Conveying assistance device and control method for conveying assistance device

Abstract

This invention provides a transport assist device and a control method for the transport assist device that can improve the safety of the transport equipment and the transported goods even if the connection with the transport equipment is lost during operation. [Solution] The transport assist device 1 includes a device body 10 having drive wheels 11, a connection mechanism 20 provided on the device body 10 including a connection part 22 that connects to a connected member 250 attached to a traveling device 200, and a connection drive unit 23 that moves the connection part 22 forward and backward toward the connected member 250, a pressure sensor 34 that outputs a detected value corresponding to the pressing force when pressed by a pressing pin 255 provided on the connected member 250 when the connection part 22 is connected, and a control unit 50 that performs control based on the output of the pressure sensor 34. The control unit 50 performs abnormal processing, including deceleration of the device body 10, when an abnormal detection state in which the detected value of the pressure sensor 34 is below a threshold continues for a predetermined time while the device body 10 connected to the traveling device 200 is traveling.

Description

Technical Field

[0001] The present invention relates to a conveyance assist device and a control method for the conveyance assist device.

Background Art

[0002] There are known conveyance assist devices such as an automated guided vehicle (AGV) and an autonomous mobile robot (AMR) that are connected to a traveling device such as a trolley, a conveyance cart, a moving bed, a stretcher, etc., which carry a load and travel on the floor surface, to assist the traveling of the traveling device. For example, Patent Document 1 discloses an AGV that conveys a trolley by coupling the operation of a device body that travels by drive wheels to the trolley by a hook and moving it.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] During the traveling of a conveyance assist device connected to a traveling device, if the connection between the traveling device and the conveyance assist device is disconnected or is likely to be disconnected, it may become impossible to control the movement of the traveling device. Therefore, even when disconnection of the connection with the traveling device occurs during traveling, it is desirable to improve the safety of the traveling device and the load carried by the traveling device.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a conveyance assist device and a control method for the conveyance assist device that can improve the safety of the traveling device and the conveyed object even when disconnection of the connection with the traveling device occurs during traveling.

Means for Solving the Problems

[0006] A transport assist device according to one aspect of the present invention is a transport assist device that assists in the transport of a traveling device by generating a driving force when connected to the traveling device, and comprises a device body having drive wheels, a connection mechanism provided on the device body including a connection part that connects to a member to be connected attached to the traveling device, and a connection drive part that moves the connection part forward and backward toward the member to be connected, a pressure sensor that outputs a detected value corresponding to the pressing force when pressed by a pressing pin provided on the member to be connected when the connection part is connected, and a control unit that performs control based on the output of the pressure sensor, wherein the control unit performs abnormal processing, including deceleration of the device body, when an abnormal detection state in which the detected value of the pressure sensor is less than a threshold continues for a predetermined time while the device body connected to the traveling device is traveling, performs abnormal processing including deceleration of the device body.

[0007] A preferred embodiment of the above-mentioned transport assistance device is that the abnormality handling includes stopping the movement of the device itself.

[0008] A preferred embodiment of the above-described transport assist device further includes an input device that receives input operations for movement instructions for the main body of the device, and the control unit executes the abnormality processing regardless of whether or not an input operation is performed to the input device.

[0009] In a preferred embodiment of the above-described transport assist device, the pressure sensor includes a first pressure sensor located on one side of the center of the connection portion and a second pressure sensor located on the other side, as viewed from the direction of movement of the connection portion by the connection drive unit, and the abnormality detection state includes the fact that the detected values ​​of both the first pressure sensor and the second pressure sensor fall below the threshold.

[0010] In a preferred embodiment of the above-described transport assistance device, the control unit resets the count of the duration of the abnormal detection state up to that point when the detected value of the pressure sensor exceeds a threshold.

[0011] In a preferred embodiment of the above-described transport assist device, the control unit acquires a non-pressure detection value, which is the detected value of the pressure sensor, in the state before the connection unit connects the connection unit to the member to be connected, and the control unit sets a value obtained by adding a predetermined margin to the non-pressure detection value as the threshold value.

[0012] In a preferred embodiment of the above-described transport assist device, the pressure sensor includes a first pressure sensor located on one side of the center of the connection portion and a second pressure sensor located on the other side, as viewed from the direction of movement of the connection portion by the connection drive unit, and the control unit sets the threshold values ​​separately for the first pressure sensor and the second pressure sensor.

[0013] In a preferred configuration of the above-described transport assist device, the predetermined time is set to a duration such that the distance traveled from the time the abnormality detection condition occurs until the device body stops is less than half the total length of the traveling device in the longitudinal direction.

[0014] In a preferred embodiment of the above-described transport assist device, the pressure sensor includes a first pair of a first pressure sensor and a second pressure sensor in a first direction in the plane viewed from the direction of movement of the connection part by the connection drive unit, and a second pair of a first pressure sensor and a second pressure sensor in a second direction perpendicular to the first direction in the plane viewed from the direction of movement of the connection part.

[0015] A control method for a transport assist device according to one aspect of the present invention includes a device body having drive wheels, a connecting part connected to a member to be connected attached to a travel device, and a connecting drive unit that moves the connecting part forward and backward toward the member to be connected, the device body being provided with a connecting mechanism, and a pressure sensor that outputs a detected value corresponding to the pressing force when pressed by a pressing pin provided on the member to be connected when the connecting part is connected, and the control method for a transport assist device that assists the transport of the travel device by generating a driving force when connected to the travel device, comprising the steps of: acquiring the detected value of the pressure sensor; detecting that the device body connected to the travel device is in motion; detecting that an abnormal detection state in which the detected value of the pressure sensor is below a threshold has continued for a predetermined time while the device body is in motion; and executing abnormal processing, including deceleration of the device body, based on the fact that the abnormal detection state has continued for a predetermined time. [Effects of the Invention]

[0016] According to the present invention, even if the connection to the traction device is lost while the vehicle is in motion, the safety of the traction device and the transported goods can be improved. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a perspective view showing the state of the transport assist device according to the embodiment before it is connected to the travel device. [Figure 2] Figure 2 is a perspective view showing a part of the internal configuration of the transport assistance device shown in Figure 1. [Figure 3] Figure 3 is a perspective view of the transport assist device from below. [Figure 4] Figure 4 is a perspective view showing an example of the configuration of the connection mechanism of the transport assist device shown in Figure 1. [Figure 5] Figure 5 is a side view showing a partial cross-section of the transport assist device shown in Figure 1 before it is connected to the travel mechanism. [Figure 6] Figure 6 is a side view showing a partial cross-section of the transport assist device shown in Figure 1 after it has been connected to the travel mechanism. [Figure 7]FIG. 7 is a plan view showing a configuration example of a cover member of a connection portion. [Figure 8] FIG. 8 is a cross-sectional view showing a cavity portion of the connection state of the cover member shown in FIG. 7. [Figure 9] FIG. 9 is a perspective view of the connected member according to the embodiment as viewed from the lower surface side. [Figure 10] FIG. 10 is a block diagram showing a configuration related to the control processing of the control unit. [Figure 11] FIG. 11 is a graph for explaining a threshold value for determining an abnormal detection state. [Figure 12] FIG. 12 is a flowchart showing the connection process of the transport assist device shown in FIG. 1. [Figure 13] FIG. 13 is a flowchart showing the error state monitoring process of the transport assist device shown in FIG. 1. [Figure 14] FIG. 14 is a flowchart showing the abnormal process of the transport assist device shown in FIG. 1. [Figure 15A] FIG. 15A is a schematic diagram showing a modification example regarding the arrangement of the pressure sensor. [Figure 15B] FIG. 15B is a schematic diagram showing a modification example regarding the arrangement of the pressing pin.

Embodiments for Carrying Out the Invention

[0018] <​​​​​​​​​ In the diagrams illustrating the embodiments, components other than those related to the invention are omitted as appropriate. Furthermore, in the following description, the horizontal direction of the transport assist device 1 is referred to as the "front-rear direction," and the intersecting direction perpendicular to both the horizontal and unidirectional directions is referred to as the "left-right direction (or width direction)." The direction perpendicular to the front-rear direction and the left-right direction is referred to as the "up-down direction."

[0021] The transport assist device 1 is a transport assist device that assists in the transport of the travel device 200 by connecting to the travel device 200 and generating driving force. The transport assist device 1 moves underneath the travel device 200 and connects to the travel device 200 from below, assisting in the travel of the travel device 200. The travel device 200 is, for example, a trolley, transport cart, mobile bed, stretcher, etc. As shown in Figure 1, the travel device 200 comprises a main body 210 on which the object to be transported is placed, and a plurality of driven wheels 220 that can maintain the main body 210 in a horizontal position and move horizontally when an external force including a horizontal component is applied, and has a gap that allows the transport assist device 1 to move underneath the main body 210. The main body 210 is provided with a handle 211 for the operator to operate the travel device 200. In this embodiment, the driven wheels 220 are swivel wheels. The driven wheels 220 are capable of swiveling and rotating in response to the action of an external force. The running device 200 can move in any direction on the floor surface using swivel wheels.

