Alert systems and forklifts

Abstract

We provide an alert system that allows operators to easily identify dangerous behavior. [Solution] An alert system comprising a forklift 1A and an alert unit 2, wherein the forklift 1A includes a sensor unit 30 that measures the load of 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, wherein the second control unit 50 performs a first determination process that determines that the forks 23 are in the process of pulling out when the reverse distance of the vehicle body 10 from the point in 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 is greater than or equal to a predetermined first angle during the pulling out operation, and the alert unit 2 issues a warning when the second control unit 50 identifies that a first dangerous act has occurred.

Description

Technical Field

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

Background Art

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

[0003] The DLU can store not only the operation status of the forklift but also the dangerous acts of the forklift in the server. Therefore, the administrator of the forklift operation management system can access the server from the management device to check the operation status and dangerous acts 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 a warning light provided on the instrument panel of the driver's seat or sounds a buzzer to notify the operator that there is a step nearby.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Dangerous behaviors involving forklifts include not only driving on uneven surfaces but also various other actions (for example, turning while unscrewing the forks or turning while unloading). However, as with the forklift described in Patent Document 1, if the warning means consist only of a buzzer and a warning light, the operator may not be able to immediately determine what kind of dangerous behavior has been detected. As a result, with the forklift described in Patent Document 1, situations may arise where dangerous behavior cannot be prevented.

[0007] The present invention has been made in view of the above circumstances, and its objective is to provide an alert system that allows operators to easily identify dangerous behaviors and a forklift that can suppress such dangerous behaviors. [Means for solving the problem]

[0008] To solve the above problems, the alert system according to the present invention is A forklift that performs loading and unloading operations within a designated work area, An alert unit that warns the operator of the forklift, An alert system that includes, The aforementioned forklift is The vehicle body, which is equipped 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, the vehicle speed of the vehicle body, and the turning angle of the steering wheel, A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that controls the alert unit, The second control unit is: A first determination process determines that the fork tines are disengaging when the vehicle body reverses within a predetermined first distance from the point in time when the load changes to a state below a predetermined first threshold, During the claw-pulling operation, if the rotation angle is greater than or equal to a predetermined first angle, a first identification process is performed to identify that a first dangerous act has occurred. The alert unit is characterized by issuing the warning when the second control unit identifies that the first dangerous act has occurred.

[0009] In the aforementioned alert system, The second control unit is: A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, During the loading operation, when the turning angle is greater than or equal to a predetermined second angle, a second identification process is performed to identify that a second dangerous act has occurred. 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 aforementioned alert system, The first control unit can be configured to, when the second control unit identifies that the first dangerous act or the second dangerous act has occurred, to restrict the vehicle speed or force the vehicle to stop as an action to restrict the loading and unloading operation.

[0011] In the aforementioned alert system, The second control unit is: An input unit to which the measurement signal from the sensor unit is input, A storage unit that stores first dangerous act data linking the determination conditions for the first dangerous act, the first dangerous act ID, and the restricted act, and second dangerous act data linking the determination conditions for the second dangerous act, the 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, The system includes an output unit that outputs a first signal relating to the first dangerous act ID and the second dangerous act ID to the alert unit, and a second signal relating to the restricted act to the first control unit, The alert unit makes the warning when the first signal is input. The first control unit can be configured to perform the restricted action when the second signal is input.

[0012] In the alert system, The alert unit is a voice alert unit that gives the warning by voice, The voice alert unit, A voice data storage unit that stores first voice data associating the first dangerous action ID with first warning voice data and second voice data associating the second dangerous action ID with second warning voice data; A voice data processing unit that plays back the first warning voice data when the first signal related to the first dangerous action ID is input and plays back the second warning voice data when the first signal related to the second dangerous action ID is input; It can be configured to include a speaker that outputs the voice being played back by the voice data processing unit.

[0013] The alert system, Further includes a distraction detection unit that detects the operator's distraction, The distraction detection unit, A camera unit that photographs the operator to generate a photographed image; An image processing unit that detects the distraction from the photographed image and outputs a detection signal to the second control unit, and is provided with, The second control unit performs a third specifying process of specifying that a third dangerous action has occurred when the detection signal is being input during the nail pulling operation or the cargo removal operation. The alert unit can be configured to give the warning when the second control unit specifies that the third dangerous action has occurred.

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

[0015] To solve the above problems, the alert system according to the present invention is A forklift that performs loading and unloading operations within a designated work area, An alert unit that warns the operator of the forklift, An alert system that includes, The aforementioned forklift is The vehicle body, which is equipped 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, the vehicle speed of the vehicle body, and the turning angle of the steering wheel, A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that controls the alert unit, The second control unit is: A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, During the loading operation, when the turning angle is greater than or equal to a predetermined second angle, a second identification process is performed to identify that a second dangerous act has occurred. The alert unit is characterized in that it issues the warning when the second control unit identifies that the second dangerous act has occurred.

