Weight change system

Abstract

To change heaviness of a pedal operation and a lever operation of a forklift truck or either of them in accordance with an operator's stress level such as to decrease concentration.SOLUTION: A heaviness changing system S comprises a heaviness changing part 21, and a change command part 306. The heaviness changing part 21 changes heaviness of a pedal 14 and a lever 15 of a forklift truck or either of them. The change command part 306 changes the heaviness of the pedal and the lever or either of them by controlling the heaviness changing part 21 in accordance with an operator's stress level.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a weight changing system for changing the weight of a pedal and / or a lever of a forklift. [Background Art]

[0002] There are various types of forklifts, such as reach-type forklifts and counter-type forklifts. Forklifts are provided with pedals and levers, and the number and functions of these components differ depending on the type of forklift.

[0003] As disclosed in Patent Document 1, a reach-type forklift includes a brake pedal and a presence pedal. The presence pedal is configured to be capable of stopping traveling and cargo handling, and a driver cannot perform traveling or cargo handling unless the driver steps on the presence pedal. Further, as disclosed in Patent Document 2, a counter-type forklift includes an accelerator pedal and a brake pedal, and an engine-type counter-type forklift further includes a clutch pedal. Among battery-powered forklifts, automatic transmission forklifts are further provided with an inching pedal instead of a clutch pedal. By stepping on the inching pedal, the driver can place the forklift in a half-clutch state and cut off traveling power.

[0004] Furthermore, as disclosed in Patent Document 3, a reach forklift is equipped with a lift lever for raising and lowering the forks, a tilt lever for changing the vertical angle of the forks, a reach lever for moving the lifting device forward and backward, and an accelerator lever for driving the forklift. Also, as disclosed in Patent Document 4, a counterbalanced forklift is equipped with a tilt lever and an accelerator lever. As disclosed in Patent Document 5, levers are generally configured to swing forward or backward from a neutral position and automatically return to the neutral position by a spring when not in operation. The invention disclosed in Patent Document 5 assists lever operation by an actuator when the amount of operation of the operating lever exceeds a predetermined value, in order to reduce operator fatigue. Another document that discloses technology for assisting the operation of vehicle levers is, for example, Patent Document 6.

[0005] By the way, when you want to operate pedals or levers quickly, it's preferable if they are lighter. However, the lighter they are, the more carefully you need to operate them to avoid making a major mistake. It would be ideal if you could always operate them carefully, but people's concentration fluctuates, and it's not always possible to maintain maximum concentration. Also, it is known that people's concentration decreases when they are under stress. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-047759 [Patent Document 2] Japanese Patent Publication No. 2017-166663 [Patent Document 3] Japanese Patent Publication No. 2016-47745 [Patent Document 4] Japanese Patent Publication No. 2017-88390 [Patent Document 5] Japanese Patent Publication No. 2002-370898 [Patent Document 6] Japanese Patent Publication No. 2003-301942 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the problem that the present invention aims to solve is to provide a weight adjustment system that can change the weight of the pedal operation and / or lever operation of a forklift in accordance with the driver's stress level, which may lead to a decrease in concentration. [Means for solving the problem]

[0008] To solve the above problems, the weight changing system according to the present invention, used in forklifts, A weight adjustment unit for changing the weight of the pedals and levers or either of them of a forklift, It includes a weight adjustment command unit that controls a weight adjustment unit to change the weight of the pedal and / or lever, or either of them, according to the driver's stress level.

[0009] The above weight changing system is preferably, It also includes a stress level estimation method to estimate the driver's stress level.

[0010] The above weight changing system is preferably, A temperature and humidity measuring means for measuring temperature and humidity, A discomfort index calculation unit that calculates the discomfort index from temperature and humidity, It further includes a stress level estimation unit that estimates the driver's stress level based on the calculated discomfort index, The change control unit modifies the weight of the pedals and / or levers, or either of them, according to the estimated driver's stress level.

[0011] The above weight changing system is preferably, A sound collection method for collecting ambient sounds, It further includes a stress level estimation unit that estimates the driver's stress level based on the volume of ambient noise, The change command unit causes the weight of the pedal and / or lever to be changed according to the estimated stress level of the driver.

[0012] Preferably, the aforementioned weight changing system further comprises: a storage unit that stores the driver's work schedule including the amount of work per unit hour; and a stress level estimation unit that refers to the work schedule and estimates the stress level of the driver according to the amount of work per unit hour. The change command unit causes the weight of the pedal and / or lever to be changed according to the estimated stress level of the driver.

[0013] Preferably, the aforementioned weight changing system further comprises: a storage unit that stores the driver's work schedule including the amount of work within the same area; and a stress level estimation unit that refers to the work schedule and estimates the stress level of the driver according to the amount of work within the same area. The change command unit causes the weight of the pedal and / or lever to be changed according to the estimated stress level of the driver.

