CN112644984A

CN112644984A - Control method, control system, conveying device and component mounting system

Info

Publication number: CN112644984A
Application number: CN202011074087.9A
Authority: CN
Inventors: 佐藤宽之
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2019-10-10
Filing date: 2020-10-09
Publication date: 2021-04-13

Abstract

Provided are a control method, a control system, a conveying device and a component mounting system, which can restrain the deviation of the conveying device from a reference posture and make the conveying device easily follow a track. The control method includes at least one of a first steering angle control process and a second steering angle control process. The first steering angle control process is a process of controlling the steering angle (theta) of the conveying device (1) having a plurality of steering wheels (2) and conveying the conveyed object in a state where the plurality of steering wheels (2) of the conveying device (1) are arranged in the front-rear direction. The second steering angle control process is a process of controlling the steering angle (theta) of the conveyor device (1) in a state where the plurality of steered wheels (2) of the conveyor device (1) are aligned in a direction intersecting the front-rear direction.

Description

Control method, control system, conveying device and component mounting system

Technical Field

The present disclosure relates generally to control methods, control systems, transport devices, and component mounting systems. More specifically, the present disclosure relates to a control method and a control system for controlling a transport device, a transport device having the control system mounted thereon, and a component mounting system using the transport device.

Background

Document 1(JP2012-53838A) discloses an apparatus for conveying materials, products, and the like by causing a plurality of unmanned transport vehicles (transport devices) to travel along a travel path such as a track laid in a factory or the like.

Disclosure of Invention

Problems to be solved by the invention

An object of the present disclosure is to provide a control method, a control system, a conveying device, and a component mounting system that suppress deviation of the conveying device from a reference posture and facilitate the conveying device to follow a track.

Means for solving the problems

A control method of an aspect of the present disclosure has at least one of a first steering angle control process and a second steering angle control process. The first steering angle control process is a process of controlling the steering angle of a conveying device having a plurality of steering wheels and conveying a conveyed article in a state where the plurality of steering wheels are aligned in the front-rear direction. The second steering angle control process is a process of controlling the steering angle of the conveyor in a state where the plurality of steered wheels of the conveyor are aligned in a direction intersecting with the front-rear direction.

The control system according to one aspect of the present disclosure includes at least one of a first steering angle control processing unit and a second steering angle control processing unit. The first steering angle control processing unit controls a steering angle of a conveying device having a plurality of steering wheels and conveying a conveyed article in a state where the plurality of steering wheels are arranged in a front-rear direction. The second steering angle control processing unit controls the steering angle of the conveyor in a state where the plurality of steered wheels of the conveyor are aligned in a direction intersecting with the front-rear direction.

The transport apparatus according to one aspect of the present disclosure includes the control system and the main body. The main body is mounted with the control system and conveys the conveyed object.

A component mounting system of an aspect of the present disclosure is a system including at least one component mounter which mounts components on a substrate. The component mounter has a component supply device that supplies the components, and a mounting body including a mounting head that mounts the components on the board. The component supply device is transported to the mounting body by the transport device controlled by the control system described above.

Effects of the invention

The present disclosure has the following advantages: the deviation of the conveying device from the reference posture is restrained, and the conveying device is easy to follow the track.

Drawings

Fig. 1 is a schematic plan view showing an example of a transport apparatus targeted by the control system of embodiment 1.

Fig. 2 is a block diagram showing an outline of the above-described control system.

Fig. 3 is an explanatory diagram illustrating an example of speed control in the operation of the control system.

Fig. 4 is an explanatory diagram of an outline of a component mounting system constructed by using the above-described control system.

Fig. 5 is a flowchart showing an example of the operation of the control system.

Fig. 6 is an explanatory diagram illustrating an example of control of the transport device by the control system of the comparative example.

Fig. 7 is an explanatory diagram illustrating another example of the operation of the control system according to embodiment 1.

Fig. 8 is an explanatory diagram illustrating still another example of the operation of the control system.

Fig. 9 is a schematic plan view showing an example of the arrangement of the sensors in the above-described transport device.

Fig. 10 is a schematic plan view showing an example of a transport device targeted by the control system of embodiment 2.

Fig. 11 is an explanatory diagram of the first steering angle in the operation of the control system.

Fig. 12 is an explanatory diagram of the second steering angle in the operation of the control system.

Fig. 13 is an explanatory diagram of a combined steering angle in the operation of the control system.

Fig. 14 is an explanatory diagram of the reverse phase control in the operation of the control system.

Fig. 15 is an explanatory diagram of the reverse phase control in the operation of the control system.

Fig. 16 is an explanatory diagram of the reverse phase control in the operation of the control system.

Fig. 17 is a flowchart showing an example of the operation of the control system.

Fig. 18 is a schematic plan view showing an example of a transport device targeted by the control system of embodiment 3.

Fig. 19 is an explanatory diagram of the amount of positional deviation and the amount of rotational deviation in the operation of the control system.

Fig. 20 is an explanatory diagram of the reference steering angle in the operation of the control system.

Fig. 21 is an explanatory diagram of the first steering angle in the operation of the control system.

Fig. 22 is an explanatory diagram of the second steering angle and the combined steering angle in the operation of the control system.

Fig. 23 is a diagram for explaining the reverse phase control in the operation of the control system.

Fig. 24 is an explanatory diagram of the reverse phase control in the operation of the control system.

Fig. 25 is an explanatory diagram of the reverse phase control in the operation of the control system.

Fig. 26 is an explanatory diagram showing an example of speed control in the operation of the control system.

Fig. 27 is an explanatory diagram of an outline of a component mounting system constructed by using the above-described control system.

Fig. 28 is a flowchart showing an example of the operation of the control system.

Fig. 29 is an explanatory diagram illustrating an example of control of the transport device by the control system of the comparative example.

Fig. 30 is an explanatory diagram illustrating an example of control of the transport device by the control system of embodiment 3.

Fig. 31 is an explanatory diagram illustrating another example of the operation of the control system.

Description of reference numerals:

100 a control system;

200 a component mounting system;

11 an acquisition unit;

12 a correction unit;

1, a conveying device;

10 a main body part;

2, a steering wheel;

21 front wheels;

22a rear wheel;

5, connecting part;

8a component supply device;

9 a component mounting machine;

90 mounting the main body;

a1 conveying material;

b1 dough movement;

an L1 orbit;

ST1 acquisition step;

ST2 correcting step;

ST3 speed correction step;

a steering angle θ;

θ 1a first steering angle;

θ 2a second steering angle;

θ 3 synthesizes the steering angle.

Detailed Description

(embodiment mode 1)

(1) Summary of the invention

As shown in fig. 1, the control method of the present embodiment is a method for controlling the transport apparatus 1 so that the transport apparatus 1 that transports the transported object a1 (see fig. 4) follows the trajectory L1. The control method is implemented by the control system 100 (see fig. 2). In the present embodiment, the article a1 includes a wheel a11 and is configured to be movable together with the transport apparatus 1.

In the present embodiment, the conveying device 1 is a device that has a plurality of steering wheels 2 arranged in the front-rear direction of the conveying device 1 and that moves on the moving surface B1 to convey the conveyed article a 1. The "front-rear direction" referred to in the present disclosure is a longitudinal direction of the conveying device 1, and is a direction in which the conveying device 1 travels is referred to as "front" and a direction in which the opposite direction is referred to as "rear". The transport apparatus 1 may be configured to be performed in a width direction orthogonal to the longitudinal direction. The front-rear direction in this case is the width direction.

The blank arrow in fig. 1 indicates the traveling direction of the conveyor 1. In addition, the double-headed arrows in fig. 1 indicate "front" and "rear" of the transport apparatus 1. The arrows in fig. 1 are designated for illustrative purposes only and are not accompanied by entities. In fig. 1, wheels such as the plurality of steerable wheels 2 of the conveyor device 1 are drawn by solid lines, but actually, these wheels are hidden in the main body portion 10 of the conveyor device 1 (described later). Note that, although the track L1 is drawn by a solid line in fig. 1, a portion of the track L1 that overlaps the transport apparatus 1 is actually hidden in the main body 10 of the transport apparatus 1. The same applies to the figures other than fig. 1.

The transportation device 1 is introduced into facilities such as a distribution center (including a distribution center), a factory, an office, a store, a school, and a hospital. The travel surface B1 is a surface on which the transport apparatus 1 travels, and when the transport apparatus 1 travels inside a facility, the floor surface of the facility and the like become the travel surface B1, and when the transport apparatus 1 travels outdoors, the floor surface and the like become the travel surface B1. Hereinafter, a case where the transport apparatus 1 is introduced into a factory will be described. In the figures other than fig. 1, the moving surface B1 is not shown.

In the present embodiment, the plurality of steered wheels 2 include a front wheel 21 located in front of the conveyor 1 and a rear wheel 22 located behind the conveyor 1. That is, the transport apparatus 1 is configured to move on the moving surface B1 by the two steering wheels 2. In the present embodiment, the conveyor 1 includes two auxiliary wheels 3 in addition to the two steered wheels 2, but these auxiliary wheels 3 are not included in the steered wheels 2 whose steering angle θ can be changed by the control system 100. Each auxiliary wheel 3 is a driven wheel. The "steering angle" in the present disclosure means an angle formed by the front-rear direction of the conveyor 1 and the wheel surface of the wheel (steering wheel 2) (in other words, the turning direction of the wheel) in a plan view of the conveyor 1 from above. The "wheel surface" in the present disclosure refers to a surface of the wheel (steered wheel 2) that is in contact with the travel surface B1.

The "rail" described in the present disclosure defines a moving path of the conveying device 1 when the conveying device 1 conveys the conveyed article a1 to a destination. In the present embodiment, the rail L1 is provided on the moving surface B1 on which the transport apparatus 1 moves. Specifically, the rail L1 is a linear object such as a magnetic tape or a magnetic marker provided on the moving surface B1. The control system 100 controls the transport apparatus 1 so that the transport apparatus 1 follows the trajectory L1 based on detection of the trajectory L1 by a sensor 4 (described later) mounted on the transport apparatus 1. Thus, the conveyor device 1 can follow the trajectory L1 and convey the conveyed article a1 to the destination. Note that "following the track" may include the movement of the transport apparatus 1 along the track L1 without overlapping the track L1, in addition to the movement of the transport apparatus 1 on the track L1.

The control method of the transport apparatus 1 according to the present embodiment includes an acquisition step ST1 and a correction step ST2 (see fig. 5).

The acquisition step ST1 is a step of acquiring offset information. The offset information is information related to the offset of the conveying device 1 with respect to the trajectory L1 on which the conveying device 1 travels. In the present embodiment, information on the offset of the sensor 4 with respect to the trajectory L1 is acquired as offset information.

The correcting step ST2 is a step of correcting the steering angle θ for each of the steered wheels 2 based on the offset information acquired in the acquiring step ST 1. That is, in the present embodiment, the steering angle θ of each of the plurality of steered wheels 2 is individually corrected, not by performing correction based on the offset information so that the plurality of steered wheels 2 are unified to the same steering angle θ. Of course, as a result of the correction step ST2, there may be a case where the steering angles θ of the respective steered wheels 2 are the same.

Therefore, the present embodiment has an advantage that the deviation of the conveying device 1 from the reference posture is suppressed and the conveying device 1 can easily follow the trajectory L1. The "reference posture" referred to in the present disclosure refers to a posture of the transport apparatus 1 in which the front-rear direction of the transport apparatus 1 is parallel to the rail L1. It should be noted that "parallel" is a concept including not only perfect parallel but also substantially parallel.

(2) Detailed description of the invention

(2.1) integral Structure

The control system 100 according to the present embodiment will be described below with reference to fig. 1 and 2. In the present embodiment, the control system 100 is incorporated in a main body 10 (described later) of the conveyor device 1, and is configured to be capable of communicating with the host system 6. That is, the conveying device 1 includes the control system 100 and the main body 10 on which the control system 100 is mounted and which conveys the conveyed article a 1. The term "capable of communication" in the present disclosure means that information can be exchanged directly or indirectly via the network NT1, the repeater 7, or the like by an appropriate communication method such as wired communication or wireless communication. In the present embodiment, the upper system 6 and the plurality of transport apparatuses 1 can communicate with each other bidirectionally, and both transmission of information from the upper system 6 to the transport apparatuses 1 and transmission of information from the transport apparatuses 1 to the upper system 6 can be realized.

The host system 6 is a system for collectively controlling the plurality of transport apparatuses 1, and is implemented by, for example, a server apparatus. The upper system 6 indirectly controls the plurality of transport devices 1 by giving instructions to the plurality of transport devices 1, respectively.

In the present embodiment, the host system 6 has a computer system including one or more processors and memories as a main structure. Therefore, the functions of the upper system 6 are realized by one or more processors executing programs stored in the memory. The program may be recorded in advance in a memory, may be provided via an electric communication line such as the internet, or may be recorded in a non-transitory recording medium such as a memory card.

