Control system and method for aerial work platforms

Abstract

To provide a control system for a high elevation working vehicle capable of preventing a worker from carelessly colliding with a structure (an obstacle) at a high place, and capable of preventing accidents of being caught between a working basket and a structure (an obstacle) at a high place by preventing fraudulent acts that an operation permission unit is fixed in an operation permission state by the worker when the worker performs high place works on the high elevation working vehicle.SOLUTION: A control system 100 for a high elevation working vehicle 1 comprises a basket 4 on which a worker rides for working and a lifter 3 to raise / lower the basket 4. The control system for the high elevation working vehicle is provided with an operation lever 60 to operate the lifter 3, a foot switch 7 to allow the operation with the operation lever 60, and an invalid signal output unit 115 to invalidate the foot switch 7. An invalidation release by the invalid signal output unit 115 is performed by the worker operating the foot switch 7.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a control system and a control method for a vehicle for working at height, which improves safety during working at height. [Background technology]

[0002] Aerial work vehicles are used for work at height in the construction of buildings, highways, bridges, etc., shipbuilding, factory maintenance, electric wire installation, etc. In general, an aerial work vehicle is equipped with a work basket in which a worker boards and works, a lifting device (lifter) that raises and lowers the work basket, an operating unit (operating lever) that is provided inside the work basket and that operates the lifting device, and a traveling device (car body) on which the lifting device is mounted and capable of running.

[0003] When performing high-altitude work using a high-altitude work vehicle, the vehicle is moved to a specified position, and then the worker gets into the work basket and operates the lifting device using the operating unit to raise the work basket to the desired height position and perform the work.

[0004] However, when the work basket rises, there is a risk of an accident in which a worker in the work basket negligently collides with a high-altitude structure (obstacle) or is pinched between the work basket and the high-altitude structure (obstacle).

[0005] In order to prevent such accidents, for example, Japanese Patent No. 6274665 describes a vehicle for working at height that includes a basket that can be raised and lowered by a lifting device and an operating device that operates the lifting device, and that detects the distance between the basket and an obstacle above using a proximity sensor, and when a preset distance is detected, notifies the worker, and stops the operation of the lifting device with an emergency stop signal, thereby preventing the basket from colliding with the obstacle above (see paragraphs

[0009] ,

[0015] ,

[0016] ,

[0023] , and Figures 1 and 2). In addition, the vehicle described in the same publication is provided with an interlocking foot switch that interlocks with the operating device, and is configured so that the lifting device cannot be operated by the operating device unless the worker presses the interlocking foot switch with his or her foot (see paragraphs

[0017] ,

[0029] , and Figure 3). In addition, the use of a similar foot switch is also described in JP 2020-75769 A (see paragraphs

[0021] to

[0022] , Figure 2) and JP Patent No. 3479442 A (see paragraphs

[0013] to

[0014] , Figure 3). Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, in a high-altitude work vehicle, in order to operate the lifting device using the operating device, the worker must press the interlocking foot switch (operation permission section) with his / her foot. However, some workers intentionally ignore this procedure and perform dangerous illegal acts such as fixing the interlocking foot switch in the pressed position (operation permission state) using tape or the like instead of pressing the interlocking foot switch with their foot. In such cases, the worker does not need to be near the interlocking foot switch, and cannot take his / her foot off the foot switch to turn it off if he / she senses danger, which greatly increases the risk of the worker colliding with or being pinched by a high-altitude structure.

[0007] The present invention has been made in consideration of the above-mentioned conventional situation, and the problem that the present invention aims to solve is to provide a control system and control method for an aerial work vehicle that can prevent accidents such as a worker inadvertently colliding with a high-altitude structure (obstacle) or being pinched between the work basket and a high-altitude structure (obstacle) when working at height using an aerial work vehicle, by preventing the worker from committing an unauthorized act of fixing the operation permission unit in the operation permission state. [Means for solving the problem]

[0008] The present invention is a control system for an aerial work vehicle equipped with a work platform on which a worker boards to perform work and a lifting mechanism for raising and lowering the work platform. The control system includes an operation unit for operating the lifting mechanism, an operation permission unit for permitting operation by the operation unit, and a disabling means for disabling the operation permission unit, and the disabling by the disabling means is released by the worker operating the operation permission unit.

[0009] According to the present invention, the operation permission unit permits operation by the operation unit, whereby the lifting mechanism is operated by the operation unit, and the work platform is raised and lowered. Meanwhile, the operation permission unit is disabled by the disabling means. The disablement by the disabling means is released by the worker operating the operation permission unit. In other words, the disablement cannot be released unless the worker operates the operation permission unit. This makes it possible to prevent fraudulent acts in which the worker fixes the operation permission state without operating the operation permission unit. As a result, accidents during high-altitude work, such as the worker colliding with a high-altitude structure (obstacle) or being pinched between the structure (obstacle), can be avoided, and work safety can be improved.

[0010] In the present invention, the device further includes a position detection unit that detects when the height of the work platform has reached a predetermined upper limit position, and the disabling means is configured to disable the operation permission unit based on the detection result by the position detection unit.

[0011] In the present invention, when the position detector detects a position, the disabling means disables the operation permission unit, thereby stopping the lifting mechanism and rendering the operation unit inoperable.

[0012] In the present invention, when the position detector detects a position, the operating unit is disabled only for the operation of raising the work platform by the lifting mechanism. In this case, the work platform maintains the height position at that time, or moves only downward by the operation of the operating unit, and does not move upward from the predetermined upper limit position, so that the safety of the work can be guaranteed.