[0022] The traveling device 200 is provided with a connecting member 250. The connecting member 250 is a member for connecting the transport assist device 1 to the traveling device 200. The connecting member 250 may be pre-installed on the traveling device 200, or it may be attached to the traveling device 200 as an add-on device. In this embodiment, the connecting member 250 is provided on the lower side of the main body 210. In addition, a guide member 230 and a stopper 240 are provided on the lower side of the main body 210 in conjunction with the connecting member 250.

[0023] The member to be connected 250 is detachably connected to the connection portion 22 of the connection mechanism 20 of the transport assist device 1, which will be described later. The member to be connected 250 is located in the center of the lower side of the main body portion 210.

[0024] The guide member 230 has a first arm 231 and a second arm 232 arranged parallel to the first arm 231. The second arm 232 does not intersect the first arm 231 and extends in one direction outward from the main body 210.

[0025] The first arm 231 and the second arm 232 are installed facing each other with the connected member 250 in between, and one end of the first arm 231 and the second arm 232 is fixed to the position of the connected member 250. The other ends of the first arm 231 and the second arm 232 extend outward. The distance between the first arm 231 and the second arm 232 is smallest at the connection point below the traveling device 200. The connection point is the horizontal relative position of the transport assist device 1 with respect to the traveling device 200 when the connection part 22 of the transport assist device 1 connects to the connected member 250.

[0026] The first arm 231 and the second arm 232 protrude downward from the connected member 250. When the transport assist device 1 is connected to the traveling device 200, the connection portion 22 of the transport assist device 1 enters between the first arm 231 and the second arm 232. The first arm 231 and the second arm 232 guide the relative position of the transport assist device 1 with respect to the traveling device 200 to the connection position below the traveling device 200.

[0027] The stopper 240 is installed on the connected member 250 at a position opposite to where the first arm 231 and the second arm 232 are installed. The stopper 240 contacts a part of the connection mechanism 20 when the transport assist device 1 is in the connection position, stopping the transport assist device 1. The stopper 240 prevents the connection part 22 from passing under the connected member 250. In other words, the stopper 240 positions the transport assist device 1 in a connection position that allows it to be connected to the travel device 200.

[0028] The transport assist device 1 comprises a device body 10, a connection mechanism 20, and a control unit 50. The transport assist device 1 also includes an input device 60.

[0029] Figure 2 is a perspective view showing part of the internal configuration of the transport assist device 1 shown in Figure 1. Figure 3 is a perspective view of the transport assist device 1 seen from below. Figure 4 is a perspective view showing an example of the configuration of the connection mechanism of the transport assist device 1 shown in Figure 1.

[0030] As shown in Figures 2 and 3, the device body 10 has drive wheels 11. The device body 10 also has driven wheels 12 and a connecting mechanism 20. In this embodiment, the device body 10 is a rectangular parallelepiped with a substantially square shape in plan view. All components of the transport assist device 1, except for some of the drive wheels 11 and driven wheels 12, are arranged inside the device body 10.

[0031] The main body of the device 10 is the base on which the drive wheel 11, the driven wheel 12, and the connecting mechanism 20 are arranged, and it is also the case that houses the drive wheel 11, the driven wheel 12, and the connecting mechanism 20.

[0032] The main body of the device 10 includes a base 102 and a case portion 101 that surrounds the upper part of the base 102. The base 102 constitutes the base of the transport assist device 1 and is formed in a plate shape, for example, forming the bottom plate of the transport assist device 1. The drive wheel 11, the driven wheel 12, and the connecting mechanism 20 are arranged on the upper surface of the base 102. The case portion 101 consists of a wall portion that rises upward from the plate-shaped perimeter of the base 102 and a top plate (see Figure 1) that faces the base 102 and covers the upper part of the wall portion.

[0033] At least two drive wheels 11 are provided on the device body 10. At least one driven wheel 12 is provided on the device body 10.

[0034] The drive wheels 11 are positioned symmetrically with respect to the center of the base 102 of the device body 10, for example. In Figure 3, the drive wheels 11 are positioned on both sides in the front-rear direction with respect to the center of the base 102. In this case, two driven wheels 12 are provided and are positioned on both sides in the left-right direction with respect to the center of the base 102.

[0035] The drive wheel 11 is a wheel capable of generating driving force to move the device body 10. The drive wheel 11 is, for example, an active caster capable of movement in all directions. The drive wheel 11 may also be, for example, an omni-wheel or a Mecanum wheel capable of movement in all directions. Rotational driving force is transmitted to the drive wheel 11 from the motor 13.

[0036] The connection mechanism 20 is provided on the main body of the device 10. The connection mechanism 20 is positioned in the center of the plate-shaped upper surface of the base 102 of the main body of the device 10, surrounded by the drive wheel 11 and the driven wheel 12. As shown in Figure 4, the connection mechanism 20 includes a link mechanism 21, a connecting part 22, and a connecting drive part 23.

[0037] The link mechanism 21 is composed of, for example, a pantograph or an X-link and is installed between the base 102 and the connecting part 22. The link mechanism 21 converts the operation of the connecting drive unit 23 into the movement of the connecting part 22.

[0038] The connecting portion 22 connects to the member to be connected 250 attached to the running device 200. The connecting portion 22 fits into the member to be connected 250 of the running device 200.

[0039] The connection drive unit 23 moves the connection part 22 forward and backward toward the connected member 250. In this embodiment, the direction of the forward and backward movement of the connection part 22 toward the connected member 250 is vertical. The connection drive unit 23 is composed of an actuator or the like and drives the link mechanism 21. In the example in Figure 4, the connection drive unit 23 is an electric linear actuator, which moves the movable part in a linear motion. The link mechanism 21 converts the linear motion of the movable part of the connection drive unit 23 into vertical motion, and moves the connection part 22, which is fixed to the upper surface of the link mechanism 21, up and down.

[0040] In this manner, the connection mechanism 20 drives the link mechanism 21 with the connection drive unit 23, causing the connection part 22 to move vertically. The connection part 22 moving downward is housed in the device body 10. The connection part 22 moving upward engages with the connected member 250 of the traveling device 200, connecting the device body 10 to the traveling device 200. The transport assist device 1, with the device body 10 connected to the traveling device 200, transports the traveling device 200 by traveling.

[0041] As shown in Figure 1, the control unit 50 is provided on the main body 10 of the device. The control unit 50 controls the operation of the transport assist device 1 (main body 10). For example, the control unit 50 causes the motor driver to drive the motor 13 when a predetermined program is executed. Based on the control signals received from the input device 60, the control unit 50 drives the motors 13 corresponding to each drive wheel 11 so that the main body 10 moves in translation and rotation. Based on the control signals received from the input device 60, the control unit 50 drives the connection drive unit 23 to move the connection unit 22 forward and backward. Details of the control unit 50 will be described later.

[0042] The input device 60 receives input operations for movement instructions for the main unit 10 of the device. The input device 60 is a remote control for operating the transport assist device 1. The input device 60 is provided separately from the main unit 10 so that it can communicate with the main unit 10 via wireless communication such as infrared communication, Bluetooth® communication, Wi-Fi® communication, or 5G communication. The input device 60 can output control signals to control the travel direction and travel speed of the main unit 10 by the drive wheels 11 in response to the input operation. The input device 60 can output control signals to control the forward and backward movement of the connection unit 22 by the connection drive unit 23 in response to the input operation. In one example, the input device 60 has a joystick 61 and a plurality of buttons 62 for operation.

[0043] The joystick 61 controls the forward / backward movement and left / right rotation of the device body 10. The input device 60 outputs a control signal to move the device body 10 based on the direction of movement determined by the direction of the joystick 61 tilt, and the travel speed or torque determined by the tilt angle.

[0044] Multiple buttons 62 are each associated with a predetermined operation. The buttons 62 include a pair of buttons 62a for operating the lateral movement of the device body 10, and a button 62b for operating the connection part 22 to connect and disconnect the device body 10 and the travel device 200. The buttons 62 may also include, for example, a pairing button for setting up pairing with a predetermined device body 10, a switch button for switching the device body 10 to be operated, and a power button for remotely starting the device body 10.

[0045] [Connection operation of transport assist device 1 to travel device 200] Next, the operation of connecting the transport assist device 1 to the travel device 200 will be explained with reference to Figures 5 and 6. Figure 5 is a side view showing a partial cross-section of the transport assist device 1 before it is connected to the travel device 200, as shown in Figure 1. Figure 6 is a side view showing a partial cross-section of the transport assist device 1 after it has been connected to the travel device 200, as shown in Figure 1.

[0046] As shown in Figure 5, when connecting, the user operates the input device 60 to lower the connection part 22. The user operates the input device 60 to move the transport assist device 1 so that it goes under the traveling device 200 to which the member to be connected 250 is attached. Then the transport assist device 1 is positioned at the connection position. At the connection position, the connection part 22 is positioned directly below the member to be connected 250, facing it vertically.

