Warning Device, Warning Method, and Warning Program

Abstract

To provide a warning device, a method for warning, and a warning program that evaluate the risk of falling of a vehicle with no running schedule routes set and can issue a warning properly to the user or the manager of the vehicle.SOLUTION: The warning device, the method for warning, and the warning program acquire load information showing the load on each wheel of a vehicle with a loading unit and road surface information showing steps or inclined parts of a road surface on which the vehicle runs. The warning device, the method for warning, and the warning program also acquire the existence position of a step or an inclined part on the basis of the road surface information and calculate center-of-gravity information of the vehicle on the basis of the load information. The warning device, the method for warning, and the warning program determine whether the vehicle is in a warning target state on the basis of the existence position and the center-of-gravity information, and issues a notification to the user when the vehicle has been determined to be in the warning target state.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a warning device, a warning method, and a warning program.

Background Art

[0002] According to the technology disclosed in Patent Document 1, when traveling on a curved road, the magnitude of the centrifugal force acting on the center-of-gravity position of the vehicle and the information on the center-of-gravity position are used to evaluate the risk of the vehicle tipping over. Then, always, a risk assessment corresponding to the road conditions ahead is presented to the driver in advance along the planned travel route from the current position where the vehicle is traveling.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology disclosed in Patent Document 1 evaluates the risk of the vehicle tipping over based on the magnitude of the centrifugal force generated when traveling on a preset planned travel route. Therefore, even when using the technology disclosed in Patent Document 1, it is not possible to evaluate the risk of the vehicle tipping over when the planned travel route is not set.

[0005] The present invention has been made in view of the problems of such conventional technologies. The object of the present invention is to provide a warning device, a warning method, and a warning program that can evaluate the risk of the vehicle tipping over when the planned travel route is not set and can appropriately issue a warning to the user or administrator of the vehicle.

Means for Solving the Problems

[0006] The warning device according to the first aspect of the present invention includes an input unit to which load information representing the load for each of a plurality of wheels of a vehicle having a luggage loading part and road surface information representing a stepped part or an inclined part of the road surface on which the vehicle travels is input, a controller, and a notification unit that notifies a user. The controller acquires the existence position of the stepped part or the inclined part based on the road surface information, and calculates the center of gravity information of the vehicle based on the load information. Further, the controller determines whether the vehicle is in a warning target state based on the existence position and the center of gravity information. The notification unit performs notification when it is determined that the vehicle is in a warning target state.

[0007] The warning method according to the second aspect of the present invention is executed by a computer, acquires load information representing the load for each of a plurality of wheels of a vehicle having a luggage loading part, and acquires road surface information representing a stepped part or an inclined part of the road surface on which the vehicle travels. Based on the road surface information, the existence position of the stepped part or the inclined part is acquired, and based on the load information, the center of gravity information of the vehicle is calculated. Then, based on the existence position and the center of gravity information, it is determined whether the vehicle is in a warning target state, and when it is determined that the vehicle is in a warning target state, the user is notified.

[0008] The warning program according to the third aspect of the present invention causes a computer to execute a process of acquiring load information representing the load for each of a plurality of wheels of a vehicle having a luggage loading part and acquiring road surface information representing a stepped part or an inclined part of the road surface on which the vehicle travels. Based on the road surface information, the computer is caused to execute a process of acquiring the existence position of the stepped part or the inclined part, and based on the load information, a process of calculating the center of gravity information of the vehicle is executed. Then, based on the existence position and the center of gravity information, a process of determining whether the vehicle is in a warning target state and performing notification to the user when it is determined that the vehicle is in a warning target state is executed by the computer.

Effects of the Invention

[0009] According to the present invention, it is possible to evaluate the risk of overturning of a vehicle for which a planned travel route has not been set, and appropriately issue a warning to the user or administrator of the vehicle.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] Next, with reference to the drawings, the warning device according to this embodiment will be described in detail. In the description, the same components are denoted by the same reference numerals and redundant description is omitted.

