Alert Systems and Forklifts

Abstract

To provide an alert system that enables an operator to easily determine dangerous actions. [Solution] An alert system including a forklift 1A and an alert unit 2, in which the forklift 1A is equipped with a sensor unit 30 that measures the load on the forks 23, the vehicle speed, and the turning angle of the rear wheels 12, a first control unit 40, and a second control unit 50, and the second control unit 50 performs a first determination process to determine that the forks 23 are in the process of removing the claws when the reversing distance of the vehicle body 10 from the point at which the load changes to a state below a predetermined first threshold is within a predetermined first distance, and a first identification process to identify that a first dangerous act has occurred when the turning angle during the claw removal operation is equal to or greater than a predetermined first angle, and the alert unit 2 issues a warning when the second control unit 50 identifies that the first dangerous act has occurred.

Description

[Technical field]

[0001] The present invention relates to an alert system and a forklift. [Background technology]

[0002] Conventionally, there has been known a forklift operation management system for managing the operation status of a forklift. The forklift operation management system is, for example, configured with a forklift equipped with a data logger unit (hereinafter, referred to as DLU), a server communicatively connected to the DLU, and a management device communicatively connected to the server.

[0003] The DLU can store not only the operation status of the forklift but also dangerous actions taken by the forklift on the server, so that the administrator of the forklift operation management system can access the server from the management device and check the operation status and dangerous actions of the forklift.

[0004] On the other hand, when a dangerous act occurs, the forklift warns the operator with a buzzer or a warning light. For example, when there is a step on the road surface, the forklift described in Patent Document 1 lights up a warning light on the instrument panel of the driver's seat or sounds a buzzer to notify the operator that a step is nearby. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-272700 Summary of the Invention [Problem to be solved by the invention]

[0006] Dangerous actions of a forklift include not only driving on a road surface with steps, but also various other actions (for example, turning while removing claws or while picking up a load). However, as with the forklift described in Patent Document 1, when the warning means are only a buzzer and a warning light, the operator may not be able to immediately determine what dangerous action has been detected. As a result, the forklift described in Patent Document 1 may not be able to prevent dangerous actions.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an alert system that allows an operator to easily determine dangerous behavior and a forklift that can suppress such dangerous behavior. [Means for solving the problem]

[0008] In order to solve the above problems, the alert system according to the present invention comprises: A forklift that performs a cargo handling traveling operation in a predetermined working area; an alert unit that issues a warning to an operator of the forklift; An alert system comprising: The forklift is A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork, the speed of the vehicle body, and the turning angle of the steering wheel; A first control unit that controls the cargo handling traveling operation; A second control unit that controls the alert unit, The second control unit is a first determination process for determining that the fork is in the process of removing the prongs when a reverse travel distance of the vehicle body from a point in time when the load has changed to a state less than a predetermined first threshold is within a predetermined first distance; performing a first identification process for identifying that a first dangerous behavior has occurred when the rotation angle is equal to or greater than a predetermined first angle during the claw removing motion; The alert unit issues the warning when the second control unit determines that the first dangerous act has occurred.

[0009] In the alert system, The second control unit is a second determination process for determining that the forks are in the process of picking up a load when the reverse distance of the vehicle body from the time when the load changes to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; A second identification process is performed to identify that a second dangerous act has occurred when the rotation angle is equal to or greater than a predetermined second angle during the load-taking operation. The alert unit can be configured to issue the warning when the second control unit identifies that the second dangerous act has occurred.

[0010] In the alert system, The first control unit can be configured to limit the speed or forcibly stop the vehicle body as a restriction action on the loading and unloading traveling operation when the second control unit identifies that the first dangerous act or the second dangerous act has occurred.

[0011] In the alert system, The second control unit is an input unit to which a measurement signal from the sensor unit is input; a storage unit that stores first dangerous act data linking a judgment condition for the first dangerous act, a first dangerous act ID, and the restricted act, and second dangerous act data linking a judgment condition for the second dangerous act, a second dangerous act ID, and the restricted act; a processing unit that performs the first determination process, the first identification process, the second determination process, and the second identification process; an output unit that outputs a first signal related to the first dangerous act ID and the second dangerous act ID to the alert unit and outputs a second signal related to the restricted act to the first control unit; the alert unit issues the warning when the first signal is input; The first control unit can be configured to perform the restricting action when the second signal is input.

[0012] In the alert system, the alert unit is a voice alert unit that issues the warning by voice, The audio alert unit is a voice data storage unit that stores first voice data in which the first dangerous action ID is linked to first warning voice data and second voice data in which the second dangerous action ID is linked to second warning voice data; a voice data processing unit that reproduces the first warning voice data when the first signal related to the first dangerous action ID is input, and reproduces the second warning voice data when the first signal related to the second dangerous action ID is input; The audio data processing unit may be configured to include a speaker that outputs the audio being reproduced.

[0013] The alert system comprises: The vehicle further includes an inattentive detection unit that detects inattentive behavior of the operator, The inattentive detection unit is a camera unit that captures an image of the operator and generates a captured image; an image processing unit that detects the inattentive behavior from the captured image and outputs a detection signal to the second control unit, The second control unit performs a third identification process to identify that a third dangerous act has occurred when the detection signal is input during the claw removal operation or the load picking operation, The alert unit can be configured to issue the warning when the second control unit identifies that the third dangerous act has occurred.

[0014] In the alert system, The first control unit can be configured to limit the speed of the vehicle body or forcibly stop the vehicle when the second control unit identifies that the third dangerous act has occurred.

[0015] In order to solve the above problems, the alert system according to the present invention comprises: A forklift that performs a cargo handling traveling operation in a predetermined working area; an alert unit that issues a warning to an operator of the forklift; An alert system comprising: The forklift is A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork, the speed of the vehicle body, and the turning angle of the steering wheel; A first control unit that controls the cargo handling traveling operation; A second control unit that controls the alert unit, The second control unit is a second determination process for determining that the forks are in the process of picking up a load when a reverse distance of the vehicle body from a point in time when the load has changed to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; A second identification process is performed to identify that a second dangerous act has occurred when the rotation angle is equal to or greater than a predetermined second angle during the load-taking operation. The alert unit issues the warning when the second control unit determines that the second dangerous act has occurred.