[0014] Preferably, the aforementioned weight changing system further comprises: a storage unit that stores the driver's work schedule including the size of the work area; and a stress level estimation unit that refers to the work schedule and estimates the stress level of the driver according to the size of the work area. The change command unit causes the weight of the pedal and / or lever to be changed according to the estimated stress level of the driver.

[0015] Preferably, the aforementioned weight changing system further comprises: a storage unit that stores the driver's work schedule including the number of people in the work area; and a stress level estimation unit that refers to the work schedule and estimates the stress level of the driver according to the number of people in the work area. The change command unit changes the weight of the pedal and / or lever in accordance with the estimated stress level of the driver.

[0016] Preferably, the weight change system described above further comprises a stress level estimation unit that estimates the stress level of the driver on the basis of at least one piece of information among: an amount of work per hour, a working time in the same area, a size of a work area, and the number of people within the work area, the change command unit changes the weight of the pedal and / or lever in accordance with the estimated stress level of the driver.

[0017] In order to solve the problem described above, a forklift according to the present invention comprises the weight change system according to any one of the above descriptions.

[0018] In order to solve the problem described above, a weight change program according to the present invention is a program for use in a weight change system comprising: a weight changing unit that changes the weight of a pedal and / or a lever of a forklift; and a computer, and causes the computer to control the weight changing unit in accordance with the stress level of the driver to change the weight of the pedal and / or lever. Effects of the Invention

[0019] The weight change system according to the present invention can change the operational weight of the pedal and / or lever of a forklift in accordance with the stress level of the driver that causes a reduction in concentration. Brief Description of the Drawings

[0020] [Figure 1] Fig. 1 is a front view of a forklift provided with the weight change system according to the first embodiment of the present invention. [Figure 2] Fig. 2 is a block diagram of the weight change system according to the first embodiment. [Figure 3] Fig. 3 is a flow chart showing the operation of the weight change system according to the first embodiment. [Figure 4] This is a block diagram of the weight changing system according to the second embodiment. [Figure 5] This is a flowchart illustrating the operation of the weight changing system according to the second embodiment. [Figure 6] This is a block diagram of the weight changing system according to the third embodiment. [Figure 7] This is a flowchart illustrating the operation of the weight changing system according to the third embodiment. [Figure 8] This is a block diagram of the weight changing system according to the fourth embodiment. [Figure 9] This is a flowchart illustrating the operation of the weight change system according to the fourth embodiment. [Modes for carrying out the invention]

[0021] <First Embodiment> A first embodiment of the weight changing system according to the present invention will be described below with reference to Figures 1 to 3. The weight changing system S according to this embodiment is configured to change the weight of both the pedal and the lever, but this is merely an example, and the weight changing system according to the present invention may be configured to change the weight of either the pedal or the lever.

[0022] <Forklift Configuration> Figure 1 is a front view of a forklift 1 equipped with a weight change system S. First, the configuration of the forklift 1 will be described. The forklift 1 is a battery-powered counterbalanced forklift. As shown in Figure 1, the forklift 1 is equipped with multiple wheels 10, a body 11, a driver's seat 12, a head guard 13, pedals 14 (see Figure 2), levers 15, left and right masts 16, left and right forks 17, a speaker 19 (see Figure 2), a microphone 20 (see Figure 2), a weight change unit 21 (see Figure 2), a stress level estimation means 22 (see Figure 2), and a control unit 30 (see Figure 2).

[0023] Multiple wheels 10 are provided on all four sides of the vehicle body 11. The driver's seat 12 is located on top of the vehicle body 11, and the head guard 13 is located above the driver's seat 12.

[0024] Pedal 14 has an accelerator pedal, a brake pedal, and an inching pedal, and is located below the driver's seat 12. In this invention, "pedal" only needs to have at least one pedal such as an accelerator pedal, a brake pedal, and an inching pedal, and does not need to have all of these pedals.

[0025] Lever 15 has a lift lever and a tilt lever and is located in front of the driver's seat 12. Lever 15 may also have a slide lever for sliding the fork 17 left and right. The “lever” in this invention only needs to have a lift lever and at least one lever such as a tilt lever, and does not need to have all of these levers.

[0026] The left and right forks 17 are configured to be able to be raised and lowered via the left and right masts 16, and the driver H operates the lift lever to raise and lower the forks 17 to perform cargo handling operations.

[0027] The microphone 20 collects the voice of the driver H, converts the collected voice into an audio signal, and transmits it to the control unit 30.