[0047] Next, the user operates the input device 60 to activate the connection mechanism 20 and raise the connection part 22. As shown in Figure 6, the raised connection part 22 approaches the connected member 250 from below and fits into the fitting hole 254 of the connected member 250 from below.

[0048] The transport assist device 1 is positioned in four directions relative to the traveling device 200: horizontal, vertical, and rotational around the vertical axis, by fitting the connecting portion 22 and the connected member 250 together.

[0049] As a result, the connecting portion 22 restricts the movement of the connected member 250 in the horizontal direction and the pivoting direction around the vertical axis, and supports the traveling device 200 from below, so that the transport assist device 1 is connected to the traveling device 200 via the connecting portion 22 and the connected member 250. When the transport assist device 1 travels, the connecting portion 22 moves in the direction of travel. The transport assist device 1 pulls the traveling device 200 in the direction of travel via the connecting portion 22. As a result, the traveling device 200 is transported in the direction in which the transport assist device 1 moved. In addition, the transport assist device 1 pulls the traveling device 200 in the pivoting direction via the connecting portion 22. As a result, the traveling device 200 pivots in accordance with the pivoting motion of the transport assist device 1.

[0050] [Connection configuration] Next, the configuration of the connection part 22 according to the embodiment will be described. In the following description, a horizontal direction is referred to as the X-axis direction, a horizontal intersection direction perpendicular to the X-axis direction is referred to as the Y-axis direction, and a vertical direction perpendicular to both the X-axis and Y-axis directions is referred to as the Z-axis direction. The direction of rotation around the Z-axis is referred to as the θ direction.

[0051] As shown in Figure 4, the connecting portion 22 comprises a holding portion 31, a load receiving member 32, and a cover member 33. The transport assist device 1 according to this embodiment includes a pressure sensor 34. The pressure sensor 34 is provided on the connecting portion 22. More specifically, the pressure sensor 34 is provided on the cover member 33 of the connecting portion 22.

[0052] The entire connecting portion 22, including the holding portion 31, the load-receiving member 32, and the cover member 33, is raised and lowered by the connecting drive unit 23.

[0053] The holding portion 31 is formed in a roughly rectangular prism shape, with a rounded square shape in plan view. The holding portion 31 holds the load-receiving member 32 and the cover member 33. The holding portion 31 is fixed to the link mechanism 21. A recess for accommodating the load-receiving member 32 is provided on the upper surface of the holding portion 31.

[0054] The load-bearing member 32 is a member that connects to the connected member 250 by fitting into the fitting hole 254 of the connected member 250. The load-bearing member 32 is positioned in a recess on the upper surface of the holding portion 31 and is supported by the holding portion 31. The load-bearing member 32 has a base portion 32A and a fitting projection portion 32B.

[0055] The base portion 32A is the part supported by the retaining portion 31, and is formed in a roughly rectangular prism shape with rounded corners in plan view. The base portion 32A is inserted from above into a recess on the upper surface of the retaining portion 31. The base portion 32A is surrounded by the peripheral wall of the recess of the retaining portion 31.

[0056] The fitting projection 32B is formed by protruding from the center of the upper surface of the base 32A and extending in the axial direction (Z-axis direction). The fitting projection 32B can be inserted into the fitting hole 254 of the connected member 250 by passing it through from below.

[0057] The upper end of the fitting projection 32B is a columnar shape with an axial direction parallel to the Z-axis direction and a constant XY cross-sectional shape. The upper end of the fitting projection 32B is a rectangular prism shape with a cross-sectional shape (XY cross-section) cut by a plane perpendicular to the axial direction, which is a square shape with rounded corners. However, in this embodiment, any columnar shape other than a perfect cylinder is acceptable, and it may be a rectangular prism or an elliptical prism. The load-receiving member 32 has its relative position to the connected member 250 fixed in the X direction, Y direction and rotational direction around the Z axis by fitting the upper end of the fitting projection 32B into the fitting hole 254.

[0058] The lower part of the fitting projection 32B is tapered and has a columnar shape that widens downwards (i.e., towards the base 32A). The outer surface of the fitting projection 32B is a curved inclined surface.

[0059] The cover member 33 is a rectangular ring-shaped protective member that covers the upper surface of the holding portion 31. The lower surface of the cover member 33 is fixed to the upper surface of the holding portion 31. The cover member 33 is a frame-shaped member positioned on the upper surface of the peripheral wall that demarcates the recess of the holding portion 31. The cover member 33 surrounds the load-receiving member 32.

[0060] Figure 7 is a plan view showing an example of the configuration of the cover member 33 of the connection portion 22. Figure 8 is a cross-sectional view showing the cavity 43 in the connected state of the cover member 33 shown in Figure 7.

[0061] The upper surface 33A of the cover member 33 faces the lower surface 251b of the connected member 250 when the load-receiving member 32 and the connected member 250 are connected. The cover member 33 has a fixing screw hole 41, a central opening 42, and a cavity 43.

[0062] The fixing screw hole 41 is a hole through which a screw is inserted to fix the cover member 33 to the upper surface side of the holding part 31. The central opening 42 is an opening through which the fitting projection 32B of the load receiving member 32 is inserted.

[0063] As shown in Figure 8, the cavity 43 includes a housing section 43A and a pin insertion hole 43B. The housing section 43A is provided as a cavity inside the cover member 33. The housing section 43A has a columnar shape at its bottom surface that conforms to the pressure sensor 34, and the pressure sensor 34 is housed at its bottom surface. When viewed in the axial direction (Z-axis direction), the housing section 43A is formed so that its longitudinal direction follows the outer edge of the cover member 33. The pin insertion hole 43B is a hole that extends in the axial direction, with one end opening to the upper surface 33A of the cover member 33 and the other end communicating with the top surface side of the housing section 43A. The pin insertion hole 43B is formed near one end in the longitudinal direction of the housing section 43A. The pressing pin 255 (see Figure 5) of the connected member 250 can be inserted into the pin insertion hole 43B from the opening on the upper surface 33A side.

[0064] As shown in Figure 7, the cover member 33 has two cavities 43. The two cavities 43 are arranged such that, when viewed in the axial direction, the position of each pin insertion hole 43B coincides with the position of each pressure pin 255 of the connected member 250. That is, the number and positions of the pin insertion holes 43B of the cavities 43 correspond to the number and positions of the pressure pins 255. The pin insertion holes 43B are arranged point-symmetrically when viewed in the axial direction. The housing portion 43A of the cavities 43 is arranged point-symmetrically so that, when viewed in the axial direction, the longitudinal direction of the housing portion 43A is along the outer edge of the cover member 33. Two cavities 43 are formed, one near each of the two diagonally opposite fixing screw holes 41.

[0065] The pressure sensor 34 is pressed by a pressing pin 255 provided on the connected member 250 when the connection part 22 is connected, and outputs a detection value corresponding to the pressing force. As shown in Figure 8, the pressure sensor 34 includes a base part 341 and a functional part 342, and is arranged in the cavity part 43. The base part 341 is housed on the bottom surface of the housing part 43A of the cover member 33. The pressure-sensitive surface 343 of the functional part 342 is located at the bottom of the pin insertion hole 43B. The pressure-sensitive surface 343 is parallel to the top surface 33A of the cover member 33 and faces the opening side of the pin insertion hole 43B.

[0066] As shown in Figure 7, the pressure sensor 34 includes a first pressure sensor 34A and a second pressure sensor 34B, positioned on one side of the center of the connection portion 22 and on the other side, as viewed from the direction of movement (Z direction) of the connection portion 22 by the connection drive unit 23. The first pressure sensor 34A is positioned in the cavity 43 on the +X and +Y side in Figure 7. The second pressure sensor 34B is positioned in the cavity 43 on the -X and -Y side in Figure 7.

[0067] In this embodiment, for example, the +Y direction is forward and the +X direction is left. The first pressure sensor 34A is positioned forward and to the left of the center of the connection portion 22 (i.e., the center of the central opening 42), and the second pressure sensor 34B is positioned backward and to the right. In other words, in Figure 7, the first pressure sensor 34A and the second pressure sensor 34B are positioned on opposite sides of the center of the connection portion 22 in the front-to-back direction (Y-axis direction). Also, the first pressure sensor 34A and the second pressure sensor 34B are positioned on opposite sides of the center of the connection portion 22 in the left-to-right direction (X-axis direction).

[0068] As shown in Figure 8, a cushioning material 45 is placed in the cavity 43. The cushioning material 45 is provided so as to cover the pressure-sensitive surface 343 of the pressure sensor 34. When viewed in the axial direction, the cushioning material 45 has the same shape as the pin insertion hole 43B. The pressure sensor 34 is pressed by the pressing pin 255 via the cushioning material 45.

[0069] [Connected component] Figure 9 is a perspective view of the connected member 250 according to the embodiment, viewed from the bottom. The connected member 250 is a member that is attached to the traveling device 200 (see Figure 1). The connected member 250 is connectable to and detachable from the connecting portion 22. By connecting the connected member 250 to the connecting portion 22, the transport assist device 1 is connected to the traveling device 200. As shown in Figures 5 and 9, the connected member 250 has a base portion 251, a hole forming portion 252, a plurality (four in the embodiment) of fixing holes 253, a fitting hole 254, and a pressing pin 255.

