Industrial vehicle

Abstract

To suppress a deviation between an industrial vehicle travel direction recognized by a control device and an actual industrial vehicle travel direction.SOLUTION: A forklift includes a vehicle speed sensor, a direction lever, an object detection section, and a control device. The direction lever determines a travel direction. The object detection section detects a position of an object present in the travel direction of the forklift. The control device comes to be in a specific state when a speed of the forklift is equal to or more than a first vehicle speed threshold. The specific state is the state where the control device recognizes that a state before a change of a travel direction command by the direction lever continues even when the travel direction command is changed and the object detection section functions based on the state before the change.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to an industrial vehicle.

Background Art

[0002] The industrial vehicle disclosed in Patent Document 1 includes a control device, a direction sensor, and a direction lever. The control device controls the industrial vehicle. The direction sensor detects the operation direction of the direction lever that determines the traveling direction. The direction sensor detects whether the direction lever is operated in a direction indicating forward or in a direction indicating backward with reference to the neutral position. The control device switches the traveling mode according to the operation of the direction lever. The traveling mode includes a forward mode and a backward mode. When the direction lever is in the forward position, the control device sets the industrial vehicle to the forward mode. When the direction lever is in the backward position, the control device sets the industrial vehicle to the backward mode. When the speed of the industrial vehicle is equal to or higher than a predetermined speed, even if the traveling direction indicated by the direction lever is changed, the control device maintains the traveling mode. In this case, the traveling direction indicated by the direction lever and the traveling direction of the industrial vehicle are opposite.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An industrial vehicle may be equipped with an object detection unit. The object detection unit detects the position of an object existing in the traveling direction of the industrial vehicle. When the control device recognizes the traveling direction indicated by the direction lever as the traveling direction of the industrial vehicle, between the time when the position of the direction lever is switched and the time when the traveling direction of the industrial vehicle is switched, the traveling direction recognized by the control device and the actual traveling direction of the industrial vehicle are reversed. In this case, the control device may not be able to recognize an object existing in the actual traveling direction of the industrial vehicle.

Means for Solving the Problems

[0005] The industrial vehicle for solving the above problems includes a traveling direction detection unit that detects the traveling direction of the industrial vehicle, a vehicle speed detection sensor that detects the speed of the industrial vehicle, a traveling direction determination unit that determines the traveling direction of the industrial vehicle, an object detection unit that detects the position of an object existing in the traveling direction of the industrial vehicle, and a control device. When the speed of the industrial vehicle detected by the vehicle speed detection sensor is equal to or higher than a first vehicle speed threshold, the control device enters a specific state. The control device recognizes that the specific state continues the state before the change even if the traveling direction command by the traveling direction determination unit changes, and the object detection unit functions based on the state before the change.

[0006] When the traveling direction command by the traveling direction determination unit changes during the traveling of the industrial vehicle, the traveling direction of the industrial vehicle is switched after the speed of the industrial vehicle decreases. When the traveling direction command by the traveling direction determination unit changes while the speed of the industrial vehicle is equal to or higher than the first vehicle speed threshold, the traveling direction of the industrial vehicle is maintained at least until the speed of the industrial vehicle becomes lower than the first vehicle speed threshold. When the speed of the industrial vehicle is equal to or higher than the first vehicle speed threshold, the control device enters a specific state. In the specific state, the control device recognizes that the state before the change continues even if the traveling direction command by the traveling direction determination unit changes. Thereby, the deviation between the traveling direction of the industrial vehicle recognized by the control device and the actual traveling direction of the industrial vehicle can be suppressed. And by the object detection unit functioning based on the state before the change even if the traveling direction command by the traveling direction determination unit changes, an object can be detected in accordance with the traveling direction of the industrial vehicle.

[0007] Regarding the above industrial vehicle, the industrial vehicle includes a notification unit that performs notification when there is a possibility that the object detected by the object detection unit comes into contact with the industrial vehicle, and the control device may determine whether there is a possibility that the object comes into contact with the industrial vehicle based on the state before the change in the specific state.

[0008] Regarding the above industrial vehicle, the industrial vehicle includes an engine and a power transmission mechanism, and the power transmission mechanism can switch between a drive transmission state in which the driving force of the engine is transmitted to the power transmission mechanism and a drive non - transmission state in which the driving force of the engine is not transmitted to the power transmission mechanism, and the control device may set the power transmission mechanism to the drive non - transmission state in the specific state.

[0009] Regarding the above industrial vehicle, the industrial vehicle includes an interlock for setting the power transmission mechanism to the drive non - transmission state, and when the travel direction command by the travel direction determination unit changes when the speed of the industrial vehicle is greater than a first vehicle speed threshold and equal to or greater than a second vehicle speed threshold, the interlock sets the power transmission mechanism to the drive non - transmission state, and the first vehicle speed threshold may be set lower than the second vehicle speed threshold.

Advantages of the Invention

[0010] According to the present invention, it is possible to suppress the deviation between the traveling direction of the industrial vehicle recognized by the control device and the actual traveling direction of the industrial vehicle.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0012] Hereinafter, an embodiment of an industrial vehicle will be described. <Forklift> As shown in FIG. 1, a forklift 10 as an industrial vehicle includes a vehicle body 11, two drive wheels 12, two steering wheels 14, and a loading and unloading device 20. In the following description, front, rear, left, and right indicate the front, rear, left, and right of the forklift 10.

[0013] The vehicle body 11 includes a head guard 15 provided above the driver's seat. The two drive wheels 12 are arranged at the front of the vehicle body 11. The two drive wheels 12 are arranged spaced apart from each other in the vehicle width direction. The two steering wheels 14 are arranged at the rear of the vehicle body 11. The two steering wheels 14 are arranged spaced apart from each other in the vehicle width direction.

[0014] The handling device 20 includes a mast 21, two forks 22, and a lift cylinder 23. The mast 21 is provided at the front part of the vehicle body 11. The forks 22 are provided so as to be able to move up and down together with the mast 21. A load is placed on the forks 22. The lift cylinder 23 is a hydraulic cylinder. The mast 21 moves up and down by the extension and contraction of the lift cylinder 23. As the mast 21 moves up and down, the forks 22 move up and down. The forklift 10 of the present embodiment performs a traveling operation and a handling operation by an operation by an operator.

[0015] <Configuration of Forklift> As shown in FIG. 2, the forklift 10 includes a traveling system 30, a control device 81, an accelerator pedal 86, an accelerator sensor 87, a tire angle sensor 88, a direction lever 89, a direction switch 90, a forward connection line 101, a reverse connection line 102, a forward detection line 103, a reverse detection line 104, an interlock 110, and an object detection unit 131.