[0016] To solve the above problems, the forklift according to the present invention is A forklift that performs cargo handling and driving operations within a designated work area, The vehicle body, which is equipped 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, The system includes a control unit that controls the cargo handling and driving operation, The control unit, A first determination process determines that the fork tines are disengaging when the vehicle body reverses within a predetermined first distance from the point in time when the load changes to a state below a predetermined first threshold, The system is characterized by performing a first restriction process that limits the vehicle speed of the vehicle body when it is determined that the claw disengagement operation is in progress.

[0017] To solve the above problems, the forklift according to the present invention is A forklift that performs cargo handling and driving operations within a designated work area, The vehicle body, which is equipped 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, The system includes a control unit that controls the cargo handling and driving operation, The control unit, A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, The system can be configured to perform a second restriction process that limits the vehicle speed of the vehicle body when it is determined that the aforementioned loading operation is in progress. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide an alert system that allows operators to easily identify dangerous behaviors and a forklift that can suppress such dangerous behaviors. [Brief explanation of the drawing]

[0019] [Figure 1] This is a diagram showing a forklift according to the first embodiment. [Figure 2] This is a block diagram of the first control unit of the forklift according to the first embodiment. [Figure 3] This is a block diagram of the second control unit and the voice alert unit of the forklift according to the first embodiment. [Figure 4] This is a diagram to explain the loading / unloading process. [Figure 5] This diagram shows the relationship between the forklift, server, and management device in the first embodiment. [Figure 6] This figure shows a forklift according to the second embodiment. [Figure 7] This is a block diagram of the second control unit, distraction detection unit, and voice alert unit of the forklift according to the second embodiment. [Figure 8] This figure shows a forklift according to the third embodiment. [Figure 9] This is a block diagram of the first control unit of the forklift according to the third embodiment. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the alert system and forklift according to the present invention will be described with reference to the attached drawings.

[0021] Figure 1 shows an alert system and a forklift 1A according to the first embodiment of the present invention. The alert system according to the first embodiment consists of at least one forklift 1A and an audio alert unit 2 provided on the forklift 1A.

[0022] Forklift 1A performs loading and unloading operations within a designated work area. These operations include loading and unloading and driving, with the driving operations including turning. The work area is, for example, an area within any building such as a factory or warehouse. The work area is provided with at least one shelf R, on which goods W (including pallets) are stored (see Figure 4).

[0023] Forklift 1A is a counterbalanced type battery forklift and comprises a vehicle body 10, a cargo handling device 20, a sensor unit 30, a first control unit 40, a second control unit 50, an audio alert unit 2, and a battery (not shown).

[0024] The lower part of the vehicle body 10 is provided with a pair of front wheels 11 and rear wheels 12. In the forklift 1A, the front wheels 11 are drive wheels driven by a travel motor, and the rear wheels 12 are steering wheels that are steered (turned) by a steering motor.

[0025] An operator's seat 13 is provided at the top of the vehicle body 10. An accelerator 14 and a brake 15 are provided at the front lower part of the driver's seat 13, and a steering wheel 16 and a cargo handling control unit 17 are provided on the dashboard in front of the driver's seat 13.

[0026] The accelerator 14 is an accelerator pedal configured to be operated by the operator in the driver's seat 13 by pressing it with their foot. When the accelerator 14 is in the ON state (pedal pressed), it accelerates the vehicle body 10 according to the amount the pedal is pressed (accelerator opening), while when it switches from the ON state to the OFF state (pedal not pressed), it generates a weak regenerative brake to decelerate the vehicle body 10.

[0027] The brake 15 is a brake pedal configured to be operated by the operator in the driver's seat 13 by pressing it with their foot. When the brake 15 is in the ON state (pedal pressed), it generates stronger regenerative braking than the regenerative braking of the accelerator 14 to decelerate the vehicle body 10, while when it is in the OFF state, it does not generate regenerative braking.

[0028] The steering wheel 16 is connected to the rear wheels 12 via a steering control mechanism 42, which will be described later. By rotating the steering wheel 16, the operator can change the direction (turning angle) of the rear wheels 12 according to the direction of rotation. When the steering wheel 16 is not being rotated (straight-line driving), 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 tilt lever are connected to the cargo handling device 20 via a cargo handling control mechanism 43, which will be described later. The operator can operate the cargo handling device 20 by operating the lift lever and 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 front pillars on the left and right, a pair of rear pillars on the left and right, and the roof.

[0031] The cargo handling device 20 comprises 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 located on the front side of the vehicle body 10 and raises and lowers the forks 23. The mast 21 comprises an outer mast and an inner mast. The outer mast includes a pair of left and right guide rails extending in the vertical direction and a cross beam connecting the upper ends of the guide rails. The inner mast is located inside the guide rails of the outer mast and moves up and down 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 the lift chain and moves up and down along the inner mast while suspended by the lift chain. The other end of the lift chain is attached to the bottom of the outer mast via a chain wheel provided on the top of the lift cylinder 26.

[0034] The forks 23 are a pair of L-shaped arms, one on each side, and are mounted on the front of the lift bracket 22. The load W is loaded onto the forks 23.

