Alert system

Abstract

We provide an alert system that allows operators to easily identify dangerous behavior. [Solution] An alert system 100A includes an industrial vehicle 1 that performs cargo handling driving operations in a predetermined work area, a wireless transmitter 2 held by a worker in the work area and transmitting a wireless signal to the industrial vehicle 1, and an audio alert unit 3 that provides an audio warning to the operator of the industrial vehicle 1, wherein the industrial vehicle 1 comprises a first control unit that controls cargo handling driving operations and a second control unit that receives a wireless signal and measures the radio wave strength of the wireless signal, and the audio alert unit 3 provides a warning by playing back pre-stored warning audio data when the radio wave strength measured by the second control unit is above a predetermined threshold.

Description

Technical Field

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

Background Art

[0002] Conventionally, a forklift operation management system for managing the operation status of forklifts has been 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 save 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, collisions with overhead obstacles or collisions with people). However, as with the forklift described in Patent Document 1, if the warning means are only a buzzer and a warning light, the operator may not be able to immediately determine what kind of dangerous behavior has been detected.

[0007] This 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 behavior. [Means for solving the problem]

[0008] To solve the above problems, the alert system according to the present invention is Industrial vehicles that perform loading and unloading operations within a designated work area, A wireless transmitter held by a worker in the aforementioned work area and transmitting wireless signals to the industrial vehicle, A voice alert unit that provides voice warnings to the operator of the industrial vehicle, An alert system that includes, The aforementioned industrial vehicle is A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that receives the aforementioned wireless signal and measures the radio wave intensity of the aforementioned wireless signal, The aforementioned voice alert unit is The second control unit is characterized in that, if the radio wave intensity measured by the second control unit is above a predetermined threshold, it plays back pre-stored warning audio data to issue the warning.

[0009] In the aforementioned alert system, The first control unit can be configured to reduce the upper limit speed of the industrial vehicle's vehicle speed as the radio wave intensity increases.

[0010] In the aforementioned alert system, The aforementioned voice alert unit is If the radio wave intensity is greater than or equal to a first threshold and less than or equal to a second threshold greater than the first threshold, the first warning audio data containing the first information is played back. If the industrial vehicle is stopped and the second determination condition is met, such that the radio wave intensity exceeds the second threshold, the second warning audio data including the second information is played. The system can be configured to play a third warning audio data containing the third information when the industrial vehicle is in motion and the third determination condition is met, such that the radio wave intensity exceeds the second threshold.

[0011] In the aforementioned alert system, The wireless signal can be configured to include information regarding the first threshold and the second threshold.

[0012] In the aforementioned alert system, The second control unit is, The input unit into which the aforementioned wireless signal is input, A storage unit that stores dangerous behavior data linking the aforementioned wireless signal, the warning determination conditions, and a unique dangerous behavior ID, A processing unit that measures the radio wave intensity and determines the determination conditions, It comprises an output unit that outputs a first signal relating to the previous dangerous act ID, The aforementioned voice alert unit is An audio data storage unit that stores audio data linking the aforementioned dangerous behavior ID and the aforementioned warning audio data, A voice data processing unit that receives the first signal and plays the warning voice data in response to the first signal, The system can be configured to include a speaker that outputs the audio of the warning audio data being played.

[0013] In the aforementioned alert system, The aforementioned dangerous behavior data is further linked to the aforementioned restrictive actions in cargo handling and driving operations. The output unit outputs a second signal relating to the restrictive action to the first control unit. The first control unit can be configured to perform the restricted action when the second signal is input.

[0014] In the alert system, the restricted action is the limitation of the vehicle speed of the industrial vehicle, the first control unit can be configured to determine the upper limit speed of the vehicle speed according to the radio wave intensity, and the greater the radio wave intensity, the smaller the upper limit speed.

[0015] The alert system further includes an area sensor provided in the work area, detecting an operator in a predetermined area of the work area, and transmitting a detection signal. The wireless transmitter can be configured to transmit the wireless signal when receiving the detection signal, and not transmit the wireless signal when not receiving the detection signal.

Advantages of the Invention

[0016] According to the present invention, an alert system that enables an operator to easily judge a dangerous action can be provided.

