transport vehicle 1 in the present embodiment automatically travels so as to go straight in the front-rear direction when entering the accommodating body C from the outside or when exiting from the accommodating body C. As shown in FIG. 2, in addition to the vehicle body 2, the transport vehicle 1 includes a reference position setting member 10, distance acquisition units 11A and 11B (first distance acquisition unit, second distance acquisition unit), and a drive unit. 12A and 12B (first drive unit, second drive unit) and control unit 20 are provided.

The reference position setting member 10 is a member arranged outside the housing body C to set the reference position of the vehicle body 2. The reference position setting member 10 is arranged at a position further rearward from the opening at the rear end of the accommodating body C, and is arranged at the step portion S here (see FIG. 1). The reference position setting member 10 is arranged at the traveling start position of the vehicle body 2 when the vehicle body 2 tries to enter the accommodation body C from the outside of the housing body C. The reference position setting member 10 has a shape extending along the width direction of the vehicle body 2. Here, the reference position setting member 10 has the shape of a rectangular parallelepiped extending along the width direction of the vehicle body 2.

The distance acquisition units 11A and 11B acquire information regarding the distance between the vehicle body 2 and the reference position setting member 10. The distance acquisition unit 11A and the distance acquisition unit 11B acquire distances between different points in the width direction of the vehicle body 2 and the reference position setting member 10. In the present embodiment, the distance acquisition unit 11A is provided near one end 2a in the width direction of the vehicle body 2, and the distance acquisition unit 11B is provided near the other end 2b in the width direction of the vehicle body 2. The distance acquisition units 11A and 11B include line encoders 21A and 21B and positioning units 22A and 22B.

The line encoders 21A and 21B are encoders that detect the length of the drawn line 21a. The line encoders 21A and 21B are provided at arbitrary positions on the rear end side of the vehicle body 2. The line encoders 21A and 21B are arranged at the same position in the front-rear direction. The line encoder 21A is provided near one end 2a in the width direction of the vehicle body 2, and the line encoder 21B is provided near the other end 2b in the width direction of the vehicle body 2. In the present embodiment, the line encoders 21A and 21B are provided on the front side of the wheels 26A and 26B on the rear side of the vehicle body 2. Therefore, the line 21a drawn from the line encoders 21A and 21B is arranged so as to avoid the axle so as not to interfere with the axles of the rear wheels 26A and 26B. However, the positions of the line encoders 21A and 21B in the front-rear direction are not particularly limited, and may be provided on the rear side of the rear wheels 26A and 26B.

The positioning portions 22A and 22B are provided on the reference position setting member 10 and are portions for fixing and positioning the end portion of the line 21a. The positioning portions 22A and 22B are configured by brackets to which the ends of the lines 21a can be detachably fixed. The positioning portions 22A and 22B are formed at the front end portion 10a of the reference position setting member 10. The position of the positioning portion 22A in the width direction is set to the same position as that of the line encoder 21A. The position of the positioning portion 22B in the width direction is set to the same position as that of the line encoder 21B.

With the above configuration, the length of the line 21a drawn out from the line encoders 21A and 21B becomes longer as the vehicle body 2 is separated from the reference position setting member 10. When the vehicle body 2 is traveling straight (the state shown in FIG. 3A), the length of the line 21a drawn from the line encoder 21A and the length of the line 21a drawn from the line encoder 21B are equal. On the other hand, when the vehicle body 2 is tilted from the straight running state (the state shown in FIG. 3B), what is the length of the line 21a drawn from the line encoder 21A and the length of the line 21a drawn from the line encoder 21B? , Different from each other.

The line encoders 21A and 21B output the length of the drawn line 21a to the control unit 20. Since the length of the line 21a drawn from the line encoder 21A is a value that changes with a change in the distance between the vicinity of one end 2a of the vehicle body 2 and the reference position setting member 10, one of the vehicle bodies 2 Corresponds to the information regarding the distance between the vicinity of the end portion 2a and the reference position setting member 10. Therefore, in the following description, the information on the length of the line 21a detected by the line encoder 21A may be referred to as "first distance information". Since the length of the line 21a drawn from the line encoder 21B is a value that changes with a change in the distance between the vicinity of the other end 2b of the vehicle body 2 and the reference position setting member 10, the other end of the vehicle body 2 Corresponds to the information regarding the distance between the vicinity of the end portion 2b and the reference position setting member 10. Therefore, in the following description, the information on the length of the line 21a detected by the line encoder 21B may be referred to as "second distance information".