[0016] <Traveling System> As shown in FIG. 3, the traveling system 30 is a mechanism for advancing the forklift 10. The traveling system 30 includes an engine 31, an output shaft 33, a rotation speed sensor 34, a power transmission mechanism 40, a solenoid valve 50, a forward solenoid 51, a reverse solenoid 52, a differential device 60, an axle 61, a vehicle speed detection sensor 62, and a traveling control device 63.

[0017] The engine 31 is the driving source for the traveling operation and the loading and unloading operation of the forklift 10. The engine 31 in this embodiment is a gasoline engine that uses gasoline as fuel. The engine 31 includes a throttle actuator 32. The throttle actuator 32 adjusts the throttle opening of a throttle valve (not shown) provided in the intake passage so as to follow the target rotational speed of the engine 31 calculated from the opening degree of the accelerator pedal 86. By adjusting the throttle opening by the throttle actuator 32, the amount of air supplied to the engine 31 is adjusted. Thereby, the rotational speed of the engine 31 is controlled. As the engine 31, a diesel engine that uses light oil as fuel may be used. As the engine 31, an engine that uses liquefied petroleum gas or compressed natural gas as fuel may be used. The output shaft 33 is connected to the engine 31. The output shaft 33 rotates by the drive of the engine 31.

[0018] The rotational speed sensor 34 is provided on the output shaft 33. The rotational speed sensor 34 detects the rotational speed of the engine 31. The rotational speed of the engine 31 is the rotational speed of the output shaft 33. The rotational speed sensor 34 outputs an electric signal corresponding to the rotational speed of the output shaft 33 to the traveling control device 63.

[0019] The power transmission mechanism 40 transmits the driving force of the engine 31 to the drive wheels 12. The power transmission mechanism 40 includes a torque converter 41 and a transmission 42. The torque converter 41 is connected to the output shaft 33. The driving force of the engine 31 is transmitted to the torque converter 41 via the output shaft 33. The torque converter 41 includes a pump connected to the output shaft 33 and a turbine. In the torque converter 41, the turbine is rotated by the working oil discharged from the pump.

[0020] The transmission 42 includes an input shaft 43, a forward clutch 44, a forward gear train 45, a reverse clutch 46, a reverse gear train 47, and an output shaft 48. The input shaft 43 is connected to the torque converter 41. The driving force is transmitted from the torque converter 41 to the transmission 42 via the input shaft 43.

[0021] The forward clutch 44 is provided on the input shaft 43. The forward gear train 45 is provided between the forward clutch 44 and the output shaft 48. The forward clutch 44 can be switched between a connected state and a disconnected state. The connected state is a state in which the input shaft 43 and the forward gear train 45 are connected. The disconnected state is a state in which the input shaft 43 and the forward gear train 45 are disconnected. When the input shaft 43 and the forward gear train 45 are connected by the forward clutch 44, the driving force is transmitted from the input shaft 43 to the forward gear train 45. The driving force transmitted to the forward gear train 45 is transmitted to the output shaft 48. When the forward clutch 44 is connected to the forward gear train 45, it can be said that the driving force of the engine 31 is transmitted to the output shaft 48. When the forward clutch 44 and the forward gear train 45 are disconnected, the driving force is not transmitted from the input shaft 43 to the forward gear train 45. As the forward clutch 44, a hydraulic clutch is used. As the hydraulic clutch, for example, a wet multi-plate clutch can be mentioned.

[0022] The reverse clutch 46 is provided on the input shaft 43. The reverse gear train 47 is provided between the reverse clutch 46 and the output shaft 48. The reverse clutch 46 can be switched between a connected state and a disconnected state. The connected state is a state in which the input shaft 43 and the reverse gear train 47 are connected. The disconnected state is a state in which the input shaft 43 and the reverse gear train 47 are disconnected. When the input shaft 43 and the reverse gear train 47 are connected by the reverse clutch 46, the driving force is transmitted from the input shaft 43 to the reverse gear train 47. The driving force transmitted to the reverse gear train 47 is transmitted to the output shaft 48. When the reverse clutch 46 is connected to the reverse gear train 47, it can be said that the driving force of the engine 31 is transmitted to the output shaft 48. When the reverse clutch 46 and the reverse gear train 47 are disconnected, the driving force is not transmitted from the input shaft 43 to the reverse gear train 47. As the reverse clutch 46, a hydraulic clutch is used. As the hydraulic clutch, for example, a wet multi-plate clutch can be mentioned.

[0023] The solenoid valve 50 controls the supply and discharge of hydraulic oil to the forward clutch 44 and the reverse clutch 46. By supplying and discharging the hydraulic oil by the solenoid valve 50, the connection state and the cutoff state of the clutches 44 and 46 are switched.

[0024] The solenoids 51 and 52 switch the supply and discharge of the hydraulic oil to the clutches 44 and 46 by the solenoid valve 50. When the forward solenoid 51 is energized, hydraulic oil is supplied from the solenoid valve 50 to the forward clutch 44. When hydraulic oil is supplied to the forward clutch 44, the forward clutch 44 is in a connected state. When the reverse solenoid 52 is energized, hydraulic oil is supplied from the solenoid valve 50 to the reverse clutch 46. When hydraulic oil is supplied to the reverse clutch 46, the reverse clutch 46 is in a connected state.

[0025] As the solenoid valve 50, one electromagnetic direction switching valve may be used. The electromagnetic direction switching valve is a solenoid valve in which the spool switches to a position where hydraulic oil is supplied to the forward clutch 44 when the forward solenoid 51 is energized, and the spool switches to a position where hydraulic oil is supplied to the reverse clutch 46 when the reverse solenoid 52 is energized. The electromagnetic direction switching valve switches the spool to a position where hydraulic oil is discharged from both clutches 44 and 46 when both the forward solenoid 51 and the reverse solenoid 52 are demagnetized. Note that the hydraulic oil for operating the forward clutch 44 and the reverse clutch 46 is supplied by a hydraulic pump existing inside the power transmission mechanism 40. The configuration regarding this hydraulic pump is a well-known configuration.

[0026] As the solenoid valve 50, two solenoid valves may be used. The two solenoid valves are respectively provided corresponding to the forward clutch 44 and the reverse clutch 46. In this case, the forward solenoid 51 and the reverse solenoid 52 may individually control the respective solenoid valves 50 to supply the hydraulic oil to both clutches 44 and 46 and discharge the hydraulic oil from both clutches 44 and 46.