[0070] The base portion 251 is the part that is attached to the running gear 200, and its plan view shape is formed as a thick plate with a square ring shape including rounded corners. The base portion 251 is attached to the running gear 200 such that its upper surface 251a (see Figure 5) faces the lower surface of the running gear 200.

[0071] As shown in Figures 5 and 9, the hole-forming portion 252 is formed in a convex shape extending downward from the lower surface 251b of the base portion 251 in a plan view, and its shape in plan view is a square-shaped convex portion with rounded corners. The hole-forming portion 252 is formed so that its center in a plan view is the center of the base portion 251. The connected member 250 is formed such that the thickness in the Z-axis direction of the hole-forming portion 252 is greater than the thickness of the square ring-shaped portion outside the outer circumference of the hole-forming portion 252.

[0072] The fixing hole 253 is a hole through which a screw is inserted to fix the connected member 250 to the lower side of the travel device 200.

[0073] The fitting hole 254 is a hole that penetrates the hole-forming portion 252 of the connected member 250 in the Z-axis direction, and the fitting projection 32B of the load-receiving member 32 can be inserted from below. The fitting hole 254 is formed in the center of the connected member 250 in a plan view. The fitting hole 254 has a tapered inner wall that gradually becomes smaller toward the top (i.e., toward the upper surface 251a side).

[0074] When the load-receiving member 32 inserts the fitting projection 32B into the fitting hole 254 from below, the upper end of the fitting projection 32B is guided by the inner wall of the fitting hole 254 and fitted. Therefore, even if the positions of the fitting projection 32B and the fitting hole 254 are misaligned in the XY plane or in the θ rotation direction around the Z axis, the fitting projection 32B is positioned in the XY plane. By fitting the fitting projection 32B into the fitting hole 254, the connecting portion 22 connects to the member to be connected 250.

[0075] The fitting projection 32B engages with the fitting hole 254, thereby positioning the connecting portion 22 and the connected member 250 in the XY plane and the θ rotation direction. Furthermore, the lower edge 252a of the hole-forming portion 252 of the connected member 250 contacts and supports the upper surface of the base portion 32A of the load-receiving member 32, thereby positioning the connecting portion 22 and the connected member 250 in the Z axis direction. In other words, the load-receiving member 32 and the connected member 250 can be positioned in four axes.

[0076] The pressure pin 255 is formed to protrude from the lower surface 251b of the base 251 and extend axially. The pressure pin 255 has a dome shape that gradually becomes smaller towards the axial tip (lower end in Figure 5). The axial length of the pressure pin 255 is longer than the depth of the pin insertion hole 43B of the cover member 33. The pressure pin 255 is a projection that presses the pressure sensor 34 when the load-receiving member 32 and the connected member 250 are connected. The pressure pin 255 presses the pressure sensor 34 (see Figure 8) via the cushioning material 45.

[0077] The connected member 250 has two pressure pins 255. When connected to the load-receiving member 32, the two pressure pins 255 are positioned such that, when viewed in the axial direction, they coincide with the positions of the respective pin insertion holes 43B of the cover member 33. That is, the number and positions of the pressure pins 255 correspond to the number and positions of the pin insertion holes 43B of the cavity 43. In this embodiment, the pressure pins 255 are arranged point-symmetrically when viewed in the axial direction (Z-axis direction).

[0078] In other words, in this embodiment, the pressing pin 255 includes two pressing pins 255A and 255B that are arranged diagonally when viewed in the axial direction (Z-axis direction). When connected, pressing pin 255A enters into the cavity 43 housing the first pressure sensor 34A and presses the first pressure sensor 34A via the cushioning material 45. When connected, pressing pin 255B enters into the cavity 43 housing the second pressure sensor 34B and presses the second pressure sensor 34B via the cushioning material 45.

[0079] When the fitting projection 32B and the fitting hole 254 engage, the pressing pin 255 is inserted into the cavity 43. At this time, the pressing pin 255 presses the pressure-sensitive surface 343 of the pressure sensor 34, which is located in the housing 43A below the cavity 43, via the cushioning material 45. The pressure sensor 34 detects the pressure applied to it by the tip of the pressing pin 255 via the cushioning material 45. In other words, the pressure sensor 34 detects the connection state between the connection part 22 and the connected member 250.

[0080] [Configuration of the control unit] Figure 10 is a block diagram showing the configuration related to the control processing of the control unit 50. The control unit 50 includes an arithmetic processing unit having a microprocessor such as a CPU (Central Processing Unit), memory such as ROM (Read Only Memory) or RAM (Random Access Memory), a storage unit 51, and hardware resources such as an input / output interface device. The functions of the control unit 50 are realized by the arithmetic processing unit executing a predetermined program stored in the storage unit 51. When the predetermined program is executed, the control unit 50 outputs control signals to each component to execute various functions according to the calculation results of the arithmetic processing unit, and outputs the calculation results to the outside.

[0081] The storage unit 51 includes a rewritable non-volatile storage device such as flash memory. The storage unit 51 stores programs for operating the CPU as the control unit 50, and various data used for controlling the operation of the transport assist device 1, such as thresholds and margins, which will be described later.

[0082] As shown in Figure 10, the control unit 50 controls the operation of the motors 13 of each drive wheel 11 based on the output of the encoder 14 and the control signals from the input device 60. Based on the output of the encoder 14 and the control signals from the input device 60, the control unit 50 calculates speed command values ​​or torque command values ​​for each axial direction of the transport assist device 1 (device body 10). Specifically, each axial direction refers to the three directions: the X-axis direction, the Y-axis direction, and the θ direction around the Z-axis. From the command values ​​calculated by the control unit 50, the output current value to each motor 13 is calculated. Based on the output current value, the operation of each motor 13 is controlled by controlling the current value supplied to each motor 13 by the motor driver. The control unit 50 controls the current value supplied to each motor 13 so that the speed in each axial direction calculated from the output of the encoder 14 approaches the corresponding speed command value for each axial direction. The operation control of each motor 13 by the control unit 50 controls the driving and direction of travel of each drive wheel 11. When the drive wheel 11 is an active caster, each drive wheel 11 has two degrees of freedom: wheel swivel and wheel rotation. Two motors 13 are provided for each drive wheel 11, and encoders 14 are also provided corresponding to each motor 13. In Figure 10, for simplicity, only one motor 13 and one encoder 14 are shown for each drive wheel 11.

[0083] The control unit 50 is powered by a battery (not shown). The battery is mounted on the main unit 10 of the device.

[0084] The control unit 50 controls the drive wheels 11 to move the device body 10 at a translational speed and a turning speed corresponding to the operation received by the input device 60, based on the control signals received from the input device 60. The translational speed is the horizontal movement speed of the transport assist device 1, and refers to the speed at which the center position in a plan view changes. The turning speed is the rotational speed of the transport assist device 1 in the θ direction, and refers to the angular velocity at which the attitude angle around the center in a plan view changes.

[0085] In this embodiment, the control unit 50 performs control based on the output of the pressure sensor 34. The control unit 50 acquires the detection result from the pressure sensor 34 and detects the connection status between the transport assist device 1 and the traveling device 200 in the connection mechanism 20 based on the detection result from the pressure sensor 34.

[0086] Specifically, the control unit 50 executes abnormal processing, including deceleration of the device body 10, when an abnormal detection state occurs for a predetermined period of time during the movement of the device body 10 connected to the travel device 200, in which the detected value of the pressure sensor 34 is below a threshold.

[0087] In other words, when the connection part 22 and the connected member 250 are connected, and the device body 10 and the traveling device 200 are in motion, the connection between the traveling device 200 (connected member 250) and the transport assist device 1 (connection part 22) may become disconnected or nearly disconnected due to, for example, the slope or unevenness of the floor surface. The control unit 50 detects such a disconnected or nearly disconnected state as an abnormality detection state based on the detection value of the pressure sensor 34. If the abnormality detection state continues for a predetermined time, the control unit 50 executes a predetermined abnormality processing.

[0088] In this embodiment, the control unit 50 sets threshold values ​​separately for the first pressure sensor 34A and the second pressure sensor 34B. Hereinafter, the threshold value for the first pressure sensor 34A will be referred to as threshold Th1, and the threshold value for the second pressure sensor 34B will be referred to as threshold Th2.

[0089] In this embodiment, the control unit 50 acquires a non-pressure detection value, which is the value detected by the pressure sensor 34 before the connection unit 23 connects the connection unit 22 to the member to be connected 250. The control unit 50 then sets a value obtained by adding a predetermined margin to the non-pressure detection value as a threshold value.

[0090] In other words, as shown in Figure 5, the control unit 50 acquires the detected value of the pressure sensor 34 in the unconnected state before connecting the transport assist device 1 to the connected member 250 by the connection mechanism 20. The detected value of the pressure sensor 34 in the unconnected state corresponds to the pressure value when the pressure sensor 34 is not pressed by the pressing pin 255, and this is called the unpressed detected value. The control unit 50 acquires the unpressed detected value for each of the multiple pressure sensors 34. From the obtained unpressed detected values, the threshold value for each pressure sensor 34 is determined separately.