[0028] Speaker 19 emits a warning voice to inform driver H of a weight change, which will be explained later. The warning voice may be, for example, "The weight of the pedals and levers will be increased. Is that alright?" if the weight of the pedals 14 and levers 15 is increased, or "The weight of the pedals and levers will be reduced. Is that alright?" if the weight of the pedals 14 and levers 15 is reduced.

[0029] The weight adjustment unit 21 changes the weight of the lever 15 and pedal 14 when operated, based on commands from the adjustment command unit 306 (see Figure 2), which will be explained later. The weight adjustment unit 21 includes a pedal weight adjustment unit that changes the weight of the pedal 14 and a lever weight adjustment unit that operates the weight of the lever 15. If the weight adjustment unit 21 is configured to change the weight of either the pedal 14 or the lever 15, it will have either the pedal weight adjustment unit or the lever weight adjustment unit.

[0030] The pedal weight adjustment unit changes the weight of the pedal 14 when the driver H presses it, based on a command from the adjustment command unit 306. The pedal weight adjustment unit is composed of, for example, a device that can adjust the weight by hydraulics, or a device that can adjust the weight by a spring.

[0031] Furthermore, for example, the pedal weight adjustment unit may also function as an assist device that assists the force applied to the pedal 14. In this case, the pedal weight adjustment unit may adjust the assist force based on a command from the adjustment command unit 306, thereby substantially changing the weight of the pedal 14 when pressed by the driver H.

[0032] Alternatively, the pedal weight adjustment unit may be configured, for example, to change the magnitude of the power or braking force of each device in response to the amount of force applied to the pedal 14, based on a command from the adjustment command unit 306. In this way, the pedal weight adjustment unit substantially changes the weight of the pedal 14.

[0033] The lever weight adjustment section is comprised of, for example, a device that can adjust the weight of the lever 15 by hydraulic pressure, or a device that can adjust the weight of the lever 15 by a spring.

[0034] Furthermore, for example, the lever weight adjustment unit may also function as an assist device that assists in the operation of the lever 15 in relation to its weight. In this case, the lever weight adjustment unit may adjust the assist force based on a command from the adjustment command unit 306, thereby substantially changing the weight of the lever 15 when operated by the driver H.

[0035] Alternatively, the lever weight adjustment unit may be configured, for example, to change the magnitude of the power of each device in response to the amount of operation of the lever 15, based on a command from the adjustment command unit 306. In this way, the lever weight adjustment unit substantially changes the weight of the lever 15.

[0036] The stress level estimation means 22 estimates the stress level of driver H. The stress level estimation means 22 may be a known method, such as measuring by electrocardiogram and pulse wave, or by measuring heart rate variability, as disclosed on the following web page, and is not particularly limited. ·https: / / www.hitachi-systems.com / ind / fses / ·https: / / medical.murata.com / ja-jp / products / fatigue

[0037] The control unit 30 is comprised of a computer located within the vehicle body 11 and includes an arithmetic unit, a storage device, and memory. The storage device stores a weight change program that causes the computer to execute as a stress level reading unit 302, a weight determination unit 303, a change notification unit 304, a response receiving unit 305, and a change command unit 306, which will be described later.

[0038] <Functional configuration of the first embodiment> Next, the functional configuration of the weight change system S will be described. As shown in Figure 2, the control unit 30 includes a storage unit 301, a stress level reading unit 302, a weight determination unit 303, a change notification unit 304, a response receiving unit 305, and a change command unit 306.

[0039] The memory unit 301 stores the relationship between the stress level and the corresponding weight of the pedal 14 and lever 15.

[0040] The stress level reading unit 302 reads the stress level of driver H, which has been estimated by the stress level estimation means 22.

[0041] The weight determination unit 303 determines the weight of the pedal 14 and lever 15 based on the stress level of the driver H that has been read and the weights of the pedal 14 and lever 15 corresponding to the stress level stored in the memory unit 301.

[0042] The change notification unit 304 determines that a change in the weight of the pedal 14 and lever 15 is necessary if the weight of the pedal 14 and lever 15 determined by the weight determination unit 303 differs from the current weight of the pedal 14 and lever 15. When the change notification unit 304 determines that a change in the weight of the pedal 14 and lever 15 is necessary, it notifies the driver H of the change in weight of the pedal 14 and lever 15 by voice through the speaker 19. However, it is undesirable for the weight of the pedal 14 and lever 15 to be changed frequently. Therefore, the change notification unit 304 is configured to leave an arbitrary interval between the notification and the next notification. This interval may be set, for example, between 5 and 30 minutes.

[0043] The response receiving unit 305 receives a predetermined response from driver H, which has been announced by the change notification unit 304, via the microphone 20. For example, the predetermined response may be words such as "Yes," "I understand," or "Got it." When the response receiving unit 305 receives a predetermined response from driver H, it transmits a response signal to the change command unit 306.