[0027] The power transmission mechanism 40 can be switched between a driving transmission state in which the driving force of the engine 31 is transmitted to the power transmission mechanism 40 and a driving non - transmission state in which the driving force of the engine 31 is not transmitted to the power transmission mechanism 40. When either the forward clutch 44 or the reverse clutch 46 is in the engaged state, the driving force of the engine 31 is transmitted to the power transmission mechanism 40, and thereby the forklift 10 moves forward. The case where either the forward clutch 44 or the reverse clutch 46 is in the engaged state is the driving transmission state. When the forward clutch 44 and the reverse clutch 46 are in the disengaged state, the driving force of the engine 31 is not transmitted to the power transmission mechanism 40. The case where the forward clutch 44 and the reverse clutch 46 are in the disengaged state is the driving non - transmission state.

[0028] The differential device 60 is connected to the output shaft 48. The axle 61 is connected to the differential device 60. The drive wheels 12 are connected to the axle 61. When the output shaft 48 rotates, the axle 61 rotates. When the drive wheels 12 rotate due to the rotation of the axle 61, the forklift 10 moves forward. If the forward clutch 44 and the forward gear train 45 are connected, the forklift 10 moves forward. If the reverse clutch 46 and the reverse gear train 47 are connected, the forklift 10 moves backward.

[0029] The vehicle speed detection sensor 62 is a sensor for detecting the vehicle speed of the forklift 10. The vehicle speed detection sensor 62 is provided, for example, on the output shaft 48 or the axle 61. The vehicle speed detection sensor 62 outputs a pulse signal corresponding to the vehicle speed of the forklift 10 to the travel control device 63.

[0030] The travel control device 63 is an engine control unit that controls the engine 31. The travel control device 63 adjusts the throttle opening by controlling the throttle actuator 32. By adjusting the throttle opening, the driving force of the engine 31 is adjusted.

[0031] <Control Device> As shown in FIG. 2, the control device 81 includes a processor 82 and a storage unit 83. Examples of the processor 82 include a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a DSP (Digital Signal Processor). The storage unit 83 includes a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage unit 83 stores program codes or instructions configured to cause the processor 82 to execute processing. The storage unit 83, that is, the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer. The control device 81 may be configured by a hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control device 81, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as an ASIC or an FPGA, or a combination thereof.

[0032] <Accelerator Sensor and Tire Angle Sensor> The accelerator sensor 87 detects the operation amount of the accelerator pedal 86. The operation amount of the accelerator pedal 86 can also be said to be the accelerator opening. The accelerator sensor 87 outputs an electric signal corresponding to the accelerator opening to the control device 81. The control device 81 can recognize the accelerator opening based on the electric signal from the accelerator sensor 87.

[0033] The tire angle sensor 88 detects the steering angle of the steering wheel 14. The tire angle sensor 88 outputs an electric signal corresponding to the steering angle to the control device 81. The control device 81 can recognize the steering angle based on the electric signal from the tire angle sensor 88.

[0034] <Direction Lever> The direction lever 89 determines the traveling direction of the forklift 10. The direction lever 89 is operated by the operator of the forklift 10. The direction lever 89 is operated to a forward position indicating forward movement or a reverse position indicating reverse movement with reference to the neutral position. For example, the forward position is a position where the direction lever 89 is tilted forward from the neutral position. The reverse position is a position where the direction lever 89 is tilted backward from the neutral position. The direction lever 89 is a traveling direction determination unit. The operator can give a traveling direction command to the forklift 10 by operating the direction lever 89. The traveling direction command is a command indicating the traveling direction of the forklift 10. The traveling direction command includes a forward command and a reverse command. The forward command is a command indicating forward movement of the forklift 10. The reverse command is a command indicating reverse movement of the forklift 10.

[0035] <Direction Switch> The direction switch 90 switches according to the operation direction of the direction lever 89. The direction switch 90 includes a movable contact 91 and three fixed contacts 92, 93, 94. The movable contact 91 is connected to the positive electrode of the battery mounted on the forklift 10. The three fixed contacts 92, 93, 94 include a neutral fixed contact 92, a forward fixed contact 93, and a reverse fixed contact 94. When the direction lever 89 is in the neutral position, the movable contact 91 and the neutral fixed contact 92 are connected. When the direction lever 89 is in the forward position, the movable contact 91 and the forward fixed contact 93 are connected. When the direction lever 89 is in the reverse position, the movable contact 91 and the reverse fixed contact 94 are connected. The direction switch 90 is a traveling direction detection unit. The direction switch 90 may be composed of three buttons including a forward position, a neutral position, and a reverse position, and the contacts may be connected when each button is operated.

[0036] <Forward Connection Line and Reverse Connection Line> The forward connection line 101 connects the forward fixed contact 93 and the forward solenoid 51. When the movable contact 91 and the forward fixed contact 93 are connected, the forward connection line 101 and the battery are electrically connected. Thereby, the forward solenoid 51 is excited. When the movable contact 91 and the forward fixed contact 93 are connected, the reverse solenoid 52 is demagnetized.

[0037] The reverse connection line 102 connects the reverse fixed contact 94 and the reverse solenoid 52. When the movable contact 91 and the reverse fixed contact 94 are connected, the reverse connection line 102 and the battery are electrically connected. Thereby, the reverse solenoid 52 is excited. When the movable contact 91 and the reverse fixed contact 94 are connected, the forward solenoid 51 is demagnetized.

[0038] When the direction lever 89 is in the forward position, the forward solenoid 51 is excited to supply hydraulic oil to the forward clutch 44. Thereby, the forklift 10 can move forward. When the direction lever 89 is in the reverse position, the reverse solenoid 52 is excited to supply hydraulic oil to the reverse clutch 46. Thereby, the forklift 10 can move backward. When the direction lever 89 is in the neutral position, both solenoids 51, 52 are demagnetized and no hydraulic oil is supplied to the clutches 44, 46. In this case, the driving force of the engine 31 is not transmitted to the power transmission mechanism 40.