(2.2) conveying device

Next, the structure of the conveying device 1 of the present embodiment will be described in more detail. As shown in fig. 1, the transport apparatus 1 is an unmanned transport vehicle for transporting a transport article a1, and autonomously travels to a destination by connecting transport articles a 1. In the present embodiment, the upper system 6 communicates with the transport apparatus 1 via the network NT1 and the relay 7, and indirectly controls the movement of the transport apparatus 1.

The conveyor 1 autonomously travels on a flat traveling surface B1 formed of, for example, a floor surface or the like. Here, the transport apparatus 1 includes a battery, for example, and operates using electric energy stored in the battery. In the present embodiment, the transport apparatus 1 travels on the travel surface B1 with the transport object a1 coupled thereto. Thus, the conveyor device 1 can convey the conveyance object a1 to a certain place by, for example, pulling or pushing the conveyance object a1 placed at the certain place by the conveyor device 1.

The transport apparatus 1 includes a main body 10. The main body 10 is formed in a rectangular parallelepiped shape. In the present embodiment, a coupling portion 5 such as a hook capable of hooking a part of the transport article a1 is provided on a side surface of the main body portion 10. The "side surface of the main body" refers to a surface along the rail L1 when the transport apparatus 1 takes the reference posture. Therefore, in the present embodiment, the conveyance object a1 can be coupled to the conveyance device 1 by hooking a part of the conveyance object a1 to the coupling portion 5. That is, the conveyor 1 includes a coupling portion 5 that couples the conveyed article a1 to one surface (side surface) of the main body portion 10 of the conveyor 1 along the trajectory L1.

The transport apparatus 1 has a plurality of (here, four) wheels at a lower portion of the main body 10. Of the four wheels, a front wheel 21 located at the front of the main body 10 and a rear wheel 22 located at the rear of the main body 10 are each the steered wheels 2. Of the 4 wheels, two wheels located at both ends in the width direction at the center of the main body 10 are auxiliary wheels 3 (driven wheels). In the present embodiment, both the steering wheels 2 also serve as drive wheels, and by driving these drive wheels individually, the conveying device 1 can be moved in a desired direction on the moving surface B1. In addition, when the conveyor 1 deviates from the path following the trajectory L1, each of the two steered wheels 2 is configured to be able to change the steering angle θ within a range sufficient to return to the path.

(2.3) control System

Next, the configuration of the control system 100 according to the present embodiment will be described in more detail. As shown in fig. 2, the control system 100 includes a detection unit 101, a control unit 102, a communication unit 103, a storage unit 104, and a travel device 105. In the present embodiment, the detection unit 101, the control unit 102, the communication unit 103, the storage unit 104, and the travel device 105 are included in the constituent elements of the control system 100, but only the control unit 102 may be included in the constituent elements of the control system 100.

The detection unit 101 detects the behavior of the main body 10, the peripheral condition of the main body 10, and the like. The term "behavior" as used in this disclosure refers to actions, situations, and the like. That is, the behavior of the main body 10 includes an operation state of the main body 10 indicating whether the main body 10 is running or stopped, a speed (and a change in speed) of the main body 10, an acceleration acting on the main body 10, a posture of the main body 10, and the like. Specifically, the detection unit 101 includes sensors such as a speed sensor, an acceleration sensor, and a gyro sensor, and detects the behavior of the main body 10 by these sensors. The Detection unit 101 includes sensors such as an image sensor (camera), a sonar sensor, a radar, and a Light Detection and Ranging, and detects the peripheral situation of the main body 10 by these sensors.

The detection unit 101 includes a position specifying unit that specifies the position of the main body 10, that is, the current position of the conveying device 1. For example, the position specifying unit includes a receiver that receives beacon signals transmitted by radio waves from a plurality of transmitters. The plurality of transmitters are arranged at a plurality of locations within the range in which the conveyor 1 moves. The position specifying unit measures the position of the main body 10 based on the positions of the plurality of transmitters and the received radio wave intensity of the beacon signal at the receiver. The position specifying unit may be implemented using a satellite Positioning System such as a GPS (Global Positioning System).

Further, the detection section 101 includes a plurality of sensors 4. The plurality of sensors 4 are respectively provided in the vicinity of the plurality of steered wheels 2. In the present embodiment, the plurality of steered wheels 2 are two front wheels 21 and two rear wheels 22. Thus, the plurality of sensors 4 are a first sensor 41 disposed in the vicinity of the front wheel 21 (here, the front end of the main body portion 10), and a second sensor 42 disposed in the vicinity of the rear wheel 22 (here, the rear end of the main body portion 10).

Each of the plurality of sensors 4 is a bar-shaped magnetic sensor, and detects the magnetic flux generated in the rail L1 to detect the relative positional relationship between the sensor 4 and the rail L1, that is, the positional displacement of the sensor 4 with respect to the rail L1. In the present embodiment, the first sensor 41 detects the positional deviation of the front wheel 21 with respect to the track L1 by detecting the positional deviation of the first sensor 41 with respect to the track L1. In addition, the second sensor 42 detects a positional deviation of the rear wheel 22 with respect to the track L1 by detecting a positional deviation of the second sensor 42 with respect to the track L1. As an example, the "positional deviation" referred to herein is represented by the shortest distance between the center of the sensor 4 and the track L1.

The communication unit 103 is configured to be able to communicate with the upper system 6. In the present embodiment, the communication unit 103 communicates with any one of the plurality of relays 7 provided in the area where the transport apparatus 1 is operated by wireless communication using radio waves as a medium. Therefore, the communication unit 103 communicates with the upper system 6 indirectly via at least the network NT1 and the repeater 7.

That is, each relay 7 is a device (access point) that relays communication between the communication unit 103 and the upper system 6. The repeater 7 communicates with the upper system 6 via the network NT 1. In the present embodiment, as an example, wireless communication conforming to standards such as Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), or low-power wireless (specific low-power wireless) that does not require permission is used for communication between the relay 7 and the communication unit 103. The network NT1 is not limited to the internet, and may be a local area communication network in an area where the transport apparatus 1 is operated or an operating company in the area.

The storage unit 104 is realized by a non-transitory recording medium such as a rewritable non-volatile semiconductor memory, for example. The storage unit 104 stores, for example, map information relating to a map of an area in which the conveyor apparatus 1 is operated, instruction information given from the upper system 6, and the like.

The traveling device 105 receives a control command from the control unit 102, and individually drives a plurality of drive wheels (two steered wheels 2 in the present embodiment) provided in the main body portion 10, thereby traveling the conveyor device 1 in a desired direction.

The control unit 102 has a main structure of a computer system having one or more processors and memories. Therefore, the functions of the control unit 102 are realized by one or more processors executing programs recorded in a memory. The program may be recorded in advance in a memory, may be provided via an electric communication line such as the internet, or may be recorded in a non-transitory recording medium such as a memory card.

The control unit 102 controls the conveying device 1 based on the detection result of the detection unit 101. In the present embodiment, the control unit 102 includes an acquisition unit 11 and a correction unit 12 for controlling the transport apparatus 1. The acquisition unit 11 and the correction unit 12 are both realized as functions executed by the control unit 102.

The acquisition unit 11 acquires offset information relating to the offset of the transport apparatus 1 with respect to the track L1 by communicating with the plurality of sensors 4. That is, the acquiring unit 11 is an executing body that acquires step ST 1. The offset information may be information generated by the sensor 4 executing appropriate processing on the detection result, or may be information generated by the acquisition unit 11 receiving the detection result of the sensor 4 executing appropriate processing on the detection result of the sensor 4.

Here, the information acquired from the first sensor 41 of the plurality of sensors 4 corresponds to information on the positional deviation of the front wheel 21 located in the vicinity of the first sensor 41 with respect to the track L1. The information acquired from the second sensor 42 of the plurality of sensors 4 corresponds to information relating to the positional displacement of the rear wheel 22 located in the vicinity of the second sensor 42 with respect to the track L1. That is, in the present embodiment, the offset information acquired by the acquisition unit 11 includes a plurality of "steered wheel offset information" relating to the positional offset of each steered wheel 2 of the plurality of steered wheels 2 with respect to the track L1. In the present embodiment, the plurality of steered wheel offset information includes first offset information relating to a positional offset of the front wheels 21 with respect to the track L1, and second offset information relating to a positional offset of the rear wheels 22 with respect to the track L1.

The correction unit 12 corrects the steering angle θ for each of the steered wheels 2 of the plurality of steered wheels 2 based on the offset information acquired by the acquisition unit 11. That is, the correction unit 12 is the main body of execution of the correction step ST 2. In the present embodiment, the correction unit 12 corrects the steering angle θ for each of the steered wheels 2 of the plurality of steered wheels 2 based on the corresponding steered wheel offset information among the plurality of steered wheel offset information acquired by the acquisition unit 11. In other words, the correcting step ST2 is a step of correcting the steering angle θ for each steered wheel 2 of the plurality of steered wheels 2 based on the corresponding steered wheel offset information.

Specifically, the correcting unit 12 corrects the steering angle θ of the front wheels 21 so that the wheel surfaces of the front wheels 21 follow the track L1, based on the first offset information acquired by the acquiring unit 11. Further, the correction unit 12 corrects the steering angle θ of the rear wheel 22 so that the wheel surface of the rear wheel 22 follows the track L1, based on the second offset information acquired by the acquisition unit 11. In the present embodiment, the correction amount of the steering angle θ of each of the front wheels 21 and the rear wheels 22 is determined by PID (Proportional-Integral-Differential) control.

For example, the steering angle θ of the front wheels 21 is represented by "θ f", the steering angle θ of the rear wheels 22 is represented by "θ b", and the steering angles θ f and θ b are represented by the following expressions (1) and (2). In equation (1), "Df" represents the offset amount of the front wheel 21, and "Kf" represents the correction coefficient (scaling coefficient) of the front wheel 21. In equation (2), "Db" represents the offset amount of the rear wheel 22, and "Kb" represents the correction coefficient (scaling coefficient) of the rear wheel 22.

[ numerical formula 1]

θf＝Kf·Df…(1)

θb＝Kb·Db…(2)

Here, the steering angles θ f and θ b expressed by the expressions (1) and (2) each represent a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the steering angles θ f and θ b are expressed by the following expressions (3) and (4), respectively. In equation (3), "Dfi" represents the deviation integral amount of the front wheel 21, "Dfd" represents the deviation differential amount of the front wheel 21, "Kfi" represents the correction coefficient (integral coefficient) of the front wheel 21, and "Kfd" represents the correction coefficient (differential coefficient) of the front wheel 21. In equation (4), "Dbi" represents an integrated amount of the offset of the rear wheel 22, "Dbd" represents a differential amount of the offset of the rear wheel 22, "Kbi" represents a correction coefficient (integral coefficient) of the rear wheel 22, and "Kbd" represents a correction coefficient (differential coefficient) of the rear wheel 22.

[ numerical formula 2]

θf＝Kf·Df+Kfi·Dfi+Kfd·Dfd…(3)

θb＝Kb·Db+Kbi·Dbi+Kbd·Dbd…(4)

In the present embodiment, the correction unit 12 corrects the steering angle θ for each of the steered wheels 2 as described above, and also corrects the speed of each of the steered wheels (drive wheels) 2. Specifically, the correction unit 12 corrects the speed (circumferential speed) of each of the steered wheels 2 based on the steering angle θ corrected as described above with respect to each of the steered wheels 2. In other words, the control method further has a speed correction step ST3 of correcting, for each steered wheel 2 of the plurality of steered wheels 2, the speed of the corresponding steered wheel 2 based on the steering angle θ corrected in the correction step ST2 in this speed correction step ST 3.

Hereinafter, a process of determining the speed of each of the plurality of steered wheels 2 will be described with reference to fig. 3. In fig. 3, the conveying device 1 is assumed to move rightward. In fig. 3, "α" represents the steering angle θ of the front wheels 21, "β" represents the steering angle θ of the rear wheels 22, and "V_α"indicates the speed of the front wheel 21," V_β"represents the speed of the rear wheel 22," W "represents the distance between the center of the front wheel 21 and the center of the rear wheel 22. In addition, in FIG. 3, "r" is_α"the turning radius of the front wheel 21 centered on the intersection X1 of the straight line extending the axis of the front wheel 21 and the straight line extending the axis of the rear wheel 22" r_β"is the turning radius of the rear wheel 22 with the center at the intersection X1 of the straight line extending the axis of the front wheel 21 and the straight line extending the axis of the rear wheel 22.