[0044] When the change command unit 306 receives a response signal, it controls the weight change unit 21 to change the weight of the pedal 14 and lever 15 so that they match the weight determined by the weight determination unit 303. As a result, the weight change system S can change the weight of the pedal 14 and lever 15 according to the level of stress, even if the driver H's concentration fluctuates due to stress.

[0045] As a result, the weight adjustment system S can make the pedal 14 and lever 15 lighter when the driver H is highly focused, allowing for quicker operation of the pedal 14 and lever 15. Conversely, when the driver H is not highly focused, the weight adjustment system S can make the pedal 14 and lever 15 heavier, preventing major operating errors.

[0046] <Flowchart of the weight changing system according to the first embodiment> Next, with reference to the flowchart in Figure 3, the operation of the weight changing system S according to the first embodiment will be explained again.

[0047] (1) First, the weight change system S reads the stress level of the driver H (see S31 in Figure 3).

[0048] (2) Next, the weight adjustment system S determines the weight of the pedal 14 and lever 15 by referring to the stress level of the driver H (see S32 in Figure 3).

[0049] (3) Next, the weight change system S determines that a change is necessary if the determined weight of the pedal 14 and lever 15 is different from the weight of the pedal 14 and lever 15 at that time (Yes in S33 of Figure 3), and notifies the driver H of the change in the weight of the pedal 14 and lever 15 (see S34 of Figure 3).

[0050] (4) Next, when the weight change system S receives permission from the driver H to make a change (Yes in S35 in Figure 3), the change command unit 306 changes the weight of the pedal 14 and the lever 15 (see S36 in Figure 3). The weight change system S also withholds changing the weight of the pedal 14 and the lever 15 until it receives permission from the driver H to make a change (No in S35 in Figure 3), and then notifies the driver H of the change in the weight of the lever 15 after a predetermined time. This prevents the weight change system S from frequently changing the weight of the pedal 14 and the lever 15, and from suddenly changing the weight of the pedal 14 and the lever 15 while the driver H is working on loading and unloading.

[0051] Thus, the weight adjustment system S changes the weight of the pedal 14 and lever 15 based on the stress level that affects the driver H's level of concentration. As a result, when the driver H is highly concentrated, the system allows for quick operation of the pedal 14 and lever 15, and when the driver H is not highly concentrated, it prevents major operating errors.

[0052] <Second Embodiment> Next, a second embodiment of the weight adjustment system according to the present invention will be described with reference to Figures 1, 4, and 5. The weight adjustment system S according to this embodiment is also configured to change the weight of both the pedal and the lever, similar to the first embodiment. Hereinafter, components similar to those in the first embodiment will be given the same reference numerals, and their detailed descriptions may be omitted.

[0053] The forklift 1 according to this embodiment is a counterbalanced forklift similar to the first embodiment, and as shown in Figures 1 and 4, it comprises a plurality of wheels 10, a body 11, a driver's seat 12, a head guard 13, pedals 14, levers 15, left and right masts 16, left and right forks 17, a speaker 19, a microphone 20, a weight changing unit 21, a thermometer 23, a hygrometer 24, and a control unit 30.

[0054] The thermometer 23 measures the temperature around the driver's seat 12, and the hygrometer 24 measures the humidity around the driver's seat 12. As in this embodiment, the "temperature and humidity measuring means" of the present invention may be configured separately as a thermometer 23 and a hygrometer 24.

[0055] The weight changing unit 21 changes the weight of the lever 15 and pedal 14 when operated, based on a command from the change command unit 306 (see Figure 4), using the same method as in the first embodiment. Similar to the first embodiment, the weight changing unit 21 includes a pedal weight changing unit for changing the weight of the pedal 14 and a lever weight changing unit for operating the weight of the lever 15.

[0056] <Functional configuration of the second embodiment> Next, the functional configuration of the weight change system S according to the second embodiment will be described. As shown in Figure 4, the control unit 30 includes a storage unit 301, a temperature and humidity reading unit 307, a discomfort index calculation unit 308, a stress level estimation unit 309, a weight determination unit 303, a change notification unit 304, a response receiving unit 305, and a change command unit 306.

[0057] Similar to the first embodiment, the memory unit 301 stores the relationship between the stress level and the corresponding weight of the pedal 14 and lever 15.

[0058] The temperature and humidity reading unit 307 reads the temperature and humidity around the driver's seat 12 as measured by the thermometer 23 and the hygrometer 24.

[0059] The discomfort index calculation unit 308 refers to the temperature and humidity around the driver's seat 12 that have been read, and calculates the discomfort index using the following formula. It is known that a person's concentration decreases depending on the level of the discomfort index. Formula: 0.81 × temperature + 0.01 × humidity (%) × (0.99 × temperature - 14.3) + 46.3

[0060] The stress level estimation unit 309 estimates the stress level based on the calculated discomfort index. The stress level estimation unit 309 estimates that the higher the discomfort index, the higher the stress level, and that the lower the discomfort index, the lower the stress level.