[0016] In order to solve the above problems, the forklift according to the present invention comprises: A forklift that performs a cargo handling traveling operation in a predetermined working area, A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork and the vehicle speed of the vehicle body; A control unit that controls the cargo handling traveling operation, The control unit is a first determination process for determining that the fork is in the process of removing the prongs when a reverse travel distance of the vehicle body from a point in time when the load has changed to a state less than a predetermined first threshold is within a predetermined first distance; When it is determined that the nail removal operation is being performed, a first restriction process is performed to restrict the vehicle speed of the vehicle body.

[0017] In order to solve the above problems, the forklift according to the present invention comprises: A forklift that performs a cargo handling traveling operation in a predetermined working area, A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork and the vehicle speed of the vehicle body; A control unit that controls the cargo handling traveling operation, The control unit is a second determination process for determining that the forks are in the process of picking up a load when a reverse distance of the vehicle body from a point in time when the load has changed to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; When it is determined that the load-receiving operation is in progress, a second restriction process is performed to restrict the speed of the vehicle body. Effect of the Invention

[0018] According to the present invention, it is possible to provide an alert system that allows an operator to easily determine dangerous behavior and a forklift that can suppress such dangerous behavior. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a forklift according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram of a first control unit of the forklift according to the first embodiment. [Diagram 3] FIG. 3 is a block diagram of a second control unit and a voice alert unit of the forklift according to the first embodiment. [Figure 4] FIG. 13 is a diagram for explaining a cargo pick-up operation. [Diagram 5] FIG. 2 is a diagram showing the relationship between a forklift, a server, and a management device in the first embodiment. [Figure 6] FIG. 11 is a diagram showing a forklift according to a second embodiment. [Figure 7] FIG. 11 is a block diagram of a second control unit, an inattentive detection unit, and a voice alert unit of a forklift according to a second embodiment. [Figure 8] FIG. 11 is a diagram showing a forklift according to a third embodiment. [Figure 9] FIG. 11 is a block diagram of a first control unit of the forklift according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an alert system and a forklift according to the present invention will be described with reference to the accompanying drawings.

[0021] 1 shows an alert system and a forklift 1A according to a first embodiment of the present invention. The alert system according to the first embodiment is composed of at least one forklift 1A and a voice alert unit 2 provided in the forklift 1A.

[0022] The forklift 1A performs a cargo handling / traveling operation in a predetermined work area. The cargo handling / traveling operation includes a cargo handling operation and a traveling operation, and the traveling operation includes a turning operation. The work area is, for example, an area in any building such as a factory or a warehouse. At least one shelf R is provided in the work area, and cargo W (including pallets) is stored on the shelf R (see FIG. 4).

[0023] The forklift 1A is a counterbalance type battery forklift, and includes a vehicle body 10, a loading device 20, a sensor unit 30, a first control unit 40, a second control unit 50, a voice alert unit 2, and a battery (not shown).

[0024] A pair of left and right front wheels 11 and rear wheels 12 are provided on the lower part of the vehicle body 10. In the forklift 1A, the front wheels 11 are drive wheels driven by a traveling motor, and the rear wheels 12 are steered wheels steered (turned) by a steering motor.

[0025] An operator's seat 13 is provided on the upper part of the vehicle body 10. An accelerator 14 and a brake 15 are provided on the lower front part of the seat 13, and a steering wheel 16 and a loading / unloading operation section 17 are provided on the dashboard in front of the seat 13.

[0026] The accelerator 14 is an accelerator pedal configured to be operable by being stepped on by an operator in the driver's seat 13. When the accelerator 14 is in an on state (pedal is depressed), it accelerates the vehicle body 10 in accordance with the amount of depression of the pedal (accelerator opening), and when it is switched from the on state to an off state (pedal is not depressed), it generates weak regenerative braking to decelerate the vehicle body 10.

[0027] The brake 15 is a brake pedal configured to be operable by the foot of an operator in the driver's seat 13. When the brake 15 is in the on state (pedal is depressed), it generates regenerative braking stronger than the regenerative braking of the accelerator 14 to decelerate the vehicle body 10, but when it is in the off state, it does not generate regenerative braking.

[0028] The handlebars 16 are connected to the rear wheels 12 via a steering control mechanism 42, which will be described later. By rotating the handlebars 16, the operator can change the direction (turning angle) of the rear wheels 12 according to the direction of rotation. When the handlebars 16 is not being rotated (when traveling straight), the turning angle of the rear wheels 12 is 0°.

[0029] The cargo handling operation unit 17 includes a lift lever and a tilt lever. The lift lever and the tilt lever are connected to the cargo handling device 20 via a cargo handling control mechanism 43, which will be described later. An operator can operate the cargo handling device 20 by operating the lift lever and the tilt lever.

[0030] A head guard 18 is provided on the upper part of the vehicle body 10 and above the driver's seat 13. The head guard 18 is composed of a pair of left and right front pillars, a pair of left and right rear pillars, and a roof.

[0031] The loading / unloading device 20 includes a mast 21, a lift bracket 22, a fork 23, a backrest 24, a tilt cylinder 25, and a lift cylinder 26.

[0032] The mast 21 is provided at the front of the vehicle body 10 and raises and lowers the fork 23. The mast 21 includes an outer mast and an inner mast. The outer mast includes a pair of left and right guide rails that extend vertically, and a cross beam that connects the upper ends of the guide rails. The inner mast is provided inside the guide rails of the outer mast and rises and lowers along the guide rails of the outer mast.

[0033] The lift bracket 22 supports the fork 23 and moves up and down along the mast 21. The lift bracket 22 is attached to one end of a lift chain and moves up and down along the inner mast while being suspended from the lift chain. The other end of the lift chain is attached to the lower part of the outer mast via a chain wheel provided on the upper part of the lift cylinder 26.

[0034] The forks 23 are a pair of left and right L-shaped arms, and are provided on the front surface of the lift bracket 22. On the forks 23, a load W is placed.

[0035] The backrest 24 is a frame for preventing the cargo W loaded on the forks 23 from collapsing backward, and is provided on the upper part of the lift bracket 22. When the mast 21 (inner mast) rises and falls, the lift bracket 22, the forks 23, and the backrest 24 also rise and fall.