[0039] <Forward detection line and reverse detection line> The forward detection line 103 connects the forward connection line 101 and the control device 81. When a voltage from the battery is applied to the forward connection line 101, the voltage is applied to the control device 81 via the forward detection line 103. The reverse detection line 104 connects the reverse connection line 102 and the control device 81. When a voltage from the battery is applied to the reverse connection line 102, the voltage is applied to the control device 81 via the reverse detection line 104. When a voltage is input from the forward detection line 103, the control device 81 can determine that the direction lever 89 is in the forward position. When a voltage is input from the reverse detection line 104, the control device 81 can determine that the direction lever 89 is in the reverse position. Specifically, the control device 81 includes a port 84 to which the forward detection line 103 is connected and a port 85 to which the reverse detection line 104 is connected. The control device 81 can determine that the direction lever 89 is in the forward position if a voltage is applied to the port 84. The control device 81 can determine that the direction lever 89 is in the reverse position if a voltage is applied to the port 85. When no voltage is input to either the forward detection line 103 or the reverse detection line 104, the control device 81 can determine that the direction lever 89 is in the neutral position. The control device 81 determines that a forward command has been input if the direction lever 89 is in the forward position. The control device 81 determines that a reverse command has been input if the direction lever 89 is in the reverse position.

[0040] <Interlock> The interlock 110 includes a forward relay 111 and a reverse relay 112. The forward relay 111 is provided on the forward connection line 101. The forward relay 111 can be switched between a connected state and a disconnected state. When the forward relay 111 is in the connected state, the forward connection line 101 and the forward solenoid 51 are electrically connected. When the forward relay 111 is in the disconnected state, the forward connection line 101 and the forward solenoid 51 are electrically disconnected. The reverse relay 112 is provided on the reverse connection line 102. The reverse relay 112 can be switched between a connected state and a disconnected state. When the reverse relay 112 is in the connected state, the reverse connection line 102 and the reverse solenoid 52 are electrically connected. When the reverse relay 112 is in the disconnected state, the reverse connection line 102 and the reverse solenoid 52 are electrically disconnected.

[0041] <Object detection unit> The object detection unit 131 includes a stereo camera 132, a detection device 133, and a notification unit 136. The stereo camera 132 includes two cameras and performs imaging with the two cameras. As shown in FIG. 1, the stereo camera 132 is disposed on the head guard 15. The stereo camera 132 is disposed so as to be able to overlook the road surface on which the forklift 10 travels from above the forklift 10. The stereo camera 132 of the present embodiment images the rear of the forklift 10. Therefore, the object detected by the object detection unit 131 is an object behind the forklift 10. The detection direction of the object detection unit 131 can be said to be the rear. The notification unit 136 and the detection device 133 may be unitized with the stereo camera 132 and disposed on the head guard 15 together with the stereo camera 132. Further, the notification unit 136 and the detection device 133 may be disposed at positions different from the head guard 15.

[0042] The detection device 133 includes a processor 134 and a storage unit 135. As the processor 134, for example, a CPU, a GPU, or a DSP is used. The storage unit 135 includes a RAM and a ROM. The storage unit 135 stores various programs for detecting an object from the images captured by the stereo camera 132. It can be said that the storage unit 135 stores program codes or instructions configured to cause the processor 134 to execute processing. The storage unit 135, that is, the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer. The detection device 133 may be constituted by a hardware circuit such as an ASIC or an FPGA. The detection device 133, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as an ASIC or an FPGA, or a combination thereof.

[0043] <Object detection processing> The detection device 133 detects an object existing behind the forklift 10 by repeatedly performing the following object detection processing at a predetermined control cycle. Further, the detection device 133 derives the position of the detected object. The position of the object is the relative position between the forklift 10 and the object.

[0044] As shown in FIG. 4, in step S100, the detection device 133 acquires an image from the stereo camera 132. Next, in step S110, the detection device 133 performs stereo processing to acquire a disparity image. The disparity image associates a disparity [px] with each pixel. The disparity image is not necessarily required to be displayed and indicates data in which a disparity is associated with each pixel in the disparity image. The disparity is obtained by comparing two images captured by the stereo camera 132 and deriving the difference in the number of pixels between the images for the same feature point appearing in each image. The feature point is a recognizable part such as the edge of an object as a boundary. The feature point can be detected from luminance information or the like.

[0045] Next, in step S120, the detection device 133 derives the coordinates of the feature points in the world coordinate system, which is a coordinate system in the real space. The world coordinate system is a coordinate system with the axis extending in the vehicle width direction of the forklift 10 in the horizontal direction as the X-axis, the axis orthogonal to the X-axis in the horizontal direction as the Y-axis, and the axis extending in the vertical direction as the Z-axis when the forklift 10 is located on the horizontal plane. The derivation of the coordinates of the feature points is performed by deriving the coordinates of the feature points in the camera coordinate system from the baseline length of the stereo camera 132, the focal length of the stereo camera 132, and the parallax image obtained in step S110, and then converting the coordinates into the coordinates in the world coordinate system. As shown in FIG. 1, the X-axis, Y-axis, and Z-axis are illustrated with arrows X, Y, and Z.

[0046] As shown in FIG. 4, in step S130, the detection device 133 extracts an object by clustering the feature points. The detection device 133 regards a set of feature points that are assumed to represent the same object among the feature points that are points representing a part of the object as one point group, and extracts the point group as an object. The detection device 133 performs clustering that regards the feature points located within a predetermined range as one point group from the coordinates of the feature points in the world coordinate system derived in step S120. The detection device 133 regards the clustered point group as one object. Note that the clustering of the feature points performed in step S130 can be performed by various methods.

[0047] Next, in step S140, the detection device 133 derives the coordinates of the object in the world coordinate system. The coordinates of the object can be derived from the coordinates of the feature points that make up the point cloud. The coordinates of the object in the world coordinate system represent the relative position between the forklift 10 and the object. Specifically, among the coordinates of the object in the world coordinate system, the X coordinate represents the horizontal distance from the origin to the object, and the Y coordinate represents the front-rear distance from the origin to the object. The origin is, for example, a coordinate with the X coordinate and the Y coordinate being the arrangement positions of the stereo camera 132 and the Z coordinate being the road surface. It is also possible to derive the Euclidean distance from the arrangement position of the stereo camera 132 to the object from the X coordinate and the Y coordinate. Among the coordinates of the object in the world coordinate system, the Z coordinate represents the height of the object from the road surface.

[0048] Next, in step S150, the detection device 133 performs a human detection process. The human detection process is a process for determining whether the object is a person. In the present embodiment, the detection device 133 performs a human detection process on an image captured by either of the two cameras of the stereo camera 132. The detection device 133 converts the coordinates of the object in the world coordinate system obtained in step S140 into camera coordinates, and converts the camera coordinates into the coordinates of the image captured by the camera. The detection device 133 performs a human detection process on the coordinates of the object in the image. The human detection process is performed, for example, using feature amounts. The detection device 133 extracts the feature amounts of the coordinates of the object in the image. Examples of feature amount extraction include methods for extracting feature amounts of local regions in an image such as HOG: Histogram of Oriented Gradients feature amounts and Haar-Like feature amounts. The detection device 133 determines whether the object is a person by comparing the feature amounts extracted from the image with dictionary data. The dictionary data is, for example, data of feature amounts extracted from each of a plurality of known image data in which people appear. In the following description, an object different from a person may be referred to as an obstacle.