Brief Description of the Drawings

[0017] [Figure 1] It is a diagram showing an alert system according to the first embodiment. [Figure 2] It is a diagram showing the relationship between the radio wave intensity and the distance of a wireless signal according to the first embodiment. [Figure 3] It is a diagram showing a forklift according to the first embodiment. [Figure 4] It is a block diagram of the first control unit of the forklift according to the first embodiment. [Figure 5] It is a block diagram of the second control unit and the voice alert unit of the forklift according to the first embodiment. [Figure 6] It is a diagram showing the relationship among the forklift, the server, and the management device in the first embodiment. [Figure 7]This is a diagram showing the alert system according to the second embodiment. [Modes for carrying out the invention]

[0018] Hereinafter, embodiments of the alert system according to the present invention will be described with reference to the attached drawings.

[0019] [First Embodiment] Figure 1 shows an alert system 100A according to a first embodiment of the present invention. The alert system 100A consists of at least one forklift 1 (corresponding to the "industrial vehicle" of the present invention) that performs cargo handling operations in a predetermined work area, at least one wireless transmitter 2, and at least one voice alert unit 3.

[0020] The work area is an area within any building, such as a factory or warehouse. The work area is equipped with multiple shelves (not shown), on which cargo W, etc., is stored. Workers working in the work area are also holding wireless transmitters 2.

[0021] The wireless transmitter 2 continuously broadcasts a wireless signal to the forklift 1. For example, a beacon can be used as the wireless transmitter 2. The wireless signal from the wireless transmitter 2 is a signal that has the unique ID information of the wireless transmitter 2. The wireless signal in this embodiment is a Bluetooth® signal, and the signal includes threshold information for the radio wave intensity of the wireless signal (the first threshold and the second threshold, described later). Therefore, the forklift 1 that receives the wireless signal can acquire the first threshold and the second threshold as threshold information upon reception. The values ​​of the first threshold and the second threshold can be set to any value in the wireless transmitter 2.

[0022] Figure 2 shows the relationship between the radio signal strength of the wireless transmitter 2 and the distance. The graph in Figure 2 shows theoretical values, with the vertical axis representing the radio signal strength (received signal strength RSSI [dBm] by forklift 1) and the horizontal axis representing the distance [m] between forklift 1 and wireless transmitter 2. As shown in Figure 2, the smaller the distance, the greater the radio signal strength (received signal strength RSSI) and the steeper the slope tends to be. On the other hand, the larger the distance, the less the radio signal strength (received signal strength RSSI) and the steeper the slope tends to be.

[0023] As shown in Figure 3, the forklift 1 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 3, 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 1, 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 an accelerator sensor 31, a brake sensor 32, and a vehicle speed sensor 33, as shown in Figure 4. The accelerator sensor 31 detects the accelerator opening degree of the accelerator 14. The brake sensor 32 detects the state of the brake 15 (on state / off state). The vehicle speed sensor 33 detects the driving speed of the vehicle body 10 (or the rotational speed of the driving motor).

[0039] 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 4, the first control unit 40 includes a driving control mechanism 41, a steering control mechanism 42, and a cargo handling control mechanism 43.

[0040] The driving control mechanism 41 acquires detection information (detection signals) from the accelerator sensor 31, brake sensor 32, and vehicle speed sensor 33, 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, etc.

[0041] The driving control mechanism 41 controls the vehicle body 10's speed to approach a predetermined target speed as part of the load handling operation. Specifically, the driving controller of the driving control mechanism 41 acquires the vehicle body 10's speed based on the detection signal from the vehicle speed sensor 33 and calculates the target speed based on the detection signal from the accelerator sensor 31 and / or the detection signal from the brake sensor 32. The driving controller performs PI control or PID control to bring the driving speed closer to the target speed.

[0042] The target speed is calculated, for example, using the formula: Target Speed ​​= Set Speed ​​× Accelerator Opening [%]. The set speed is the speed pre-set in the driving controller. However, if restrictions are imposed due to the restrictive actions described later, the value of the set speed may be changed according to the radio wave strength of the wireless signal from the wireless transmitter 2.