Here, the turning radius of the front wheels 21 and the turning radius of the rear wheels 22 vary depending on the steering angle θ of the front wheels 21 and the steering angle θ of the rear wheels 22. Therefore, the turning radius of the front wheel 21 and the turning radius of the rear wheel 22 are substantially different from each other. Therefore, there is a possibility that: when the speed of the front wheels 21 is the same as the speed of the rear wheels 22, the angular speed of the front wheels 21 does not match the angular speed of the rear wheels 22, and the motion of the front wheels 21 cannot be matched with the motion of the rear wheels 22, and the conveyor 1 is difficult to follow the track L1 due to, for example, the idle rotation of one of the steered wheels 2.

In contrast, in the present embodiment, the correction unit 12 corrects the speed of each of the steered wheels 2 based on the steering angle θ, so that the angular speed of the front wheels 21 matches the angular speed of the rear wheels 22, and the operation of the front wheels 21 matches the operation of the rear wheels 22. Here, the ratio of the speed of the front wheels 21 to the speed of the rear wheels 22 when the angular velocity of the front wheels 21 and the angular velocity of the rear wheels 22 match (hereinafter simply referred to as "speed ratio") is expressed by the following equation (5).

[ numerical formula 3]

That is, the speed ratio can be determined based on the steering angle θ of the front wheels 21 and the steering angle θ of the rear wheels 22, independently of the size of the conveyor 1 (for example, the distance "W" between the centers of the front wheels 21 and the rear wheels 22).

As described above, the correction unit 12 controls the conveyor 1 to follow the trajectory L1 by correcting the steering angle θ for each of the front wheels 21 and the rear wheels 22 and correcting the speed of each of the front wheels 21 and the rear wheels 22 based on the corrected steering angle θ.

(2.4) component mounting System

As shown in fig. 4, in the present embodiment, the conveyed article a1 is, for example, a component supply device 8 having one or more feeders. The component supply device 8 is used to supply components to a mounting body 90 of a component mounting machine 9 installed in a factory. The "component mounter" referred to herein is, for example, a machine that mounts components on an object such as a substrate. The mounting body 90 includes a mounting head that mounts a component to a substrate. That is, in the present embodiment, the transport apparatus 1 transports the component supply apparatus 8 as the transport object a1 to the installation location of the mounting body 90 of the component mounter 9 under the control of the control system 100. This enables the component mounting system 200 to be constructed. In other words, the component mounting system 200 is a system including at least one component mounter 9 that mounts components on a substrate. Further, the component supply device 8 is conveyed to the mounting body 90 by the conveying device 1 controlled by the control system 100.

Here, the transport device 1 is preferably connectable to a portion of the component supply device 8 that is located on the opposite side of the portion where the component is discharged to the mounting body 90. In this case, when the component supply device 8 is conveyed to the installation place of the mounting body 90 of the component mounting machine 9, the part of the component supply device 8 from which the components are discharged faces the mounting body 90. Therefore, when the component supply device 8 is transported to the installation place of the mounting body 90 of the component mounting machine 9, the operation of changing the direction of the component supply device 8 so that the discharge portion is directed toward the mounting body 90 is not performed.

(3) Movement of

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 5. In the operation example shown in fig. 5, it is assumed that the transport apparatus 1 is in the process of transporting the transport object a1 and moving to the destination following the trajectory L1. During the movement of the conveying device 1, the acquisition unit 11 acquires the first offset information by periodically acquiring the detection result from the first sensor 41 (S1). Similarly, the acquisition unit 11 acquires second offset information by periodically acquiring the detection result from the second sensor 42 (S2). The acquisition of the first offset information and the acquisition of the second offset information by the acquisition unit 11 are performed substantially simultaneously. Steps S1 and S2 correspond to the acquisition step ST 1.

Next, the correction unit 12 corrects the steering angle θ of the front wheels 21 based on the first offset information acquired by the acquisition unit 11 (S3). Similarly, the correcting unit 12 corrects the steering angle θ of the rear wheel 22 based on the second offset information acquired by the acquiring unit 11 (S4). The correction of the steering angle θ of the front wheels 21 and the correction of the steering angle θ of the rear wheels 22 by the correcting portion 12 are performed almost simultaneously. Steps S3, S4 correspond to the correction step ST 2.

Then, the correcting unit 12 corrects the speed ratio of the front wheels 21 and the rear wheels 22 based on the corrected steering angle θ of the front wheels 21 and the corrected steering angle θ of the rear wheels 22 (S5). That is, the correction portion 12 corrects the speed of the front wheels 21 and the speed of the rear wheels 22. Step S5 corresponds to the speed correction step ST 3.

Then, the control unit 102 controls the front wheels 21 based on the steering angle θ of the front wheels 21 corrected by the correction unit 12 and the speed of the front wheels 21 (S6). Similarly, the control unit 102 controls the rear wheels 22 based on the steering angle θ of the rear wheels 22 corrected by the correction unit 12 and the speed of the rear wheels 22 (S7). Thereafter, the above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S8: yes). Thereby, the transport apparatus 1 moves to the destination following the trajectory L1 while suppressing deviation from the reference posture.

(4) Advantages of the invention

Hereinafter, advantages of the control system 100 according to the present embodiment will be described in comparison with a control system of a comparative example. As shown in fig. 6, the control system assumed as a comparative example controls the conveying device 1 that conveys the conveyed article a 1. Instead of two sensors 4, the conveyor 1 has a sensor 40 at the front end of the conveyor 1. Then, the control system of the comparative example controls the conveying device 1 so that the conveying device 1 follows the trajectory L1 based on the detection result of the sensor 40.

In the control system of the comparative example, when the transport apparatus 1 is controlled so that the transport apparatus 1 follows the trajectory L1, the positional deviation of the sensor 40 with respect to the trajectory L1 can be corrected, but it is difficult to correct the deviation of the entire transport apparatus 1 with respect to the trajectory L1.

Here, in the transport apparatus 1 shown in fig. 6, since the steering wheel 2 is located at a position deviated from the center of gravity of the transported object a1, a deviation in the traveling resistance occurs, and thereby the forward traveling performance of the transport apparatus 1 is easily lost. Therefore, in the case where the conveyor device 1 that conveys the conveyed article a1 is controlled by the control system of the comparative example, the conveyor device 1 follows the trajectory L1 in a state inclined from the reference posture due to the offset of the travel resistance between the conveyed article a1 and the conveyor device 1. Therefore, when the conveying apparatus 1 is controlled by the control system of the comparative example, there are problems as follows: the ratio of the transport device 1 and the transport object a1 to the width of the passage tends to increase, making it difficult to move the transport device 1 on a narrow passage.

In contrast, in the present embodiment, the correction unit 12 corrects the steering angle θ for each of the steered wheels 2 of the plurality of steered wheels 2 based on the corresponding steered wheel offset information among the plurality of steered wheel offset information acquired by the acquisition unit 11. That is, in the present embodiment, the positional deviation of the front wheels 21 with respect to the track L1 is corrected so that the front wheels 21 follow the track L1, and the positional deviation of the rear wheels 22 with respect to the track L1 is corrected so that the rear wheels 22 follow the track L1.

Therefore, in the present embodiment, since the conveying device 1 is controlled so that all the steered wheels 2 (here, the front wheels 21 and the rear wheels 22) follow the trajectory L1, even when the conveyed object a1 is conveyed and is moving, correction is performed so that the posture of the conveying device 1 becomes the reference posture. Therefore, the present embodiment has an advantage that the deviation of the conveying device 1 from the reference posture is suppressed and the conveying device 1 can easily follow the trajectory L1.

(5) Modification example

The above-described embodiment is merely one embodiment of various embodiments of the present disclosure. The above embodiment may be modified in various ways according to design and the like as long as the object of the present disclosure can be achieved. The same functions as those of the control method (control system 100) of the above embodiment may be embodied by a computer program, a non-transitory recording medium on which a computer program is recorded, or the like. A program according to an aspect of the present disclosure causes one or more processors to execute the control method described above.

Modifications of the above embodiment will be described below. The following modifications can be applied in combination as appropriate.

The control system 100 of the present disclosure includes a computer system in the control unit 102 or the like, for example. The computer system has a processor and a memory as hardware as a main structure. The functions as the control system 100 of the present disclosure are realized by a processor executing a program recorded in a memory of a computer system. The program may be recorded in advance in a memory of the computer system, may be provided via an electric communication line, or may be recorded in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that is readable by the computer system. A processor of a computer system is constituted by one or more electronic circuits including a semiconductor Integrated Circuit (IC) or a large scale integrated circuit (LSI). The integrated circuits such as IC and LSI are referred to as system LSI, VLSI (Very Large Scale Integration) or ULSI (Ultra Large Scale Integration), which are called different integrated circuits depending on the degree of Integration. Furthermore, an FPGA (Field-Programmable Gate Array) programmed after the manufacture of the LSI or a logic device capable of reconstructing a connection relationship inside the LSI or circuit division inside the LSI can also be used as the processor. The plurality of electronic circuits may be integrated in one chip or may be disposed in a plurality of chips in a distributed manner. The plurality of chips may be collected in one device or may be provided in a plurality of devices in a distributed manner. The computer system described herein includes a microcontroller having more than one processor and more than one memory. Thus, with regard to the microcontroller, it may also be constituted by one or more electronic circuits including a semiconductor integrated circuit or a large scale integrated circuit.

Further, it is not essential to integrate a plurality of functions in the control system 100 into one housing in the control system 100, and the components of the control system 100 may be provided in a plurality of housings in a distributed manner. Further, the functions of at least a part of the control system 100 may be realized by cloud (cloud computing) or the like.

In the above embodiment, for example, as shown in fig. 7, the control system 100 may cause the transport apparatus 1 to follow the track L1 by a so-called differential control in which the steering angle θ of the plurality of steered wheels 2 is fixed and the transport apparatus 1 is moved by a speed difference between the plurality of steered wheels 2.

In the above embodiment, for example, as shown in fig. 8, the control system 100 may rotate the transport apparatus 1 as follows: the steering angle θ of the plurality of steered wheels 2 is fixed, and the plurality of steered wheels 2 are made to follow a circular orbit having as the center an intersection X1 where straight lines extending the axes of the plurality of steered wheels 2 intersect.

In the above embodiment, for example, as shown in fig. 9, a plurality of sensors 4 may be disposed between a plurality of steered wheels 2. In fig. 9, the plurality of sensors 4 are drawn by solid lines, but actually, the plurality of sensors 4 are hidden in the main body portion 10 of the transport apparatus 1 (described later). The same applies to fig. 10 to 16.

In the above embodiment, the correction unit 12 may not perform control for correcting the speed of each of the steered wheels 2. In this case, as in the above-described embodiment, it is not necessary that all of the plurality of steered wheels 2 also serve as driving wheels, and at least one of the steered wheels 2 also serves as driving wheels.

In the above embodiment, instead of correcting the speeds of the steered wheels 2, the correction unit 12 may correct the torques applied to the axles of the steered wheels 2.

In the above embodiment, the correction amount of the steering angle θ of each of the plurality of steered wheels 2 may be determined by P (Proportional ) control or PI (Proportional-Integral) control, in addition to PID control.

In the above embodiment, the rail L1 may not be provided on the travel surface B1. That is, the track L1 may not have any entity. For example, the trajectory L1 may be a virtual trajectory in the map information given to the transport apparatus 1. In this case, the sensor 4 is not a magnetic sensor, but may be a system in which a positional deviation of the position of the sensor 4 with respect to the virtual orbit is detected by a combination of a satellite positioning system such as GPS and LiDAR, for example.

In the above embodiment, the control system 100 is mounted on the transport apparatus 1, but is not limited thereto. For example, the host system 6 may function as the control system 100. In this case, the upper system 6 executes an acquisition step ST1, and acquires the detection result of the sensor 4 from the conveying device 1 by wireless communication in the acquisition step ST1, thereby acquiring the offset information. In this case, the upper system 6 executes the correction step ST2 and the speed correction step ST3, and in the correction step ST2 and the speed correction step ST3, the steering angle θ and the speed are corrected for each of the plurality of steered wheels 2 based on the acquired offset information, and the command to change to the corrected steering angle θ and speed is transmitted to the transport apparatus 1 by wireless communication.

In the above embodiment, the connection portion 5 is not limited to a mode in which a hook or the like hooks a part of the transported object a1, and may be a mode in which the transported object a1 is attracted by an electromagnet.

In the above embodiment, the conveyor 1 may not have the connection portion 5. For example, the transport apparatus 1 may have a structure in which the transport object a1 is loaded on the transport apparatus 1. That is, the transport device 1 may be a system capable of transporting the transported object a 1.

(embodiment mode 2)

(1) Detailed description of the invention

The conveyor device 1 according to the present embodiment is different from the conveyor device 1 according to embodiment 1 described above in that a plurality of sensors 4 (here, a first sensor 41 and a second sensor 42) are disposed between a plurality of steered wheels 2 (here, front wheels 21 and rear wheels 22), as shown in fig. 10.