[0012] [Example of Vehicle Configuration] With reference to FIGS. 1 and 2, the forklift F to which the warning device according to this embodiment is applied will be described. FIG. 1 is a side view showing the forklift to which the warning device according to this embodiment is applied. FIG. 2 is a bottom view showing the forklift to which the warning device according to this embodiment is applied.

[0013] The forklift F (vehicle) includes a fork portion 51 that moves up and down, a backrest portion 52, a mast portion 53, front wheels (left front wheel TY1, right front wheel TY2) that are driving wheels, and rear wheels (left rear wheel TY3, right rear wheel TY4) that are drive wheels, and the like.

[0014] The forklift F may be an engine vehicle having an internal combustion engine such as a gasoline engine as a drive source, or may be a battery vehicle having an electric motor driven by electric power supplied from a secondary battery (battery) that can be charged from a generator or the like as a drive source.

[0015] The fork portion 51 and the backrest portion 52 are attached so as to be vertically movable with respect to the mast portion 53 fixed to the vehicle body of the forklift F. The fork portion 51 and the mast portion 53 together are referred to as a load loading portion.

[0016] An in-vehicle camera CM1 is provided above the mast portion 53 that supports the fork portion 51 and the mast portion 53. The in-vehicle camera CM1 images the road surface in front of the forklift F. Also, an in-vehicle camera CM2 is provided above the rear part of the forklift F. The in-vehicle camera CM2 images the road surface behind the forklift F.

[0017] The positions where the in-vehicle camera CM1 and the in-vehicle camera CM2 are provided only need to be able to image the road surface around the forklift F, and are not limited to the examples given here. Also, the in-vehicle camera CM1 and the in-vehicle camera CM2 may image the road surface on the side of the forklift F.

[0018] A measurement unit 11 that measures the loads applied to the front wheels and rear wheels of the forklift F and the rotation speeds of the front wheels and rear wheels is attached to the vehicle body of the forklift F. In FIG. 2, sensors WS1, WS2, WS3, and WS4 are shown as the measurement unit 11. The sensor WS1 measures the load and rotation speed applied to the left front wheel TY1. The sensor WS2 measures the load and rotation speed applied to the right front wheel TY2. The sensor WS3 measures the load and rotation speed applied to the left rear wheel TY3. The sensor WS4 measures the load and rotation speed applied to the right rear wheel TY4.

[0019] The sensors WS1 and WS2 may measure the loads and rotation speeds applied to the left front wheel TY1 and the right front wheel TY2 via the axle 61, respectively. The sensors WS3 and WS4 may measure the loads and rotation speeds applied to the left rear wheel TY3 and the right rear wheel TY4 via the axle 62, respectively.

[0020] In addition, an acceleration sensor (G sensor) for detecting the acceleration (longitudinal G, lateral G, and vertical G) during movement may be attached to the vehicle body of the forklift F. The measurement unit 11 may include the acceleration sensor.

[0021] Further, a position sensor for acquiring the position information of the forklift F may be attached to the vehicle body of the forklift F. For example, the position sensor may be a GPS sensor. The GPS sensor receives radio waves from a plurality of GPS (Global Positioning System) satellites, performs predetermined calculation processing, and acquires information on latitude and longitude representing the current position of the forklift F from the received signals. Thereby, the position information (vehicle position) of the forklift F can be acquired. The measurement unit 11 may include the position sensor.

[0022] The operator (driver) of the forklift F operates a steering wheel 71, a shift lever 72, and pedals such as an accelerator pedal and a brake pedal (not shown). By this operation, operations such as raising and lowering of the fork portion 51, forward movement, backward movement, right turn, and left turn of the forklift F are performed to carry out cargo handling work and the like.

[0023] The vehicle to which the warning device according to the present embodiment is applied is not limited to the forklift F. The vehicle may be a vehicle that performs loading, unloading, and transportation of luggage, products, etc. within a factory, warehouse, or the like.