[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 detection information (detection 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 5, 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 receives the wireless signal from the wireless transmitter 2 and the detection signal from the sensor unit 30. Specifically, the input unit 51 receives the wireless signal from the wireless transmitter 2 held by the worker in the work area, and also receives the detection signal from at least the vehicle speed sensor 33 as the detection signal from the sensor unit 30. The input unit 51 may be included in the processing unit 53.

[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 three hazardous behavior data shown in Table 1 below.

[0049] [Table 1]

[0050] The hazardous act data for ID "001" associates ID "001" with the hazardous act "Collision with a person at a distance," the judgment condition "Radio wave strength is above the first threshold and below the second threshold," and the restrictive act "Vehicle speed limit." The hazardous act "Collision with a person at a distance" defines a hazardous act in which the forklift 1 approaches and collides with a person (in this embodiment, a worker) who is located at a distance greater than a predetermined distance. This distance can be set to any value on the forklift 1. The judgment condition "Radio wave strength is above the first threshold and below the second threshold" sets the judgment condition for the hazardous act as being that the radio wave strength of the wireless signal measured by the processing unit 53 is above the first threshold and below the second threshold, which is greater than the first threshold. The restrictive act "Vehicle speed limit" defines that if the above judgment condition is met, the first control unit 40 will impose a speed limit (for example, an upper limit of 4 [km / h]). In other words, the forklift 1 is prohibited from traveling at a speed exceeding the upper limit. Furthermore, the first control unit 40 may set the upper limit speed to a smaller value as the radio wave intensity of the wireless signal measured by the processing unit 53 increases.

[0051] The dangerous behavior data for ID "002" associates ID "002" with the dangerous behavior "Collision with a person at close range (while stationary)", the judgment condition "While stationary, radio wave strength exceeds the second threshold", and the restricted behavior "Departure prohibited". The dangerous behavior "Collision with a person at close range (while stationary)" defines a dangerous behavior in which a stationary forklift 1 approaches a person within a predetermined distance and collides with them. The judgment condition "While stationary, radio wave strength exceeds the second threshold" sets the judgment condition for this dangerous behavior as the driving speed detected by the vehicle speed sensor 33 being 0 and the radio wave strength of the wireless signal measured by the processing unit 53 exceeding the second threshold. The restricted behavior "Departure prohibited" defines that if the above judgment condition is met, the first control unit 40 will prohibit driving operation. In other words, the forklift 1 will not move even if the accelerator 14 is in the ON position.

[0052] The dangerous behavior data for ID "003" associates ID "003" with the dangerous behavior "Collision with a person at close range (while driving)", the judgment condition "Radio wave strength exceeds the second threshold while driving", and the restricted behavior "Forced stop". The dangerous behavior "Collision with a person at close range (while driving)" defines a dangerous behavior in which a forklift 1 in motion approaches a person within a predetermined distance and collides with it. The judgment condition "Radio wave strength exceeds the second threshold while driving" is defined as the driving speed detected by the vehicle speed sensor 33 taking a value other than 0 (for example, a positive value when moving forward and a negative value when moving backward), and the radio wave strength of the wireless signal measured by the processing unit 53 exceeding the second threshold. The restricted behavior "Forced stop" defines that if the above judgment condition is met, the first control unit 40 will decelerate the vehicle body 10 and eventually bring it to a stop.

[0053] 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 limiting action, it gradually changes the set speed to a small absolute value until it is finally zero. Furthermore, the first control unit 40 may change the set speed to a small absolute value as the radio wave intensity of the wireless signal measured by the processing unit 53 increases.

[0054] 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.

[0055] The processing unit 53 determines whether the judgment conditions for each dangerous act are met and identifies the dangerous acts (dangerous act data) that meet the judgment conditions. Specifically, the processing unit 53 measures the radio wave intensity of the radio signal from the radio transmitter 2 input to the input unit 51 at a predetermined period, and obtains a first threshold and a second threshold from the radio signal, and compares the measured radio wave intensity with the first threshold and the second threshold. Based on the results of the above comparison and the detection signal from the sensor unit 30 input to the input unit 51 (for example, the detection signal from the vehicle speed sensor 33), the processing unit 53 determines whether the judgment conditions for each dangerous act stored in the storage unit 52 are met and identifies the dangerous acts (dangerous act data) that meet the judgment conditions.