In the control system 100 according to the present embodiment, the offset information acquired by the acquisition unit 11 is different from the control system 100 according to embodiment 1. Specifically, in the present embodiment, the offset information includes rotational offset information and positional offset information. The rotational offset information is information related to the inclination offset of the conveying device 1 from the reference posture of the conveying device 1 with respect to the trajectory L1. The positional deviation information is information related to the positional deviation of the conveying device 1 from the reference posture.

In the present embodiment, the acquisition unit 11 acquires the rotational displacement information and the positional displacement information based on the detection results of the first sensor 41 and the second sensor 42, respectively. Specifically, the acquisition unit 11 acquires, as the positional displacement information, an intermediate value between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1 (i.e., the positional displacement amount D1 between the control point P1 of the main body portion 10 of the transport apparatus 1 and the track L1). The control point P1 is the center of the main body portion 10 of the transport apparatus 1. In addition, the control point P1 is an intermediate point between the center of the first sensor 41 and the center of the second sensor 42. The acquiring unit 11 acquires, as the rotational offset information, the rotational offset amount D2, which is an angle in which the distance D11 between the center of the first sensor 41 and the center of the second sensor 42 and the difference D12 are tangent (tangent), and the rotational offset amount D2. The difference D12 is a difference between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1.

Note that the control system 100 according to the present embodiment differs from the control system 100 according to embodiment 1 described above in that the correction unit 12 corrects the steering angle θ of each of the plurality of steered wheels 2. Specifically, in the present embodiment, the correction unit 12 corrects the steering angle θ for each of the steered wheels 2 of the plurality of steered wheels 2 based on the rotational offset information and the positional offset information acquired by the acquisition unit 11. In other words, the correcting step ST2 is a step of correcting the steering angle θ for each of the steered wheels 2 of the plurality of steered wheels 2 based on the rotational offset information and the positional offset information.

Hereinafter, a process of correcting the steering angle θ of each of the plurality of steered wheels 2 by the correction unit 12 will be described with reference to fig. 11 to 13. First, the correction unit 12 calculates a first steering angle θ 1 for each steered wheel 2 of the plurality of steered wheels 2. The first steering angle θ 1 is an angle obtained based on the positional deviation information. As shown in fig. 11, the first steering angle θ 1 is an angle at which the transport apparatus 1 is moved in parallel without being rotated so that the positional deviation D1 (see fig. 10) becomes zero (that is, the control point P1 rides on the track L1). Therefore, the first steering angle θ 11 of the front wheel 21 and the first steering angle θ 12 of the rear wheel 22 have the same value.

Next, the correction unit 12 calculates a second steering angle θ 2 for each of the steered wheels 2 of the plurality of steered wheels 2. The second steering angle θ 2 is an angle obtained based on the rotational offset information. As shown in fig. 12, the second steering angle θ 2 is an angle at which the conveying device 1 is rotated so that the rotational offset amount D2 (see fig. 10) becomes zero (that is, the conveying device 1 is in the reference posture). Here, the second steering angle θ 21 of the front wheels 21 and the second steering angle θ 22 of the rear wheels 22 are in opposite phases to each other as will be described later.

Then, the correction unit 12 corrects the steering angle θ based on a combined steering angle θ 3 obtained by combining the calculated first steering angle θ 1 and the second steering angle θ 2 for each of the plurality of steered wheels 2. In other words, the correcting step ST2 is a step of correcting the steering angle θ based on the combined steering angle θ 3 obtained by combining the first steering angle θ 1 and the second steering angle θ 2 for each of the plurality of steered wheels 2. As shown in fig. 13, the combined steering angle θ 31 of the front wheels 21 is an angle obtained by adding the first steering angle θ 11 of the front wheels 21 and the second steering angle θ 21 of the front wheels 21. The combined steering angle θ 32 of the rear wheels 22 is an angle obtained by adding the first steering angle θ 12 of the rear wheels 22 and the second steering angle θ 22 of the rear wheels 22.

Here, when calculating the second steering angle θ 2, the correction unit 12 executes reverse phase control for calculating the second steering angle θ 2 of each of the plurality of steered wheels 2 so that the second steering angle θ 21 of the front wheels 21 and the second steering angle θ 22 of the rear wheels 22 are in reverse phase with each other. The "mutually opposite phases" referred to in the present disclosure means a relationship between the steering angle θ of the front wheels 21 when the front wheels 21 are rotated clockwise or counterclockwise and the steering angle θ of the rear wheels 22 when the rear wheels 22 are rotated in the direction opposite to the front wheels 21. For example, when the second steering angle θ 21 of the front wheels 21 is assumed to be 30 degrees, the second steering angle θ 22 of the rear wheels 22 becomes-30 degrees when the relationship of the phases opposite to each other is satisfied. In other words, the correction step ST2 has the steps of: when the steering angle θ is corrected based on the rotational offset information, the steering angle θ of the front wheels 21 of the plurality of steered wheels 2 positioned in front of the conveyor 1 and the steering angle θ of the rear wheels 22 of the plurality of steered wheels 2 positioned behind the conveyor 1 are in opposite phases to each other.

The advantages of the above-described reverse phase control will be described below with reference to fig. 14 to 16. First, it is assumed that the conveyor 1 is controlled by correcting the steering angle θ of each of the front wheels 21 and the rear wheels 22 by the first steering angle θ 1 calculated by the correction unit 12. In this case, as shown in fig. 14, inertia indicated by an inertia vector V1 toward the first steering angle θ 1 acts on the conveying device 1.

In this state, it is assumed that the conveyor 1 is controlled by correcting only the front wheels 21 by the steering angle θ 110 obtained by further adding the second steering angle θ 21. In this case, as shown in fig. 15, when a yaw moment about the grounding point of the rear wheel 22 and the travel surface B1 acts on the transport apparatus 1, the inertia vector V1 changes sharply to the inertia vector V2. As described above, when the inertia acting on the transport apparatus 1 changes rapidly, there is a possibility that the balance between the transport apparatus 1 and the transported object a1 is easily broken or the loss of the propulsive force of the transport apparatus 1 becomes large.

In contrast, in the present embodiment, the above-described problem is solved by performing the above-described reverse phase control. That is, when the correction unit 12 executes the reverse phase control in the state in which the transport apparatus 1 is shown in fig. 14, inertia indicated by the inertia vector V3 directed in the tangential direction of the rotation orbit of the transport apparatus 1 acts on the transport apparatus 1 as shown in fig. 16. Since the inertia vector V3 is in substantially the same direction as the inertia vector V1 immediately before the reverse phase control is executed, the change in inertia acting on the transport device 1 can be suppressed as much as possible. Therefore, the present embodiment has an advantage that the balance between the transport apparatus 1 and the transported object a1 is hardly lost and the loss of the propulsive force of the transport apparatus 1 can be suppressed.

For example, the combined steering angle θ 31 of the front wheels 21 and the combined steering angle θ 32 of the rear wheels 22 are expressed by the following expressions (6) to (9). In equation (8), "Dx" represents the amount of positional deviation, and "Kx" represents the positional correction coefficient (scaling coefficient). In equation (9), "Dr" represents a rotational shift amount, and "Kr" represents a rotation correction coefficient (scaling coefficient).

[ numerical formula 4]

θ31＝θ1+θ2…(6)

θ32＝θ1-θ2…(7)

θ1＝Kx·Dx…(8)

θ2＝Kr·Dr…(9)

Here, each of the steering angles θ 1 and θ 2 expressed by the expressions (8) and (9) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the steering angles θ 1 and θ 2 are expressed by the following expressions (10) and (11), respectively. In equation (10), "Dxi" represents an integral amount of positional deviation, "Dxd" represents a differential amount of positional deviation, "Kxi" represents a positional correction coefficient (integral coefficient), and "Kxd" represents a positional correction coefficient (differential coefficient). In equation (11), "Dri" represents an integral amount of rotational deviation, "Drd" represents a differential amount of rotational deviation, "Kri" represents a rotation correction coefficient (integral coefficient), and "Krd" represents a rotation correction coefficient (differential coefficient).

[ numerical formula 5]

θ1＝Kx·Dx+Kxi·Dxi+Kxd·Dxd…(10)

θ2＝Kr·Dr+Kri·Dri+Krd·Drd…(11)

(2) Movement of

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 17. In the operation example shown in fig. 17, it is assumed that the transport apparatus 1 is in the process of transporting the transport object a1 and moving to the destination following the trajectory L1. During the movement of the transport apparatus 1, the acquisition unit 11 acquires the positional deviation information and the rotational deviation information by periodically acquiring the detection results from the first sensor 41 and the second sensor 42 (S9). Step S9 corresponds to acquisition step ST 1.

Next, the correction unit 12 calculates the first steering angle θ 1 of each of the front wheels 21 and the rear wheels 22 based on the positional deviation information acquired by the acquisition unit 11 (S10). The correction unit 12 calculates the second steering angle θ 2 of each of the front wheels 21 and the rear wheels 22 based on the rotational offset information acquired by the acquisition unit 11 (S11). Then, the correction unit 12 calculates a combined steering angle θ 3 of each of the front wheels 21 and the rear wheels 22 based on the calculated first steering angle θ 1 and second steering angle θ 2 (S12). Then, the correcting unit 12 corrects the steering angle θ of each of the front wheels 21 and the rear wheels 22 based on the calculated combined steering angle θ 3 (S13). Steps S10 to S13 correspond to the correction step ST 2.

Then, the correcting unit 12 corrects the speed ratio of the front wheels 21 and the rear wheels 22 based on the corrected steering angle θ of the front wheels 21 and the corrected steering angle θ of the rear wheels 22 (S14). That is, the correction portion 12 corrects the speed of the front wheels 21 and the speed of the rear wheels 22. Step S14 corresponds to the speed correction step ST 3.

Then, the control unit 102 controls the front wheels 21 based on the steering angle θ of the front wheels 21 corrected by the correction unit 12 and the speed of the front wheels 21 (S15). Similarly, the control unit 102 controls the rear wheels 22 based on the steering angle θ of the rear wheels 22 corrected by the correction unit 12 and the speed of the rear wheels 22 (S16). Thereafter, the above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S17: yes). Thereby, the transport apparatus 1 moves to the destination following the trajectory L1 while suppressing deviation from the reference posture.

(3) Advantages of the invention

As described above, in the present embodiment, all the steered wheels 2 (here, the front wheels 21 and the rear wheels 22) of the conveyor 1 are controlled so as to correct the inclination deviation of the conveyor 1 from the reference posture of the conveyor 1 with respect to the rail L1 and the positional deviation of the conveyor 1 from the reference posture. Therefore, in the present embodiment, even when the transport object a1 is being transported and moved, the posture of the transport device 1 is corrected so as to be the reference posture. Therefore, in the present embodiment, as in embodiment 1, there is an advantage that the deviation of the conveying device 1 from the reference posture is suppressed and the conveying device 1 can easily follow the trajectory L1.

(4) Modification example

The configuration described in embodiment 2 can be appropriately combined with the various configurations (including the modifications) described in embodiment 1.

In embodiment 2, the correcting unit 12 corrects the steering angle θ based on the combined steering angle θ 3 for each of the steered wheels 2 of the plurality of steered wheels 2, but the present invention is not limited thereto. For example, the correction unit 12 may alternately execute the process of correcting the steering angle θ based on the first steering angle θ 1 and the process of correcting the steering angle θ based on the second steering angle θ 2. In other words, the correction step ST2 may be configured to alternately execute the first lowering step and the second lowering step for each steered wheel 2 of the plurality of steered wheels 2. The first lower step is a step of correcting the steering angle θ based on the rotational offset information, and corresponds to a step of correcting the steering angle θ based on the first steering angle θ 1 calculated in step S10 of fig. 17. The second lower step is a step of correcting the steering angle θ based on the positional deviation information, and corresponds to a step of correcting the steering angle θ based on the second steering angle θ 2 calculated in step S11 of fig. 17.

In embodiment 2 described above, the sensor 4 is a system for detecting physical quantities capable of generating positional displacement information and rotational displacement information. For example, the sensor 4 may be a system in which a plurality of bar-shaped magnetic sensors are arranged in a ring shape, or may be one magnetic sensor in a ring shape. The sensor 4 may be an imaging device provided on either one of the conveying devices 1 to image the trajectory L1. The sensor 4 may be an imaging device that images the transport apparatus 1 from outside the transport apparatus 1. Further, if the sensor 4 does not require the accuracy of the positional offset information and the rotational offset information, it may be a GPS module or a geomagnetic sensor.

In embodiment 2 described above, the correction unit 12 may not perform the reverse phase control when calculating the second steering angle θ 2. That is, the correction unit 12 may set the second steering angle θ 21 of the front wheels 21 and the second steering angle θ 22 of the rear wheels 22 to be in phase with each other.