The drive units 12A and 12B are portions that generate a driving force for the vehicle body 2 to travel. The drive units 12A and 12B are provided at different positions in the width direction of the vehicle body 2. Specifically, the drive unit 12A includes a front wheel 27A on one end 2a side and a motor 28A that rotates the wheel 27A. The drive unit 12B includes a front wheel 27B on the other end 2b side and a motor 28B that rotates the wheel 27B. The motors 28A and 28B receive the control signal from the control unit 20 and rotate the wheels 27A and 27B at a rotation speed based on the control signal.

The control unit 20 includes an ECU [Electronic Control Unit] that comprehensively manages the entire transport vehicle 1. The ECU is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like. In the ECU, for example, various functions are realized by loading the program stored in the ROM into the RAM and executing the program loaded in the RAM in the CPU. The ECU may be composed of a plurality of electronic units. The control unit 20 includes a traveling state acquisition unit 31 and a drive control unit 32. The ECU can also be controlled by a command from an external device (WMS [Warehouse Management System], WCS [Warehouse Control System], etc.).

The traveling state acquisition unit 31 acquires the traveling state of the vehicle body 2. The traveling state acquisition unit 31 acquires the traveling state of the vehicle body 2 based on the first distance information acquired by the distance acquisition unit 11A and the second distance information acquired by the distance acquisition unit 11B. When the first distance information and the second distance information are equal to each other, the traveling state acquisition unit 31 determines that the vehicle body 2 is in a straight-ahead state and is traveling normally as shown in FIG. 3A. .. The traveling state acquisition unit 31 determines an abnormality in the traveling state of the vehicle body based on the deviation between the first distance information and the second distance information. When the amount of deviation between the first distance information and the second distance information exceeds the threshold value, the traveling state acquisition unit 31 determines that the traveling state of the vehicle body is abnormal. For example, when either the wheels 27A or 27B slips depending on the condition of the floor surface of the housing body C, or when the direction of the vehicle body 2 changes due to a step on the floor surface of the housing body C, etc., FIG. 3B As shown in the above, the vehicle body 2 is in a state of being inclined from the reference direction SD. If the vehicle body 2 continues automatic traveling in this state, the vehicle body 2 may meander. Therefore, when the vehicle body 2 is tilted from the reference direction SD as shown in FIG. 3B, the traveling state acquisition unit 31 determines that the traveling state is abnormal.

The drive control unit 32 controls the drive units 12A and 12B. The drive control unit 32 drives the drive unit 12A and the drive unit 12B at the same rotation speed so that the vehicle body 2 travels straight. On the other hand, when there is an abnormality in the traveling state, the drive control unit 32 performs control for correcting the abnormal state. The drive control unit 32 corrects the deviation between the first distance information and the second distance information by setting the drive unit 12A and the drive unit 12B to different rotation speeds. For example, when the distance between one end 2a of the vehicle body 2 and the reference position setting member 10 is larger than the distance between the other end 2b and the reference position setting member 10, the value of the first distance information Is larger than the value of the second distance information. In this case, the drive control unit 32 controls the rotation speed of the drive unit 12B so as to be relatively larger than the rotation speed of the drive unit 12A. As a result, the other end 2b side of the vehicle body 2 travels faster than the one end 2a side, so that the inclination of the vehicle body 2 is corrected and the vehicle can return to the straight-ahead state.

Next, an example of the processing content of the control unit 20 will be described with reference to FIG. FIG. 4 is a flowchart showing the processing contents of the control unit 20.

As shown in FIG. 4, first, the traveling state acquisition unit 31 of the control unit 20 acquires the first distance information and the second distance information from the distance acquisition units 11A and 11B (step S10). Next, the traveling state acquisition unit 31 determines whether or not there is an abnormality in the traveling state (step S20). In S20, the traveling state acquisition unit 31 compares the first distance information and the second distance information, and determines whether or not the deviation between the two, that is, the difference between the two values is within a predetermined threshold range. do. When the traveling state acquisition unit 31 determines that the difference between the values of the first distance information and the second distance information is within the threshold range, the vehicle body 2 is in a straight-ahead state (see FIG. 3A). It is determined that there is no abnormality in the running state. In this case, the process shown in FIG. 4 is completed, and the process is started again from S10.