[0035] The backrest 24 is a frame that prevents the load W loaded on the forks 23 from collapsing backward, and is installed on top of the lift bracket 22. When the mast 21 (inner mast) is raised or lowered, the lift bracket 22, forks 23, and backrest 24 also move up and down.

[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 retracts and the mast 21 tilts backward. When the tilt lever is returned to the neutral position (a position where it is neither tilted forward nor 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 retracts and the inner mast descends, and when the lift lever is tilted backward, the lift cylinder 26 extends and the inner mast rises. When the lift lever is returned to the neutral position (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 load W loaded on the fork 23. As the load sensor 31, 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. The vehicle speed sensor 32 measures the vehicle speed of the vehicle body 10. As the vehicle speed sensor 32, for example, a speed sensor that measures the travel speed of the vehicle body 10 from the rotation speed and rotation direction of the travel motor can be used. The turning angle sensor 33 measures the turning angle of the rear wheel 12. As the turning angle sensor 33, for example, an angle sensor that measures the turning angle of the rear wheel 12 from the rotation angle of the handle 16, or an angle sensor that measures the turning angle of the rear wheel 12 from the rotation angle of the pivot axis of the rear wheel 12 can be used.

[0039] Furthermore, the sensor unit 30 includes an accelerator sensor 34 and a brake sensor 35, as shown in Figure 2. The accelerator sensor 34 detects the accelerator opening degree 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 located inside the vehicle body 10 and controls the cargo handling and driving operations and communicates with the second control unit 50. As shown in Figure 2, the first control unit 40 includes a driving control mechanism 41, a steering control mechanism 42, and a cargo handling control mechanism 43.

[0041] The driving control mechanism 41 acquires measurement signals from the accelerator sensor 34, brake sensor 35, and vehicle speed sensor 32, and controls the front wheels 11, which are the drive 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 driving control mechanism 41 controls the vehicle body 10's speed to approach a predetermined target speed as part of the load handling driving operation. Specifically, the driving controller of the driving control mechanism 41 acquires the vehicle body 10's speed 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 driving controller performs PI control or PID control to bring the driving speed closer to the target speed. The target speed is calculated, for example, using the formula: Target speed = Set speed × Accelerator opening [%]. The set speed is a speed preset in the driving controller.

[0043] The steering control mechanism 42 acquires detection information (detection signals) regarding the rotation direction and amount of rotation of the steering wheel 16, and controls the rear wheels 12, which are the steering 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 acquires 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 conventional battery forklifts.

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

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

[0047] The memory unit 52 stores multiple hazardous activity data, which associates a unique hazardous activity ID (hereinafter referred to as ID), a predefined hazardous activity, a hazardous activity determination condition, and an activity that restricts cargo handling and driving operations. In this embodiment, the ID is a number, but the ID may also be a letter or a symbol, or a combination of letters, symbols, and numbers.

[0048] Operators and system administrators can modify the contents of the hazardous behavior data stored in the memory unit 52, and can also add new hazardous behavior data. For example, multiple hazardous behavior data can include the two hazardous behavior data shown in Table 1 below.

[0049] [Table 1]

[0050] The dangerous behavior data for ID "001" associates ID "001" with the dangerous behavior "Swimming during fork release operation," the judgment condition "Swimming occurs during fork release operation," and the restrictive behavior "Vehicle speed limit." The dangerous behavior "Swimming during fork release operation" defines a dangerous behavior (corresponding to the "first dangerous behavior" of this invention) in which forklift 1A performs a swinging operation while fork release operation is in progress. The judgment condition is that the detection of a swinging operation during fork release operation detection is the condition for determining the dangerous behavior. The restrictive behavior "Vehicle speed limit" defines that if the judgment condition is met, the first control unit 40 will impose a vehicle speed limit (for example, an upper speed limit of 4 [km / h]). In other words, forklift 1A is prohibited from traveling at a speed exceeding the upper speed limit.

[0051] The hazardous act data for ID "002" associates ID "002" with the hazardous act "Swinging during load handling," the judgment condition "Swinging during load handling," and the restrictive act "Vehicle speed limit." The hazardous act "Swinging during load handling" defines the hazardous act (corresponding to the "second hazardous act" of the present invention) in which forklift 1A performs a turning operation while handling load. The judgment condition is that the detection of a turning operation during the detection of load handling is used as the judgment condition for the hazardous act. The restrictive act "Vehicle speed limit" defines that if the judgment condition is met, the first control unit 40 will impose a vehicle speed limit (for example, an upper limit speed of 4 [km / h]).

[0052] Furthermore, the restriction action "Vehicle Speed ​​Limit" for ID "001" and / or ID "002" may be changed to the restriction action "Forced Stop". The restriction action "Forced Stop" defines that, if the above determination conditions are met, the first control unit 40 will decelerate the vehicle body 10 and eventually bring it to a stop. For example, the first control unit 40 calculates the target speed of the vehicle body 10 using the formula: Target speed = Set speed × Accelerator opening [%]. The accelerator opening is 0 [%] when the accelerator 14 is off, and when the accelerator 14 is on, it increases in proportion to the amount the accelerator 14 is pressed, up to a maximum of 100 [%]. When the first control unit 40 performs the above restriction action, it gradually changes the set speed to a value with a small absolute value until it is finally zero.