[0061] The weight determination unit 303 determines the weight of the pedal 14 and lever 15 based on the estimated stress level and the weights of the pedal 14 and lever 15 corresponding to the stress level stored in the memory unit 301.

[0062] Similar to the first embodiment, when the change notification unit 304 determines that it is necessary to change the weight of the pedal 14 and lever 15, it notifies the driver H of the change in weight of the pedal 14 and lever 15 by voice via the speaker 19.

[0063] The response receiving unit 305, similar to the first embodiment, receives a predetermined response from driver H, which has been announced by the change notification unit 304, via the microphone 20, and transmits the response signal to the change command unit 306.

[0064] When the change command unit 306 receives a response signal, it controls the weight change unit 21 to change the weight of the pedal 14 and lever 15 to the weight determined by the weight determination unit 303, similar to the first embodiment. As a result, the weight change system S can change the weight of the pedal 14 and lever 15 according to the degree of stress related to the discomfort index, even if the driver H's concentration fluctuates due to stress related to the discomfort index.

[0065] <Flowchart of the weight change system according to the second embodiment> Next, with reference to the flowchart in Figure 5, the operation of the weight changing system S according to the second embodiment will be explained again.

[0066] (1) First, the weight change system S reads the temperature and humidity around the driver's seat 12 (see S51 in Figure 5), and calculates the discomfort index based on the read temperature and humidity (see S52 in Figure 5).

[0067] (2) Next, the weight adjustment system S estimates the driver H's stress level based on the calculated discomfort index (see S53 in Figure 5).

[0068] (3) Next, the weight adjustment system S determines the weight of the pedal 14 and lever 15 by referring to the estimated stress level of the driver H (see S54 in Figure 5).

[0069] (4) Next, the weight change system S determines that a change is necessary if the determined weight of the pedal 14 and lever 15 is different from the weight of the pedal 14 and lever 15 at that time (Yes in S55 of Figure 5), and notifies the driver H of the change in the weight of the pedal 14 and lever 15 (see S56 of Figure 5).

[0070] (5) Next, when the weight change system S receives permission from the driver H to make a change (Yes in S57 of Figure 5), the change command unit 306 changes the weight of the pedal 14 and the lever 15 (see S58 of Figure 5). The weight change system S also withholds changing the weight of the pedal 14 and the lever 15 until it receives permission from the driver H to make a change (No in S57 of Figure 5), and will notify the driver H of the change in the weight of the lever 15 after a predetermined time.

[0071] Thus, the weight adjustment system S according to this embodiment changes the weight of the pedal 14 and lever 15 based on the stress level related to the discomfort index, which affects the level of concentration of the driver H. As a result, when the driver H is highly concentrated, the pedal 14 and lever 15 can be operated quickly, and when the driver H is not highly concentrated, major operating errors can be prevented.

[0072] <Third Embodiment> Next, a third embodiment of the weight changing system according to the present invention will be described with reference to Figures 1, 6, and 7. The weight changing system S according to this embodiment is also configured to change the weight of both the pedal and the lever, similar to the embodiment described above. Hereinafter, components similar to those in the embodiment above will be given the same reference numerals and their detailed descriptions may be omitted.

[0073] The forklift 1 according to this embodiment is a counterbalanced forklift similar to the embodiment described above, and as shown in Figures 1 and 6, it comprises a plurality of wheels 10, a body 11, a driver's seat 12, a head guard 13, a pedal 14, a lever 15, left and right masts 16, left and right forks 17, a speaker 19, a microphone 20, a weight changing unit 21, a sound collection means 25, and a control unit 30.

[0074] The sound collection means 25 collects ambient noise around the forklift 1. For example, ambient noise includes noise from work machinery and presses operating within the facility. It is known that noise from work machinery and presses can cause stress to people and reduce their concentration.

[0075] The weight changing unit 21 changes the weight of the lever 15 and pedal 14 when operated, based on a command from the change command unit 306 (see Figure 6), using the same method as in the above embodiment. The weight changing unit 21 also includes a pedal weight changing unit for changing the weight of the pedal 14 and a lever weight changing unit for operating the weight of the lever 15, similar to the above embodiment.

[0076] <Functional configuration of the third embodiment> Next, the functional configuration of the weight change system S according to the third embodiment will be described. As shown in Figure 6, the control unit 30 includes a storage unit 301, a volume reading unit 310, a stress level estimation unit 309, a weight determination unit 303, a change notification unit 304, a response receiving unit 305, and a change command unit 306.