[0091] Figure 11 is a graph illustrating the threshold values ​​for determining the abnormal detection state. The control unit 50 sets the threshold Th1 for the first pressure sensor 34A by adding a margin MG to the non-pressure detection value RA obtained from the first pressure sensor 34A. The control unit 50 sets the threshold Th2 for the second pressure sensor 34B by adding a margin MG to the non-pressure detection value RB obtained from the second pressure sensor 34B. The margin MG is a preset constant. The difference between the non-pressure detection values ​​RA and RB is due to, for example, individual differences in the pressure sensor 34, dimensional variations in the pressing pin 255 and cushioning material 45, and variations in the assembly state of each component. Figure 11 is an illustrative graph illustrating the concept of threshold values, and the relationship between the non-pressure detection values ​​RA and RB and the size of the margin MG are not limited to the illustrated example.

[0092] The method for setting the threshold is not limited to this. The threshold may be, for example, the non-pressure detection value multiplied by a predetermined margin. In this case, the margin is a coefficient of 1 or more.

[0093] The control unit 50 acquires the non-pressure detection values ​​(RA, RB) of each pressure sensor 34 before connecting the transport assist device 1, and stores threshold values ​​Th1 and Th2 calculated based on the acquired non-pressure detection values ​​(RA, RB) in the storage unit 51. While the transport assist device 1 is running in the connected state, the control unit 50 detects that an abnormality has occurred by comparing the detection values ​​of each pressure sensor 34 with the threshold values.

[0094] In this embodiment, an abnormality detection state includes the case where the detection values ​​of both the first pressure sensor 34A and the second pressure sensor 34B fall below a threshold. That is, the control unit 50 determines that an abnormality detection state exists when the detection value of the first pressure sensor 34A falls below the threshold Th1 and the detection value of the second pressure sensor 34B falls below the threshold Th2. The control unit 50 determines that an abnormality detection state does not exist when the detection value of the first pressure sensor 34A is equal to or greater than the threshold Th1, or when the detection value of the second pressure sensor 34B is equal to or greater than the threshold Th2.

[0095] When the control unit 50 detects an abnormality during operation while connected to the travel device 200, it counts the duration of the abnormality. However, if the value detected by the pressure sensor 34 exceeds a threshold, the control unit 50 resets the count of the duration of the abnormality up to that point.

[0096] The control unit 50 performs an abnormality determination process when the duration of the abnormality detection state exceeds a predetermined time. The abnormality determination process includes recording a value indicating that an abnormality has occurred in the flag information that indicates whether or not an abnormality has occurred in the transport assist device 1. Specifically, the flag information is binary data, either abnormal (e.g., "1") or no abnormality (e.g., "0"). In this case, the abnormality determination process writes the value "1" to the flag information.

[0097] The control unit 50 executes error processing when the flag information contains a value ("1") indicating that an error has occurred. Error processing includes decelerating the device body 10 while it is in motion. In this embodiment, error processing includes stopping the device body 10 from moving. Therefore, if the duration of the error detection state exceeds a predetermined time, the control unit 50 controls the device body 10 to decelerate and eventually stop it.

[0098] Furthermore, in this embodiment, the control unit 50 performs error processing regardless of whether or not an input operation is performed on the input device 60. In other words, while the control unit 50 is performing error processing, it prioritizes the error processing even if the user performs an input operation on the input device 60 (i.e., even if it receives a control signal from the input device 60 corresponding to the input operation). While the control unit 50 is performing error processing, it ignores input operations via the input device 60 (i.e., input operations that instruct the movement of the device body 10).

[0099] In this embodiment, when the control unit 50 initiates abnormality processing and stops the main unit 10 of the device, it stops the signal output control to the motor 13 of the drive wheel 11. Therefore, after the abnormality processing is performed, even if the user inputs a movement command via the joystick 61 of the input device 60, the control unit 50 maintains the stopped state of the main unit 10. On the other hand, the control unit 50 accepts a reset operation or a restart operation of the main unit 10. In response to accepting a reset operation or a restart operation, the control unit 50 resets the flag information. When the reset writes a value indicating no abnormality ("0") to the flag information, the abnormality processing is terminated. As a result, the user can operate the input device 60 to move the main unit 10 of the device.

[0100] The predetermined time threshold for the duration of the abnormality detection state is not particularly limited. The predetermined time can be set according to, for example, the maximum speed of the transport assist device 1 in the connected state, the type and size of the connected traveling device 200, and the type of transported object transported by the traveling device 200. The predetermined time can also be set according to the distance traveled from the time the abnormality detection state occurs until the device body 10, which is traveling at the set maximum speed or steady speed, comes to a stop.

[0101] For example, the predetermined time is set to a duration such that the distance traveled from the time an abnormality is detected until the device body 10 stops is less than half the total length L of the travel device 200 in the longitudinal direction. As shown in Figure 1, a typical travel device 200 has its longitudinal direction as the front-rear direction and mainly travels forward or turns left and right from a forward-facing direction. When the device body 10 is connected to the central part of the travel device 200, a distance of approximately half the total length L is formed between the device body 10 and the end of the travel device 200 in the direction of movement (i.e., the front end). If the connection between the device body 10 and the travel device 200 is disconnected during travel and an abnormality is detected, the distance traveled until the device body 10 stops due to abnormality processing will be less than half the total length L of the travel device 200 in the longitudinal direction. Therefore, even if the connection is disconnected and the traveling device 200 stops, and only the main unit 10 continues to move, the main unit 10 can be stopped before it jumps out from under the traveling device 200 and forward.

[0102] Furthermore, the predetermined time may be set such that, for example, the distance traveled from the time an abnormality is detected until the device body 10 stops is less than a predetermined value. For example, the predetermined time may be set such that the distance traveled from the time an abnormality is detected until the device body 10 stops is 1 meter or less.

[0103] If the predetermined time is too long, it is undesirable because it will take too long for the abnormality processing to start. The predetermined time may be set to a predetermined value of, for example, 5 seconds or less. The predetermined time may be set to a predetermined value of, for example, 2 seconds or less. If the predetermined time is too short, there is a high possibility that abnormality processing will start even in cases where the detected value temporarily falls below the threshold due to vibrations caused by unevenness in the floor surface, for example. To suppress this, the predetermined time may be set to a predetermined value of, for example, 0.2 seconds or more. The predetermined time may be set to a predetermined value of, for example, 0.5 seconds or more. In this embodiment, the predetermined time may be set to, for example, 1 second.

[0104] [Control Method] (Connection process) Next, the control method of the transport assist device 1 by the control unit 50 will be explained. First, the process of connecting the transport assist device 1 to the traveling device 200 will be explained. Figure 12 is a flowchart showing the connection process of the transport assist device 1 shown in Figure 1.

[0105] The process shown in Figure 12 is executed by the control unit 50 of the transport assist device 1 based on operation input via the input device 60 and a predetermined control program and data.

[0106] In step S100, the control unit 50 controls the operation of the drive wheels 11 in response to the operation signal from the input device 60. The user operates the input device 60 to move the transport assist device 1 to the connection position with the travel equipment 200. The transport assist device 1 is positioned below the connected member 250 by the first arm 231, the second arm 232, and the stopper 240, as shown in Figure 5.

[0107] In this state, the user operates the input device 60 to send a command to perform a connection operation to the transport assist device 1. Upon receiving the command to perform the connection operation, the control unit 50 acquires the detected value (non-pressure detected value) of the pressure sensor 34 in step S101. The control unit 50 calculates the threshold values ​​(Th1, Th2) of the detected values ​​of the first pressure sensor 34A and the second pressure sensor 34B, respectively, from the non-pressure detected values ​​(RA, RB) of the first pressure sensor 34A and the second pressure sensor 34B, and a predetermined margin MG, and stores them in the storage unit 51.

[0108] In step S102, the control unit 50 connects the connection part 22 to the member to be connected 250. That is, the control unit 50 operates the connection drive unit 23 of the connection mechanism 20 to raise the connection part 22 toward the member to be connected 250. Based on a predetermined control program and data, the control unit 50 raises the connection part 22 by a predetermined amount. As a result, as shown in Figure 6, the fitting projection 32B of the connection part 22 fits into the fitting hole 254 of the member to be connected 250. The fitting of the fitting projection 32B and the fitting hole 254 connects the transport assist device 1 to the traveling device 200.

[0109] Furthermore, when connected, the pressing pin 255 of the connected member 250 enters the pin insertion hole 43B and presses the pressure sensor 34 via the cushioning material 45. As a result, the pressing force of the pressing pin 255A causes the detected value of the first pressure sensor 34A to rise above the unpressed detected value RA, and the pressing force of the pressing pin 255B causes the detected value of the second pressure sensor 34B to rise above the unpressed detected value RB.