[0053] Furthermore, the memory unit 52 may store dangerous behavior data that links an ID with a dangerous behavior and a judgment condition (but does not link with actions that restrict cargo handling operations). Examples of such dangerous behaviors include not wearing a seat belt, low battery level, and forgetting to apply the parking brake.

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

[0055] The first determination process is a process for determining whether the fork release operation is in progress. The processing unit 53, which has started the first determination process, determines whether the load has changed from a state of being above a predetermined first threshold to a state of being below 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 state with a load and a state without a load. For example, when the load W held by the fork 23 is placed on the shelf R, the fork 23 changes from a state with a load to a state without a load, so the measurement signal (measured value) of the load sensor 31 changes from a state of being above the first threshold to a state of being below the first threshold.

[0056] When the load changes to a state below the first threshold, the processing unit 53 calculates the reverse distance of the vehicle body 10 from the point in time when the load changed to a state below the first threshold, based on the measurement signal from the vehicle speed sensor 32 acquired by the input unit 51. At the same time, the processing unit 53 determines whether the load is below the first threshold and whether the reverse distance is within a preset first distance. Here, the first distance is set to a value greater than the longitudinal dimension of the fork 23, for example. In other words, the first distance is set to a value that allows determination of whether the fork 23 has completely disengaged from the pallet of the cargo W. Note that the first distance may be set to be less than or equal to the longitudinal dimension of the fork 23.

[0057] As described above, during the first determination process, the processing unit 53 determines that the forklift 1A is in the process of removing its forks if the load is below the first threshold and the reverse distance is within the first distance.

[0058] The first identification process is a process for identifying the dangerous act "turning during tine-retraction operation." The first identification process may be performed when the first determination process determines that tine-retraction operation is in progress. The first identification process may be included as part of the first determination process.

[0059] The processing unit 53, which has initiated the first identification process, determines whether or not the rear wheel 12 rotated during the claw release operation based on the measurement signal from the rotation angle sensor 33 acquired by the input unit 51. For example, the processing unit 53 determines that the rear wheel 12 rotated if the rotation angle of the rear wheel 12 is greater than or equal to 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 act "turning during claw release operation," i.e., the dangerous act data with ID "001," when the load is less than the first threshold and the reverse distance is within the first distance, and the turning angle is greater than or equal to the first angle.

[0061] The second determination process is a process for determining whether a load retrieval operation is in progress. The processing unit 53, which has started the second determination process, determines whether the load has changed from a state below a predetermined second threshold to a state above the second threshold, based on the measurement signal from the load sensor 31 acquired by the input unit 51. The second threshold is set to a value that can distinguish between a state with a load and a state without a load. For example, when a load W placed on shelf R is lifted by the fork 23, the fork 23 changes from a state without a load to a state with a load, so the measurement signal (measured value) from the load sensor 31 changes from a state below the second threshold to a state above the second threshold. Note that the second threshold may be set to the same value as the first threshold.

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

[0063] As described above, during the second determination process, the processing unit 53 determines that the forklift 1A is in the process of unloading if the load is equal to or greater than the second threshold and the reverse distance is within the second distance.

[0064] The second identification process is a process for identifying the dangerous act "turning during a loading operation." The second identification process may be performed when the second determination process determines that a loading operation is in progress. The second identification process may be included as 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 rotated during the loading operation, based on the measurement signal from the rotation angle sensor 33 acquired by the input unit 51. For example, the processing unit 53 determines that the rear wheels 12 have rotated if the rotation angle of the rear wheels 12 is greater than or equal to a predetermined second angle. The second angle can be set to any value greater than 0°.

[0066] As described above, during the second specific processing, the processing unit 53 identifies the dangerous act "turning during load handling," i.e., the dangerous act data with ID "002," when the load is equal to or greater than the second threshold and the reverse 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 relating to the ID of the dangerous behavior data identified by the processing unit 53 to the voice alert unit 2, and a second signal relating to the restricted behavior associated with that 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 voice alert unit 2 is located at the bottom of the roof of the head guard 18 and comprises a voice data storage unit 2A, a voice data processing unit 2B, and a speaker 2C. The voice alert unit 2 provides voice warnings (alerts) to the operator of the forklift 1A.

[0069] The voice of the present invention is a voice that includes linguistic speech capable of conveying information to an operator. The voice of the present invention does not include sound effects alone, such as buzzer sounds, but it may include sound effects if they are placed before or after the linguistic speech.

[0070] The audio data storage unit 2A stores multiple audio data sets, each associated with an ID and containing warning audio data (hereinafter referred to as warning audio data). These multiple audio data sets include, for example, the two audio data sets shown in Table 2 below.

[0071] [Table 2]

[0072] The audio data for ID "001" is ID "001" with the warning audio data "Do not turn. Forks are being withdrawn." The warning audio data for ID "001" includes the words (information) "turning" and "fork withdrawal," which are elements of the dangerous act that an operator would associate with "turning motion" and "fork withdrawal motion."