[0077] The memory unit 301 stores, similar to the embodiment described above, the correspondence between the stress level and the corresponding weight of the pedal 14 and lever 15.

[0078] The volume reading unit 310 reads the volume of ambient sound collected by the sound collection means 25.

[0079] The stress level estimation unit 309 estimates the stress level based on the volume of ambient noise. The stress level estimation unit 309 estimates that the higher the noise volume, the higher the stress level, and that the lower the noise volume, the lower the stress level.

[0080] Similar to the second embodiment, the weight determination unit 303 determines the weights of the pedals 14 and levers 15 based on the estimated stress level and the weights of the pedals 14 and levers 15 corresponding to the stress levels stored in the memory unit 301.

[0081] The change notification unit 304, in the same manner as in the above embodiment, notifies the driver H of the change in the weight of the pedal 14 and lever 15 by voice via the speaker 19, and the response receiving unit 305, in the same manner as in the above embodiment, receives a predetermined response from the driver H via the microphone 20 and transmits the response signal to the change command unit 306.

[0082] When the change command unit 306 receives a response signal, it controls the weight change unit 21, similar to the embodiment described above, to change the weight of the pedal 14 and lever 15 so that they become the weight determined by the weight determination unit 303. As a result, the weight change system S can change the weight of the pedal 14 and lever 15 according to the level of stress related to the noise level, even if the driver H's concentration fluctuates due to noise-related stress.

[0083] <Flowchart of the weight change system according to the third embodiment> Next, with reference to the flowchart in Figure 7, the operation of the weight changing system S according to the third embodiment will be explained again.

[0084] (1) First, the weight changing system S reads the volume of the noise (see S71 in Figure 7) and estimates the stress level based on the read volume of the noise (see S72 in Figure 7).

[0085] (2) Next, the weight adjustment system S determines the weight of the pedal 14 and lever 15 by referring to the estimated stress level of the driver H (see S73 in Figure 7).

[0086] (3) Next, the weight change system S determines that a change is necessary if the determined weight of the pedal 14 and lever 15 is different from the weight of the pedal 14 and lever 15 at that time (Yes in S74 of Figure 7), and notifies the driver H of the change in the weight of the pedal 14 and lever 15 (see S75 of Figure 7).

[0087] (4) Next, when the weight change system S receives permission from the driver H to make a change (Yes in S76 in Figure 7), the change command unit 306 changes the weight of the pedal 14 and the lever 15 (see S77 in Figure 7). The weight change system S also withholds changing the weight of the pedal 14 and the lever 15 until it receives permission from the driver H to make a change (No in S76 in Figure 7), and will notify the driver H of the change in the weight of the lever 15 after a predetermined time.

[0088] Thus, the weight adjustment system S according to this embodiment changes the weight of the pedal 14 and lever 15 based on the stress level related to the noise level, which affects the driver H's level of concentration. As a result, when the driver H is highly concentrated, the pedal 14 and lever 15 can be operated quickly, and when the driver H is not highly concentrated, major operating errors can be prevented.

[0089] <Fourth Embodiment> Next, a fourth embodiment of the weight changing system according to the present invention will be described with reference to Figures 1, 8, and 9. The weight changing system S according to this embodiment is also configured to change the weight of both the pedal and the lever, similar to the embodiments described above. Hereinafter, components similar to those in the embodiments above will be given the same reference numerals and their detailed descriptions may be omitted.

[0090] The forklift 1 according to this embodiment is a counterbalanced forklift similar to the embodiment described above, and as shown in Figures 1 and 8, it comprises a plurality of wheels 10, a body 11, a driver's seat 12, a head guard 13, pedals 14, levers 15, left and right masts 16, left and right forks 17, a camera 26, a speaker 19, a microphone 20, a weight changing unit 21, and a control unit 30.

[0091] Camera 26 is, for example, fixed to the head guard 13 and configured to capture the face of driver H as he gets into the forklift 1 and generate a facial image. The facial image generated by camera 26 is transmitted to the control unit 30.

[0092] The weight changing unit 21 changes the weight of the lever 15 and pedal 14 when operated, based on a command from the change command unit 306 (see Figure 8), using the same method as in the above embodiment. The weight changing unit 21 also includes a pedal weight changing unit for changing the weight of the pedal 14 and a lever weight changing unit for operating the weight of the lever 15, similar to the above embodiment.

[0093] <Functional configuration of the fourth embodiment> Next, the functional configuration of the weight change system S according to the fourth embodiment will be described. As shown in Figure 8, the control unit 30 includes a storage unit 301, a driver identification unit 311, a stress level estimation unit 309, a weight determination unit 303, a change notification unit 304, a response receiving unit 305, and a change command unit 306.