[0024] [Configuration Example of Warning Device] Referring to FIG. 3, the configuration and the like of the warning device 1 according to the present embodiment will be described. FIG. 3 is a block diagram showing an example of the configuration of the warning device according to the present embodiment. The warning device 1 may be mounted on, for example, the forklift F, or may be mounted on a terminal carried by a user or an administrator of the forklift F.

[0025] As shown in FIG. 3, the warning device 1 includes an input unit 21, a controller 100, and a notification unit 400. Additionally, the warning device 1 may include a measurement unit 11, a road surface condition detection unit 13, and a database 15. The measurement unit 11 is mounted on the forklift F, but the road surface condition detection unit 13 and the database 15 may be mounted on the forklift F or may be installed outside the forklift F.

[0026] The measurement unit 11, the road surface condition detection unit 13, and the database 15 are connected to the input unit 21, and the input unit 21 and the notification unit 400 are connected to the controller 100. Here, "connection" may be by either a wired or wireless method.

[0027] The measurement unit 11 measures the loads applied to the front and rear wheels of the forklift F and the rotation speeds of the front and rear wheels. The information regarding the loads applied to the front and rear wheels, obtained by the measurement unit 11, is transmitted to the input unit 21 as load information representing the loads for each of the plurality of wheels of the forklift F. Also, the information regarding the rotation speeds of the front and rear wheels, obtained by the measurement unit 11, is transmitted to the input unit 21 as rotation speed information representing the rotation speeds for each of the plurality of wheels of the forklift F.

[0028] The measurement unit 11 may include an acceleration sensor that detects the acceleration of the forklift F during movement. The information on the acceleration of the forklift F during movement is transmitted to the input unit 21 as acceleration information. Also, it may include a position sensor that acquires the position information of the forklift F. The position information of the forklift F is transmitted to the input unit 21.

[0029] The road surface condition detection unit 13 (detection unit) detects a stepped portion or an inclined portion on the road surface around the forklift F based on an image captured by the in-vehicle camera CM1 or the in-vehicle camera CM2. For example, the road surface condition detection unit 13 may detect a stepped portion or an inclined portion based on image analysis. The road surface condition detection unit 13 generates road surface information representing the detected stepped portion or inclined portion. The road surface information includes the position information of the stepped portion or inclined portion, the magnitude of the step at the stepped portion, and the magnitude of the inclination at the inclined portion. The road surface information is transmitted to the input unit 21.

[0030] The position information included in the road surface information may be the position information representing the position of the forklift F when the road surface condition detection unit 13 detects a stepped portion or an inclined portion. Alternatively, the position information included in the road surface information may be calculated based on the positional relationship between the road surface condition detection unit 13 and the stepped portion or inclined portion and the position information representing the position of the forklift F.

[0031] The road surface condition detection unit 13 may generate road surface information representing a stepped portion or an inclined portion based on point cloud data representing the shape of the road surface around the forklift F acquired by a three-dimensional laser measurement device mounted on the forklift F.

[0032] The database 15 (storage unit) stores the road surface information generated by the road surface condition detection unit 13. The database 15 may store not only the road surface information generated by a specific single road surface condition detection unit 13 but also the road surface information generated from a plurality of road surface condition detection units 13. The road surface information stored in the database 15 is transmitted to the input unit 21 as needed.

[0033] The input unit 21 acquires the information transmitted from the measurement unit 11, the road surface condition detection unit 13, and the database 15. The various information acquired by the input unit 21 is transmitted to the controller 100.

[0034] When it is determined by the controller 100, which will be described later, that the forklift F is in a warning target state, the notification unit 400 notifies the user.

[0035] For example, the notification unit 400 notifies that there is a step or slope on the road surface where the forklift F travels. In addition, the notification unit 400 notifies that it is necessary to pay attention to the travel of the forklift F. The notification unit 400 may be a liquid crystal display, an organic EL display, or the like.

[0036] The notification unit 400 is not limited to presenting various information by visual information. The notification unit 400 may present information to the user by auditory information, or may generate vibration and present information to the user by the stimulus of the vibration. For example, the notification unit 400 may be a sound source, an amplifier, a speaker, etc. for generating and emitting sound.