[0049] <Notification unit> The notification unit 136 is a device that notifies the operator of the forklift 10. Examples of the notification unit 136 include a buzzer that notifies by sound, a lamp that notifies by light, or a combination thereof.

[0050] <Control performed by the control device> The control device 81, the travel control device 63, and the object detection unit 131 are configured to be able to acquire information from each other. The control device 81, the travel control device 63, and the object detection unit 131 acquire information from each other by performing communication according to a vehicle communication protocol such as CAN (Controller Area Network) or LIN (Local Interconnect Network).

[0051] The control device 81 derives the vehicle speed of the forklift 10. The vehicle speed of the forklift 10 can be derived by using the detection result of the vehicle speed detection sensor 62, the gear ratio, the outer diameter of the drive wheel 12, the steering angle detected by the tire angle sensor 88, and the like. The detection result of the vehicle speed detection sensor 62 can be acquired from the travel control device 63. The gear ratio and the outer diameter of the drive wheel 12 may be stored in the storage unit 83 in advance. In the following description, the vehicle speed refers to the vehicle speed of the forklift 10.

[0052] The control device 81 switches between the connected state and the disconnected state of the forward relay 111 and the reverse relay 112. When the switchback operation is not being performed, the control device 81 places the forward relay 111 and the reverse relay 112 in the connected state. When the switchback operation is performed when the vehicle speed is equal to or higher than the second vehicle speed threshold, the control device 81 places the forward relay 111 and the reverse relay 112 in the disconnected state. When the vehicle speed becomes lower than the second vehicle speed threshold, the control device 81 places the forward relay 111 and the reverse relay 112 in the connected state. The switchback operation is an operation in which the direction command by the direction lever 89 changes. The change in the direction command includes a change from a forward command to a reverse command and a change from a reverse command to a forward command. When the forward relay 111 and the reverse relay 112 are placed in the disconnected state, the solenoids 51 and 52 are demagnetized regardless of the position of the direction lever 89, and thus the driving force of the engine 31 is not transmitted to the power transmission mechanism 40. That is, the power transmission mechanism 40 enters a non-driving transmission state. Thereby, the load on the power transmission mechanism 40 when the switchback operation is performed when the vehicle speed is equal to or higher than the second vehicle speed threshold can be reduced. The lower the second vehicle speed threshold, the more the load on the power transmission mechanism 40 can be reduced. On the other hand, the lower the second vehicle speed threshold, the longer the time until the traveling direction of the forklift 10 is switched during the switchback operation. Based on these factors, the second vehicle speed threshold can be arbitrarily set.

[0053] The control device 81 operates the notification unit 136 by transmitting a notification command to the object detection unit 131. Specifically, the object detection unit 131 includes an operating unit that operates the notification unit 136, and when the notification command is received, the operating unit operates the notification unit 136.

[0054] <Notification area> The control device 81 performs notification control. The notification control is control performed during the travel of the forklift 10, and is control for performing notification by the notification unit 136 according to the detection status of an object by the object detection unit 131. First, the notification area used for the notification control will be described.

[0055] As shown in FIG. 5, a notification area AA1 used for notification control is set within the detectable range of the object by the object detection unit 131. The detectable range of the object by the object detection unit 131 can also be said to be the imaging range by the stereo camera 132. In the present embodiment, the notification area AA1 is the same area as the detectable range of the object by the object detection unit 131. The notification area AA1 is an area that extends from the arrangement position of the stereo camera 132 to the rear of the forklift 10 and in the vehicle width direction of the forklift 10. The notification area AA1 is an area defined by the X coordinate and the Y coordinate in the world coordinate system.

[0056] <Predicted trajectory> The control device 81 derives the predicted trajectory T of the forklift 10. The predicted trajectory T is a trajectory that is predicted to be passed by the forklift 10. In the present embodiment, the control device 81 derives the predicted trajectory T that is predicted to be passed by the forklift 10 when the traveling direction of the forklift 10 is the reverse direction.

[0057] The predicted trajectory T can be derived from the steering angle of the steering wheel 14 and the dimensional information of the forklift 10. The dimensional information of the forklift 10 includes the dimension [mm] from the central axis of the drive wheel 12 to the rear end of the vehicle body 11, the wheelbase [mm], and the vehicle width [mm]. Since the dimensional information of the forklift 10 is known information, it can be stored in advance in the storage unit 83 of the control device 81 or the like. The predicted trajectory T is a trajectory between the trajectory LT passed by the left end LE of the vehicle body 11 and the trajectory RT passed by the right end RE of the vehicle body 11. The control device 81 derives the X coordinate and the Y coordinate in the world coordinate system of the predicted trajectory T extending behind the forklift 10.

[0058] As shown in FIGS. 5 and 6, when the forklift 10 is moving straight, the predicted trajectory T is a trajectory that extends linearly in the reverse direction from the forklift 10. As shown in FIGS. 7 and 8, when the forklift 10 is turning, the predicted trajectory T is a trajectory that bends in the reverse direction from the forklift 10. When the forklift 10 is turning to the right, the predicted trajectory T extends to the right. When the forklift 10 is turning to the left, the predicted trajectory T extends to the left. It can be said that the control device 81 derives the predicted trajectory T that extends in the turning direction when the forklift 10 is turning.

[0059] The forklift 10 shown in FIG. 6 has a higher vehicle speed than the forklift 10 in the state shown in FIG. 5. Similarly, the forklift 10 shown in FIG. 8 has a higher vehicle speed than the forklift 10 shown in FIG. 7. As shown in FIGS. 5 to 8, the control device 81 makes the predicted trajectory T longer in the traveling direction as the vehicle speed of the forklift 10 increases. In the present embodiment, the trajectory derivation threshold value YT is changed according to the vehicle speed. The trajectory derivation threshold value YT is a threshold value set with respect to the Y coordinate in the world coordinate system, and the higher the vehicle speed, the farther the Y coordinate from the forklift 10. The control device 81 derives the predicted trajectory T from the forklift 10 to the trajectory derivation threshold value YT. Note that the fact that the predicted trajectory T becomes longer in the traveling direction as the vehicle speed of the forklift 10 increases is not limited to a mode in which the vehicle speed of the forklift 10 and the length of the predicted trajectory T in the traveling direction are in a proportional relationship, and as long as there is a correlation that the length of the predicted trajectory T in the traveling direction increases as the vehicle speed of the forklift 10 increases. The predicted trajectory T is derived within the notification area AA1.