[0073] The audio data for ID "002" is ID "002" with the warning audio data "Do not turn. We are unloading cargo." The warning audio data for ID "002" includes the words (information) "turning" and "unloading cargo," which are elements of dangerous conduct that an operator would associate with "turning" and "unloading cargo."

[0074] Operators and system administrators can modify the warning audio data stored in the audio data storage unit 2A and add new audio data. For example, a memory card capable of rewriting warning audio data can be used as the audio data storage unit 2A. Examples of memory cards include SD cards and USB memory sticks. Operators and administrators can, for example, generate warning audio data in a file format such as WAV and store it in the audio data storage unit 2A.

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

[0076] Speaker 2C is connected to the audio data processing unit 2B and outputs the audio of the warning audio data being played by the audio data processing unit 2B. For example, if the audio data processing unit 2B is playing the warning audio data with ID "001" "Do not turn. Forks are being withdrawn.", Speaker 2C will output the audio "Do not turn. Forks are being withdrawn."

[0077] As described above, in the alert system and forklift 1A according to this embodiment, the voice alert unit 2 provides voice warnings (alerts) to the operator. Therefore, the operator can easily determine which dangerous behavior has been detected. For example, the operator can immediately determine that dangerous behaviors with ID "001" or ID "002" have been detected by listening to the information contained in the voice alert unit 2, and take appropriate action.

[0078] Furthermore, in the alert system and forklift 1A according to this embodiment, since the restricted actions for cargo handling are linked to the defined dangerous actions, even if the operator's response is delayed, the first control unit 40 will restrict the cargo handling operation based on the restricted actions. For this reason, the alert system and forklift 1A according to this embodiment can suppress the defined dangerous actions.

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

[0080] Server 3 is connected to forklift 1A in a communication-enabled manner. Server 3 may be a physical server or a virtual server such as a cloud server. While the forklift 1A is playing back warning audio data from the audio alert unit 2, it can upload (save) video data captured and generated by the drive recorder included in the sensor unit 30 to server 3.

[0081] The management device 4 is connected to the server 3 in a communication-enabled manner. The management device 4 may be, for example, a personal computer (PC) or a smartphone. The management device 4 can acquire the video data from the server 3. This allows the administrator of the alert system to check the video data on the management device 4 when the warning audio data is played back.

[0082] [Second Embodiment] Figure 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 consists of at least one forklift 1B and an audio alert unit 2 provided on the forklift 1B.

[0083] Forklift 1B has the same configuration as forklift 1A of the first embodiment, except that it is equipped with a distraction detection unit 60 and performs control related to the distraction detection unit 60.

[0084] The distraction detection unit 60 is for detecting when the operator in the driver's seat 13 is distracted, and is located, for example, at the bottom of the roof of the head guard 18. As shown in Figure 7, the distraction detection unit 60 comprises a camera unit 61 and an image processing unit 62.

[0085] The camera unit 61 photographs the operator and generates an image. The image processing unit 62 performs known and arbitrary image processing on the image generated by the camera unit 61 to detect the operator's distraction. The image processing unit 62 can detect the operator's distraction from the direction of the operator's face and gaze.

[0086] The image processing unit 62 may, for example, detect operator distraction if the operator's face is not facing the front of the vehicle body 10, or if the operator's gaze is not directed towards the front of the vehicle body 10. To broaden the detection range for distraction, the vertical direction may also be considered, and the image processing unit 62 may detect operator distraction if the operator's face is not facing the cargo W, or if the operator's gaze is not directed towards the cargo W.

[0087] The input unit 51 receives a detection signal related to the detection of the operator's distraction from the image processing unit 62, which has detected the operator's distraction.

[0088] In addition to the dangerous behavior data for ID "001" and the dangerous behavior data for ID "002", the memory unit 52 pre-stores the dangerous behavior data for ID "003" and the dangerous behavior data for ID "004" shown in Table 3 below.

[0089] [Table 3]

[0090] The hazardous behavior data for ID "003" associates ID "003" with the hazardous behavior "Distraction during fork removal operation," the judgment condition "Distraction during fork removal operation," and the restrictive behavior "Vehicle speed limit." The hazardous behavior "Distraction during fork removal operation" defines the hazardous behavior (corresponding to the "third hazardous behavior" of the present invention) in which the operator is distracted while the fork removal operation of forklift 1A is in progress. The judgment condition is that the detection of distraction during the detection of fork removal operation is used as the judgment condition for the hazardous behavior. The restrictive behavior "Vehicle speed limit" defines that if the judgment condition is met, the first control unit 40 will impose a vehicle speed limit (for example, an upper limit speed of 4 [km / h]).

[0091] The hazardous behavior data for ID "004" associates ID "004" with the hazardous behavior "Distraction during loading operation," the judgment condition "Distraction during loading operation," and the restrictive behavior "Vehicle speed limit." The hazardous behavior "Distraction during loading operation" defines the hazardous behavior (corresponding to the "third hazardous behavior" of the present invention) in which the operator is distracted while loading forklift 1A. The judgment condition is that the detection of distraction during the detection of loading operation is used as the judgment condition for the hazardous behavior. The restrictive behavior "Vehicle speed limit" defines that if the judgment condition is met, the first control unit 40 will impose a vehicle speed limit (for example, an upper speed limit of 4 [km / h]).