(embodiment mode 3)

Hereinafter, a control method according to embodiment 3 will be described with reference to fig. 18. In the present embodiment, a method of controlling the transport apparatus 1 when the plurality of steered wheels 2 (here, the first wheels 21 and the second wheels 22) are aligned in a direction intersecting the front-rear direction will be described.

Here, in the case where a plurality of steered wheels 2 are aligned in the front-rear direction as in

embodiments

1 and 2 and in the case where they are aligned in the direction intersecting the front-rear direction as in embodiment 3, the control method may be different or a common control method may be used. When the control method is different, the control method may be switched according to the orientation of the plurality of steered wheels 2.

That is, the control system of the present embodiment includes at least one of the first steering angle control processing unit and the second steering angle control processing unit. The first steering angle control processing unit controls the steering angle θ of the conveying device 1 in a state where the plurality of steered wheels 2 of the conveying device 1 having the plurality of steered wheels 2 and conveying the conveyed article a1 are aligned in the front-rear direction. The second steering angle control processing unit controls the steering angle θ of the conveyor device 1 in a state where the plurality of steered wheels 2 of the conveyor device 1 are aligned in a direction intersecting the front-rear direction. In the present embodiment, the control unit 102 has a function as a first steering angle control processing unit and a function as a second steering angle control processing unit.

The control method according to the present embodiment includes at least one of the first steering angle control process and the second steering angle control process. The first steering angle control process is a process of controlling the steering angle θ of the conveying device 1 in a state where the plurality of steered wheels 2 of the conveying device 1 having the plurality of steered wheels 2 and conveying the conveyed article a1 are aligned in the front-rear direction. The second steering angle control process is a process of controlling the steering angle θ of the conveyor device 1 in a state where the plurality of steered wheels 2 of the conveyor device 1 are aligned in a direction intersecting the front-rear direction.

As an example of a control method of the steering angle θ in the first steering angle control process and the second steering angle control process, there is a first control method of correcting the steering angle θ based on corresponding steered wheel offset information for each steered wheel 2 of the plurality of steered wheels 2 (see embodiment 1). As another example of the control method, there is a second control method in which the steering angle θ is corrected based on the rotational offset information and the positional offset information (see embodiment 2).

When the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction, the second control method is preferably adopted, but the first control method may also be adopted. In the case of the first control method, for example, the sensors 4 are disposed on both the left and right sides of fig. 18, and the first sensor 41 on the left side detects the positional deviation of the first sensor 41 with respect to the track L1, whereby the positional deviation of the first wheel 21 with respect to the track L1 can be detected. Further, the second sensor 42 on the right side detects the positional deviation of the second sensor 42 with respect to the track L1, and thereby can detect the positional deviation of the second wheel 22 with respect to the track L1. The conveyor 1 may be controlled so that the respective amounts of positional displacement of the first wheel 21 and the second wheel 22 are equal to each other.

Hereinafter, the following will be explained: when the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction, a second control method is adopted as a control method of the conveyor 1.

(1) Summary of the invention

In the present embodiment, the conveying device 1 includes a plurality of steering wheels 2 arranged in a direction intersecting with the front-rear direction of the conveying device 1, and conveys the conveyed article a1 while moving on the moving surface B1. The "front-rear direction" referred to in the present disclosure is a width direction of the conveying device 1, and is a direction in which the conveying device 1 travels is referred to as "front" and a reverse direction thereof is referred to as "rear". In the present embodiment, the "direction intersecting with the front-rear direction" is the longitudinal direction of the transport device 1, and is the left-right direction in fig. 18. As in embodiment 1, the transport device 1 may be configured to travel in the longitudinal direction. The front-rear direction in this case is the longitudinal direction.

The blank arrow in fig. 18 indicates the traveling direction of the conveyor 1. In fig. 18, the crisscross arrows indicate "front", "rear", "left", and "right" of the transport apparatus 1. The arrows in fig. 18 are designated for illustrative purposes only and are not accompanied by entities. In fig. 18, wheels such as the plurality of steerable wheels 2 of the conveyor device 1 are drawn by solid lines, but actually, these wheels are hidden in the main body portion 10 of the conveyor device 1 (described later). Note that, in fig. 18, the track L1 is drawn by a solid line, but actually, a portion of the track L1 that overlaps with the transport apparatus 1 is hidden in the main body 10 of the transport apparatus 1. The same applies to the figures other than fig. 18.

In the present embodiment, the plurality of steering wheels 2 includes a first wheel 21 located at a first end in the longitudinal direction of the conveyor 1 and a second wheel 22 located at a second end in the longitudinal direction of the conveyor 1. That is, the transport apparatus 1 is configured to move on the moving surface B1 by the two steering wheels 2. In the present embodiment, the conveyor 1 includes four auxiliary wheels 3 in addition to the two steered wheels 2, but these auxiliary wheels 3 are not included in the steered wheels 2 whose steering angle θ (see fig. 20) can be changed by the control system 100.

The control method of the transport apparatus 1 according to the present embodiment includes an acquisition step ST1 and a correction step ST2 (see fig. 28).

The acquisition step ST1 is a step of acquiring the rotational offset information and the positional offset information. The rotational offset information is information related to the inclination offset of the conveying device 1 from the reference posture of the conveying device 1 with respect to the trajectory L1. The positional deviation information is information related to the positional deviation of the conveying device 1 from the reference posture. The "reference posture" referred to in the present disclosure means a posture of the transport apparatus 1 in which the front-rear direction of the transport apparatus 1 is parallel to the rail L1. It should be noted that "parallel" is a concept including not only perfect parallel but also substantially parallel. In the present embodiment, the acquisition unit 11 acquires the rotational displacement information and the positional displacement information based on the detection results of the first sensor 41 and the second sensor 42, which will be described later.

The correcting step ST2 is a step of correcting the steering angle θ for each of the steered wheels 2 based on the rotational offset information and the positional offset information acquired in the acquiring step ST 1. That is, in the present embodiment, the steering angle θ of each of the plurality of steered wheels 2 is individually corrected, not by performing correction based on the rotational offset information and the positional offset information so that the plurality of steered wheels 2 are unified into the same steering angle θ. Of course, as a result of the correction step ST2, there may be a case where the steering angles θ of the respective steered wheels 2 are the same.

Therefore, the present embodiment has an advantage that the deviation of the conveying device 1 from the reference posture is suppressed and the conveying device 1 can easily follow the trajectory L1.

(2) Detailed description of the invention

(2.1) integral Structure

As in embodiment 1, the upper system 6 shown in fig. 2 communicates with the transport apparatus 1 via the network NT1 and the relay 7, and indirectly controls the movement of the transport apparatus 1. The relationship between the transport apparatus 1 and the host system 6, the network NT1, and the relay unit 7 is the same as that in embodiment 1, and therefore, the description thereof is omitted.

(2.2) conveying device

As shown in fig. 18, the transport apparatus 1 includes a main body 10. The main body 10 is formed in a rectangular parallelepiped shape. In the present embodiment, a coupling portion 5 such as a hook capable of hooking a part of the transport article a1 is provided on a side surface of the main body portion 10. The "side surface of the main body" referred to herein is a surface intersecting the trajectory L1 when the transport apparatus 1 takes the reference posture. Therefore, in the present embodiment, the conveyance object a1 can be coupled to the conveyance device 1 by hooking a part of the conveyance object a1 to the coupling portion 5. That is, the conveyor 1 includes a coupling portion 5 for coupling the conveyed article a1 on a surface (back surface) of the main body portion 10 of the conveyor 1 that intersects the trajectory L1.

The transport apparatus 1 has a plurality of (here, six) wheels at a lower portion of the main body 10. Of the six wheels, a first wheel 21 located at a first end (left end) in the longitudinal direction (left-right direction) of the main body portion 10 and a second wheel 22 located at a second end (right end) in the longitudinal direction of the main body portion 10 are both steered wheels 2. Of the six wheels, two wheels located on both sides across the first sensor 41 at the front end of the main body portion 10 and two wheels located on both sides across the second sensor 42 at the rear end of the main body portion 10 are auxiliary wheels 3 (driven wheels). In the present embodiment, both the steering wheels 2 also serve as drive wheels, and by driving these drive wheels individually, the conveying device 1 can be moved in a desired direction on the moving surface B1. In addition, when the conveyor 1 deviates from the path following the trajectory L1, each of the two steered wheels 2 is configured to be able to change the steering angle θ within a range sufficient to return to the path.

(2.3) control System

Next, the configuration of the control system 100 according to the present embodiment will be described in more detail. As shown in fig. 2, the control system 100 includes a detection unit 101, a control unit 102, a communication unit 103, a storage unit 104, and a travel device 105. The configuration of the detection unit 101, the control unit 102, the communication unit 103, the storage unit 104, and the travel device 105, which is similar to that of embodiment 1, is omitted from description.

The detection unit 101 includes a plurality of sensors 4. The plurality of sensors 4 (here, the first sensor 41 and the second sensor 42) are respectively provided between the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22). The first sensor 41 is provided between the two auxiliary wheels 3 at the front end of the main body 10. The second sensor 42 is provided between the two auxiliary wheels 3 at the rear end of the main body 10.

Each of the plurality of sensors 4 is a bar-shaped magnetic sensor, and detects the magnetic flux generated in the rail L1 to detect the relative positional relationship between the sensor 4 and the rail L1, that is, the positional displacement of the sensor 4 with respect to the rail L1. As an example, the "positional deviation" referred to herein is represented by the shortest distance between the center of the sensor 4 and the track L1.

The acquisition unit 11 acquires the rotational offset information and the positional offset information by communicating with the plurality of sensors 4. That is, the acquiring unit 11 is an executing body that acquires step ST1 (see fig. 28). In the present embodiment, the acquisition unit 11 acquires the rotational displacement information and the positional displacement information based on the detection results of the first sensor 41 and the second sensor 42, respectively. Specifically, as shown in fig. 19, the acquisition unit 11 acquires, as the positional displacement information, an intermediate value between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1 (i.e., the positional displacement amount D1 between the control point P1 of the main body portion 10 of the transport device 1 and the track L1). The control point P1 is the center of the main body portion 10 of the transport apparatus 1. In addition, the control point P1 is an intermediate point between the center of the first sensor 41 and the center of the second sensor 42. The acquiring unit 11 acquires, as the rotational offset information, the rotational offset amount D2, which is an angle in which the distance D11 between the center of the first sensor 41 and the center of the second sensor 42 and the difference D12 are tangent (tangent), and the rotational offset amount D2. The difference D12 is a difference between the distance between the center of the first sensor 41 and the track L1 and the distance between the center of the second sensor 42 and the track L1.

The correction unit 12 corrects the steering angle θ for each of the steered wheels 2 based on the rotational displacement information and the positional displacement information acquired by the acquisition unit 11. That is, the correction unit 12 is the main body of execution of the correction step ST2 (see fig. 28). In the present embodiment, the correction unit 12 corrects the steering angle θ of the first wheels 21 and the steering angle θ of the second wheels 22 individually based on the rotational offset information and the positional offset information acquired by the acquisition unit 11. In the present embodiment, the correction amount of the steering angle θ of each of the first wheels 21 and the second wheels 22 is determined by PID (Proportional-Integral-Differential) control.

Hereinafter, a process of correcting the steering angle θ of each of the plurality of steered wheels 2 by the correcting unit 12 will be described with reference to fig. 20 to 22. First, the correction unit 12 calculates a reference steering angle θ 0 for each of the steered wheels 2 of the plurality of steered wheels 2. The reference steering angle θ 0 is an angle in which the steered wheels 2 are advanced along the track L1, and is an angle obtained based on the rotational offset information. In other words, the correction step ST2 includes a step of correcting each of the plurality of steered wheels 2 so that the steering angle θ coincides with the reference steering angle θ 0.

Fig. 20 shows the transport apparatus 1 when the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is set to the reference steering angle θ 0. As shown in fig. 20, the reference steering angle θ 0 of each of the plurality of steered wheels 2 coincides with the rotational offset amount D2. That is, the reference steering angle θ 0 is calculated by obtaining the rotational offset amount D2. In fig. 20, the steering angle θ (reference steering angle θ 0) of the first wheel 21 and the steering angle θ (reference steering angle θ 0) of the second wheel 22 have the same value.

Next, the correction unit 12 calculates a first steering angle θ 1 for each steered wheel 2 of the plurality of steered wheels 2. The first steering angle θ 1 is an angle obtained based on the positional deviation information. The first steering angle θ 1 is an angle at which the transport apparatus 1 is not rotated but moved in parallel so that the positional deviation D1 becomes zero (i.e., the control point P1 rides on the trajectory L1). Fig. 21 shows the conveyor 1 when the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is an angle obtained by adding the reference steering angle θ 0 to the first steering angle θ 1. Here, the first steering angle θ 1 of the first wheel 21 and the first steering angle θ 1 of the second wheel 22 have the same value. Therefore, in fig. 21, the steering angle θ of the first wheel 21 and the steering angle θ of the second wheel 22 have the same value. In the present embodiment, the first steering angle θ 1 is represented by the following formula (12). In equation (12), "K1" represents a correction coefficient for the positional displacement amount D1.