[0037] The controller 100 is a general-purpose microcomputer including a CPU (Central Processing Unit), a memory, and an input / output unit. A computer program (warning program) for functioning as a part of the warning device 1 is installed in the controller 100. By executing the computer program, the controller 100 functions as a plurality of information processing circuits (110, 120, 130).

[0038] Here, an example is shown in which a plurality of information processing circuits (110, 120, 130) provided in the controller 100 are realized by software. However, it is also possible to prepare dedicated hardware for executing each of the following information processes to constitute the information processing circuits (110, 120, 130). Also, the plurality of information processing circuits (110, 120, 130) may be constituted by individual hardware.

[0039] The controller 100 includes a center of gravity calculation unit 110, a position acquisition unit 120, and a determination unit 130 as a plurality of information processing circuits (110, 120, 130).

[0040] Based on the load information, the center-of-gravity calculation unit 110 calculates the center-of-gravity information of the forklift F. More specifically, the center-of-gravity calculation unit 110 calculates the total load applied to all the wheels of the forklift F (the total load measured by the sensors WS1 to WS4), and as the center-of-gravity information, calculates the ratio of the load applied to each wheel to the total load.

[0041] As the center-of-gravity information, the center-of-gravity calculation unit 110 calculates the ratio of the load applied to the front wheels (front-wheel load: the total load measured by the sensors WS1 and WS2) to the total load applied to all the wheels of the forklift F. Further, as the center-of-gravity information, the center-of-gravity calculation unit 110 calculates the ratio of the load applied to the rear wheels (rear-wheel load: the total load measured by the sensors WS3 and WS4) to the total load applied to all the wheels of the forklift F.

[0042] Also, the center-of-gravity calculation unit 110 may calculate the total load applied to the front wheels of the forklift F (the total load measured by the sensors WS1 and WS2). And the center-of-gravity calculation unit 110 may calculate, as the center-of-gravity information, the ratio of the load applied to each front wheel (left front wheel TY1, right front wheel TY2) (left load, right load) to the total load.

[0043] The reason why the center-of-gravity calculation unit 110 calculates the total and ratio for the front wheels is due to the fact that the fork part 51 as the load-carrying part is located on the front-wheel side of the forklift F (especially in front of the front wheels when viewed from the vehicle body of the forklift F). This is because the load applied to the front wheels of the forklift F is useful for evaluating the tipping risk of the forklift F.

[0044] In the case where the load-carrying part is located on the rear-wheel side of the vehicle (especially behind the rear wheels), the center-of-gravity calculation unit 110 may calculate the total load applied to the rear wheels of the forklift F (the total load measured by the sensors WS3 and WS4). And the center-of-gravity calculation unit 110 may calculate, as the center-of-gravity information, the ratio of the load applied to each rear wheel (left rear wheel TY3, right rear wheel TY4) to the total load.

[0045] The position acquisition unit 120 acquires the existence positions of step portions or inclined portions existing around the forklift F based on the road surface information. Note that the position acquisition unit 120 may extract only step portions where the magnitude of the step at the step portion is equal to or greater than a predetermined value and acquire the existence positions of the extracted step portions. Further, the position acquisition unit 120 may extract only inclined portions where the magnitude of the inclination at the inclined portion is equal to or greater than a predetermined value and acquire the existence positions of the extracted inclined portions. By performing the extraction, the calculation load on the determination unit 130 described later can be reduced.

[0046] Here, the predetermined value used for the extraction of the step portion and the inclined portion may be changed according to the height positions of the fork portion 51 and the mast portion 53, or the weight of the load loaded on the fork portion 51. For example, the larger the height positions of the fork portion 51 and the mast portion 53 are, the smaller the predetermined value may be set. Also, the heavier the load loaded on the fork portion 51 is, the smaller the predetermined value may be set. By changing the predetermined value, it is possible to accurately determine the risk of tipping over the forklift F while reducing the calculation load on the determination unit 130.

[0047] In addition, the position acquisition unit 120 may acquire the vehicle position of the forklift F via the input unit 21.