[0060] <Notification Control> The notification control will be described. The notification control is repeatedly performed at a predetermined control cycle. As shown in FIG. 9, in step S1, the control device 81 determines whether a specific condition is satisfied. The specific condition is that the state where the vehicle speed is less than the first vehicle speed threshold value continues for a predetermined time. The vehicle speed is the absolute value of the speed calculated using the detection result of the vehicle speed detection sensor 62. The first vehicle speed threshold value can be set to any value. In the present embodiment, the first vehicle speed threshold value is a value less than the second vehicle speed threshold value. The predetermined time is a time longer than the control cycle. The predetermined time is set so that when the vehicle speed is instantaneously determined to be less than the first vehicle speed threshold value despite being greater than or equal to the first vehicle speed threshold value due to the influence of noise, the specific condition is not determined to be satisfied. If the determination result in step S1 is affirmative, the control device 81 performs the process of step S2. If the determination result in step S1 is negative, the control device 81 performs the process of step S3. When the specific condition is not satisfied, the vehicle speed is greater than or equal to the first vehicle speed threshold value. It can also be said that when the vehicle speed is greater than or equal to the first vehicle speed threshold value, the process of step S3 is performed.

[0061] In step S2, the control device 81 enters the normal state. The normal state is a state in which the traveling direction of the forklift 10 is determined from the detection result of the direction switch 90. The control device 81 determines that the traveling direction of the forklift 10 is the forward direction if the direction lever 89 is in the forward position. The control device 81 determines that the traveling direction of the forklift 10 is the reverse direction if the direction lever 89 is in the reverse position. After finishing the process of step S2, the control device 81 performs the process of step S4.

[0062] In step S3, the control device 81 enters a specific state. The specific state is a state in which, even if the travel direction command by the direction lever 89 changes, it is recognized that the state before the change continues. If the travel direction command in the previous control cycle is a forward command, the control device 81 determines that the forward command continues even if a reverse command is input from the direction switch 90. If the travel direction command in the previous control cycle is a reverse command, the control device 81 determines that the reverse command continues even if a forward command is input from the direction switch 90. That is, while the specific state continues, the travel direction command does not change even if the direction lever 89 is operated. In the case of the specific state, the vehicle speed is equal to or higher than the first vehicle speed threshold. The second vehicle speed threshold is a value larger than the first vehicle speed threshold. Therefore, it can be said that the control device 81 sets the power transmission mechanism 40 to the drive non-transmission state when the vehicle speed is equal to or higher than the second vehicle speed threshold in the case of the specific state. After finishing the process of step S3, the control device 81 performs the process of step S4.

[0063] In step S4, the control device 81 determines whether or not a notification condition is satisfied. The notification condition is a condition for determining whether or not to perform notification by the notification unit 136. The notification condition is satisfied when there is a possibility that the forklift 10 contacts an object. The notification condition varies depending on whether the object is a person or an obstacle. If the determination result in step S4 is affirmative, that is, if the notification condition is satisfied, the control device 81 performs the process of step S5. In step S5, the control device 81 performs notification by the notification unit 136. Hereinafter, the notification condition will be described. The travel direction used for determining the notification condition varies depending on whether the control device 81 is in the normal state or the specific state. If the control device 81 is in the normal state, the travel direction of the forklift 10 is determined from the detection result of the direction switch 90. If the control device 81 is in the specific state, the travel direction of the forklift 10 is determined from the travel direction command in the previous control cycle. It can be said that the control device 81 determines whether or not there is a possibility that the object contacts the forklift 10 based on the state before the travel direction command changes in the specific state.

[0064] <When the object is a person> The notification condition when the object is a person is that the forklift 10 is moving backward and a person exists in the notification area AA1. When the object detected by the object detection unit 131 is a person, the notification unit 136 performs notification when the forklift 10 is moving backward and a person exists in the notification area AA1. At this time, when a person exists within the predicted trajectory T, the notification may be made stronger than when a person exists outside the predicted trajectory T. Making the notification stronger means, for example, increasing the buzzer sound if the notification unit 136 is a buzzer. If the notification unit 136 is a combination of a lamp and a buzzer, it means switching from notification using only one of the lamp and the buzzer to notification using both. This makes it easier for the passenger to recognize the presence of an object within the predicted trajectory T.

[0065] <When the object is an obstacle> The notification condition when the object is an obstacle is that the forklift 10 is moving backward and an obstacle exists within the predicted trajectory T. When the object detected by the object detection unit 131 is an obstacle, the notification unit 136 performs notification when the forklift 10 is moving backward and an obstacle exists within the predicted trajectory T.

[0066] [Operation of the embodiment] As shown in FIG. 10, assume that with the forklift 10 moving backward, an object O1 exists behind the forklift 10. Arrow D1 indicates the actual traveling direction of the forklift 10. Arrow D2 indicates the traveling direction recognized by the control device 81. When the operator of the forklift 10 performs a switchback operation, the reverse command by the direction lever 89 is switched to a forward command. When the traveling direction of the forklift 10 is switched, the speed of the forklift 10 decreases. For example, when switching the traveling direction of the forklift 10 from the reverse direction to the forward direction, after changing the direction lever 89 to the forward position, the speed of the forklift 10 decreases. Then, with the speed of the forklift 10 reaching 0 km / h as the boundary, the traveling direction of the forklift 10 is switched to the forward direction. When the traveling direction command by the direction lever 89 changes while the speed of the forklift 10 is equal to or higher than the first vehicle speed threshold, it can be said that the traveling direction of the forklift 10 is maintained until at least the speed of the forklift 10 becomes lower than the first vehicle speed threshold.

[0067] Suppose that the control device 81 is maintained in the normal state regardless of the speed of the forklift 10. In this case, when the direction lever 89 is changed to the forward position, the control device 81 recognizes the actual traveling direction of the forklift 10 as the forward direction. In this case, even when the forklift 10 is actually continuing to move backward, the notification by the notification unit 136 stops when the direction lever 89 is changed to the forward position. That is, even though the distance L1 between the forklift 10 and the object O1 is decreasing, the notification by the notification unit 136 stops when the direction lever 89 is changed to the forward position.