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

[0093] The processing unit 53 performs a third identification process as a control related to the distraction detection unit 60 to determine whether the conditions for determining a dangerous act related to distraction are met, and identifies dangerous acts (dangerous act data) that meet the conditions.

[0094] The third identification process includes a process for identifying the dangerous act "distraction during fore-removal operation" and a process for identifying the dangerous act "distraction during load-taking operation." The third identification process may be performed when the first determination process determines that fore-removal operation is in progress, or when the second determination process determines that load-taking operation is in progress. The third identification process may be included in part of the first and second determination processes.

[0095] When the processing unit 53, which has initiated the third identification process, determines in the first determination process that a claw-removal operation is in progress, and the input unit 51 has received a detection signal from the image processing unit 62, it identifies the dangerous act data for the dangerous act "distraction during claw-removal operation," i.e., ID "003." On the other hand, when the processing unit 53 determines in the second determination process that a cargo-unloading operation is in progress, and the input unit 51 has received a detection signal from the image processing unit 62, it identifies the dangerous act data for the dangerous act "distraction during cargo-unloading operation," i.e., ID "004."

[0096] The output unit 54 transmits a first signal relating to the ID of the dangerous behavior data identified by the processing unit 53 to the voice alert unit 2, and a second signal relating to the restricted behavior associated with that 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 audio data storage unit 2A further includes the audio data with ID "003" and the audio data with ID "004" as shown in Table 4 below.

[0098] [Table 4]

[0099] The audio data for ID "003" is linked to the warning audio data "Do not look away." The warning audio data for ID "003" contains words (information) that the operator will associate with "looking away," which is a constituent element of dangerous conduct. The audio data for ID "004" is similar.

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

[0101] Furthermore, in the alert system and forklift 1B according to this embodiment, since the restricted actions for cargo handling are linked to the defined dangerous actions, even if the operator's response is delayed, the first control unit 40 will restrict the cargo handling operation based on the restricted actions. For this reason, the alert system and forklift 1B according to this embodiment can suppress the defined dangerous actions.

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

[0103] For example, the audio data storage unit 2A may associate the ID with the number of plays or the playback time. If the number of plays is associated, the warning audio data can be played a specified number of times, and if the playback time is associated, the warning audio data can be played repeatedly for a specified playback time.

[0104] On the other hand, playing the warning audio data multiple times may cause discomfort to the operator. In this case, the danger level may be associated with the ID in the storage unit 52 or the audio data storage unit 2A. The audio data processing unit 2B preferably plays the warning audio data multiple times when the danger level exceeds a predetermined threshold level, and the number of plays increases as the danger level increases. For example, the danger levels may be classified as danger level 1, danger level 2, and danger level 3, and the danger level and the number of plays may be associated with the ID in the audio data storage unit 2A, with danger level 1 being played once, danger level 2 being played twice, and danger level 3 being played three times.

[0105] Furthermore, if the output timing of the second signal is associated with the dangerous act ID in the memory unit 52, the output timing can be set to "after a predetermined time has elapsed since the timing of outputting the first signal." Here, the predetermined time can be set appropriately according to the danger level.

[0106] As described above, when the danger levels are classified as danger level 1, danger level 2, and danger level 3, the predetermined time can be set as follows: danger level 1 is set as the first predetermined time, danger level 2 is set as the second predetermined time which is shorter than the first predetermined time, and danger level 3 is set as the third predetermined time which is shorter than the second predetermined time. The third predetermined time may be zero. For example, dangerous acts with ID "001" and ID "002" may be set as danger level 3, and dangerous acts with ID "003" and ID "004" may be set as danger level 1. When the processing unit 53 identifies a dangerous act with ID "003" or ID "004", the voice alert unit 2 issues a voice warning (alert) to the operator, and if the dangerous act with ID "003" or ID "004" is detected even after the first predetermined time has elapsed, the first control unit 40 may execute a restrictive action based on the second signal.

[0107] As described above, by changing the output timing of the second signal according to the danger level of the dangerous activity, it is possible to minimize the decrease in the work efficiency of forklift 1B while suppressing dangerous activities and ensuring safety.

[0108] [Third Embodiment] Figure 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 and / or second embodiment.

[0109] Forklift 1C has the same configuration as 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 a swivel angle sensor 33, and it does not have a second control unit 50 and an audio alert unit 2.

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

[0111] In addition to controlling the driving control mechanism 41 of the first embodiment, the driving control mechanism 41' performs control based on the measurement signal (measured value) of the load sensor 31. This control includes a first determination process, a first limiting process, a second determination process, and a second limiting process.

[0112] The first determination process is the same as the first determination process performed by the processing unit 53 in the first embodiment. That is, the travel control mechanism 41' determines that the forklift 1C is in the process of pulling out its forks when the load is less than a first threshold and the reverse distance is within a first distance.