[0048] The determination unit 130 determines whether or not the forklift F is in a warning target state based on the existence position and the center of gravity information. For example, the determination unit 130 may determine that the forklift F is in a warning target state when the ratio of the load applied to the rear wheels (rear wheel load) of the forklift F to the total load applied to all the wheels of the forklift F is less than a first threshold value.

[0049] Further, the determination unit 130 may determine that the forklift F is in a warning target state when the ratio of the left load to the total of the left load applied to the left front wheel TY1 and the right load applied to the right front wheel TY2 of the forklift F is less than the second threshold value. The determination unit 130 may determine that the forklift F is in a warning target state when the ratio of the right load to the total of the left load and the right load is less than the second threshold value.

[0050] Here, the first threshold value may be set to a smaller value compared to the second threshold value. Thereby, the risk of the forklift F tipping over in the front-rear direction can be determined more strictly than the risk of the forklift F tipping over in the lateral direction.

[0051] Further, the first threshold value and the second threshold value may be changed according to the height positions of the fork portion 51 and the mast portion 53, or the weight of the load loaded on the fork portion 51. For example, the larger the height positions of the fork portion 51 and the mast portion 53 are, the smaller the first threshold value and the second threshold value may be set. Also, the heavier the load loaded on the fork portion 51 is, the smaller the first threshold value and the second threshold value may be set. By changing the first threshold value and the second threshold value, the risk of the forklift F tipping over can be accurately determined.

[0052] In addition, the determination unit 130 may determine that the forklift F is in a warning target state when the distance between the vehicle position of the forklift F and the position where the step or slope is present is equal to or less than a predetermined distance. Here, the predetermined distance may be set in advance based on the size of the vehicle body of the forklift F, or may be set based on the size of the step at the step location or the slope at the slope location.

[0053] The determination unit 130 may perform a process of determining whether or not the forklift F is in a warning target state by combining one or more of the above-described processes. When combining a plurality of processes, the determination unit 130 may hold a warning flag and set or cancel the warning flag based on the result of the process. Details will be described later with reference to the flowcharts of FIGS. 4 and 5.

[0054] When the determination unit 130 determines that the forklift F is in a warning target state, it may stop the control of the fork portion 51 and the backrest portion 52 which are the load mounting portions. For example, when the determination unit 130 determines that the forklift F is in a warning target state, it may stop the lifting and lowering operation of the fork portion 51.

[0055] When the determination unit 130 determines that the forklift F is in a warning target state, it may stop the control of the traveling of the forklift F. For example, when the determination unit 130 determines that the forklift F is in a warning target state, it may stop operations accompanied by changes in the vehicle position and vehicle attitude such as forward movement, backward movement, right turn, and left turn of the forklift F.

[0056] In addition, the determination unit 130 may determine whether or not the acceleration when the forklift F passes through a step portion or an inclined portion is equal to or greater than a predetermined value based on the vehicle position of the forklift F, the existence position of the step portion or the inclined portion, and the acceleration information. Here, the concept of "passing" may include not only the case where the forklift F passes through a step portion or an inclined portion, but also the case where the forklift F passes through a region where the distance to the step portion or the inclined portion is less than a predetermined distance (when passing near).

[0057] When it is determined by the determination unit 130 that the acceleration is equal to or greater than a predetermined value, the controller 100 may output the road surface information generated by the road surface condition detection unit 13 to the database 15 in association with the vehicle position. The database 15 may store the road surface information output from the controller 100 in association with the vehicle position.

[0058] [Processing Procedure of Warning Device] Next, the processing procedure of the vehicle operation state detection device according to the present embodiment will be described with reference to the flowcharts of FIGS. 4 and 5.

[0059] Note that the processing shown in the flowcharts of FIGS. 4 and 5 may start when the ignition of the forklift F is turned on and may be repeatedly executed while the ignition is on. Also, the processing shown in the flowchart of FIG. 3 and the processing shown in the flowchart of FIG. 5 may be executed in parallel or alternately.