[0036] The tilt cylinder 25 is a hydraulic cylinder for tilting the mast 21 in the forward and backward directions. In this embodiment, when the tilt lever is tilted forward, the tilt cylinder 25 extends and the mast 21 tilts forward, and when the tilt lever is tilted backward, the tilt cylinder 25 contracts and the mast 21 tilts backward. When the tilt lever is returned to the neutral position (a position that does not tilt the mast 21 forward or backward), the tilting of the mast 21 stops.

[0037] The lift cylinder 26 is a hydraulic cylinder for raising and lowering the mast 21. In this embodiment, when the lift lever is tilted forward, the lift cylinder 26 contracts and the inner mast descends, and when the lift lever is tilted backward, the lift cylinder 26 expands and the inner mast rises. When the lift lever is returned to the neutral position (a position where the inner mast is neither tilted forward nor backward), the raising and lowering of the inner mast stops.

[0038] The sensor unit 30 includes a load sensor 31, a vehicle speed sensor 32, and a turning angle sensor 33. The load sensor 31 measures the load of the baggage W loaded on the fork 23. For example, a pressure sensor that measures the presence or absence of a load from the pressure of the lift cylinder 26 can be used as the load sensor 31. The vehicle speed sensor 32 measures the vehicle speed of the vehicle body 10. For example, a speed sensor that measures the traveling speed of the vehicle body 10 from the rotation speed and rotation direction of the traveling motor can be used as the vehicle speed sensor 32. The turning angle sensor 33 measures the turning angle of the rear wheel 12. For example, an angle sensor that measures the turning angle of the rear wheel 12 from the rotation angle of the handlebar 16, or an angle sensor that measures the turning angle of the rear wheel 12 from the rotation angle of the turning shaft of the rear wheel 12 can be used as the turning angle sensor 33.

[0039] 2, the sensor unit 30 includes an accelerator sensor 34 and a brake sensor 35. The accelerator sensor 34 detects the accelerator opening of the accelerator 14. The brake sensor 35 detects the state of the brake 15 (on state / off state).

[0040] The first control unit 40 is provided inside the vehicle body 10, and controls the loading / unloading traveling operation and communicates with the second control unit 50. The first control unit 40 includes a traveling control mechanism 41, a steering control mechanism 42, and a loading / unloading control mechanism 43, as shown in FIG.

[0041] The driving control mechanism 41 acquires measurement signals from the accelerator sensor 34, the brake sensor 35, and the vehicle speed sensor 32, and controls the front wheels 11, which are driving wheels. The driving control mechanism 41 includes, for example, a driving controller, a driving inverter, a driving motor, a hydraulic circuit, and the like.

[0042] The travel control mechanism 41 performs speed control for controlling the loading / unloading travel operation to bring the travel speed of the vehicle body 10 closer to a predetermined target speed. Specifically, the travel controller of the travel control mechanism 41 acquires the travel speed of the vehicle body 10 based on the measurement signal of the vehicle speed sensor 32, and calculates the target speed based on the detection signal of the accelerator sensor 34 and / or the detection signal of the brake sensor 35. The travel controller performs PI control or PID control to bring the travel speed closer to the target speed. The target speed is calculated, for example, by the formula: target speed = set speed x accelerator opening [%]. The set speed is a speed that is preset in the travel controller.

[0043] The steering control mechanism 42 obtains detection information (detection signals) relating to the direction and amount of rotation of the handle 16, and controls the rear wheels 12, which are steered wheels. The steering control mechanism 42 includes, for example, a steering motor, a power steering device, a hydraulic circuit, etc. The steering control mechanism 42 has the same configuration as the steering control mechanism in a conventional battery forklift.

[0044] The cargo handling control mechanism 43 receives operation signals (measurement signals) from the cargo handling operation unit 17 (lift lever and tilt lever) and controls the cargo handling device 20. The cargo handling control mechanism 43 includes, for example, a cargo handling controller, a cargo handling inverter, a cargo handling motor, a hydraulic circuit, etc. The cargo handling control mechanism 43 has the same configuration as the cargo handling control mechanism in a conventional battery forklift.

[0045] The second control unit 50 includes, for example, a data logger unit (DLU), and is provided on a front pillar of the head guard 18. As shown in FIG 3, the second control unit 50 includes an input unit 51, a storage unit 52, a processing unit 53, and an output unit 54.

[0046] The input unit 51 acquires the measurement signals of the sensor unit 30. Specifically, the input unit 51 acquires a measurement signal relating to the presence or absence of a load on the fork 23 from the load sensor 31, acquires a measurement signal relating to the vehicle speed of the vehicle body 10 from the vehicle speed sensor 32, and acquires a measurement signal relating to the turning angle of the rear wheel 12 from the turning angle sensor 33.

[0047] The storage unit 52 stores a plurality of dangerous action data items that are linked to a unique dangerous action ID (hereinafter, ID), predefined dangerous actions, judgment conditions for dangerous actions, and restricted actions for cargo handling travel operations. In this embodiment, the ID is a number, but the ID may be a letter or a symbol, or a combination of letters, symbols, and numbers.

[0048] The operator or the system administrator can change the content of the dangerous act data stored in the storage unit 52 and can also add new dangerous act data. For example, the multiple dangerous act data can include two dangerous act data shown in Table 1 below.

[0049] [Table 1]

[0050] The dangerous action data of ID "001" is obtained by linking the dangerous action "turning during claw removal operation", the judgment condition "turning during claw removal operation", and the restricted action "vehicle speed limit" to ID "001". The dangerous action "turning during claw removal operation" defines the dangerous action of the forklift 1A performing a turning operation during a claw removal operation (corresponding to the "first dangerous action" of the present invention). The judgment condition is set as the judgment condition for the dangerous action that a turning operation is detected while a claw removal operation is detected. The restricted action "vehicle speed limit" defines that the first control unit 40 performs a vehicle speed limit (for example, an upper limit speed of 4 [km / h]) when the judgment condition is satisfied. In other words, the forklift 1A is prohibited from traveling at a speed exceeding the upper limit speed.