[0056] The output unit 54 transmits a first signal relating to the ID of the dangerous activity data identified by the processing unit 53 to the voice alert unit 3. If the ID is associated with an activity that restricts cargo handling operations, the output unit 54 transmits a second signal relating to that restricted activity to the first control unit 40.

[0057] If a restricted action is associated with a dangerous action ID, an output timing for outputting a second signal may also be associated with that dangerous action ID. The output timing may be, for example, "simultaneously with the timing of outputting the first signal" or "after a predetermined time has elapsed since the timing of outputting the first signal." The predetermined time can be set appropriately depending on the dangerous action. If an output timing is associated with a dangerous action ID, the output unit 54 outputs the second signal at the associated output timing.

[0058] The voice alert unit 3 is located at the bottom of the roof of the head guard 18 and comprises a voice data storage unit 3A, a voice data processing unit 3B, and a speaker 3C. The voice alert unit 3 provides voice warnings (alerts) to the operator of the forklift 1.

[0059] 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.

[0060] The audio data storage unit 3A 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 three audio data sets shown in Table 2 below.

[0061] [Table 2]

[0062] The audio data for ID "001" is an audio data for ID "001" that is linked to the warning audio data "There is a person here." The warning audio data for ID "001" contains information (words) that would make the operator think of "a person," which is a constituent element of a dangerous act. This information corresponds to the "first information" of the present invention.

[0063] The audio data for ID "002" is created by associating the warning audio data "There is a person nearby." with ID "002". In addition to the first information described above, the warning audio data for ID "002" includes information (words) indicating distance (short distance), namely "nearby". Distance is information (words) directly related to the danger level of a dangerous act. Therefore, the operator can immediately recognize that there is a person nearby and the danger level is high. This information indicating distance corresponds to the "second information" of the present invention.

[0064] The audio data for ID "003" is created by associating ID "003" with the warning audio data "Apply the brakes. There is a person nearby." The warning audio data for ID "003" includes, in addition to the first and second pieces of information described above, information (words) related to cargo handling driving actions to avoid dangerous behavior, such as "Apply the brakes." This information corresponds to the "third piece of information" of the present invention.

[0065] Operators and system administrators can modify the warning audio data stored in the audio data storage unit 3A 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 3A. 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 3A.

[0066] The audio data processing unit 3B acquires a first signal related to the ID output from the output unit 54 and plays back the warning audio data associated with the ID in the audio data storage unit 3A. For example, if the first signal related to ID "001" is received from the output unit 54, the audio data processing unit 3B plays back the warning audio data "There is a person here." for the audio data of ID "001". The audio data processing unit 3B includes, for example, a voice player module.

[0067] Speaker 3C is connected to the audio data processing unit 3B and outputs the audio of the warning audio data being played by the audio data processing unit 3B. For example, if the audio data processing unit 3B is playing the warning audio data "There is a person here." with ID "001", speaker 3C will output the audio "There is a person here."

[0068] As described above, in the alert system 100A according to this embodiment, the voice alert unit 3 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 "003" has been detected by listening to the information (words) contained in the voice alert unit 3, and take appropriate action.

[0069] Furthermore, in the alert system 100A according to this embodiment, defined dangerous actions are linked to actions that restrict cargo handling operations. Therefore, even if the operator's response is delayed, the first control unit 40 will restrict cargo handling operations based on the aforementioned restrictive actions. For this reason, the alert system 100A according to this embodiment can avoid defined dangerous actions.

[0070] (Frequency of warning voice data activation) 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.

[0071] For example, the audio data storage unit 3A 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.

[0072] 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 3A. The audio data processing unit 3B preferably plays the warning audio data multiple times when the danger level exceeds a predetermined threshold level, and increases the number of plays 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 3A, with danger level 1 being played once, danger level 2 being played twice, and danger level 3 being played three times.

[0073] 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.