[0068] On the other hand, in this embodiment, when the speed of the forklift 10 is equal to or higher than the first vehicle speed threshold value, the control device 81 enters a specific state. In the specific state, the control device 81 recognizes that even if the traveling direction command by the direction lever 89 changes, the state before the change continues. In the example shown in FIG. 11, even if the reverse command changes to the forward command due to the forklift 10 performing a switchback operation, the control device 81 recognizes that the reverse command continues. Thereby, the control device 81 can recognize the traveling direction of the forklift 10 as the reverse direction until the speed of the forklift 10 becomes less than the first vehicle speed threshold value. Then, even if the traveling direction command by the direction lever 89 changes, the object detection unit 131 functions based on the state before the change, so that an object can be detected in accordance with the traveling direction of the forklift 10. That the object detection unit 131 functions means that an object in the traveling direction of the forklift 10 is detected by the object detection unit 131. Thereby, even while the forklift 10 continues to move by inertia, the notification by the notification unit 136 can be continued until the speed of the forklift 10 becomes less than the first vehicle speed threshold value. If the conditions such as the speed of the forklift 10 at the time of performing the switchback operation are the same, the distance L1 between the forklift 10 and the object O1 when the notification by the notification unit 136 stops can be made shorter than that shown in FIG. 10.

[0069] [Effects of the Embodiment] (1) When the vehicle speed is equal to or higher than the first vehicle speed threshold value, the control device 81 enters a specific state. Even if the traveling direction command of the direction lever 89 changes, the control device 81 can recognize that the traveling direction of the forklift 10 is maintained until the speed of the forklift 10 becomes less than the first vehicle speed threshold value. Regardless of the speed of the forklift 10, compared with the case of recognizing the traveling direction of the forklift 10 from the operation position of the direction lever 89, the deviation between the traveling direction of the forklift 10 recognized by the control device 81 and the actual traveling direction of the forklift 10 can be suppressed. Then, the object detection unit 131 functions based on the traveling direction recognized in this way, so that an object can be detected in accordance with the traveling direction of the forklift 10.

[0070] (2) When the traveling direction command of the direction lever 89 changes in a specific state, the control device 81 determines whether there is a possibility that the object and the forklift 10 may come into contact based on the traveling direction before the traveling direction command changes. Thereby, when the switchback operation is performed, it is possible to suppress the notification by the notification unit 136 from stopping even though the forklift 10 is approaching the object.

[0071] (3) The control device 81 sets the power transmission mechanism 40 to a non-power transmission state in a specific state. In the case of the embodiment, the control device 81 sets the power transmission mechanism 40 to a non-power transmission state when the speed is equal to or higher than the second vehicle speed threshold in the speed range in which the control device 81 enters the specific state. When the power transmission mechanism 40 is in the non-power transmission state, the time until the traveling direction of the forklift 10 changes during the switchback operation becomes longer. For example, assume that the traveling direction of the forklift 10 is the reverse direction and the direction lever 89 is operated to switch the reverse command to the forward command. At this time, when the power transmission mechanism 40 is in the non-power transmission state, the distance that the forklift 10 travels in the reverse direction due to inertia becomes longer. In other words, the distance required for the traveling direction of the forklift 10 to switch from the reverse direction to the forward direction becomes longer. As a result, regardless of the speed of the forklift 10, when the control device 81 is maintained in the normal state, the distance of deviation between the traveling direction of the forklift 10 recognized by the control device 81 and the actual traveling direction of the forklift 10 becomes longer. When the notification unit 136 performs notification when there is a possibility that the object and the forklift 10 may come into contact, the distance during which the notification unit 136 does not perform notification even though the forklift 10 is approaching the object becomes longer. On the other hand, by causing the control device 81 to enter the specific state, it is possible to shorten the distance of deviation between the traveling direction of the forklift 10 recognized by the control device 81 and the actual traveling direction of the forklift 10. When the notification unit 136 performs notification when there is a possibility that the object and the forklift 10 may come into contact, it is possible to shorten the distance during which the notification unit 136 does not perform notification even though the forklift 10 is approaching the object.

[0072] (4) The control device 81 sets the power transmission mechanism 40 to a non - driving state by means of the interlock 110. The interlock 110 is provided to reduce the load on the power transmission mechanism 40 when the switch - back operation is performed when the vehicle speed is equal to or higher than the second vehicle speed threshold. On the other hand, by providing the interlock 110, when the switch - back operation is performed when the vehicle speed is equal to or higher than the second vehicle speed threshold, the time until the traveling direction of the forklift 10 changes becomes longer. By making the first vehicle speed threshold smaller than the second vehicle speed threshold, when the switch - back operation is performed when the vehicle speed is equal to or higher than the second vehicle speed threshold, the control device 81 can recognize that the traveling direction of the forklift 10 is maintained until the vehicle speed becomes less than the first vehicle speed threshold after the switch - back operation is performed. Thereby, the deviation between the traveling direction of the forklift 10 recognized by the control device 81 and the actual traveling direction of the forklift 10 during the switch - back operation can be suppressed.

[0073] (5) The specific condition is that the state where the vehicle speed is less than the first vehicle speed threshold continues for a predetermined time. Due to the influence of noise, there may be a case where the vehicle speed is instantaneously determined to be less than the first vehicle speed threshold even though the vehicle speed is equal to or higher than the first vehicle speed threshold. By making the continuation for a predetermined time a condition for the specific condition, false determination due to the influence of noise can be suppressed.

[0074] [Modification Example] The embodiment can be implemented with the following modifications. The embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0075] ○ As shown in FIG. 12, the traveling system 30 may include a brake mechanism 200. The brake mechanism 200 includes a brake actuator 201, a brake wheel cylinder 202, and a brake controller 203.

[0076] The brake actuator 201 is an actuator that controls the hydraulic oil supplied to the brake wheel cylinder 202. The brake actuator 201 controls the supply of hydraulic oil by, for example, an electromagnetic valve.

[0077] The brake wheel cylinder 202 is provided on the drive wheel 12. The brake wheel cylinder 202 may be provided on the steering wheel 14. The brake wheel cylinder 202 generates frictional braking force by pressing the brake pads against the brake disc with the hydraulic oil supplied from the brake actuator 201.

[0078] The hardware configuration of the brake controller 203 is, for example, the same as that of the control device 81. The brake controller 203 controls the brake actuator 201 according to a command from the control device 81. It can be said that the control device 81 can control the brake mechanism 200 by sending a command to the brake controller 203.

[0079] The control device 81 may apply a braking force to the forklift 10 by controlling the brake mechanism 200 instead of setting the power transmission mechanism 40 to the drive non - transmission state in a specific state. The control device 81 may apply a braking force to the forklift 10 by controlling the brake mechanism 200 in addition to setting the power transmission mechanism 40 to the drive non - transmission state in a specific state.