[0060] FIG. 4 is a flowchart showing a first example of the processing of the warning device according to the present embodiment. In step S101, the input unit 21 acquires load information.

[0061] In step S103, the center-of-gravity calculation unit 110 calculates the center-of-gravity information of the forklift F based on the load information.

[0062] In step S105, the determination unit 130 determines whether the ratio of the load applied to the rear wheels (rear-wheel load) of the forklift F to the total load applied to all the wheels of the forklift F is less than a first threshold value.

[0063] When the ratio of the rear-wheel load is less than the first threshold value (YES in step S105), in step S107, the determination unit 130 determines that the forklift F is in a warning target state ("front load bias"). Also, the notification unit 400 notifies the user that it is in a "front load bias" state. Then, the process proceeds to step S123.

[0064] When the ratio of the rear-wheel load is not less than the first threshold value (NO in step S105), in step S109, the determination unit 130 determines whether the ratio of the left-side load to the total of the left-side load and the right-side load of the forklift F is less than a second threshold value.

[0065] When the ratio of the left load is less than the second threshold (YES in step S109), in step S111, the determination unit 130 determines that the forklift F is in a warning target state ("right load bias"). Further, the notification unit 400 notifies the user that there is a "right load bias". Then, the process proceeds to step S123.

[0066] When the ratio of the left load is not less than the second threshold (NO in step S109), in step S113, the determination unit 130 determines whether the ratio of the right load in the total of the left load and the right load of the forklift F is less than the second threshold.

[0067] When the ratio of the right load is less than the second threshold (YES in step S113), in step S115, the determination unit 130 determines that the forklift F is in a warning target state ("left load bias"). Further, the notification unit 400 notifies the user that there is a "left load bias". Then, the process proceeds to step S123.

[0068] When the ratio of the right load is not less than the second threshold (NO in step S113), in step S121, the determination unit 130 releases the warning flag.

[0069] On the other hand, when it is determined by the determination unit 130 that the forklift F is in a warning target state, in step S123, the determination unit 130 sets the warning flag.

[0070] Next, FIG. 5 is a flowchart showing a second example of the process of the warning device according to the present embodiment. In step S201, the input unit 21 acquires road surface information.

[0071] The road surface information may be input from the road surface condition detection unit 13 or may be input from the database 15.

[0072] In step S203, the position acquisition unit 120 acquires the existence position of a step portion or an inclined portion based on the road surface information.

[0073] In step S205, the position acquisition unit 120 acquires the vehicle position of the forklift F.

[0074] In step S207, the determination unit 130 determines whether the distance between the vehicle position of the forklift F and the position where the step portion or the inclined portion exists is equal to or less than a predetermined distance.

[0075] If the distance between the positions where the step portion or the inclined portion exists is not equal to or less than the predetermined distance (NO in step S207), the process of the flowchart in FIG. 5 is terminated.

[0076] On the other hand, if the distance between the positions where the step portion or the inclined portion exists is equal to or less than the predetermined distance (YES in step S207), in step S209, the determination unit 130 determines whether a warning flag is set.

[0077] If the warning flag is set (YES in step S209), in step S211, the determination unit 130 determines that the forklift F is in a warning target state ("Danger of inclination / step"). Further, the notification unit 400 notifies the user that "There is a danger of inclination / step".

[0078] On the other hand, if the warning flag is not set (NO in step S209), in step S213, the determination unit 130 determines that the forklift F is in a warning target state ("Caution for inclination / step"). Further, the notification unit 400 notifies the user that "Caution for inclination / step".

[0079] In step S215, the input unit 21 acquires acceleration information.

[0080] In step S217, the determination unit 130 determines whether the acceleration when the forklift F passes through the step portion or the inclined portion is equal to or greater than a predetermined value.

[0081] When the acceleration is equal to or greater than a predetermined value (YES in step S217), in step S219, the controller 100 outputs the road surface information generated by the road surface condition detection unit 13 to the database 15. The database 15 stores the road surface information output from the controller 100.