[0113] The first restriction process concerns the speed restriction of the forklift 1C. If the travel control mechanism 41' determines that the forklift 1C is in the process of removing its forks, it restricts the speed of the forklift 1C (for example, an upper speed limit of 4 km / h). This prevents the forklift 1C from traveling at a speed exceeding the upper speed limit while it is removing its forks.

[0114] The second determination process is the same as the second determination process performed by the processing unit 53 in the first embodiment. That is, the travel control mechanism 41' determines that the forklift 1C is in the process of unloading if the load is equal to or greater than the second threshold and the reverse distance is within the second distance.

[0115] The second restriction process concerns the speed limit of the forklift 1C. If the travel control mechanism 41' determines that the forklift 1C is in the process of unloading, it sets a speed limit for the forklift 1C (for example, an upper speed limit of 4 km / h). This prevents the forklift 1C from traveling at a speed exceeding the upper speed limit while unloading.

[0116] According to the forklift 1C of this embodiment, the vehicle speed of the vehicle body 10 is limited before the actual turning operation is performed, thereby improving the operator's safety awareness and suppressing dangerous actions such as "turning during fore-unloading operation" or "turning during load-taking operation." In addition, similar to forklift 1C, the vehicle speed can also be limited before the turning operation is performed in forklift 1A. In this case, the first control unit 40 performs the limiting action (vehicle speed limiting) before the second control unit 50 identifies the above-mentioned dangerous action.

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

[0118] The alert system according to the present invention includes a forklift that performs cargo handling driving operations in a predetermined work area, and an alert unit that warns the operator of the forklift. The forklift comprises a vehicle body equipped with steering wheels, forks provided on the front of the vehicle body, a sensor unit that measures the load on the forks, the vehicle speed of the vehicle body, and the turning angle of the steering wheels, a first control unit that controls the cargo handling driving operations, and a second control unit that controls the alert unit. The second control unit performs a first determination process that determines that the forks are being disengaged when the vehicle body has moved backward for a predetermined distance from the point in time when the load has changed to a state below a predetermined first threshold, and a first identification process that identifies a first dangerous act as having occurred when the turning angle is greater than or equal to a predetermined first angle during the fork disengagement operation. The alert unit can be configured as appropriate, as long as it issues a warning when the second control unit identifies that a first dangerous act has occurred.

[0119] Furthermore, the alert system according to the present invention is an alert system that includes a forklift that performs cargo handling driving operations in a predetermined work area, and an alert unit that warns the operator of the forklift, wherein the forklift comprises a vehicle body provided with steering wheels, forks provided on the front side of the vehicle body, a sensor unit that measures the load on the forks, the vehicle speed of the vehicle body, and the turning angle of the steering wheels, a first control unit that controls the cargo handling driving operations, and a second control unit that controls the alert unit, wherein the second control unit performs a second determination process that determines that cargo handling operations are in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold is within a predetermined second distance, and a second identification process that identifies a second dangerous act as occurring when the turning angle is greater than or equal to a predetermined second angle during cargo handling operations, and the alert unit can be configured as appropriate to issue a warning when the second control unit identifies that a second dangerous act has occurred.

[0120] The alert unit is preferably an audio alert unit that issues warnings by voice, but warnings may also be issued by means other than voice. The alert unit may warn the operator by, for example, illuminating a warning light or emitting a sound effect that does not include voice (e.g., a buzzer or electronic sound). By varying the color or state of the light, the type of sound effect, etc., according to the dangerous behavior, the operator can determine the dangerous behavior.

[0121] In the above embodiment, the forklifts 1A and 1B were equipped with the voice alert unit 2, but the voice alert unit of the present invention can be installed 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 was equipped with a distraction detection unit 60, but the distraction detection unit of the present invention can be installed in a location other than the forklift 1B (for example, on a shelf R in the work area).

[0123] The forklift according to the present invention is a forklift that performs cargo handling driving operations in a predetermined work area, and comprises a vehicle body provided with steering wheels, forks provided on the front side of the vehicle body, a sensor unit that measures the load on the forks and the vehicle speed of the vehicle body, and a control unit that controls the cargo handling driving operations, wherein the control unit performs a first determination process that determines that the forks are being disengaged when the reverse distance of the vehicle body from the point in time when the load changes to a state below a predetermined first threshold is within a predetermined first distance, and a first restriction process that limits the vehicle speed of the vehicle body when it is determined that the forks are being disengaged. The configuration can be changed as appropriate.

[0124] Furthermore, the forklift according to the present invention is a forklift that performs cargo handling driving operations in a predetermined work area, and comprises a vehicle body provided with steering wheels, forks provided on the front side of the vehicle body, a sensor unit that measures the load on the forks and the vehicle speed of the vehicle body, and a control unit that controls the cargo handling driving operations, and the configuration of the control unit can be changed as appropriate, provided that it performs a second determination process that determines that a cargo picking operation is in progress with the forks when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, and a second restriction process that limits the vehicle speed of the vehicle body when it is determined that a cargo picking operation is in progress.