[0051] The dangerous action data of ID "002" is obtained by linking the dangerous action "turning during load-receiving operation", the judgment condition "turning during load-receiving operation", and the restricted action "vehicle speed limit" to ID "002". The dangerous action "turning during load-receiving operation" defines the dangerous action of the forklift 1A performing a turning operation during a load-receiving operation (corresponding to the "second dangerous action" of the present invention). The judgment condition is set as the judgment condition for the dangerous action, that is, the detection of a turning operation while detecting a load-receiving operation. The restricted action "vehicle speed limit" defines that the first control unit 40 performs a vehicle speed limit (for example, an upper speed limit of 4 [km / h]) when the judgment condition is satisfied.

[0052] The restriction action "vehicle speed limit" of ID "001" and / or ID "002" may be changed to a restriction action "forced stop". The restriction action "forced stop" defines that the first control unit 40 decelerates the vehicle body 10 and finally stops it when the above judgment condition is satisfied. For example, the first control unit 40 calculates the target speed of the vehicle body 10 by the calculation formula: target speed = set speed x accelerator opening [%]. The accelerator opening is 0 [%] when the accelerator 14 is in the off state, and increases in proportion to the amount of depression of the accelerator 14 when the accelerator 14 is in the on state, up to a maximum of 100 [%]. When the first control unit 40 executes the above restriction action, it changes the set speed to a value with a small absolute value in stages and finally to zero.

[0053] The storage unit 52 may store dangerous behavior data in which the ID, the dangerous behavior, and the judgment condition are linked (without linking the restricted behavior of the cargo handling traveling operation). The dangerous behavior corresponds to, for example, not wearing a seat belt, low battery level, forgetting to apply the parking brake, etc.

[0054] The processing unit 53 performs a first judgment process, a first identification process, a second judgment process and a second identification process to determine whether the judgment conditions for each dangerous act are satisfied, and identifies dangerous acts (risky act data) that satisfy the judgment conditions.

[0055] The first determination process is a process for determining whether or not the claw removal operation is in progress. The processing unit 53, which has started the first determination process, determines whether or not the load has changed from a state equal to or greater than a predetermined first threshold to a state less than the first threshold, based on the measurement signal of the load sensor 31 acquired by the input unit 51. The first threshold is set to a value that can distinguish between a loaded state and an unloaded state. For example, when the baggage W held by the forks 23 is placed on the shelf R, the forks 23 change from a loaded state to an unloaded state, and the measurement signal (measured value) of the load sensor 31 changes from a state equal to or greater than the first threshold to a state less than the first threshold.

[0056] When the load changes to a state less than the first threshold, the processing unit 53 calculates the reverse distance of the vehicle body 10 from the time when the load changes to a state less than the first threshold based on the measurement signal of the vehicle speed sensor 32 acquired by the input unit 51. At the same time, the processing unit 53 judges whether the load is less than the first threshold and the reverse distance is within a first distance set in advance. Here, the first distance is set to a value greater than the dimension of the fork 23 in the front-rear direction, for example. In other words, the first distance is set to a value that can determine whether the fork 23 has completely come out of the pallet of the baggage W. The first distance may be set to be equal to or less than the dimension of the fork 23 in the front-rear direction.

[0057] As described above, in the first determination process, when the load is less than the first threshold value and the reverse distance is within the first distance, the processing unit 53 determines that the forklift 1A is in the claw removal operation.

[0058] The first identification process is a process for identifying the dangerous behavior of "turning while pulling out a claw." The first identification process may be performed when it is determined in the first determination process that the claw pulling out process is in progress. The first identification process may be included as a part of the first determination process.

[0059] The processing unit 53, which has started the first identification process, determines whether or not the rear wheel 12 has been turned during the claw removal operation, based on the measurement signal of the turning angle sensor 33 acquired by the input unit 51. For example, the processing unit 53 determines that the rear wheel 12 has been turned when the turning angle of the rear wheel 12 is equal to or greater than a predetermined first angle. The first angle can be set to any value greater than 0°.

[0060] As described above, during the first identification process, the processing unit 53 identifies the dangerous action of “turning while removing claws”, i.e., the dangerous action data with ID “001”, when the load is less than the first threshold, the reverse distance is within the first distance, and the turning angle is equal to or greater than the first angle.

[0061] The second determination process is a process for determining whether or not a load-taking operation is in progress. The processing unit 53, which has started the second determination process, determines whether or not the load has changed from a state less than a predetermined second threshold to a state equal to or greater than the second threshold, based on the measurement signal of the load sensor 31 acquired by the input unit 51. The second threshold is set to a value that can distinguish between a loaded state and an unloaded state. For example, when a load W placed on a shelf R is lifted by the fork 23, the fork 23 changes from an unloaded state to a loaded state, and the measurement signal (measured value) of the load sensor 31 changes from a state less than the second threshold to a state equal to or greater than the second threshold. The second threshold may be set to the same value as the first threshold.

[0062] When the load changes to a state equal to or greater than the second threshold, the processing unit 53 calculates the reverse distance of the vehicle body 10 from the time when the load changes to a state equal to or greater than the second threshold based on the measurement signal of the vehicle speed sensor 32 acquired by the input unit 51. At the same time, the processing unit 53 determines whether the load is equal to or greater than the second threshold and the reverse distance is within a preset second distance. Here, the second distance is set to a value larger than the dimension L in the front-rear direction of the loading space of the shelf R as shown in FIG. 4. In other words, the second distance is set to a value that allows determination of whether the baggage W has been completely removed from the shelf R. The second distance may be set to a value equal to or less than the dimension L in the front-rear direction of the loading space of the shelf R.

[0063] As described above, in the second determination process, when the load is equal to or greater than the second threshold and the reverse distance is within the second distance, the processor 53 determines that the forklift 1A is in the cargo-retrieving operation.

[0064] The second identification process is a process for identifying the dangerous act of "turning while carrying out a load-taking operation." The second identification process may be performed when it is determined in the second determination process that a load-taking operation is being performed. The second identification process may be included as a part of the second determination process.

[0065] The processing unit 53, which has started the second identification process, determines whether or not the rear wheels 12 have been turned during the load-collecting operation, based on the measurement signal of the turning angle sensor 33 acquired by the input unit 51. For example, the processing unit 53 determines that the rear wheels 12 have been turned when the turning angle of the rear wheels 12 is equal to or greater than a predetermined second angle. The second angle can be set to any value greater than 0°.