[0074] As described above, when classifying the danger levels 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, the dangerous acts with ID "002" and ID "003" may be set as danger level 3, the dangerous act with ID "001" may be set as danger level 2, and the dangerous act "distracted driving" may be set as danger level 1. When the camera included in the sensor unit 30 detects the dangerous act "distracted driving", the voice alert unit 3 issues a voice warning (alert) to the operator, and if "distracted driving" is still detected after the first predetermined time has elapsed, the first control unit 40 may execute the restrictive action "deceleration (or speed limit)" based on the second signal.

[0075] 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 1 while avoiding dangerous activities and ensuring safety.

[0076] (Operational Management System) As shown in Figure 6, the alert system 100A may include a server 4 and a management device 5, and constitute an operational management system for the forklift 1.

[0077] Server 4 is connected to the forklift 1 in a communication-enabled manner. Server 4 may be, for example, a physical server or a virtual server such as a cloud server. The forklift 1 can upload (save) video data generated by the drive recorder (corresponding to the "shooting unit" of this invention) included in the sensor unit 30 to Server 4 while the warning audio data is being played back. Preferably, the uploaded video data includes not only the video (image) during the playback of the warning audio data, but also video (image) for a predetermined period (for example, 10 seconds) before and after playback.

[0078] The management device 5 is connected to the server 4 in a communication-enabled manner. The management device 5 may be, for example, a personal computer (PC) or a smartphone. The management device 5 can acquire the video data from the server 4. This allows the administrator of the alert system 100A to check the video data on the management device 5 when the warning audio data is played back.

[0079] [Second Embodiment] Figure 7 shows an alert system 100B according to a second embodiment of the present invention. The alert system 100B has the same configuration as the first embodiment, except that it includes at least one wireless transmitter 2' instead of at least one wireless transmitter 2, and further includes at least one area sensor 6.

[0080] When the area sensor 6 detects a person (in this embodiment, a worker holding the wireless transmitter 2') in a predetermined area of ​​the work area, it transmits a detection signal to the wireless transmitter 2'. More specifically, while the area sensor 6 is detecting a worker, it continues to transmit a detection signal to the wireless transmitter 2' held by the worker at a predetermined interval. When the worker moves and the area sensor 6 can no longer detect the worker, it stops transmitting the detection signal. For example, a 2D-LiDAR can be used for the area sensor 6.

[0081] The wireless transmitter 2' broadcasts a wireless signal to the forklift 1, similar to that in the first embodiment, while receiving a detection signal from the area sensor 6. The wireless transmitter 2' includes, for example, a signal generation and transmission unit that generates and broadcasts a wireless signal, a power supply unit that receives a detection signal from the area sensor 6 and supplies power to the signal generation and transmission unit, and a switch (transistor or relay) interposed in the power supply line connecting the signal generation and transmission unit and the power supply unit. The power supply unit turns on the switch and supplies power to the signal generation and transmission unit while receiving a detection signal from the area sensor 6. The signal generation and transmission unit continues to broadcast a wireless signal while power is supplied. On the other hand, when no detection signal is received from the area sensor 6, the power supply unit turns off the switch and does not supply power to the signal generation and transmission unit. As a result, the signal generation and transmission unit is in a state where it does not broadcast a wireless signal (standby state). For example, a beacon can be used as the wireless transmitter 2'.

[0082] The alert system 100B according to this embodiment can achieve the same effects as the first embodiment. Furthermore, by linking the area sensor 6 and the wireless transmitter 2' in the alert system 100B according to this embodiment, it is possible to minimize the decrease in the work efficiency of the forklift 1 while avoiding dangerous actions and ensuring safety.

[0083] [Differentiation] Although embodiments of the alert system according to the present invention have been described above, the present invention is not limited to the above embodiments.

[0084] The alert system of the present invention includes an industrial vehicle that performs cargo handling operations in a predetermined work area, a wireless transmitter held by a worker in the work area and transmitting a wireless signal to the industrial vehicle, and an audio alert unit that provides an audio warning to the operator of the industrial vehicle. The industrial vehicle comprises a first control unit that controls cargo handling operations and a second control unit that receives a wireless signal and measures the radio wave strength of the wireless signal. The audio alert unit can be configured as appropriate, provided that it plays back pre-stored warning audio data to provide a warning when the radio wave strength measured by the second control unit exceeds a predetermined threshold.