[0094] Similar to the above embodiment, the memory unit 301 stores the correspondence between the stress level and the corresponding weight of the pedal 14 and lever 15. Furthermore, the memory unit 301 stores the facial image and work schedule for each of the multiple drivers H. The work schedule includes at least one piece of information from the following: the amount of work per hour, the work area, the size of the work area, and the number of people in the work area. The "size of the work area" is a numerical representation of the size and width of the area where the forklift 1 performs cargo handling operations, such as the width of the aisle for the forklift 1.

[0095] The driver identification unit 311 refers to the facial image generated by the camera 26 and the facial image stored in the memory unit 301 to identify the driver H who will be boarding the vehicle from among the multiple drivers H stored in the memory unit 301.

[0096] The stress level estimation unit 309 reads the schedule for the identified driver H from the storage unit 301. The stress level estimation unit 309 then estimates the stress level of driver H based on at least one of the following pieces of information: workload per hour, working time in the same area, size of the work area, and number of people in the work area. The stress level estimation unit 309 also calculates the working time in the same area from the work area and working time included in the schedule.

[0097] The stress level estimation unit 309 may have a trained model that outputs the stress level of driver H based on at least one piece of information, such as the amount of work per hour (quota), the working time in the same area, the size of the work area, and the number of workers in the work area.

[0098] This pre-trained model is machine-learned using training data that takes at least one of the following as input data: workload per hour, working time in the same area, size of the work area, and number of workers in the work area, and outputs stress levels. It is known that the higher the workload per hour, the higher the stress level of driver H. It is also known that if the working time in the same area is long and the work becomes monotonous, or if the work area is small, the stress level of driver H will increase. Furthermore, it is known that if the number of people in the work area increases, the possibility of contact with forklift 1 increases, and therefore the stress level of driver H will increase. The pre-trained model learns these correlations.

[0099] As a result, the trained model outputs a higher stress level the greater the amount of work per unit of time and the number of people in the work area. Furthermore, the trained model outputs a higher stress level the longer the work time in the same area. Additionally, the trained model outputs a higher stress level the smaller the work area.

[0100] Therefore, the stress level estimation unit 309 uses this trained model to estimate the stress level such that the stress level increases as the amount of work per hour and the number of people in the work area increase, the work time in the same area increases, and the work area decreases.

[0101] The weight determination unit 303 determines the weight of the pedal 14 and lever 15 based on the estimated stress level and the weights of the pedal 14 and lever 15 corresponding to the stress level stored in the memory unit 301, similar to the embodiment described above.

[0102] The change notification unit 304, in the same manner as in the above embodiment, notifies the driver H of the change in the weight of the pedal 14 and lever 15 by voice via the speaker 19, and the response receiving unit 305, in the same manner as in the above embodiment, receives a predetermined response from the driver H via the microphone 20 and transmits the response signal to the change command unit 306.

[0103] When the change command unit 306 receives a response signal, it controls the weight change unit 21 to change the weight of the pedal 14 and lever 15 to the weight determined by the weight determination unit 303, similar to the embodiment described above. As a result, the weight change system S can change the weight of the pedal 14 and lever 15 according to the stress level, even if the driver H's concentration level fluctuates due to stress related to at least one of the following: the amount of work per hour, the working time in the same area, the size of the work area, and the number of workers in the work area.

[0104] <Flowchart of the weight change system according to the fourth embodiment> Next, with reference to the flowchart in Figure 9, the operation of the weight changing system S according to the fourth embodiment will be explained again.

[0105] (1) First, the weight change system S identifies the driver H (see S91 in Figure 9) and reads the schedule (see S92 in Figure 9), and then estimates the stress level based on the read schedule (see S93 in Figure 9).

[0106] (2) Next, the weight adjustment system S determines the weight of the pedal 14 and lever 15 by referring to the estimated stress level of the driver H (see S94 in Figure 9).

[0107] (3) Next, the weight change system S determines that a change is necessary if the determined weight of the pedal 14 and lever 15 is different from the weight of the pedal 14 and lever 15 at that time (Yes in S95 of Figure 9), and notifies the driver H of the change in the weight of the pedal 14 and lever 15 (see S96 of Figure 9).

[0108] (4) Next, when the weight change system S receives permission from the driver H to make a change (Yes in S97 in Figure 9), the change command unit 306 changes the weight of the pedal 14 and the lever 15 (see S98 in Figure 9). The weight change system S also withholds changing the weight of the pedal 14 and the lever 15 until it receives permission from the driver H to make a change (No in S97 in Figure 9), and will notify the driver H of the change in the weight of the lever 15 after a predetermined time.