[0066] As described above, during the second identification process, the processing unit 53 identifies the dangerous action data of ID "002", i.e., "turning while picking up cargo", when the load is equal to or greater than the second threshold, the reversing distance is within the second distance, and the turning angle is equal to or greater than the second angle.

[0067] The output unit 54 transmits a first signal related to the ID of the risky action data identified by the processing unit 53 to the audio alert unit 2, and transmits a second signal related to the restricted action linked to the ID to the first control unit 40. The transmission timing of the first signal and the second signal may be the same or different.

[0068] The audio alert unit 2 is provided under the roof of the head guard 18, and includes an audio data storage unit 2A, an audio data processing unit 2B, and a speaker 2C. The audio alert unit 2 issues an audio warning (alert) to the operator of the forklift 1A.

[0069] The voice of the present invention includes a linguistic voice capable of conveying information to an operator. The voice of the present invention does not include a sound effect alone such as a buzzer sound, but may include a sound effect before or after the linguistic voice.

[0070] The voice data storage unit 2A stores a plurality of voice data in which data of a voice for warning (hereinafter, called "warning voice data") is linked to an ID. The plurality of voice data includes, for example, two voice data shown in Table 2 below.

[0071] [Table 2]

[0072] The voice data of ID "001" is the ID "001" linked with the warning voice data "Do not turn. The forks are being removed." The warning voice data of ID "001" contains the words (information) "turning" and "removing the forks" that the operator associates with the "turning action" and "removing the forks" that are constituent elements of a dangerous act.

[0073] The voice data of ID "002" is obtained by linking the warning voice data "Do not turn. Loading is in progress" to ID "002". The warning voice data of ID "002" contains the words (information) "turning" and "loading" that the operator associates with the "turning operation" and "loading operation" that are constituent elements of dangerous acts.

[0074] An operator or a manager of the system can change the warning voice data stored in the voice data storage unit 2A and can also add new voice data. For example, a memory card capable of rewriting warning voice data can be used as the voice data storage unit 2A. The memory card is, for example, an SD card or a USB memory. For example, the operator or manager can generate warning voice data in a file format such as WAV format and store it in the voice data storage unit 2A.

[0075] The voice data processing unit 2B acquires the first signal output from the output unit 54, and reproduces warning voice data linked to the ID of the first signal in the voice data storage unit 2A. For example, when a first signal related to the ID "001" is received from the output unit 54, the voice data processing unit 2B reproduces the warning voice data of the ID "001" "Do not turn. Forks are being withdrawn." The voice data processing unit 2B includes, for example, a voice player module.

[0076] The speaker 2C is connected to the audio data processing unit 2B and outputs the sound of the warning audio data being played back by the audio data processing unit 2B. For example, when the audio data processing unit 2B is playing back the warning audio data with ID "001" "Do not turn. Forks are being removed," the speaker 2C outputs the sound "Do not turn. Forks are being removed."

[0077] As described above, in the alert system and forklift 1A according to this embodiment, the audio alert unit 2 issues an audio warning (alert) to the operator. This allows the operator to easily determine which dangerous behavior has been detected. For example, the operator can immediately determine that dangerous behavior of ID "001" or ID "002" has been detected by listening to the information contained in the audio from the audio alert unit 2, and can take appropriate action.

[0078] In addition, in the alert system and forklift 1A according to the present embodiment, the defined dangerous acts are linked to restricted acts of cargo handling travel, so even if the operator's response is delayed, the first control unit 40 restricts the cargo handling travel based on the restricted acts. Therefore, the alert system and forklift 1A according to the present embodiment can suppress the defined dangerous acts.

[0079] (Operation management system) As shown in FIG. 5, the alert system according to the first embodiment may include a server 3 and a management device 4, and may configure an operation management system for a forklift 1A.

[0080] The server 3 is communicatively connected to the forklift 1A. The server 3 may be, for example, a physical server or a virtual server such as a cloud. The forklift 1A can upload (save) video data captured and generated by a drive recorder included in the sensor unit 30 to the server 3 while the audio alert unit 2 is playing back warning audio data.

[0081] The management device 4 is communicatively connected to the server 3. The management device 4 may be, for example, a personal computer (PC) or a smartphone. The management device 4 is capable of acquiring the video data from the server 3. This allows the administrator of the alert system to check, on the management device 4, the video data when the warning audio data is being played back.

[0082] [Second embodiment] 6 shows an alert system and a forklift 1B according to a second embodiment of the present invention. The alert system according to the second embodiment is composed of at least one forklift 1B and a voice alert unit 2 provided in the forklift 1B.

[0083] The forklift 1B has the same configuration as the forklift 1A of the first embodiment, except that it includes an inattentive behavior detection unit 60 and performs control related to the inattentive behavior detection unit 60.

[0084] The inattentive behavior detection unit 60 is for detecting inattentive behavior of the operator in the driver's seat 13, and is provided, for example, under the roof of the head guard 18. As shown in FIG. 7, the inattentive behavior detection unit 60 includes a camera unit 61 and an image processing unit 62.

[0085] The camera unit 61 photographs the operator and generates a photographed image. The image processing unit 62 performs publicly known and arbitrary image processing on the photographed image generated by the camera unit 61, and detects whether the operator is looking aside. The image processing unit 62 can detect whether the operator is looking aside from the direction of the operator's face and the direction of his / her line of sight.

[0086] The image processing unit 62 may detect the operator's looking aside, for example, when the operator's face is not facing the front of the vehicle body 10 or when the operator's gaze is not facing the front of the vehicle body 10. If the detection range for looking aside is to be expanded, the image processing unit 62 may detect the operator's looking aside, taking into consideration the up and down directions as well, when the operator's face is not facing the baggage W or when the operator's gaze is not facing the baggage W.

[0087] The input unit 51 acquires a detection signal relating to the detection of the operator's inattentive behavior from the image processing unit 62 that has detected the inattentive behavior.

[0088] The storage unit 52 prestores risky action data with ID "003" and risky action data with ID "004" shown in Table 3 below, in addition to risky action data with ID "001" and risky action data with ID "002".