[0110] (Error status monitoring process) Next, the error state monitoring process of the transport assist device 1 will be described. Figure 13 is a flowchart showing the error state monitoring process of the transport assist device 1 shown in Figure 1. The control unit 50 executes the error state monitoring process in response to the connection state in which the connection part 22 of the transport assist device 1 is connected to the connected member 250 of the traveling device 200. That is, when the connection state is in which the connection part 22 is positioned in the raised position, the control unit 50 executes the error state monitoring process.

[0111] The control method for the transport assist device 1 according to this embodiment includes a step S110 for acquiring the detected value of the pressure sensor 34. That is, in step S110, the control unit 50 acquires the detected value of the pressure sensor 34 in the connected state. The control unit 50 acquires the detected values ​​of each of the multiple pressure sensors 34 (first pressure sensor 34A and second pressure sensor 34B).

[0112] The control method for the transport assist device 1 according to this embodiment includes a step S111 for detecting whether the device body 10 connected to the traveling device 200 is in motion. That is, in step S111, the control unit 50 determines whether the transport assist device 1 is in a transport travel state. The transport travel state is a connected state and a travel state. The control unit 50 can detect whether it is in a travel state based, for example, on the output of the encoder 14, the current output to the motor 13, or the fact that the speed command value calculated in the control processing of the motor 13 is non-zero. If the transport assist device 1 is not in a transport travel state (step S111; NO), the control unit 50 terminates the error state monitoring process.

[0113] The system includes a step (steps S112, S113, S114) to detect if an abnormal detection state in which the detected value of the pressure sensor 34 is below a threshold continues for a predetermined time while the main unit 10 is in motion. Specifically, when the transport assist device 1 is in transport motion (step S111; YES), the control unit 50 determines in step S112 whether the detected values ​​of each of the multiple pressure sensors 34 are below a threshold.

[0114] If the detection value of the first pressure sensor 34A is less than the threshold Th1 and the detection value of the second pressure sensor 34B is less than the threshold Th2 (step S112; YES), the control unit 50 proceeds to step S113. This case, where the detection value of the first pressure sensor 34A is less than the threshold Th1 and the detection value of the second pressure sensor 34B is less than the threshold Th2, corresponds to an abnormality detection state.

[0115] In step S113, the control unit 50 measures (counts) the elapsed time during which the detected value of each pressure sensor 34 is below a threshold (abnormal detection state). Then, in step S114, the control unit 50 determines whether a predetermined time has elapsed during the abnormal detection state. Here, the predetermined time is, for example, 1 second. If the control unit 50 determines that the predetermined time has elapsed during the abnormal detection state (step S114; YES), it proceeds to step S115. In this way, steps S112, S113, and S114 detect that the abnormal detection state, in which the detected value of the pressure sensor 34 is below a threshold, has continued for a predetermined time.

[0116] In step S115, the control unit 50 performs an abnormality detection process. Specifically, the control unit 50 records a value ("1") indicating that an abnormality has occurred in the flag information that indicates whether or not an abnormality has occurred in the transport assist device 1. As a result, an error flag is recorded in the flag information. After the abnormality detection process, the control unit 50 terminates the error status monitoring process.

[0117] Furthermore, if the elapsed time of the abnormality detection state has not exceeded a predetermined time (step S114; NO), the control unit 50 terminates the error state monitoring process without performing any abnormality determination processing.

[0118] Furthermore, if the detection values ​​of each pressure sensor 34 are greater than or equal to thresholds (Th1, Th2) (step S112; NO), the control unit 50 proceeds to step S116. In other words, the control unit 50 executes the process in step S116 when there is no abnormality detection condition, that is, when the detection value of the first pressure sensor 34A is greater than or equal to threshold Th1, or when the detection value of the second pressure sensor 34B is greater than or equal to threshold Th2.

[0119] In step S116, the control unit 50 resets the count of the duration of the abnormal detection state up to that point. Therefore, for example, even if an abnormal detection state is detected and the count of the duration of the abnormal detection state starts in step S113, if the detected value of any pressure sensor 34 becomes greater than or equal to a threshold before that duration reaches the predetermined time (1 second) in step S114, the count of the duration of the abnormal detection state is reset to zero in step S116.

[0120] The control unit 50 repeatedly executes the error state monitoring process from step S110 to step S116 while the connection part 22 and the connected member 250 are connected, that is, while the connection part 22 is in the raised position. The control unit 50 executes the error state monitoring process at a sufficiently short period corresponding to the sampling rate of the detected value of the pressure sensor 34.

[0121] Therefore, if an abnormality is detected during any execution cycle of the error state monitoring process (resulting in YES in step S112), the count of the duration of the abnormality is accumulated in subsequent execution cycles. Until the count of the duration of the abnormality is reached a predetermined time (1 second), it is determined to be NO in step S114, and the abnormality determination process is not executed. Subsequently, when the count of the duration of the abnormality is reached the predetermined time, the abnormality determination in step S115 is executed. If the abnormality is no longer detected during any execution cycle before the count of the duration of the abnormality is reached the predetermined time (resulting in NO in step S112), the duration count is reset to zero at that point.

[0122] (Error handling) Next, the handling of abnormalities in the transport assist device 1 will be described. Figure 14 is a flowchart showing the handling of abnormalities in the transport assist device 1 shown in Figure 1. The control unit 50 constantly monitors the flag information in the storage unit 51. That is, the control unit 50 repeatedly executes the process shown in Figure 14 until the power supply is cut off.

[0123] In step S120, the control unit 50 determines whether or not an abnormal flag is recorded in the flag information. That is, the control unit 50 determines whether or not the value of the flag information is a value indicating an abnormality ("1"). If no value indicating an abnormality is recorded in the flag information, that is, if the value of the flag information is "0" (step S120; NO), the control unit 50 terminates without performing any abnormality processing.

[0124] The control method for the transport assist device 1 according to the embodiment includes the steps (S121, S122, S123) of executing abnormal processing, including deceleration of the device body 10, based on the abnormal detection state continuing for a predetermined time (i.e., an abnormal flag being recorded due to abnormal determination).

[0125] Specifically, if an abnormality flag is recorded, that is, if the value of the flag information is "1" (step S120; YES), the control unit 50 executes the abnormality processing from steps S121 to S123.

[0126] In step S121, the control unit 50 writes data indicating an error state to the status of the transport assist device 1. The status of the transport assist device 1 includes at least a normal state and an error state. The control unit 50 constantly performs a process to notify the status of the transport assist device 1. The status of the transport assist device 1 is displayed in a way that distinguishes each type of state on a status indicator provided on at least one of the device body 10 and the input device 60. Therefore, when the status of the transport assist device 1 becomes an error state, the indicator display switches to an error display from that point onward. The status indicator is, for example, an indicator lamp.

[0127] In step S122, the control unit 50 overwrites the speed command value of the device body 10 to 0 [m / s]. That is, the control unit 50 calculates the speed command value based on the output of the encoder 14 and the control signal corresponding to the input operation to the input device 60 (joystick 61), but in step S122, it forcibly overwrites this speed command value to 0 [m / s]. For this reason, the control unit 50 performs error processing regardless of whether or not an input operation has been performed to the input device 60.

[0128] When the speed command value is set to 0 [m / s], the device body 10 is controlled to move closer to 0 [m / s]. In other words, the device body 10 decelerates from its current speed and eventually comes to a stop at a speed of 0 [m / s].

[0129] In step S123, the control unit 50 stops the signal output from the drive wheel 11 to the motor 13. In other words, the control unit 50 stops the current supply to the motor 13 and terminates the operation control of the drive wheel 11. Even if the control unit 50 receives a control signal corresponding to an input operation from the input device 60, it does not perform operation control of the main unit 10. In this way, the control unit 50 performs error processing regardless of whether or not there is an input operation to the input device 60. After that, the control unit 50 terminates the error processing.

[0130] As described above, after step S123 is executed, the operation control of the drive wheels 11 is stopped until a reset or restart operation of the device body 10 is accepted. Therefore, if the device body 10 stops due to abnormal processing, the user will need to reset or restart the device body 10 to resume operation.

[0131] As described above, the transport assist device 1 of the embodiment is a transport assist device that assists in the transport of a traveling device 200 by generating driving force when connected to the traveling device 200, and comprises a device body 10 having drive wheels 11, a connection mechanism 20 provided on the device body 10 including a connection part 22 that connects to a connected member 250 attached to the traveling device 200, and a connection drive unit 23 that moves the connection part 22 forward and backward toward the connected member 250, a pressure sensor 34 that outputs a detected value corresponding to the pressing force when pressed by a pressing pin 255 provided on the connected member 250 when the connection part 22 is connected, and a control unit 50 that performs control based on the output of the pressure sensor 34, and the control unit 50 performs abnormal processing including deceleration of the device body 10 when an abnormal detection state in which the detected value of the pressure sensor 34 is less than a threshold continues for a predetermined time while the device body 10 connected to the traveling device 200 is traveling.