[0085] In the above embodiment, the forklift 1 was equipped with an audio alert unit 3, but the audio alert unit of the present invention can be installed in a location other than the forklift 1 (for example, the work area).

[0086] In the above embodiment, the wireless signal from the wireless transmitter 2 is susceptible to the surrounding environment, and the fluctuations in radio wave strength (received signal strength RSSI) are large. Therefore, if the measured value of the wireless signal is used directly in the forklift 1, there is a risk that warnings and restriction actions will be repeated unnecessarily. As a countermeasure, the forklift 1 may use the average value of the radio wave strength of the wireless signal over a predetermined period of time (for example, several seconds) as the measured value.

[0087] Although the industrial vehicle of the present invention was described using a counterbalanced type forklift as an example in the above embodiment, it may also be a reach type forklift or another type of forklift. Furthermore, the industrial vehicle of the present invention is not limited to a forklift; any vehicle other than a forklift (for example, a transport vehicle) may be used as long as it performs cargo handling and driving operations. [Explanation of symbols]

[0088] 100A, 100B Alert System 1 Forklift 2 Wireless Transmitter 3. Voice Alert Unit 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 40 First Control Unit 50 Second Control Unit

Claims

1. Industrial vehicles that perform loading and unloading operations within a designated work area, A wireless transmitter held by a worker in the aforementioned work area and transmitting wireless signals to the industrial vehicle, A voice alert unit that provides voice warnings to the operator of the industrial vehicle, An alert system that includes, The aforementioned industrial vehicle is A first control unit that controls the cargo handling and driving operation, The system includes a second control unit that receives the aforementioned wireless signal and measures the radio wave intensity of the aforementioned wireless signal, The aforementioned voice alert unit is If the radio wave intensity measured by the second control unit exceeds a predetermined threshold, the warning is issued by playing back pre-stored warning audio data. An alert system characterized by the following features.

2. The first control unit reduces the upper limit speed of the industrial vehicle's vehicle speed as the radio wave intensity increases. The alert system according to feature 1.

3. The aforementioned voice alert unit is If the radio wave intensity is greater than or equal to a first threshold and less than or equal to a second threshold greater than the first threshold, the first warning audio data containing the first information is played back. If the industrial vehicle is stopped and the second determination condition is met, such that the radio wave intensity exceeds the second threshold, the second warning audio data including the second information is played. If the industrial vehicle is in motion and the radio wave intensity exceeds the second threshold, the third judgment condition is met, the third warning audio data containing the third information is played. The alert system according to feature 1.

4. The wireless signal includes information regarding the first threshold and the second threshold. The alert system according to feature 3.

5. The second control unit is, The input unit into which the aforementioned wireless signal is input, A storage unit that stores dangerous behavior data linking the aforementioned wireless signal, the warning determination conditions, and a unique dangerous behavior ID, A processing unit that measures the radio wave intensity and determines the determination conditions, It includes an output unit that outputs a first signal relating to the previous dangerous act ID, The aforementioned voice alert unit is A voice data storage unit that stores voice data linking the aforementioned dangerous behavior ID and the aforementioned warning voice data, A voice data processing unit that receives the first signal and plays back the warning voice data in response to the first signal, It includes a speaker that outputs the audio of the warning audio data being played. The alert system according to feature 1.

6. The aforementioned dangerous behavior data is further linked to the aforementioned restrictive actions in cargo handling and driving operations. The output unit outputs a second signal relating to the restrictive action to the first control unit. The first control unit performs the restriction action when the second signal is input. The alert system according to claim 5, characterized in that it is the same as described above.

7. The aforementioned restriction is a restriction on the speed of the industrial vehicle. The first control unit determines the upper limit of the vehicle speed according to the radio wave intensity, and reduces the upper limit of the vehicle speed as the radio wave intensity increases. The alert system described in feature 6.

8. The system further includes an area sensor provided in the work area, which detects the worker in a predetermined area of ​​the work area and transmits a detection signal. The wireless transmitter transmits the wireless signal when it receives the detection signal, but does not transmit the wireless signal when it does not receive the detection signal. The alert system according to feature 1.

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