[0089] [Table 3]

[0090] The dangerous action data of ID "003" is obtained by linking the dangerous action "looking aside while removing claws", the judgment condition "looking aside during removing claws", and the restricted action "vehicle speed limit" to ID "003". The dangerous action "looking aside while removing claws" defines the dangerous action of the operator looking aside while removing claws of the forklift 1A (corresponding to the "third dangerous action" of the present invention). The judgment condition is set as the judgment condition for the dangerous action, that is, the detection of looking aside while detecting the removal of claws. The restricted action "vehicle speed limit" defines that the first control unit 40 imposes a vehicle speed limit (for example, an upper speed limit of 4 [km / h]) when the judgment condition is satisfied.

[0091] The dangerous action data of ID "004" is obtained by linking the dangerous action "looking aside while receiving a load", the judgment condition "looking aside while receiving a load", and the restricted action "vehicle speed limit" to ID "004". The dangerous action "looking aside while receiving a load" defines the dangerous action of the operator looking aside while receiving a load with the forklift 1A (corresponding to the "third dangerous action" of the present invention). The judgment condition is set as the judgment condition for the dangerous action, that is, the detection of looking aside while detecting the load receiving operation. The restricted action "vehicle speed limit" defines that the first control unit 40 imposes a vehicle speed limit (for example, an upper speed limit of 4 [km / h]) when the judgment condition is satisfied.

[0092] The restricted action "vehicle speed limit" for ID "003" and / or ID "004" may be changed to the restricted action "forced stop" as in the first embodiment.

[0093] The processing unit 53 performs a third identification process as control related to the inattentive detection unit 60, thereby determining whether or not the judgment conditions for dangerous behavior related to inattentive behavior are satisfied, and identifies dangerous behavior (risky behavior data) that satisfies the judgment conditions.

[0094] The third identification process includes a process for identifying the dangerous behavior of "looking aside while removing a claw" and a process for identifying the dangerous behavior of "looking aside while picking up a load." The third identification process may be performed when it is determined in the first determination process that the claw is being removed, or when it is determined in the second determination process that the load is being picked up. The third identification process may be included as part of the first determination process and the second determination process.

[0095] When the processing unit 53 starts the third identification process and determines that a claw pulling out action is in progress in the first determination process and the input unit 51 acquires a detection signal from the image processing unit 62, the processing unit 53 identifies the dangerous action of “looking aside while pulling out a claw”, i.e., the dangerous action data of ID “003”. On the other hand, when the processing unit 53 determines that a load picking action is in progress in the second determination process and the input unit 51 acquires a detection signal from the image processing unit 62, the processing unit 53 identifies the dangerous action of “looking aside while picking up a load”, i.e., the dangerous action data of ID “004”.

[0096] The output unit 54 transmits a first signal related to the ID of the risky action data identified by the processing unit 53 to the audio alert unit 2, and transmits a second signal related to the restricted action linked to the ID to the first control unit 40. The transmission timing of the first signal and the second signal may be the same or different.

[0097] The voice data storage unit 2A further includes voice data with ID "003" and voice data with ID "004" shown in Table 4 below.

[0098] [Table 4]

[0099] The voice data with ID "003" is the ID "003" with the warning voice data "Do not look away." The warning voice data with ID "003" contains words (information) that the operator associates with "looking away," which is a constituent element of a dangerous act. The voice data with ID "004" is the same.

[0100] As described above, in the alert system and forklift 1B according to this embodiment, the audio alert unit 2 issues an audio warning (alert) to the operator. This allows the operator to easily determine which dangerous behavior has been detected. For example, the operator can immediately determine which of the dangerous behaviors ID "001" to ID "004" has been detected by listening to the information contained in the audio from the audio alert unit 2, and can take appropriate action.

[0101] In addition, in the alert system and forklift 1B according to the present embodiment, the defined dangerous acts are linked to restricted acts of cargo handling travel, so even if the operator's response is delayed, the first control unit 40 restricts the cargo handling travel based on the restricted acts. Therefore, the alert system and forklift 1B according to the present embodiment can suppress the defined dangerous acts.

[0102] (Frequency of warning audio data activation) In the above example, the frequency of the warning audio data is assumed to be once, but the frequency of the warning audio data can be changed as appropriate.

[0103] For example, the ID may be linked to the playback count or playback time in the audio data storage unit 2A. When the playback count is linked, the warning audio data can be played back a specified number of times, and when the playback time is linked, the warning audio data can be played back repeatedly for a specified playback time.

[0104] On the other hand, if the warning voice data is played back multiple times, the operator may feel uncomfortable. In this case, the storage unit 52 or the voice data storage unit 2A may associate the ID with the danger level. When the danger level exceeds a predetermined threshold level, it is preferable that the voice data processing unit 2B plays back the warning voice data multiple times, and increases the number of times of playback as the danger level increases. For example, the danger levels may be classified into danger level 1, danger level 2, and danger level 3, and the danger level 1 may be played back once, the danger level 2 may be played back twice, and the danger level 3 may be played back three times, and the danger level and the number of times of playback may be associated with the ID in the voice data storage unit 2A.

[0105] Furthermore, in the case where the output timing of the second signal is linked to the risky behavior ID in the storage unit 52, the output timing can be set to "a predetermined time after the timing of outputting the first signal." Here, the predetermined time can be set appropriately according to the risk level.

[0106] When the risk levels are classified as risk level 1, risk level 2, and risk level 3 as described above, the predetermined time may be a first predetermined time for risk level 1, a second predetermined time shorter than the first predetermined time for risk level 2, and a third predetermined time shorter than the second predetermined time for risk level 3. The third predetermined time may be zero. For example, the risky actions of IDs "001" and "002" may be risk level 3, and the risky actions of IDs "003" and "004" may be risk level 1. When the processing unit 53 identifies the risky action of ID "003" or ID "004", the audio alert unit 2 may issue an audio warning (alert) to the operator, and when the risky action of ID "003" or ID "004" is still detected even after the first predetermined time has elapsed, the first control unit 40 may execute the restricted action based on the second signal.

[0107] By changing the output timing of the second signal according to the risk level of the dangerous behavior as described above, it is possible to minimize the decrease in the work efficiency of the forklift 1B, while suppressing the dangerous behavior and ensuring safety.

[0108] [Third embodiment] 8 shows a forklift 1C according to a third embodiment of the present invention. The forklift 1C can be included in the alert system according to the first embodiment and / or the second embodiment.