[0082] When the acceleration is less than the predetermined value (NO in step S217), the process of the flowchart in FIG. 5 ends.

[0083] [Effects of the Embodiment] As described in detail above, according to the warning device, warning method, and warning program according to the present embodiment, load information representing the load for each of a plurality of wheels of a vehicle having a load loading section is acquired, and road surface information representing a stepped portion or an inclined portion of the road surface on which the vehicle travels is acquired. Based on the road surface information, the existence position of the stepped portion or the inclined portion is acquired, and based on the load information, the center of gravity information of the vehicle is calculated. Based on the existence position and the center of gravity information, it is determined whether the vehicle is in a warning target state, and when it is determined that the vehicle is in a warning target state, notification is given to the user.

[0084] Thereby, it is possible to evaluate the risk of tipping over of a vehicle for which a planned travel route has not been set, and appropriately issue a warning to the user or administrator of the vehicle. In particular, when a bias occurs in the center of gravity position of the vehicle when passing around a stepped portion or an inclined portion, a warning can be issued assuming that there is a risk of the vehicle tipping over.

[0085] Further, according to the warning device, warning method, and warning program according to the present embodiment, in a vehicle having a load loading section in front of the front wheels of the vehicle, it may be configured to calculate the total load applied to all the wheels of the vehicle. And when the ratio of the load applied to the rear wheels of the vehicle in the total is less than a first threshold value, it may be determined that the vehicle is in a warning target state. Thereby, it is possible to determine the risk of tipping over of the vehicle in the front-rear direction.

[0086] Furthermore, according to the warning device, warning method, and warning program according to this embodiment, in a vehicle having a luggage loading section in front of the front wheels of the vehicle, it may be configured to calculate the total of the right load applied to the right front wheel of the vehicle and the left load applied to the left front wheel of the vehicle. And when the ratio occupied by the right load or the ratio occupied by the left load in the total is less than a second threshold value, it may be determined that the vehicle is in a warning target state. Thereby, the risk of the vehicle tipping over in the lateral direction can be determined.

[0087] Moreover, according to the warning device, warning method, and warning program according to this embodiment, it may be configured to acquire the vehicle position of the vehicle and determine that the vehicle is in a warning target state when the distance between the vehicle position and the existence position is equal to or less than a predetermined distance. Thereby, when the vehicle approaches a step portion or an inclined portion, the risk of the vehicle tipping over can be determined.

[0088] Furthermore, according to the warning device, warning method, and warning program according to this embodiment, when it is determined that the vehicle is in a warning target state, it may be configured to stop the control of the luggage loading section. Thereby, when there is a risk of the vehicle tipping over, it is possible to suppress the risk of the vehicle tipping over increasing due to the up and down movement of the luggage loading section or the like.

[0089] Moreover, according to the warning device, warning method, and warning program according to this embodiment, it may be configured to generate road surface information based on an image obtained by imaging the surroundings of the vehicle. Thereby, even when the vehicle travels on a road surface for which the road surface information is not registered in a database or the like, the risk of the vehicle tipping over can be determined.

[0090] Furthermore, according to the warning device, warning method, and warning program according to this embodiment, it may be configured to acquire the vehicle position of the vehicle and the acceleration of the vehicle. Then, when the acceleration when the vehicle passes through a step portion or an inclined portion is equal to or greater than a predetermined value, the generated road surface information may be stored in association with the vehicle position. Thereby, road surface information that is not registered in a database or the like can be newly registered in the database or the like. In addition, the administrator can confirm the step portion or the inclined portion afterwards and utilize it for road surface repair work.

[0091] Each function shown in the above-described embodiment can be implemented by one or more processing circuits. The processing circuit includes a programmed processor, an electric circuit, etc., and further includes a device such as an application-specific integrated circuit (ASIC) and circuit components arranged to execute the described functions.

[0092] Although the present embodiment has been described above, the present embodiment is not limited to these, and various modifications are possible within the scope of the gist of the present embodiment.