On the other hand, in S20, when the traveling state acquisition unit 31 determines that the difference between the values of the first distance information and the second distance information exceeds the threshold value, the vehicle body 2 is tilted from the reference direction SD. (Refer to FIG. 3B), it is determined that there is an abnormality in the running state. In this case, the drive control unit 32 corrects the deviation between the first distance information and the second distance information (step S30). In S30, the drive control unit 32 corrects the deviation between the first distance information and the second distance information by setting the drive unit 12A and the drive unit 12B to different rotation speeds.

The traveling state acquisition unit 31 acquires the first distance information and the second distance information from the distance acquisition units 11A and 11B (step S40). Next, the traveling state acquisition unit 31 determines whether or not the correction is completed and the traveling state has returned to normal (step S50). In S50, the traveling state acquisition unit 31 compares the first distance information and the second distance information, and determines whether or not the deviation between the two, that is, the difference between the two values is within a predetermined threshold range. do. When the traveling state acquisition unit 31 determines that the difference between the values of the first distance information and the second distance information is within the threshold range, the vehicle body 2 is in a straight-ahead state (see FIG. 3A). It is determined that it has returned, and it is determined that the correction has been completed. In this case, the process shown in FIG. 4 is completed, and the process is started again from S10. If it is determined in S50 that the correction is not completed, the process is repeated from S30. At this time, the drive control unit 32 may maintain the rotation speeds of the drive units 12A and 12B at the values set in the previous S30 and continue the correction at the rotation speeds, and the rotation speeds are further higher than those in the previous S30. The difference may be large.

Next, the operation / effect of the transport vehicle 1 according to the present embodiment will be described.

The transport vehicle 1 according to the present embodiment acquires information on the distance between the reference position setting member 10 which is arranged outside the housing body C and sets the reference position of the vehicle body and the vehicle body 2 and the reference position setting member 10. The distance acquisition unit 11A and the distance acquisition unit 11B are provided. For example, when the vehicle body 2 is tilted from the straight traveling state, the distance between the portion on the one end 2a side and the portion on the other end 2b side in the width direction of the vehicle body 2 with respect to the reference position setting member 10. There is a gap. On the other hand, the distance acquisition unit 11A and the distance acquisition unit 11B acquire information on the distance between different points in the width direction of the vehicle body 2 and the reference position setting member 10. Therefore, by comparing the first distance information acquired by the distance acquisition unit 11A with the second distance information acquired by the distance acquisition unit 11B, the traveling state of the vehicle body 2 can be accurately grasped. As a result, the transport vehicle 1 can be accurately controlled automatically. Since the reference position setting member 10 used for acquiring the distance information is arranged outside the accommodating body C, it is installed again even if the traveling environment changes due to the change of the accommodating body C. Etc. can be eliminated. As described above, accurate automatic control can be performed regardless of the traveling environment.

The transport vehicle 1 further includes a traveling state acquisition unit 31 that acquires the traveling state of the vehicle body 2, and the traveling state acquisition unit 31 is acquired by the first distance information acquired by the distance acquisition unit 11A and the distance acquisition unit 11B. Based on the deviation from the second distance information, the abnormality of the traveling state of the vehicle body 2 is determined. In this way, it is possible to easily grasp the abnormality of the traveling state by using the deviation between the first distance information and the second distance information.

The transport vehicle 1 further includes a drive unit 12A and a drive unit 12B provided at different positions in the width direction of the vehicle body 2, and a drive control unit 32 for controlling the drive unit 12A and the drive unit 12B. 32 corrects the deviation between the first distance information and the second distance information by setting the drive unit 12A and the drive unit 12B to different rotation speeds. As a result, the drive control unit 32 can return the vehicle body 2 to the normal traveling state.