[0080] ○ The control device 81 does not have to set the power transmission mechanism 40 to the drive non - transmission state in a specific state. In this case, the forklift 10 does not have to be equipped with the interlock 110. ○The object does not have to change the notification conditions depending on whether it is a person or an obstacle. In this case, the detection device 133 does not have to perform person detection processing. The notification conditions may be that the forklift 10 is moving backward and an object exists within the predicted trajectory T. The notification conditions may be that the forklift 10 is moving backward and an object exists in the notification area AA1. When the predicted trajectory T is not used as the notification condition, the control device 81 does not have to derive the predicted trajectory T.

[0081] ○The control device 81 may perform deceleration control of the forklift 10 by recognizing the traveling direction of the forklift 10. For example, when the notification conditions are satisfied, deceleration control for decelerating the forklift 10 may be performed. In this case, the notification by the notification unit 136 may or may not be performed.

[0082] ○The control device 81 may put the power transmission mechanism 40 in a non-power-transmitting state by means of an inching valve. The inching valve adjusts whether to distribute the driving force of the engine 31 to the power transmission mechanism 40 or to a hydraulic pump. The power transmission mechanism 40 may be put in a non-power-transmitting state by preventing the driving force of the engine 31 from being distributed to the power transmission mechanism 40 by means of the inching valve.

[0083] ○The specific condition may be that the vehicle speed is less than the first vehicle speed threshold. ○The power transmission mechanism 40 may be configured such that the power-transmitting state and the non-power-transmitting state are switched according to a command from the control device 81. In this case, during the switchback operation, the control device 81 may give a command to the power transmission mechanism 40 to put the power transmission mechanism 40 in a non-power-transmitting state.

[0084] ○The object detection unit 131 may detect the position of an object existing in the forward direction among the traveling directions of the forklift 10. In this case, the stereo camera 132 is arranged facing the front of the forklift 10. When the object detection unit 131 detects the position of an object existing in the forward direction of the forklift 10, the notification area AA1 is an area that expands forward from the forklift 10. In this case, in the notification control, the control in which the "rear" and "front" described in the embodiment are reversed is performed.

[0085] The object detection unit 131 may be able to detect the position of an object existing in either the reverse direction or the forward direction among the traveling directions of the forklift 10. For example, a stereo camera for forward movement and a stereo camera for reverse movement may be provided, or a fish-eye camera may be provided. In this case, the notification area AA1 includes a front area that expands forward from the forklift 10 and a rear area that expands rearward from the forklift 10. The control device 81 changes the notification conditions according to the traveling direction of the forklift 10. For example, when the traveling direction of the forklift 10 is the reverse direction, the control device 81 causes the notification unit 136 to perform notification according to the same notification conditions as in the embodiment. When the traveling direction of the forklift 10 is the forward direction, the control device 81 causes the notification unit 136 to perform notification according to the notification conditions in which "reverse" is replaced with "forward" among the notification conditions of the embodiment.

[0086] ○The traveling direction determination unit may be any as long as it can be operated by the passenger of the forklift 10. The traveling direction determination unit may be, for example, a push button. ○Instead of the stereo camera 132, the object detection unit 131 may use a monocular camera, a ToF (Time of Flight) camera, LIDAR (Laser Imaging Detection and Ranging), a millimeter-wave radar, or the like. The object detection unit 131 may include a combination of a plurality of sensors such as the stereo camera 132 and LIDAR.

[0087] ○The notification unit 136 may be provided in addition to the object detection unit 131. ○The notification unit 136 may be directly operated by the control device 81. ○The forklift 10 may be switchable between automatic operation and manual operation.

[0088] ○The forklift 10 may be an electric forklift that performs a traveling operation by a motor. ○The forklift 10 may be one in which both a vehicle speed command and a determination of a traveling direction are made by a direction lever. This type of forklift is, for example, a reach forklift.

[0089] ○The rotation speed sensor 34 may be used as a traveling direction detection unit. ○The detection device 133 may be used as a control device. ○The industrial vehicle may be a tractor used for transporting loads or the like, an order picker used for picking operations, or the like.

Explanation of Signs

[0090] 10... Forklift as an industrial vehicle, 31... Engine, 40... Power transmission mechanism, 81... Control device, 89... Direction lever as a traveling direction determination unit, 90... Direction switch as a traveling direction detection unit, 110... Interlock, 131... Object detection unit, 136... Notification unit.

Claims

1. A traveling direction detection unit that detects the traveling direction of an industrial vehicle, A vehicle speed detection sensor that detects the speed of the industrial vehicle, A traveling direction determination unit that determines the traveling direction of the industrial vehicle, An object detection unit that detects the position of an object existing in the traveling direction of the industrial vehicle, An alarm unit that gives an alarm when there is a risk of contact between the object detected by the object detection unit and the industrial vehicle, A control device, and is provided with, When the speed of the industrial vehicle detected by the vehicle speed detection sensor is equal to or higher than a first vehicle speed threshold value, the control device enters a specific state, The control device recognizes that the specific state continues the state before the change even if the traveling direction command by the traveling direction determination unit changes, and the object detection unit functions based on the state before the change, The control device is, In the specific state, it is determined whether there is a risk of contact between the object and the industrial vehicle based on the state before the change, When the industrial vehicle is going straight, a predicted trajectory that extends linearly and when the industrial vehicle is turning, a predicted trajectory that extends in the turning direction is derived, When the object exists on the predicted trajectory, the alarm by the alarm unit is continued until the speed of the industrial vehicle becomes less than the first vehicle speed threshold value. An industrial vehicle.

2. The industrial vehicle is, An engine, A power transmission mechanism, and is provided with, The power transmission mechanism can switch between a drive transmission state in which the driving force of the engine is transmitted to the power transmission mechanism and a drive non - transmission state in which the driving force of the engine is not transmitted to the power transmission mechanism, In the specific state, the control device sets the power transmission mechanism to the drive non - transmission state. The industrial vehicle according to claim 1.

3. The industrial vehicle is provided with an interlock for setting the power transmission mechanism to the drive non - transmission state, When the traveling direction command by the traveling direction determination unit changes when the speed of the industrial vehicle is equal to or higher than a second vehicle speed threshold value, the control device sets the power transmission mechanism to the drive non - transmission state by the interlock, The first vehicle speed threshold value is set lower than the second vehicle speed threshold value. The industrial vehicle according to claim 2.

Images