Explanation of Reference Numerals

[0093] 1 Warning device 11 Measurement unit 13 Road surface condition detection unit (detection unit) 15 Database (storage unit) 21 Input unit 51 Fork unit (cargo loading unit) 52 Backrest unit 53 Mast unit 100 Controller 110 Center of gravity calculation unit 120 Position acquisition unit 130 Determination unit 400 Notification unit F Forklift (vehicle) TY1 Left front wheel TY2 Right front wheel TY3 Left rear wheel TY4 Right rear wheel

Claims

1. An input unit to which load information representing the load for each of a plurality of wheels of a vehicle having a load carrying part, and road surface information representing a stepped part or an inclined part of a road surface on which the vehicle travels are input; A controller; A notification unit that notifies a user; A detection unit that generates the road surface information based on an image captured around the vehicle; A storage unit; A warning device comprising: The controller: Based on the road surface information, obtains the existence position of the stepped part or the inclined part; Based on the load information, calculates the center of gravity information of the vehicle; Based on the existence position and the center of gravity information, determines whether the vehicle is in a warning target state; The notification unit performs notification when it is determined that the vehicle is in the warning target state; The input unit receives input of the vehicle position of the vehicle and the acceleration of the vehicle; When the acceleration when the vehicle passes through the stepped part or the inclined part is equal to or greater than a predetermined value, the storage unit stores the road surface information generated by the detection unit in association with the vehicle position; Warning device.

2. The vehicle has the load carrying part in front of the front wheels of the vehicle, The controller determines that the vehicle is in the warning target state when the ratio of the load applied to the rear wheels of the vehicle to the total load applied to all the wheels of the vehicle is less than a first threshold value. The warning device according to claim 1.

3. The vehicle has the load carrying part in front of the front wheels of the vehicle, The controller determines that the vehicle is in the warning target state when the ratio of the right load applied to the right front wheel of the vehicle or the ratio of the left load applied to the left front wheel of the vehicle, out of the total of the right load and the left load, is less than a second threshold value. The warning device according to claim 1 or 2.

4. The vehicle position of the vehicle is input to the input unit, The controller, The warning device according to any one of claims 1 to 3, wherein the controller determines that the vehicle is in the warning target state when the distance between the vehicle position and the existence position is equal to or less than a predetermined distance.

5. The warning device according to any one of claims 1 to 4, wherein the controller stops the control of the luggage loading unit when it determines that the vehicle is in the warning target state.

6. A warning method executed by a computer, Obtain load information representing the load for each of a plurality of wheels of a vehicle having a luggage loading unit, Obtain road surface information representing a stepped portion or an inclined portion of the road surface on which the vehicle travels, Based on the road surface information, obtain the existence position of the stepped portion or the inclined portion, Based on the load information, calculate the center of gravity information of the vehicle, Based on the existence position and the center of gravity information, determine whether the vehicle is in a warning target state, When it is determined that the vehicle is in the warning target state, notify the user, Generate the road surface information based on an image obtained by imaging the surroundings of the vehicle, Receive an input of the vehicle position of the vehicle and the acceleration of the vehicle, When the acceleration when the vehicle passes through the stepped portion or the inclined portion is equal to or greater than a predetermined value, store the generated road surface information in association with the vehicle position. Warning method.

7. Obtain load information representing the load for each of a plurality of wheels of a vehicle having a load-carrying part, Obtain road surface information representing a stepped portion or an inclined portion of the road surface on which the vehicle travels, Based on the road surface information, obtain the existence position of the stepped portion or the inclined portion, Based on the load information, calculate the center-of-gravity information of the vehicle, Based on the existence position and the center-of-gravity information, determine whether the vehicle is in a warning target state, When it is determined that the vehicle is in the warning target state, notify the user, Generate the road surface information based on an image capturing the surroundings of the vehicle, Receive an input of the vehicle position of the vehicle and the acceleration of the vehicle, When the acceleration when the vehicle passes through the stepped portion or the inclined portion is equal to or greater than a predetermined value, store the generated road surface information in association with the vehicle position A warning program for causing a computer to execute the process.

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