[0125] In the above embodiment, the forklift according to the present invention was described using a counterbalanced type forklift as an example, but it may also be a reach type forklift or another type of forklift. [Explanation of symbols]

[0126] 1A, 1B, 1C Forklifts 2. Voice alert section 10 Vehicle Body 11 Front Wheel 12 Rear wheels 13. Driver's seat 14 Accelerator 15 Brake 16 handle 17. Cargo Handling Operations Section 18 Headguard 20 Cargo handling equipment 21 Mast 22 Lift Bracket 23 Forks 24 Backrest 25 Tilt Cylinder 26 Lift Cylinder 30 Sensor section 31. Load Sensor 32. Vehicle speed sensor 33 Swivel Angle Sensor 40, 40' First control unit 50 Second Control Unit 60 Distraction detection unit

Claims

1. A forklift that performs loading and unloading operations within a designated work area, An alert unit that warns the operator of the forklift, An alert system that includes, The aforementioned forklift is The vehicle body, which is equipped 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, the vehicle speed of the vehicle body, and the turning angle of the steering wheel, A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that controls the alert unit, The second control unit is, A first determination process determines that the fork tine disengagement operation is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state below a predetermined first threshold is within a predetermined first distance, During the claw-pulling operation, if the rotation angle is greater than or equal to a predetermined first angle, a first identification process is performed to identify that a first dangerous act has occurred. The alert unit issues the warning when the second control unit identifies that the first dangerous act has occurred. An alert system characterized by the following features.

2. The second control unit is, A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, During the aforementioned loading operation, if the turning angle is greater than or equal to a predetermined second angle, a second identification process is performed to identify that a second dangerous act has occurred. The alert unit issues the warning when the second control unit identifies that the second dangerous act has occurred. The alert system according to feature 1.

3. When the first control unit determines that the first or second dangerous act has occurred, it will perform actions to restrict the loading and unloading operation, such as limiting the vehicle speed or forcing the vehicle to stop. The alert system according to feature 2.

4. The second control unit is, An input unit to which the measurement signal from the sensor unit is input, A storage unit that stores first dangerous act data linking the determination conditions for the first dangerous act, the first dangerous act ID, and the restricted act, and second dangerous act data linking the determination conditions for the second dangerous act, the 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, The system includes an output unit that outputs a first signal relating to the first dangerous act ID and the second dangerous act ID to the alert unit, and a second signal relating to the restricted act to the first control unit, The alert unit makes the warning when the first signal is input. The first control unit performs the restriction action when the second signal is input. The alert system according to feature 3.

5. The alert unit is an audio alert unit that provides the aforementioned warning by voice, The aforementioned voice alert unit is An audio data storage unit that stores first audio data linking the first dangerous act ID and first warning audio data, and second audio data linking the second dangerous act ID and second warning audio data, An audio data processing unit that plays the first warning audio data when the first signal relating to the first dangerous act ID is input, and plays the second warning audio data when the first signal relating to the second dangerous act ID is input, The audio data processing unit includes a speaker that outputs the audio being played back by the audio data processing unit. The alert system described in feature 4.

6. The system further includes a distraction detection unit that detects when the operator is distracted, The aforementioned distraction detection unit is A camera unit that photographs the operator and generates an image, The system includes an image processing unit that detects the distracted gaze 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-pulling operation or the load-removing operation. The alert unit issues the warning when the second control unit identifies that the third dangerous act has occurred. The alert system according to feature 2.

7. The first control unit, when the second control unit identifies that the third dangerous act has occurred, will limit the vehicle speed or force the vehicle to stop. The alert system described in feature 6.

8. A forklift that performs loading and unloading operations within a designated work area, An alert unit that warns the operator of the forklift, An alert system that includes, The aforementioned forklift is The vehicle body, which is equipped 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, the vehicle speed of the vehicle body, and the turning angle of the steering wheel, A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that controls the alert unit, The second control unit is, A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, During the aforementioned loading operation, if the turning angle is greater than or equal to a predetermined second angle, a second identification process is performed to identify that a second dangerous act has occurred. The alert unit issues the warning when the second control unit identifies that the second dangerous act has occurred. An alert system characterized by the following features.

9. A forklift that performs cargo handling and driving operations within a designated work area, The vehicle body, which is equipped 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, The system includes a control unit that controls the cargo handling and driving operation, The control unit, A first determination process determines that the fork tine disengagement operation is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state below a predetermined first threshold is within a predetermined first distance, If it is determined that the aforementioned claw-removal operation is in progress, a first restriction process is performed to limit the vehicle speed of the vehicle body. A forklift characterized by the following features.

10. A forklift that performs cargo handling and driving operations within a designated work area, The vehicle body, which is equipped 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, The system includes a control unit that controls the cargo handling and driving operation, The control unit, A second determination process determines that the load unloading operation by the forks is in progress when the reverse distance of the vehicle body from the point in time when the load changes to a state of a predetermined second threshold or higher is within a predetermined second distance, If it is determined that the aforementioned loading operation is in progress, a second restriction process is performed to limit the vehicle speed of the vehicle body. A forklift characterized by the following features.

Images