[ numerical formula 6]

θ1＝K1·D1…(12)

Here, the first steering angle θ 1 represented by equation (12) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the first steering angle θ 1 is expressed by the following expression (13). In equation (13), "Dli" represents an integral amount of the positional deviation, "D1D" represents a differential amount of the positional deviation, "K1 i" represents a positional correction coefficient (integral coefficient), and "K1D" represents a positional correction coefficient (differential coefficient).

[ number formula 7]

θ1＝K1.D1+K1i.D1i+K1d.D1d…(13)

Next, the correction unit 12 calculates a second steering angle θ 2 for each of the steered wheels 2 of the plurality of steered wheels 2. The second steering angle θ 2 is an angle obtained based on the rotational offset information. The second steering angle θ 2 is an angle at which the conveying device 1 is turned so that the rotational offset D2 becomes zero (that is, the conveying device 1 is in the reference posture). Fig. 22 shows the conveyor 1 in which the steering angle θ of each of the plurality of steered wheels 2 (here, the first wheel 21 and the second wheel 22) is set to an angle obtained by adding the reference steering angle θ 0 to the first steering angle θ 1 and the second steering angle θ 2. Here, the second steering angle θ 21 of the first wheel 21 and the second steering angle θ 22 of the second wheel 22 are in opposite phases to each other as will be described later. Therefore, in fig. 22, the steering angle θ of the first wheel 21 and the steering angle θ of the second wheel 22 are different from each other.

In the present embodiment, the second steering angle θ 2 (the second steering angle θ 21 of the first wheels 21 and the second steering angle θ 22 of the second wheels 22) is expressed by the following equations (14) to (18). In expressions (14) and (15), "R0" represents a radius of gyration centered on point X0 of the corrected control point P1. The point X0 represents the intersection of the straight line extending the axis of the first wheel 21 and the straight line extending the axis of the second wheel 22. In equation (16), "K2" represents a correction coefficient for the rotational offset amount D2. In equations (17) and (18), "T0" represents the distance between the center of the first wheel 21 and the center of the second wheel 22.

[ number formula 8]

T＝T0cos(θ0+θ1)…(17)

W0＝T0sin(θ0+θ1)…(18)

Here, the radius gyration R0 expressed by equation (16) represents a proportional term (P term) in the PID control. When the integral term and the differential term in the PID control are included, the radius gyration R0 is expressed by the following expression (19). In equation (19), "D2 i" represents an integral amount of rotational misalignment, "D2D" represents a differential amount of rotational misalignment, "K2 i" represents a rotation correction coefficient (integral coefficient), and "K2D" represents a rotation correction coefficient (differential coefficient).

[ numerical formula 9]

Then, the correction unit 12 corrects the steering angle θ based on a combined steering angle θ 3 (see fig. 22) obtained by combining the calculated reference steering angle θ 0, the first steering angle θ 1, and the second steering angle θ 2 for each of the plurality of steered wheels 2. In other words, the correcting step ST2 is a step of correcting the steering angle θ based on the combined steering angle θ 3 obtained by combining the first steering angle θ 1 and the second steering angle θ 2 for each of the plurality of steered wheels 2. As shown in fig. 22, the combined steering angle θ 3 of the first wheel 21 is an angle obtained by adding the reference steering angle θ 0 of the first wheel 21, the first steering angle θ 1 of the first wheel 21, and the second steering angle θ 21 of the first wheel 21. The combined steering angle θ 3 of the second wheels 22 is an angle obtained by adding the reference steering angle θ 0 of the second wheels 22, the first steering angle θ 1 of the second wheels 22, and the second steering angle θ 22 of the second wheels 22.

Here, when calculating the second steering angle θ 2, the correction unit 12 executes reverse phase control for calculating the second steering angle θ 2 of each of the plurality of steered wheels 2 so that the second steering angle θ 21 of the first wheel 21 and the second steering angle θ 22 of the second wheel 22 are in reverse phase with each other. The term "mutually opposite phases" as used in the present disclosure means a relationship between the steering angle θ of the first wheel 21 when the first wheel 21 is rotated clockwise or counterclockwise and the steering angle θ of the second wheel 22 when the second wheel 22 is rotated in the opposite direction to the first wheel 21. For example, when the second steering angle θ 21 of the first wheel 21 is assumed to be 30 degrees, the second steering angle θ 22 of the second wheel 22 becomes-30 degrees when the relationship of the phases opposite to each other is satisfied. In other words, the correction step ST2 has the steps of: when the steering angle θ is corrected based on the rotational offset information, the steering angle θ of the first wheel 21 positioned at the first end (left end) in the longitudinal direction of the conveyor 1 among the plurality of steered wheels 2 and the steering angle θ of the second wheel 22 positioned at the second end (right end) in the longitudinal direction of the conveyor 1 among the plurality of steered wheels 2 are in opposite phases to each other.

The advantages of the above-described reverse phase control will be described below with reference to fig. 23 to 25, taking the transport apparatus 1A as an example. The following description of the advantages of the reverse phase control is also true of the transport apparatus 1 shown in fig. 18. The conveying apparatus 1A is different from the conveying apparatus 1 shown in fig. 18 in that the longitudinal direction of the conveying apparatus 1 is set as the traveling direction. That is, in the conveyor 1A, the longitudinal direction of the conveyor 1A is the front-rear direction, the first wheel 21 is the front wheel 21A, and the second wheel 22 is the rear wheel 22A. The conveyor 1A is different from the conveyor 1 shown in fig. 18 in that it includes two auxiliary wheels. In fig. 23 to 25, the plurality of sensors 4, the coupling portion 5, and the conveyed article a1 are not shown.

First, it is assumed that the conveyor 1A is controlled by correcting the steering angle θ of each of the front wheels 21A and the rear wheels 22A by the first steering angle θ 1 calculated by the correction unit 12. In this case, as shown in fig. 23, inertia indicated by an inertia vector V1 directed toward the first steering angle θ 1 acts on the conveying device 1A.

In this state, it is assumed that the conveyor 1A is controlled by correcting only the front wheels 21A by the steering angle θ 110 obtained by further adding the second steering angle θ 21. In this case, as shown in fig. 24, when a yaw moment about the grounding point of the rear wheel 22A and the travel surface B1 acts on the transport apparatus 1A, the inertia vector V1 changes sharply toward the inertia vector V2. As described above, when the inertia acting on the transport apparatus 1A changes rapidly, there is a possibility that the balance between the transport apparatus 1A and the transported object a1 is easily broken or the loss of the propulsive force of the transport apparatus 1A becomes large.

In contrast, the above problem can be solved by performing the above-described reverse phase control. That is, when the correction unit 12 executes the reverse phase control in the state in which the transport device 1A is shown in fig. 23, inertia indicated by an inertia vector V3 directed in the tangential direction of the rotation orbit of the transport device 1A acts on the transport device 1A as shown in fig. 25. Since the inertia vector V3 is in substantially the same direction as the inertia vector V1 immediately before the reverse phase control is executed, the change in inertia acting on the transport device 1A can be suppressed as much as possible. Therefore, there are advantages in that the balance between the transport apparatus 1A (transport apparatus 1) and the transported object a1 is hardly lost and the loss of the propulsive force of the transport apparatus 1A (transport apparatus 1) can be suppressed.

In the present embodiment, the correction unit 12 corrects the steering angle θ for each of the steered wheels 2 as described above, and corrects the speed of each of the steered wheels (drive wheels) 2. Specifically, the correction unit 12 corrects the speed (circumferential speed) of each of the steered wheels 2 based on the steering angle θ corrected as described above with respect to each of the steered wheels 2. In other words, the control method further has a speed correction step ST3 of correcting, for each steered wheel 2 of the plurality of steered wheels 2, the speed of the corresponding steered wheel 2 based on the steering angle θ corrected in the correction step ST2 in this speed correction step ST 3.

Hereinafter, a process of determining the speed of each of the plurality of steered wheels 2 will be described with reference to fig. 26, taking the conveyor 1A as an example. The transport apparatus 1A shown in fig. 26 is the same as the transport apparatus 1A shown in fig. 23 to 25. In fig. 26, the conveying device 1A is assumed to move rightward. In fig. 26, "α" represents the steering angle θ of the front wheels 21A, "β" represents the steering angle θ of the rear wheels 22A, and "V_α"indicates the speed of the front wheel 21A," V_R"indicates the speed of the rear wheel 22A," W "indicates the distance between the center of the front wheel 21A and the center of the rear wheel 22AThe distance of (c). In addition, in FIG. 26, "r" is_α"represents the turning radius of the front wheel 21A around the intersection X1 of the straight line extending the axis of the front wheel 21A and the straight line extending the axis of the rear wheel 22A," r_β"represents the turning radius of the rear wheel 22A around the intersection X1 between the axial direction of the front wheel 21A and the axial direction of the rear wheel 22A.

Here, the turning radius of the front wheels 21A and the turning radius of the rear wheels 22A vary according to the steering angle θ of the front wheels 21A and the steering angle θ of the rear wheels 22A. Therefore, the turning radius of the front wheel 21A and the turning radius of the rear wheel 22A are substantially different from each other. Therefore, there is a possibility that: when the speed of the front wheels 21A is the same as the speed of the rear wheels 22A, the angular speed of the front wheels 21A does not match the angular speed of the rear wheels 22A, and the operation of the front wheels 21A cannot be matched with the operation of the rear wheels 22A, and it is difficult for the transport apparatus 1A to follow the track L1 because one of the steered wheels 2 is idling.

In contrast, the correction unit 12 corrects the speed of each of the steered wheels 2 based on the steering angle θ, so that the angular speed of the front wheel 21A matches the angular speed of the rear wheel 22A, and the operation of the front wheel 21A matches the operation of the rear wheel 22A. Here, the ratio between the speed of the front wheels 21A and the speed of the rear wheels 22A when the angular velocity of the front wheels 21A and the angular velocity of the rear wheels 22A match (hereinafter simply referred to as "speed ratio") is expressed by the following expression (20).

[ numerical formula 10]

That is, the speed ratio can be determined based on the steering angle θ of the front wheels 21A and the steering angle θ of the rear wheels 22A, independently of the size of the conveyor 1A (e.g., the distance "W" between the centers of the front wheels 21A and the centers of the rear wheels 22A).

As described above, the correction unit 12 controls the conveyor 1A (the conveyor 1) to follow the track L1 by correcting the steering angle θ for each of the front wheels 21A (the first wheels 21) and the rear wheels 22A (the second wheels 22) and correcting the speed of each of the front wheels 21A (the first wheels 21) and the rear wheels 22A (the second wheels 22) based on the corrected steering angle θ.

(2.4) component mounting System

Fig. 27 is a diagram showing a state in which the transport object a1 is transported to the component mounting machine 9 by using the transport apparatus 1 of the present embodiment. The configurations of the conveyed article a1 and the component mounter 9 are the same as those in embodiment 1, and therefore, descriptions thereof are omitted.

(3) Movement of

An example of the operation of the control system 100 according to the present embodiment will be described below with reference to fig. 28. In the operation example shown in fig. 28, it is assumed that the transport apparatus 1 is in the process of transporting the transport object a1 and moving to the destination following the trajectory L1. During the movement of the transport apparatus 1, the acquisition unit 11 acquires the positional deviation information and the rotational deviation information by periodically acquiring the detection results from the first sensor 41 and the second sensor 42 (S1). Step S1 corresponds to acquisition step ST 1.

Next, the correction unit 12 calculates the reference steering angle θ 0 of each of the first wheels 21 and the second wheels 22 based on the positional deviation information acquired by the acquisition unit 11 (S2), and calculates the first steering angle θ 1 of each of the first wheels 21 and the second wheels 22 (S3). The correction unit 12 calculates the second steering angle θ 2 of each of the first wheels 21 and the second wheels 22 based on the rotational offset information acquired by the acquisition unit 11 (S4). Then, the correction unit 12 calculates a combined steering angle θ 3 of each of the first wheels 21 and the second wheels 22 based on the calculated reference steering angle θ 0, the first steering angle θ 1, and the second steering angle θ 2 (S5). Then, the correcting unit 12 corrects the steering angle θ of each of the first wheels 21 and the second wheels 22 based on the calculated combined steering angle θ 3 (S6). Steps S2 to S6 correspond to the correction step ST 2.

Then, the correcting unit 12 corrects the speed ratio of the first wheels 21 and the second wheels 22 based on the corrected steering angle θ of the first wheels 21 and the corrected steering angle θ of the second wheels 22 (S7). That is, the correcting unit 12 corrects the speed of the first wheel 21 and the speed of the second wheel 22. Step S7 corresponds to the speed correction step ST 3.