[0109] The forklift 1C has the same configuration as the forklift 1A of the first embodiment, except that it is equipped with a first control unit 40' (corresponding to the "control unit" of the present invention) instead of the first control unit 40, the sensor unit 30 does not include the turning angle sensor 33, and the forklift 1C does not include the second control unit 50 and the voice alert unit 2.

[0110] As shown in FIG. 9, the first control unit 40' has the same configuration as that of the first embodiment, except that a driving control mechanism 41' is provided instead of the driving control mechanism 41.

[0111] The travel control mechanism 41′ performs control based on a measurement signal (measurement value) of the load sensor 31, in addition to the control of the travel control mechanism 41 of the first embodiment. The control includes a first determination process, a first restriction process, a second determination process, and a second restriction process.

[0112] The first determination process is similar to the first determination process performed by the processor 53 in the first embodiment. That is, when the load is less than the first threshold and the reverse distance is within the first distance, the travel control mechanism 41′ determines that the forklift 1C is in the claw removal operation.

[0113] The first restriction process is a process related to limiting the vehicle speed of the forklift 1C. When the travel control mechanism 41' determines that the state of the forklift 1C is in the claw removal operation, the travel control mechanism 41' restricts the vehicle speed of the forklift 1C (for example, an upper limit speed of 4 [km / h]). This prohibits the forklift 1C from traveling at a speed exceeding the upper limit speed during the claw removal operation.

[0114] The second determination process is similar to the second determination process performed by the processor 53 in the first embodiment. That is, when the load is equal to or greater than the second threshold and the reverse distance is within the second distance, the travel control mechanism 41′ determines that the forklift 1C is in a load-receiving operation.

[0115] The second restriction process is a process related to limiting the vehicle speed of the forklift 1C. When the travel control mechanism 41' determines that the state of the forklift 1C is in a load-receiving operation, the travel control mechanism 41' restricts the vehicle speed of the forklift 1C (for example, an upper limit speed of 4 [km / h]). This prohibits the forklift 1C from traveling at a speed exceeding the upper limit speed during a load-receiving operation.

[0116] According to the forklift 1C of this embodiment, the vehicle speed of the vehicle body 10 is limited before a turning operation is actually performed, so that the safety awareness of the operator can be improved and the dangerous acts of "turning while removing a claw" or "turning while picking up a load" can be suppressed. Note that, like the forklift 1C, the forklift 1A can also limit the vehicle speed before a turning operation is performed. In this case, the first control unit 40 performs the limiting action (vehicle speed limit) before the second control unit 50 identifies the above-mentioned dangerous act.

[0117] Although the embodiments of the alert system and the forklift according to the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0118] The alert system according to the present invention is an alert system including a forklift performing a loading / unloading traveling operation in a specified working area and an alert unit that issues a warning to the operator of the forklift, wherein the forklift is equipped with a vehicle body having a steering wheel, forks provided on the front side of the vehicle body, a sensor unit that measures the load of the forks, the vehicle speed of the vehicle body and the turning angle of the steering wheel, a first control unit that controls the loading / unloading traveling operation, and a second control unit that controls the alert unit, wherein the second control unit performs a first determination process that determines that the forks are performing a claw removal operation when the reversing distance of the vehicle body from the time when the load changes to a state below a predetermined first threshold is within a predetermined first distance, and a first identification process that identifies that a first dangerous act has occurred when the turning angle during the claw removal operation is equal to or greater than a predetermined first angle, and the configuration of the alert unit can be modified as appropriate as long as it issues a warning when the second control unit identifies that the first dangerous act has occurred.

[0119] Furthermore, the alert system according to the present invention is an alert system including a forklift performing a loading / unloading traveling operation in a specified working area and an alert unit that issues a warning to the operator of the forklift, wherein the forklift is equipped with a vehicle body having a steering wheel, a fork provided on the front side of the vehicle body, a sensor unit that measures the load on the fork, the vehicle speed of the vehicle body and the turning angle of the steering wheel, a first control unit that controls the loading / unloading traveling operation, and a second control unit that controls the alert unit, wherein the second control unit performs a second determination process that determines that a loading operation is being performed by the fork when the reverse distance of the vehicle body from the time when the load changes to a state equal to or greater than a specified second threshold is within a specified second distance, and a second identification process that identifies that a second dangerous act has occurred when the turning angle is equal to or greater than a specified second angle during the loading operation, and the configuration of the alert unit can be appropriately changed as long as it issues a warning when the second control unit identifies that the second dangerous act has occurred.

[0120] The alert unit is preferably an audio alert unit that issues an alert by voice, but may issue an alert by means other than voice. The alert unit may, for example, issue an alert to the operator by turning on an alarm light or by issuing a sound effect that does not include voice (for example, a buzzer or electronic sound). By varying the color or state of the light, the type of sound effect, etc., depending on the dangerous behavior, the operator can determine whether the behavior is dangerous.

[0121] In the above embodiment, the forklifts 1A and 1B are provided with the audio alert unit 2, but the audio alert unit of the present invention can be provided in a location other than the forklifts 1A and 1B (for example, on a shelf R in the work area).

[0122] In the above embodiment, the forklift 1B is provided with the inattentive detection unit 60, but the inattentive detection unit of the present invention can be provided in a location other than the forklift 1B (for example, on the shelf R in the work area).

[0123] The forklift of the present invention is a forklift that performs loading and unloading travel operations in a specified working area, and is equipped with a vehicle body with a steering wheel, a fork provided on the front side of the vehicle body, a sensor unit that measures the load on the fork and the vehicle speed of the vehicle body, and a control unit that controls the loading and unloading travel operations, and the control unit can be configured as appropriate so long as it performs a first determination process that determines that the fork is in the process of removing the claws when the reversing distance of the vehicle body from the point at which the load changes to a state below a predetermined first threshold is within a predetermined first distance, and a first restriction process that restricts the vehicle speed of the vehicle body when it is determined that the fork is in the process of removing the claws.