[0109] Thus, the weight adjustment system S according to this embodiment changes the weight of the pedal 14 and lever 15 based on the stress level related to at least one of the factors that affect the driver H's level of concentration: the amount of work per hour, the working time in the same area, the size of the work area, and the number of workers in the work area. As a result, when the driver H is highly concentrated, the pedal 14 and lever 15 can be operated quickly, and when the driver H is not highly concentrated, major operating errors can be prevented.

[0110] Although various embodiments of the weight changing system according to the present invention have been described above, the present invention is not limited to the above embodiments. The weight changing system according to the present invention may be implemented, for example, by combining the above embodiments, or by implementing each of the following modifications or by combining each of the modifications.

[0111] <Variation> The forklift 1 may be a reach forklift. In this case, pedal 14 may include a presence pedal. The forklift 1 may also be an engine-powered forklift. In this case, pedal 14 may include a clutch pedal. Furthermore, if the forklift 1 is a reach forklift, lever 15 may include an accelerator lever. As described above, the "pedal" in the present invention includes at least one of the above pedals, and the "lever" includes at least one of the above levers, and the weight changing system according to the present invention changes the weight of at least one of the above levers and pedals.

[0112] • Any of the components of the control unit 30 may be configured, for example, by a server computer located on the cloud. In this case, the weight changing system S changes the weight of the pedal 14 and the lever 15 or either of them by communicating with this server computer.

[0113] The method by which the driver identification unit 311 identifies driver H is not particularly limited. For example, the driver identification unit 311 may identify each driver H by reading a card or the like held by each driver H.

[0114] The forklift 1 may be equipped with a monitor instead of a speaker 19, and the change notification unit 304 may notify the user via this monitor that the weight of the lever 15 and the pedal 14 or either of them will be changed.

[0115] The forklift 1 may be equipped with a button instead of a microphone 20, and the response receiving unit 305 may receive a response from the driver H via the button.

[0116] The weight determination unit 303 may determine the weight of the pedal 14 and the lever 15, or either of them, based on the sum of the stress levels, such as when combining embodiments. [Explanation of symbols]

[0117] S Weight change system H Driver 1 Forklift 10 wheels 11 Car body 12 Driver's seat 13 Headguard 14 pedals 15 Lever 16 Mast 17 Forks 19 speakers 20 microphones 21 Weight change section 22. Methods for Estimating Stress Level 23 Thermometer 24 Hygrometer 25 Sound collection means 26 cameras 30 Control Unit 301 Storage section 302 Stress level reading unit 303 Weight determination unit 304 Notice of Changes 305 Response Department 306 Change Command Unit 307 Temperature and Humidity Reading Unit 308 Discomfort index calculation section 309 Stress Level Estimation Section 310 Volume reading section 311 Driver Identification Department

Claims

1. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A temperature and humidity measuring means for measuring temperature and humidity, A discomfort index calculation unit that calculates the discomfort index from temperature and humidity, The system includes a stress level estimation unit that estimates the driver's stress level based on the calculated discomfort index, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

2. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A sound collection method for collecting ambient sounds, The system includes a stress level estimation unit that estimates the driver's stress level based on the volume of ambient noise, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

3. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A storage unit that stores the driver's work schedule, which includes the amount of work per hour, The system includes a stress level estimation unit that, referring to the aforementioned work schedule, estimates the stress level of the driver according to the amount of work per hour, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

4. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A storage unit that stores the driver's work schedule, which includes the amount of work to be done within the same area, The system includes a stress level estimation unit that, by referring to the work schedule, estimates the stress level of the driver according to the amount of work in the same area, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

5. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A storage unit that stores the driver's work schedule, which includes the size of the work area, The system includes a stress level estimation unit that, by referring to the work schedule, estimates the stress level of the driver according to the size of the work area, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

6. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and A storage unit that stores the driver's work schedule, including the number of people in the work area, The system includes a stress level estimation unit that estimates the stress level of the driver based on the number of people in the work area, by referring to the work schedule, The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

7. A weight changing system used in a forklift, A weight changing unit for changing the weight of the pedals and levers or either of them of the forklift, A change command unit controls the weight changing unit according to the driver's stress level to change the weight of the pedal and / or the lever, and The system includes a stress level estimation unit that estimates the stress level of the driver based on at least one piece of information, such as the amount of work per hour in the work schedule, the working time in the same area, the size of the work area, and the number of people in the work area. The aforementioned change command unit is a weight change system that changes the weight of the pedal and / or the lever, or either of them, according to the estimated stress level of the driver.

8. A forklift comprising a weight changing system according to any one of claims 1 to 7.

9. A program used in a weight change system comprising a weight change unit that changes the weight of the pedals and / or levers of a forklift, and a computer, A weight change program that causes the computer to operate as the change command unit and the stress level estimation unit according to any one of claims 1 to 7.

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