[0132] According to the transport assist device 1 of this embodiment, if the connection between the transport assist device 1 and the travel device 200 becomes disconnected or nearly disconnected while the transport assist device 1 is traveling, the contact pressure of the pressing pin 255 against the pressure sensor 34 decreases, causing the detected value of the pressure sensor 34 to drop. Therefore, the disconnected or nearly disconnected state can be detected based on the detected value of the pressure sensor 34. The control unit 50 executes abnormal processing, including deceleration of the device body 10, if the abnormal detection state in which the detected value of the pressure sensor 34 is below a threshold continues for a predetermined time. As a result, if the connection between the transport assist device 1 and the travel device 200 becomes disconnected or nearly disconnected while the transport assist device 1 is traveling, the transport assist device 1 and the travel device 200 can be decelerated. This improves the safety of the travel device 200 and the transported goods, even if the connection with the travel device 200 is disconnected during travel.

[0133] Furthermore, in the transport assistance device 1 of this embodiment, the abnormality handling includes stopping the movement of the device body 10.

[0134] As a result, if the connection between the transport assist device 1 and the transport assist device 200 becomes disconnected or is about to become disconnected while the transport assist device 1 is in motion, the transport assist device 1 can be decelerated to a complete stop. This further improves safety in the event of disconnection during operation.

[0135] Furthermore, the transport assistance device 1 of this embodiment further includes an input device 60 that receives input operations for movement instructions for the device body 10, and the control unit 50 performs abnormality processing regardless of whether or not an input operation is performed to the input device 60.

[0136] As a result, when the transport assist device 1 decelerates due to abnormality processing, deceleration will occur regardless of (and in priority to) the user's input command to accelerate, even if the user inputs an acceleration command. This further improves safety in the event of disconnection during operation, as abnormality processing takes priority even if the user continues to input commands without noticing the disconnection.

[0137] Furthermore, in the transport assist device 1 of the embodiment, the pressure sensor 34 includes a first pressure sensor 34A positioned on one side of the center of the connection part 22 and a second pressure sensor 34B positioned on the other side, as viewed from the direction of movement of the connection part 22 by the connection drive unit 23, and the abnormality detection state includes the case where the detection values ​​of both the first pressure sensor 34A and the second pressure sensor 34B fall below thresholds (Th1, Th2).

[0138] For example, if the floor surface is sloped or uneven, or if the transported object is unevenly loaded onto the travel device 200, the transport assist device 1 and the travel device 200 may tilt relative to each other, potentially reducing the pressing force on the pressure sensor 34 by the pressing pin 255 even when connected. Therefore, by positioning the first pressure sensor 34A and the second pressure sensor 34B on opposite sides of the center of the connection part 22, in cases where the transport assist device 1 is tilted but the connection has not been released, even if the detection value of one of the first pressure sensor 34A and the second pressure sensor 34B decreases, the detection value of the other remains high. Thus, by detecting an abnormal state when the detection values ​​of both the first pressure sensor 34A and the second pressure sensor 34B fall below a threshold, the system becomes less susceptible to the effects of temporary fluctuations in detection values ​​due to unevenness or slope, and can accurately determine whether the connection between the connection part 22 and the connected member 250 has been released.

[0139] Furthermore, in the transport assistance device 1 of the embodiment, the control unit 50 resets the count of the duration of the abnormal detection state up to that point when the detected value of the pressure sensor 34 exceeds a threshold.

[0140] This allows for the suppression of false detections by resetting the duration count in cases where the connection state is maintained even though an abnormality was detected only temporarily, or when the detected value fluctuates due to vibrations or other factors.

[0141] Furthermore, in the transport assist device 1 of the embodiment, the control unit 50 acquires non-pressure detection values ​​(RA, RB), which are the detection values ​​of the pressure sensor 34 in the state before the connection unit 23 connects the connection unit 22 to the member to be connected 250, and the control unit 50 sets the values ​​obtained by adding a predetermined margin MG to the non-pressure detection values ​​as threshold values ​​(Th1, Th2).

[0142] This allows the thresholds (Th1, Th2) to be appropriately set based on the detected value of the pressure sensor 34 when no pressing force is being applied by the pressing pin 255 (non-pressure detected value). Therefore, it becomes less susceptible to the effects of dimensional tolerances, assembly variations, and individual differences in sensors in the transport assist device 1.

[0143] Furthermore, in the transport assist device 1 of the embodiment, the pressure sensor 34 includes a first pressure sensor 34A positioned on one side of the center of the connection part 22 and a second pressure sensor 34B positioned on the other side, as viewed from the direction of movement of the connection part 22 by the connection drive unit 23, and the control unit 50 sets threshold values ​​(Th1, Th2) separately for the first pressure sensor 34A and the second pressure sensor 34B.

[0144] This allows for the setting of appropriate thresholds (Th1, Th2) separately for the first pressure sensor 34A and the second pressure sensor 34B. Therefore, it is possible to reduce the impact of dimensional tolerances in the installation position of each pressure sensor 34, assembly variations, and individual differences in the sensors.

[0145] Furthermore, in the transport assistance device 1 of the embodiment, the predetermined time is set to a time length such that the distance traveled from the time an abnormality detection condition occurs until the device body 10 stops is less than half the total length L in the longitudinal direction of the traveling device 200.

[0146] According to this, when the connection between the connecting part 22 and the connected member 250 is released, the transport assist device 1 will stop after traveling a distance equivalent to half the total length L of the running device 200. Even if the transport assist device 1 is positioned in the lower center of the running device 200, and the transport assist device 1 continues to move while the running device 200 remains after the connection is released, the transport assist device 1 can stop without flying out from below the running device 200 in the direction of travel. Therefore, even if there are users or pedestrians around the running device 200, safety is improved by suppressing the flying out of the transport assist device 1.

[0147] Furthermore, the control method for the transport assist device 1 of the embodiment includes a device body 10 having drive wheels 11, a connecting part 22 that connects to a connected member 250 attached to a traveling device 200, and a connecting drive unit 23 that moves the connecting part 22 toward the connected member 250, and a connecting mechanism 20 provided on the device body 10, and a pressure sensor 34 that outputs a detected value corresponding to the pressing force when pressed by a pressing pin 255 provided on the connected member 250 when the connecting part 22 is connected, and the transport assist device 1 assists the transport of the traveling device 200 by generating driving force when connected to the traveling device 200, and the control method for the transport assist device 1 includes a step of acquiring the detected value of the pressure sensor 34, a step of detecting that the device body 10 connected to the traveling device 200 is traveling, a step of detecting that an abnormal detection state in which the detected value of the pressure sensor 34 is less than a threshold has continued for a predetermined time while the device body 10 is traveling, and a step of executing abnormal processing including deceleration of the device body 10 based on the fact that the abnormal detection state has continued for a predetermined time.

[0148] According to the control method for the transport assist device 1 of this embodiment, if the connection between the transport assist device 1 and the traveling device 200 becomes disconnected or is about to become disconnected while the transport assist device 1 is traveling, the contact pressure of the pressing pin 255 against the pressure sensor 34 decreases, causing the detected value of the pressure sensor 34 to drop. Therefore, the disconnected or about-disconnected state can be detected based on the detected value of the pressure sensor 34. The control unit 50 executes abnormal processing, including deceleration of the device body 10, if the abnormal detection state in which the detected value of the pressure sensor 34 is below a threshold continues for a predetermined time. As a result, if the connection between the transport assist device 1 and the traveling device 200 becomes disconnected or is about to become disconnected while the transport assist device 1 is traveling, the transport assist device 1 and the traveling device 200 can be decelerated. This improves the safety of the traveling device 200 and the transported goods, even if the connection with the traveling device 200 is disconnected while traveling.

[0149] [Differentiation] It should be noted that this embodiment is not limited to the above-described form. That is, it can be implemented with various modifications without departing from the core principles of this embodiment.

[0150] For example, the number and arrangement of the pressure sensors 34 are not limited to the configuration of this embodiment and may be set as appropriate. Figure 15A is a schematic diagram showing a modified example regarding the arrangement of the pressure sensors. Figure 15B is a schematic diagram showing a modified example regarding the arrangement of the pressure pins.

[0151] In the modified example shown in Figure 15A, the pressure sensor 34 includes a first pair P1 of a first pressure sensor 34A-1 and a second pressure sensor 34B-1 in a first direction D1 in the plane viewed from the direction of movement of the connection part 22 by the connection drive unit 23, and a second pair P2 of a first pressure sensor 34A-2 and a second pressure sensor 34B-2 in a second direction D2 that is perpendicular to the first direction D1 in the plane viewed from the direction of movement of the connection part 22.

[0152] In the example shown in Figure 15A, the first direction D1 coincides with the left-right direction (i.e., the X direction) of the device body 10. The first pair P1 includes a first pressure sensor 34A-1 located on the +X side with respect to the center of the connection portion 22, and a second pressure sensor 34B-1 located on the -X side. In this case, as shown in Figure 15B, the connected member 250 is provided with a first pair of pressure pins 255 corresponding to the first pair P1. The first pair of pressure pins 255 includes a pressure pin 255A-1 on the +X side with respect to the center of the fitting hole 254, and a pressure pin 255B-1 on the -X side. When the connection portion 22 is connected to the connected member 250, the first pressure sensor 34A-1 is pressed by the pressure pin 255A-1, and the second pressure sensor 34B-1 is pressed by the pressure pin 255B-1.