Then, the control unit 102 controls the first wheels 21 based on the steering angle θ of the first wheels 21 corrected by the correction unit 12 and the speed of the first wheels 21 (S8). Similarly, the control unit 102 controls the second wheels 22 based on the steering angle θ of the second wheels 22 corrected by the correction unit 12 and the speed of the second wheels 22 (S9). Thereafter, the above-described processing is periodically repeated (for example, every several tens of milliseconds) until the conveying device 1 reaches the destination (S10: yes). Thereby, the transport apparatus 1 moves to the destination following the trajectory L1 while suppressing deviation from the reference posture.

(4) Advantages of the invention

Hereinafter, advantages of the control system 100 according to the present embodiment will be described in comparison with a control system of a comparative example. As shown in fig. 29, the control system assumed as a comparative example controls the conveying device 300 that conveys the conveyed article a 1. The conveying apparatus 300 is different from the conveying apparatus 1 in that the conveying apparatus 300 includes a sensor 40 located at a central portion of the conveying apparatus 300 instead of the two sensors 4. The conveyor device 300 differs from the conveyor device 1 in that it includes two

drive wheels

210 and 220, which cannot change the steering angle θ, instead of the first wheels 21 and the second wheels 22. That is, the conveyor 300 is a so-called differential conveyor that moves by using the speed difference between the two

drive wheels

210 and 220. As shown in fig. 29, the center of the transport device 300 is assumed to be located at a position offset from the trajectory L1.

The control system of the comparative example controls the respective speeds of the two

drive wheels

210, 220 based on the detection result of the sensor 40 so that the center of the sensor 40 (i.e., the center of the conveyor 300) rides on the track L1. In the example shown in fig. 29, the control system of the comparative example controls the

drive wheels

210 and 220 such that the speed of the other drive wheel 220 is higher than the speed of the one drive wheel 210. Thereby, the conveyor 300 turns counterclockwise, and therefore, as shown in fig. 30, the conveyor 300 is controlled so that the center of the sensor 40 is caught on the rail L1.

However, in the example shown in fig. 30, the center of the sensor 40 is on the track L1, but the transport device 300 is inclined with respect to the reference posture. In the control system of the comparative example, since the center of the sensor 40 is on the track L1, the

drive wheels

210 and 220 are controlled so that the speeds of the

drive wheels

210 and 220 become the same speed. Therefore, the conveyor 300 keeps the state of being inclined with respect to the reference posture and advances, and therefore, the center of the conveyor 300 is shifted again with respect to the trajectory L1.

In this way, in the control system of the comparative example, the process of controlling the

drive wheels

210 and 220 so that the center of the sensor 40 is placed on the track L1 is repeated until the conveyor 300 assumes the reference posture. Therefore, the control system of the comparative example has a problem that the time required for the conveyor 300 to follow the trajectory L1 while maintaining the reference posture is likely to be long.

In the control system of the comparative example, although the positional deviation of the sensor 40 with respect to the trajectory L1 can be corrected, it is difficult to correct the deviation of the entire conveying device 300 with respect to the trajectory L1. Therefore, when the conveyor device 300 that conveys the conveyance object a1 is controlled by the control system of the comparative example, the conveyor device 300 follows the trajectory L1 in a state inclined from the reference posture due to the offset of the travel resistance between the conveyance object a1 and the conveyor device 300. Therefore, when the conveying device 300 is controlled by the control system of the comparative example, there is a problem that: the ratio of the conveyor 300 and the conveyed article a1 to the width of the passage tends to increase, making it difficult to move the conveyor 300 on a narrow path.

In contrast, in the present embodiment, all the steering wheels 2 (here, the first wheels 21 and the second wheels 22) of the conveyor 1 are controlled so as to correct the inclination deviation of the conveyor 1 from the reference posture of the conveyor 1 with respect to the rail L1 and the positional deviation of the conveyor 1 from the reference posture. Here, in the present embodiment, even when the transport object a1 is being transported and moved, the posture of the transport device 1 is corrected so as to be the reference posture. Therefore, the present embodiment has an advantage that the deviation of the conveying device 1 from the reference posture is suppressed and the conveying device 1 can easily follow the trajectory L1. Further, the present embodiment has an advantage that it is easy to shorten the time required for the conveyor 1 to follow the trajectory L1 while maintaining the reference posture, as compared with the control system of the comparative example.

(5) Modification example

The configuration described in embodiment 3 can be adopted in appropriate combination with the various configurations (including the modifications) described in

embodiments

1 and 2.

In embodiment 3 described above, for example, as shown in fig. 31, the control system 100 may rotate the transport apparatus 1 as follows: the steering angle θ of the plurality of steered wheels 2 is fixed, and the plurality of steered wheels 2 follow a circumferential orbit centered on an intersection point X1 where the respective axial directions of the plurality of steered wheels 2 intersect.

In embodiment 3 described above, the correction unit 12 corrects the steering angle θ based on the combined steering angle θ 3 for each of the plurality of steered wheels 2, but the present invention is not limited thereto. For example, the correction unit 12 may alternately execute a process of correcting the steering angle θ based on the reference steering angle θ 0, a process of correcting the steering angle θ based on the first steering angle θ 1, and a process of correcting the steering angle θ based on the second steering angle θ 2. In other words, the correction step ST2 may be configured to alternately execute the first low step and the second low step for each steered wheel 2 of the plurality of steered wheels 2. The first low step is a step of correcting the steering angle θ based on the rotational offset information, and corresponds to a step of correcting the steering angle θ based on the first steering angle θ 1 calculated in step S3 of fig. 28. The second low step is a step of correcting the steering angle θ based on the positional deviation information, and corresponds to a step of correcting the steering angle θ based on the second steering angle θ 2 calculated in step S4 of fig. 28.

In embodiment 3 described above, the correction unit 12 may not perform the reverse phase control when calculating the second steering angle θ 2. That is, the correction unit 12 may set the second steering angle θ 21 of the first wheel 21 and the second steering angle θ 22 of the second wheel 22 to be in phase with each other.

The control method of the transport apparatus 1 may include only one of a first steering angle control process of controlling the steering angle θ of the transport apparatus 1 in a state where the plurality of steered wheels 2 are aligned in the front-rear direction and a second steering angle control process of controlling the steering angle θ of the transport apparatus 1 in a state where the plurality of steered wheels 2 are aligned in a direction intersecting the front-rear direction. The control method of the transport apparatus 1 may include both the first steering angle control process and the second steering angle control process.

(conclusion)

As described above, the control method of the first aspect has at least one of the first steering angle control process and the second steering angle control process. The first steering angle control process is a process of controlling the steering angle (theta) of the conveying device (1) in a state where a plurality of steering wheels (2) of the conveying device (1) having the plurality of steering wheels (2) and conveying the conveyed object (A1) are arranged in the front-rear direction. The second steering angle control process is a process of controlling the steering angle (theta) of the conveyor device (1) in a state where the plurality of steered wheels (2) of the conveyor device (1) are aligned in a direction intersecting the front-rear direction.

According to this aspect, there is an advantage that the deviation of the conveying device (1) from the reference posture is suppressed and the conveying device (1) can easily follow the trajectory (L1).

In the control method of the second aspect, the first steering angle control process has an acquisition step (ST1) and a correction step (ST2) in addition to the first aspect. The acquisition step (ST1) is a step of acquiring offset information relating to an offset of the conveying device (1) with respect to a track (L1) on which the conveying device (1) travels. The conveying device (1) is provided with a plurality of steering wheels (2) arranged along the front-back direction and conveys conveyed objects (A1). The correcting step (ST2) is a step of correcting the steering angle (θ) for each of the plurality of steered wheels (2) on the basis of the offset information acquired in the acquiring step (ST 1).

In the control method of the third aspect, on the basis of the second aspect, the offset information includes a plurality of steered wheel offset information associated with positional offsets of the plurality of steered wheels (2) with respect to the track (L1), respectively. The correction step (ST2) corrects the steering angle (theta) for each of the steered wheels (2) on the basis of the corresponding steered wheel offset information.

In the control method of the fourth aspect, on the basis of the second aspect, the offset information includes rotational offset information relating to a tilt offset of the conveying device (1) from a reference attitude of the conveying device (1) with respect to the rail (L1), and positional offset information relating to a positional offset of the conveying device (1) from the reference attitude. The correction step (ST2) corrects the steering angle (theta) on the basis of the rotational offset information and the positional offset information on the basis of each of the plurality of steered wheels (2).

In the control method of the fifth aspect, in addition to the fourth aspect, the correcting step (ST2) alternately executes the first lowering step and the second lowering step for each steered wheel (2) of the plurality of steered wheels (2). The first lowering step corrects the steering angle (θ) based on the positional shift information. The second lower step corrects the steering angle (θ) based on the rotational offset information.

In the control method of the sixth aspect, in addition to the fourth aspect, the correcting step (ST2) corrects the steering angle (θ) based on the synthesized steering angle (θ 3) for each of the plurality of steered wheels (2). The combined steering angle (theta 3) is an angle obtained by combining a first steering angle (theta 1) obtained based on the positional deviation information and a second steering angle (theta 2) obtained based on the rotational deviation information.

In the control method of the seventh aspect, in addition to any one of the fourth to sixth aspects, the correcting step (ST2) sets the steering angle (θ) of the front wheels (21) and the steering angle (θ) of the rear wheels (22) in anti-phase with each other when correcting the steering angle (θ) based on the rotational offset information. The front wheels (21) are located in front of the conveyor (1) among the plurality of steerable wheels (2). The rear wheel (22) is located behind the conveyor (1) among the plurality of steerable wheels (2).

According to this aspect, there is an advantage that the balance between the transport device (19) and the transported object (a1) is not easily broken and the loss of the propulsive force of the transport device (1) can be suppressed.

The control method of the eighth aspect further includes a speed correction step (ST3) in addition to any one of the second to seventh aspects. The speed correction step (ST3) is a step of correcting the speed of each of the steered wheels (2) on the basis of the steering angle (θ) corrected in the correction step (ST2) for each of the steered wheels (2).

According to this aspect, since it is easy to match the movement of each of the plurality of steered wheels (2), there is an advantage that it is easy for the conveyor (1) to follow the track (L1).

In the control method according to a ninth aspect, in addition to any one of the second to eighth aspects, the plurality of steered wheels (2) include front wheels (21) located in front of the conveyor device (1) and rear wheels (22) located behind the conveyor device (1).

According to this aspect, there is an advantage that the deviation of the two-wheel type conveyor device (1) from the reference posture is suppressed and the conveyor device (1) can easily follow the track (L1).

In the control method according to the tenth aspect, in addition to any one of the second to ninth aspects, the rail (L1) is provided on a moving surface (B1) on which the transport apparatus (1) moves.

According to this aspect, compared to the case where the track (L1) is a virtual track on an electronic map, there is an advantage in that the displacement of the transport device (1) with respect to the track (L1) is easily detected.

In the control method according to an eleventh aspect of the present invention, in addition to any one of the second to tenth aspects, the transport device (1) includes a coupling section (5), and the coupling section (5) couples the transported object (a1) to a surface of the main body section (10) of the transport device (1) along the rail (L1).

This has the advantage that even a transport object (A1) that is difficult to load on the transport device (1) can be transported easily.

In the control method according to the twelfth aspect, the second steering angle control process includes an acquisition step (ST1) and a correction step (ST2) in addition to any one of the first to eleventh aspects. The acquisition step (ST1) is a step of acquiring the rotational offset information and the positional offset information. The rotational offset information is information relating to a tilt offset of the conveying device (1) from a reference posture of the conveying device (1) with respect to the track (L1). The positional deviation information is information relating to the positional deviation of the conveying device (1) from a reference posture. The conveying device (1) is provided with a plurality of steering wheels (2) which are arranged in a direction intersecting with the front-back direction, and conveys a conveyed object (A1). The correcting step (ST2) is a step of correcting the steering angle (θ) for each of the plurality of steered wheels (2) on the basis of the rotational offset information and the positional offset information acquired in the acquiring step (ST 1).

In the control method according to the thirteenth aspect, in addition to the twelfth aspect, the correcting step (ST2) includes a step of correcting the steering angle (θ) to a reference steering angle (θ 0) that is a direction in which the vehicle travels along the track (L1) for each of the plurality of steered wheels (2).

In the control method of the fourteenth aspect, in addition to the thirteenth aspect, the correcting step (ST2) alternately executes the first low step and the second low step for each steered wheel (2) of the plurality of steered wheels (2). The first lower step corrects the steering angle (θ) based on the positional offset information. The second lower step corrects the steering angle (θ) based on the rotational offset information.