[0124] In addition, the forklift of the present invention is a forklift that performs loading and unloading travel operations in a specified working area, and is equipped with a vehicle body with a steering wheel, a fork provided on the front side of the vehicle body, a sensor unit that measures the load on the fork and the vehicle speed of the vehicle body, and a control unit that controls the loading and unloading travel operations, and the control unit can be configured as appropriate as long as it performs a second determination process that determines that a loading operation is being performed using the fork when the reverse distance of the vehicle body from the point at which the load changes to a state equal to or greater than a specified second threshold is within a specified second distance, and a second restriction process that restricts the vehicle speed of the vehicle body when it is determined that a loading operation is being performed.

[0125] Although the forklift according to the present invention has been described by taking a counterbalance type forklift as an example in the above embodiment, it may be a reach type forklift or another type of forklift. [Explanation of symbols]

[0126] 1A, 1B, 1C Forklift 2. Audio alert section 10 Vehicle body 11 Front wheel 12 Rear wheel 13 Driver's seat 14 Axel 15 Brake 16 Handle 17 Cargo handling operation section 18 Head Guard 20 Cargo handling equipment 21 Mast 22 Lift bracket 23. Fork 24 Backrest 25 Tilt Cylinder 26 Lift cylinder 30 Sensor section 31 Load Sensor 32 Vehicle speed sensor 33 Rotation angle sensor 40, 40' First control section 50 Second Control Section 60 Inattentive detection unit

Claims

1. A forklift that performs a cargo handling traveling operation in a predetermined working area; an alert unit that issues a warning to an operator of the forklift; An alert system comprising: The forklift is A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork, the speed of the vehicle body, and the turning angle of the steering wheel; A first control unit that controls the cargo handling traveling operation; A second control unit that controls the alert unit, The second control unit is a first determination process for determining that the fork is being removed when a reverse travel distance of the vehicle body from a point in time when the load has changed to a state less than a predetermined first threshold is within a predetermined first distance; performing a first identification process for identifying that a first dangerous behavior has occurred when the rotation angle is equal to or greater than a predetermined first angle during the claw removing motion; The alert unit issues the warning when the second control unit determines that the first dangerous act has occurred. An alert system comprising:

2. The second control unit is a second determination process for determining that the forks are in the process of picking up a load when the reverse distance of the vehicle body from the time when the load changes to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; performing a second identification process for identifying that a second dangerous act has occurred when the rotation angle is equal to or greater than a predetermined second angle during the load-taking operation; The alert unit issues the warning when the second control unit determines that the second dangerous act has occurred.

2. The alert system of claim 1.

3. The first control unit performs a speed limit or a forced stop of the vehicle body as a restrictive action of the loading / unloading traveling operation when the second control unit determines that the first dangerous act or the second dangerous act has occurred.

3. The alert system of claim 2.

4. The second control unit is an input unit to which a measurement signal from the sensor unit is input; a storage unit that stores first dangerous act data linking a determination condition for the first dangerous act, a first dangerous act ID, and the restricted act, and second dangerous act data linking a determination condition for the second dangerous act, a second dangerous act ID, and the restricted act; a processing unit that performs the first determination process, the first identification process, the second determination process, and the second identification process; an output unit that outputs a first signal related to the first dangerous act ID and the second dangerous act ID to the alert unit and outputs a second signal related to the restricted act to the first control unit, The alert unit issues the warning when the first signal is input, The first control unit performs the restricting action when the second signal is input.

4. The alert system of claim 3.

5. the alert unit is a voice alert unit that issues the warning by voice, The audio alert unit is a voice data storage unit that stores first voice data in which the first dangerous action ID is associated with first warning voice data and second voice data in which the second dangerous action ID is associated with second warning voice data; a voice data processing unit that reproduces the first warning voice data when the first signal related to the first dangerous action ID is input, and reproduces the second warning voice data when the first signal related to the second dangerous action ID is input; a speaker that outputs the sound being reproduced by the sound data processing unit; 5. The alert system of claim 4.

6. The vehicle further includes an inattentive detection unit that detects inattentive behavior of the operator, The inattentive detection unit is a camera unit that captures an image of the operator and generates a captured image; an image processing unit that detects the inattentive behavior from the captured image and outputs a detection signal to the second control unit, The second control unit performs a third identification process to identify that a third dangerous act has occurred when the detection signal is input during the claw removal operation or the load picking operation, The alert unit issues the warning when the second control unit determines that the third dangerous act has occurred.

3. The alert system of claim 2.

7. The first control unit restricts a speed of the vehicle body or forcibly stops the vehicle when the second control unit determines that the third dangerous act has occurred.

7. The alert system of claim 6.

8. A forklift that performs a cargo handling traveling operation in a predetermined working area; an alert unit that issues a warning to an operator of the forklift; An alert system comprising: The forklift is A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork, the speed of the vehicle body, and the turning angle of the steering wheel; A first control unit that controls the cargo handling traveling operation; A second control unit that controls the alert unit, The second control unit is a second determination process for determining that the forks are in the process of picking up a load when a reverse distance of the vehicle body from a point in time when the load has changed to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; performing a second identification process for identifying that a second dangerous act has occurred when the rotation angle is equal to or greater than a predetermined second angle during the load-taking operation; The alert unit issues the warning when the second control unit determines that the second dangerous act has occurred. An alert system comprising:

9. A forklift that performs a cargo handling traveling operation in a predetermined working area, A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork and the vehicle speed of the vehicle body; A control unit that controls the cargo handling traveling operation, The control unit is a first determination process for determining that the fork is being removed when a reverse travel distance of the vehicle body from a point in time when the load has changed to a state less than a predetermined first threshold is within a predetermined first distance; a first limiting process for limiting a vehicle speed of the vehicle body when it is determined that the nail removal operation is being performed; A forklift truck characterized by:

10. A forklift that performs a cargo handling traveling operation in a predetermined working area, A vehicle body provided with a steering wheel; A fork provided on the front side of the vehicle body; a sensor unit for measuring the load of the fork and the vehicle speed of the vehicle body; A control unit that controls the cargo handling traveling operation, The control unit is a second determination process for determining that the forks are in the process of picking up a load when a reverse distance of the vehicle body from a point in time when the load has changed to a state equal to or greater than a predetermined second threshold is within a predetermined second distance; a second limiting process for limiting the speed of the vehicle body when it is determined that the load-receiving operation is in progress; A forklift truck characterized by:

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