[0153] In the example shown in Figure 15A, the second direction D2 coincides with the front-to-back direction (i.e., the Y direction) of the device body 10. The second pair P2 includes a first pressure sensor 34A-2 located on the +Y side with respect to the center of the connection portion 22, and a second pressure sensor 34B-2 located on the -Y side. As shown in Figure 15B, the connected member 250 is provided with a second pair of pressure pins 255 corresponding to the second pair P2. The second pair of pressure pins 255 includes a pressure pin 255A-2 on the +Y side with respect to the center of the fitting hole 254, and a pressure pin 255B-2 on the -Y side. When the connection portion 22 is connected to the connected member 250, the first pressure sensor 34A-2 is pressed by the pressure pin 255A-2, and the second pressure sensor 34B-2 is pressed by the pressure pin 255B-2.

[0154] As shown in Figure 15A, it is preferable that the first direction D1 and the second direction D2 are one and the other in the front-rear direction and left-right direction (i.e., the X direction and the Y direction) of the device body 10. This allows for appropriate detection of whether or not the connection between the connected member 250 and the connecting part 22 has been released, even when the traveling device 200 and the device body 10 are tilted relative to each other in either direction. The first direction D1 and the second direction D2 may be directions different from the X direction and the Y direction, and may be one and the other in the diagonal direction of the device body 10.

[0155] As described above, in the modified transport assist device 1, the pressure sensor 34 includes a first pair P1 of a first pressure sensor 34A-1 and a second pressure sensor 34B-1 in a first direction D1 in the plane viewed from the direction of movement of the connection part 22 by the connection drive unit 23, and a second pair P2 of a first pressure sensor 34A-1 and a second pressure sensor 34B-1 in a second direction D2 that is perpendicular to the first direction D1 in the plane viewed from the direction of movement of the connection part 22.

[0156] As a result, pairs of pressure sensors 34, which are positioned on both sides via the connection part 22, are provided in two directions that are mutually orthogonal to the center of the connection part 22. For example, if the first pair P1 is positioned in the front-to-back direction, the second pair P2 is positioned in the left-to-right direction. This ensures that, as long as the connection is maintained, the detected value of any of the pressure sensors 34 remains above the threshold (Th1, Th2) regardless of the direction in which the transport assist device 1 and the travel device 200 tilt relative to each other. Furthermore, if the connection part 22 completely detaches from the connected member 250, the detected values ​​of all pressure sensors 34 decrease, allowing for the detection of disconnection. Therefore, even when the floor surface is sloped or uneven, or when the transported object is unevenly loaded onto the travel device 200, it is possible to accurately determine whether or not the connection has been disconnected.

[0157] In addition, the abnormality handling only needs to include deceleration of the device body 10 while it is in motion, and the content of the other processing is not particularly limited. The abnormality handling does not have to include stopping the device body 10 from moving. In other words, the abnormality handling only needs to decelerate the device body 10 to a sufficiently low speed.

[0158] Furthermore, during abnormality handling, the device body 10 may also receive input operations to the input device 60 and move in the direction corresponding to the input operation. In this case, an upper limit may be set on the speed command value so that a low speed state is maintained while abnormality handling is being performed.

[0159] Furthermore, in the embodiment, an example was shown in which, when determining whether the abnormal detection state has continued for a predetermined time, the count of the duration of the abnormal detection state is reset when the detected value of the pressure sensor 34 exceeds a threshold, but this is not limited to this. For example, even if the detected value changes from below the threshold to above the threshold, the count may not be reset if the time during which the detected value has been above the threshold is less than a certain period of time, and the count of the duration of the abnormal detection state may only be reset when it exceeds a certain period of time.

[0160] Furthermore, although the embodiment shows an example in which a value obtained by adding a predetermined margin to the non-pressure detection value is set as the threshold, the threshold may be set to a predetermined value that has been set in advance. Also, when the transport assist device 1 is equipped with multiple pressure sensors 34, the threshold values ​​for the multiple pressure sensors 34 may be set to the same value instead of setting the threshold values ​​for the multiple pressure sensors 34 separately.

[0161] Furthermore, although the embodiment shows an example in which the input device 60 comprises a joystick 61 and a plurality of buttons 62, the configuration of the input device 60 is not limited to the embodiment and is arbitrary. The input device 60 may be, for example, a push-button switch, a lever-type controller, or a gamepad. The input device 60 may also be an information and communication terminal such as a smartphone or tablet terminal. In this case, input operations can be received via a touch panel provided on the terminal.

[0162] Furthermore, the input device 60 may be able to communicate with the main unit 10 via global communication, and may be able to be operated remotely. [Explanation of Symbols]

[0163] 1. Conveying assistance device 10 Main unit of the device 11 drive wheels 12 Driven wheels 13 Motors 20 Connection mechanism 21 Link mechanism 22 Connection part 23 Connection drive unit 34 Pressure Sensor 34A, 34A-1, 34A-2 First pressure sensor 34B, 34B-1, 34B-2 Second pressure sensor 50 Control Unit 60 Input devices 200 Running equipment 250 Connected member 255, 255A, 255B, 255A-1, 255A-2, 255B-1, 255B-2 Compression Pins D1 1st direction D2 2nd direction L total length P1 1st Pair P2 2nd pair Th1 threshold Th2 threshold

Claims

1. A transport assist device that assists in the transport of a transport device by connecting to the transport device and generating driving force, A device body having drive wheels, A connection mechanism provided on the main body of the device includes a connecting portion that connects to a member to be connected attached to the traveling device, and a connection drive portion that moves the connecting portion forward and backward toward the member to be connected, A pressure sensor that outputs a detected value corresponding to the pressing force when the connecting portion is pressed by a pressing pin provided on the connected member, The system comprises a control unit that performs control based on the output of the pressure sensor, The control unit, while the device body connected to the travel device is in motion, executes abnormal processing, including deceleration of the device body, if an abnormal detection state in which the detected value of the pressure sensor falls below a threshold continues for a predetermined period of time. Conveying assistance device.

2. The aforementioned abnormality handling includes stopping the movement of the device body. The transport assist device according to claim 1.

3. The device further includes an input device that receives input operations for movement instructions for the main body of the device, The control unit executes the error processing regardless of whether or not an input operation is performed on the input device. The transport assist device according to claim 1.

4. The pressure sensor includes a first pressure sensor positioned on one side of the center of the connection portion and a second pressure sensor positioned on the other side, as viewed from the direction of movement of the connection portion by the connection drive unit. The abnormality detection state includes the fact that the detected values ​​of both the first pressure sensor and the second pressure sensor have fallen below the threshold. The transport assist device according to claim 1.

5. When the detected value of the pressure sensor exceeds a threshold, the control unit resets the count of the duration of the abnormal detection state up to that point. The transport assist device according to claim 1.

6. The control unit acquires the non-pressure detection value, which is the detected value of the pressure sensor, in the state before the connection unit connects the connection unit to the member to be connected. The control unit sets the threshold value to a value obtained by adding a predetermined margin to the non-pressure detection value. The transport assist device according to claim 1.

7. The pressure sensor includes a first pressure sensor positioned on one side of the center of the connection portion and a second pressure sensor positioned on the other side, as viewed from the direction of movement of the connection portion by the connection drive unit. The control unit sets the threshold values ​​separately for the first pressure sensor and the second pressure sensor. The transport assist device according to claim 6.

8. The predetermined time is set to a duration such that the distance traveled from the time the abnormality detection condition occurs until the device body stops is less than half the total length of the traveling device in the longitudinal direction. The transport assist device according to claim 2.

9. The aforementioned pressure sensor is The first pair of the first pressure sensor and the second pressure sensor in a first direction in the plane as viewed from the direction of movement of the connection by the connection drive unit, A second pair of the first pressure sensor and the second pressure sensor in a second direction perpendicular to the first direction in the plane viewed from the direction of movement of the connection portion, The transport assist device according to claim 7.

10. A device body having drive wheels, The device body includes a connection mechanism comprising a connecting portion that connects to a member to be connected attached to a travel device, and a connection drive unit that moves the connecting portion forward and backward toward the member to be connected, The system includes a pressure sensor that outputs a detected value corresponding to the pressing force when pressed by a pressing pin provided on the connected member during connection of the connection portion, A control method for a transport assist device that assists in the transport of the transport device by generating a driving force when connected to the transport device, The steps include: acquiring the detected value from the pressure sensor, A step of detecting that the main body of the device connected to the aforementioned traveling device is in motion, The steps include detecting that an abnormal detection state in which the detected value of the pressure sensor falls below a threshold continues for a predetermined period of time while the device body is in motion, The system includes the step of performing abnormality processing, including deceleration of the main body of the device, based on the fact that the abnormality detection state has continued for a predetermined time. A control method for a transport assistance device.

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