In the control method of the fifteenth aspect, in addition to the thirteenth aspect, the correcting step (ST2) corrects the steering angle (θ) based on the synthesized steering angle (θ 3) for each of the plurality of steered wheels (2). The combined steering angle (theta 3) is an angle obtained by combining a first steering angle (theta 1) obtained based on the positional deviation information and a second steering angle (theta 2) obtained based on the rotational deviation information.

In the control method according to a sixteenth aspect, in addition to any one of the twelfth to fifteenth aspects, the correcting step (ST2) sets the steering angle (θ) of the first wheel (21) and the steering angle (θ) of the second wheel (22) in anti-phase with each other when correcting the steering angle (θ) based on the rotational offset information. The first wheel (21) is located at a first end of the conveyor (1) in the longitudinal direction among the plurality of steerable wheels (2). The second wheel (22) is located at a second end in the longitudinal direction of the conveyor (1) among the plurality of steerable wheels (2).

According to this aspect, there are advantages in that the balance between the transport device (1) and the transported object (a1) is not easily broken, and the loss of the propulsive force of the transport device (1) can be suppressed.

The control method according to the seventeenth aspect further includes a speed correction step (ST3) in addition to any one of the twelfth to sixteenth aspects. The speed correction step (ST3) is a step of correcting the speed of each of the steered wheels (2) on the basis of the steering angle (θ) corrected in the correction step (ST2) for each of the steered wheels (2).

In the eighteenth aspect of the control method according to any one of the twelfth to seventeenth aspects, the plurality of steering wheels (2) includes a first wheel (21) located at a first end in a longitudinal direction of the conveyor (1) and a second wheel (22) located at a second end in the longitudinal direction of the conveyor (1).

In the control method according to a nineteenth aspect, in addition to any one of the twelfth to eighteenth aspects, the rail (L1) is provided on a moving surface (B1) on which the transport device (1) moves.

In the control method according to the twentieth aspect, in addition to any one of the twelfth to nineteenth aspects, the conveyor device (1) includes a coupling portion (5), and the coupling portion (5) couples the conveyed article (a1) to a surface of the main body portion (10) of the conveyor device (1) that intersects the rail (L1).

In the control method according to a twenty-first aspect of the present invention, in addition to any one of the first to twentieth aspects, the first steering angle control process includes a first acquisition step (ST 1: see fig. 5 and 17) and a first correction step (ST 2: see fig. 5 and 17). The first acquisition step (ST1) is a step of acquiring offset information relating to an offset of a conveyor device (1) that has a plurality of steerable wheels (2) arranged in the front-rear direction and conveys a conveyed article (a1) with respect to a track (L1) on which the conveyor device (1) travels. The first correction step (ST2) is a step of correcting the steering angle (θ) for each of the plurality of steered wheels (2) on the basis of the offset information acquired in the first acquisition step (ST 1). The second steering angle control process includes a second acquisition step (ST 1: see fig. 28) and a second correction step (ST 2: see fig. 28). The second acquisition step (ST1) is a step of acquiring the rotational offset information and the positional offset information. The rotational offset information is information relating to the inclination offset of the conveying device (1) from the reference attitude of the conveying device (1) with respect to the rail (L1), and the conveying device (1) has a plurality of steering wheels (2) arranged in a direction intersecting the front-rear direction and conveys the conveyed article (A1). The positional deviation information is information relating to the positional deviation of the conveying device (1) from a reference posture. The second correction step (ST2) is a step of correcting the steering angle (θ) for each of the plurality of steered wheels (2) on the basis of the rotational offset information and the positional offset information acquired in the second acquisition step (ST 1).

A twenty-second aspect is a program for causing one or more processors to execute the control method according to any one of the first to twenty-first aspects.

A control system (100) according to a twenty-third aspect is provided with at least one of a first steering angle control processing unit and a second steering angle control processing unit. The first steering angle control processing unit controls the steering angle (theta) of the conveying device (1) in a state where a plurality of steering wheels (2) of the conveying device (1) which has the plurality of steering wheels (2) and conveys the conveyed object (A1) are arranged in the front-rear direction. The second steering angle control processing unit controls the steering angle (theta) of the conveying device (1) in a state where a plurality of steering wheels (2) of the conveying device (1) are arranged in a direction intersecting the front-rear direction

A control system (100) according to a twenty-fourth aspect is the twenty-third aspect, wherein the first steering angle control processing unit includes an acquisition unit (11) and a correction unit (12). An acquisition unit (11) acquires offset information relating to the offset of the conveying device (1) relative to a track (L1) on which the conveying device (1) travels. The conveying device (1) is provided with a plurality of steering wheels (2) arranged along the front-back direction and conveys conveyed objects (A1). A correction unit (12) corrects the steering angle (theta) for each of the plurality of steered wheels (2) on the basis of the offset information acquired by the acquisition unit (11).

A control system (100) according to a twenty-fifth aspect is the twenty-third or twenty-fourth aspect, wherein the second steering angle control processing unit includes an acquisition unit (11) and a correction unit (12). An acquisition unit (11) acquires the rotational offset information and the positional offset information. The rotational offset information is information relating to a tilt offset of the conveying device (1) from a reference posture of the conveying device (1) with respect to the track (L1). The positional deviation information is information relating to the positional deviation of the conveying device (1) from a reference posture. The conveying device (1) is provided with a plurality of steering wheels (2) which are arranged in a direction intersecting with the front-back direction, and conveys a conveyed object (A1). A correction unit (12) corrects the steering angle (theta) for each of the plurality of steered wheels (2) on the basis of the rotational offset information and the positional offset information acquired by the acquisition unit (11).

A conveyance device (1) according to a twenty-sixth aspect is provided with the control system (100) according to any one of the twenty-third to twenty-fifth aspects, and a main body section (10). A control system (100) is mounted on the main body (10) and conveys a conveyed object (A1).

A component mounting system (200) of a twenty-seventh aspect is a system including at least one component mounter (9) that mounts components on a substrate. The component mounting machine (9) has a component supply device (8) that supplies components, and a mounting body (90) that includes a mounting head that mounts components on a substrate. The component supply device (8) is conveyed to the mounting body (90) by a conveying device (1) controlled by the control system (100) of any one of the twenty-third to twenty-fifth aspects.

According to this aspect, the component supply device (8) can be stably conveyed to the installation location of the mounting body (90) of the component mounting machine (9) by the conveying device (1), and therefore, there is an advantage that the component supply to the mounting body (90) can be easily stabilized.

In a component mounting system (200) according to a twenty-eighth aspect, in addition to the twenty-seventh aspect, the transport device (1) can be coupled to a portion of the component supply device (8) that is located on a side opposite to a portion where the component is discharged to the mounting body (90).

According to this aspect, there are the following advantages: when the component supply device (8) is conveyed to the installation position of the installation body (90) of the component installation machine (9), the operation of changing the direction of the component supply device (8) to enable the discharge position to face the installation body (90) is not needed.

The methods according to the second to twenty-first aspects are not essential to the control method, and can be omitted as appropriate.

However, the control method of the eighth aspect may be executed regardless of whether there is control for correcting the conveying device 1 so as to follow the trajectory L1. That is, the control method of the twenty-ninth aspect has a speed control step of the conveying device (1). The conveying device (1) is provided with a plurality of steering wheels (2) arranged along the front-back direction and conveys conveyed objects (A1). The speed control step is a step of correcting the speed of each of the plurality of steered wheels (2) on the basis of the steering angle (theta) for each of the steered wheels (2).

Claims

1. A control method includes at least one of a first steering angle control process and a second steering angle control process,

in the first steering angle control process, the steering angle of the conveying device is controlled in a state where a plurality of steering wheels of the conveying device having the plurality of steering wheels and conveying the conveyed object are arranged in a front-rear direction,

in the second steering angle control process, the steering angle of the conveying device is controlled in a state where the plurality of steered wheels of the conveying device are aligned in a direction intersecting with a front-rear direction.

2. The control method according to claim 1,

the first steering angle control process includes:

an acquisition step of acquiring offset information relating to an offset of the transport device with respect to a track on which the transport device travels, the transport device having the plurality of steering wheels arranged in the front-rear direction and transporting the transported object; and

a correction step of correcting the steering angle for each of the plurality of steered wheels based on the offset information acquired in the acquisition step.

3. The control method according to claim 2, wherein,

the offset information includes a plurality of steered wheel offset information associated with positional offsets of the plurality of steered wheels with respect to the track, respectively,

the correcting step corrects the steering angle based on corresponding steered wheel offset information for each of the plurality of steered wheels.

4. The control method according to claim 2, wherein,

the offset information includes rotational offset information related to a tilt offset of the conveying device from a reference attitude of the conveying device with respect to the rail and positional offset information related to a positional offset of the conveying device from the reference attitude,

the correcting step corrects the steering angle for each of the plurality of steered wheels based on the rotational offset information and the positional offset information.

5. The control method according to claim 4,

the correcting step alternately performs, for each of the plurality of steered wheels, a first lower step of correcting the steering angle based on the positional offset information and a second lower step of correcting the steering angle based on the rotational offset information.

6. The control method according to claim 4,

the correcting step corrects the steering angle for each of the plurality of steered wheels based on a combined steering angle obtained by combining a first steering angle obtained based on the positional deviation information and a second steering angle obtained based on the rotational deviation information.

7. The control method according to any one of claims 4 to 6,

the correcting step, when correcting the steered angle based on the rotational offset information, makes the steered angle of a front wheel positioned in front of the conveying device among the steered wheels and the steered angle of a rear wheel positioned behind the conveying device among the steered wheels in a reverse phase.

8. The control method according to any one of claims 2 to 6,

the control method further has a speed correction step of correcting, for each of the plurality of steered wheels, a speed of the corresponding steered wheel based on the steering angle corrected in the correction step.

9. The control method according to claim 1,

the second steering angle control process includes:

an acquisition step of acquiring rotational displacement information relating to a tilt displacement of the transport device from a reference posture of the transport device with respect to a track, the transport device having the plurality of steering wheels arranged in a direction intersecting a front-rear direction and transporting the transported object, and positional displacement information relating to a positional displacement of the transport device from the reference posture; and

a correction step of correcting the steering angle for each of the plurality of steered wheels based on the rotational offset information and the positional offset information acquired in the acquisition step.

10. The control method according to claim 9, wherein,

the correcting step comprises the following steps: the steering angle is corrected to a reference steering angle that becomes a direction in which the track advances, for each of the plurality of steered wheels.

11. The control method according to claim 10,

12. The control method according to claim 10,

13. The control method according to any one of claims 9 to 12,

the correcting step, when correcting the steered angle based on the rotational offset information, makes the steered angle of a first wheel of the steered wheels located at a first end in a longitudinal direction of the conveyor device and the steered angle of a second wheel of the steered wheels located at a second end in the longitudinal direction of the conveyor device in a reverse phase with each other.

14. The control method according to any one of claims 9 to 12,

the control method corrects, for each of the plurality of steered wheels, the speed of the corresponding steered wheel based on the steering angle corrected in the correcting step.

15. The control method according to claim 1,

the first steering angle control process includes:

a first acquisition step of acquiring offset information relating to an offset of the transport device with respect to a track on which the transport device travels, the transport device having the plurality of steering wheels arranged in the front-rear direction and transporting the transported object; and

a first correction step of correcting the steering angle for each of the plurality of steered wheels based on the offset information acquired in the first acquisition step,

the second steering angle control process includes:

a second acquisition step of acquiring rotational displacement information relating to a tilt displacement of the transport device from a reference posture of the transport device with respect to the track, the transport device having the plurality of steering wheels aligned in a direction intersecting with a front-rear direction and transporting the transported object, and positional displacement information relating to a positional displacement of the transport device from the reference posture; and

a second correction step of correcting the steering angle for each of the plurality of steered wheels based on the rotational offset information and the positional offset information acquired in the second acquisition step.

16. A control system includes at least one of a first steering angle control processing unit and a second steering angle control processing unit,

the first steering angle control processing unit controls a steering angle of a conveying device having a plurality of steering wheels and conveying a conveyed article in a state where the plurality of steering wheels are arranged in a front-rear direction,

the second steering angle control processing unit controls the steering angle of the conveyor in a state where the plurality of steered wheels of the conveyor are aligned in a direction intersecting with the front-rear direction.

17. A conveyor device is provided with:

the control system of claim 16; and

and a main body part which carries the control system and conveys the conveyed object.

18. A component mounting system includes at least one component mounter which mounts components to a substrate,

the component mounting apparatus includes:

a component supply device that supplies the component; and

a mounting body including a mounting head that mounts the component to the substrate,

the component supply device is transported to the mounting body by the transport device controlled by the control system according to claim 16.

19. The component mounting system of claim 18,

the transport device may be coupled to a portion of the component supply device that is located on a side opposite to a portion where the component is discharged to the mounting body.