Each of the distance acquisition unit 11A and the distance acquisition unit 11B is provided on the line encoders 21A and 21B for detecting the length of the drawn line 21a and the reference position setting member 10, and the end portion of the line 21a is fixed and positioned. The positioning portions 22A and 22B are provided. In this way, the distance acquisition units 11A and 11B can accurately acquire the distance by using the line encoders 21A and 21B. When the line encoders 21A and 21B are used, the line 21a exists on the rear side of the vehicle body 2 in addition to the reference position setting member 10. Therefore, when carrying the luggage W, the work is performed so as not to interfere with the reference position setting member 10 and the line 21a.

The present invention is not limited to the above-described embodiment.

In the above-described embodiment, the traveling state acquisition unit 31 makes each determination using the values of the line encoders 21A and 21B as they are. Instead, the control unit 20 converts the values of the line encoders 21A and 21B by calculation (for example, the distance between the rear end portion of the vehicle body 2 and the reference position setting member 10), and the traveling state acquisition unit 31. May use the converted value as distance information. In this case, the control unit 20 also functions as a distance acquisition unit.

Further, in the above-described embodiment, when the traveling state of the vehicle body 2 is normal, the length of the line 21a drawn from the line encoder 21A and the length of the line 21a drawn from the line encoder 21B are the same. Instead of this, the length of the line 21a drawn out from the line encoder 21A and the length of the line 21a drawn out from the line encoder 21B may be different in the normal running state. For example, the positions of the line encoder 21A and the line encoder 21B in the front-rear direction may be different due to the structural convenience of the vehicle body 2. Further, the positions of the positioning portion 22A and the positioning portion 22B in the front-rear direction may be different depending on the convenience of installation. Further, the positions of the positioning portions 22A and 22B in the width direction may be deviated from those of the line encoders 21A and 21B. In such a case, the control unit 20 may convert the values of the line encoders 21A and 21B into values that make it easy to compare the first distance information and the second distance information.

For example, a line encoder was used as a distance acquisition unit. Instead of this, the distance acquisition unit may be configured by using a non-contact type sensor. For example, the distance acquisition unit may be configured by providing laser sensors at different positions in the width direction of the vehicle body 2 and providing a reflector for reflecting the laser light in the reference position setting unit. In this case, a plurality of measuring instruments are provided on the vehicle body 2, but even one measuring instrument is adopted as long as it can measure the distances at different positions in the width direction of the vehicle body. May be good. For example, when the transmission / reception units of lasers are arranged so as to spread in the width direction in one measuring instrument, the distances at different positions in the width direction of the vehicle can be measured. In this case, the first distance acquisition unit and the second distance acquisition unit are included in one measuring instrument.

1 ... Transport vehicle, 2 ... Body, 10 ... Reference position setting member, 11A ... Distance acquisition unit (first distance acquisition unit), 11B ... Distance acquisition unit (second distance acquisition unit), 12A ... Drive unit (first) 1 drive unit), 12B ... drive unit (second drive unit), 21A, 21B ... line encoder, 21a ... line, 22A, 22B ... positioning unit.

Claims (4)

A self-propelled transport vehicle that loads and unloads luggage inside the containment body.
The car body that runs and
A reference position setting member arranged outside the housing and setting a reference position of the vehicle body,
A first distance acquisition unit and a second distance acquisition unit for acquiring information regarding the distance between the vehicle body and the reference position setting member are provided.
The first distance acquisition unit and the second distance acquisition unit are transport vehicles that acquire information on distances between locations different from each other in the width direction of the vehicle body and the reference position setting member. Further provided with a running state acquisition unit for acquiring the running state of the vehicle body,
The traveling state acquisition unit is based on the deviation between the first distance information acquired by the first distance acquisition unit and the second distance information acquired by the second distance acquisition unit. The transport vehicle according to claim 1, wherein an abnormality in the traveling state of the vehicle body is determined. A first drive unit and a second drive unit provided at different positions in the width direction of the vehicle body,
A drive control unit that controls the first drive unit and the second drive unit is further provided.
The drive control unit corrects the deviation between the first distance information and the second distance information by setting the first drive unit and the second drive unit to different rotation speeds. , The transport vehicle according to claim 2. Each of the first distance acquisition unit and the second distance acquisition unit
A line encoder that detects the length of the drawn line,
The transport vehicle according to any one of claims 1 to 3, further comprising a positioning portion provided on the reference position setting member and fixing and positioning an end portion of the line.

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