[0013] In the present invention, the disablement by the disabling means is released by the operator once returning the operation permitted unit to the state before operation permission. In other words, the disablement cannot be released unless the operator once returns the operation permitted unit to the state before operation permission. Therefore, if the operation permitted unit is fixed in the operation permitted state due to fraud without the operator operating it, it is troublesome to once return the operation permitted unit to the state before operation permission in order to release the disablement. This makes it possible to prevent the operation permitted unit from being fixed in the operation permitted state without the operator operating it.

[0014] In the present invention, the disabling means disables the operation permission unit when a predetermined time set in advance by a timer has elapsed since the start of operation permission by the operation permission unit. In this way, the operation permission unit can be disabled by setting the timer, making it possible to work at heights safely.

[0015] In the present invention, when the operation permission section is invalidated before the predetermined time set in advance by the timer has elapsed from the start of operation permission by the operation permission section, the timer is cleared.

[0016] In the present invention, the operation permission unit has an emergency stop function for bringing the lifting mechanism to an emergency stop. In this case, the operation permission unit can be quickly switched to an emergency stop while the worker is operating the operation permission unit, thereby further improving the safety of the work.

[0017] In the present invention, when the lifting mechanism is stopped in an emergency, an emergency stop process is performed in which the lifting mechanism gradually lowers the work platform, making it possible to rescue the worker from a dangerous situation if the worker is trapped or in danger of being trapped.

[0018] The control method for the control system of the aerial work vehicle according to the present invention includes the following steps: i) An operation permission step in which the operation permission unit permits operation by the operation unit, thereby enabling the operation of the lifting mechanism by the operation unit. ii) A disabling step in which the disabling means disables the operation permission unit. iii) A disablement canceling step in which the operator operates the operation permission unit to cancel the disablement caused by the disablement means.

[0019] According to the present invention, in the operation permission step, the operation permission unit permits the operation by the operation unit, whereby the lifting mechanism is operated by the operation unit, and the work platform is raised and lowered. Next, in the disabling step, the operation permission unit is disabled by the disabling means. Then, in the disabling release step, the disabling by the disabling means is released by the worker operating the operation permission unit, that is, the disabling cannot be released unless the worker operates the operation permission unit. This makes it possible to prevent fraudulent acts in which the worker fixes the operation permission state without operating the operation permission unit. As a result, accidents during high-altitude work, such as the worker colliding with a high-altitude structure (obstacle) or being pinched between the structure (obstacle), can be avoided, and work safety can be improved.

[0020] In the present invention, when it is detected in the disabling step that the height of the work platform has reached a predetermined upper limit position, or when a predetermined time set in advance by a timer has elapsed since the start of operation permission by the operation permission unit, the disabling means disables the operation permission unit. This makes it possible to perform work at height more safely.

[0021] In the present invention, the disablement is released in the disablement release step by the operator returning the operation permitted unit to the state before operation permission. In other words, the disablement cannot be released unless the operator returns the operation permitted unit to the state before operation permission. Therefore, if the operation permitted unit is fixed in the operation permitted state due to an illegal act without the operator operating it, it is troublesome to return the operation permitted unit to the state before operation permission in order to release the disablement. This makes it possible to prevent the operation permitted unit from being fixed in the operation permitted state without the operator operating it. Effect of the Invention

[0022] As described above, according to the present invention, a control system and control method for an aerial work vehicle can be provided that can prevent accidents such as a worker inadvertently colliding with a high-altitude structure (obstacle) or being pinched between the work basket and a high-altitude structure (obstacle) when working at height using an aerial work vehicle, by preventing the worker from intentionally fixing the operation permission unit in the operation permission state due to the fraudulent act. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic front view of an example of a high-altitude work vehicle to which a control system according to an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a partially enlarged schematic view of the aerial work platform vehicle (FIG. 1), showing an operating lever and a foot switch in the basket. [Diagram 3] FIG. 2 is a functional block diagram of the control system (FIG. 1). [Figure 4] 2 shows a first pattern of a time chart of the control system (FIG. 1). [Figure 4A] 2 shows a second pattern of the time chart of the control system (FIG. 1). [Diagram 5] 13 shows a third pattern of the time chart of the control system (FIG. 1). [Figure 6] 13 shows a fourth pattern of the time chart of the control system (FIG. 1). [Figure 7] 13 shows a fifth pattern of the time chart of the control system (FIG. 1). [Figure 8] 1 shows an example of a flow chart of the control system (FIG. 1), and corresponds to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Figures 1 to 8 are diagrams for explaining a control system for an aerial work vehicle according to one embodiment of the present invention, where Figures 1 and 2 are schematic configuration diagrams of an aerial work vehicle to which the control system is applied, Figure 3 is a functional block diagram of the control system, Figures 4 to 7 are time charts of each element that constitutes the control system, and Figure 8 is a flowchart for explaining the operation of the control system.

[0025] As shown in Fig. 1, the vehicle for high-altitude work 1 comprises a body 2 capable of traveling on a floor surface FL, a lifter (lifting mechanism) 3 mounted on the body 2 and capable of rising and lowering, and a basket (work platform) 4 attached to the top of the lifter 3 and on which a worker boards to perform high-altitude work. Here, a scissors-type lifter with a pantograph structure is taken as an example of the lifter 3.

[0026] The lifter 3 is equipped with multiple links 30 that are configured to be extendable and retractable in the vertical direction, and one or more actuators (lifting mechanism drive units) 31 (only some of which are shown in the figure) for extending and retracting each link 30. When driven by the actuators 31, each link 30 extends and retracts, causing the basket 4 to rise and fall.

[0027] The basket 4 is composed of a floor board 40, and a plurality of vertical columns 41 and horizontal handrails 42 attached thereon. One or more sensors (position detection units) 5 are provided on the upper part of the basket 4 to detect that the height of the basket 4 has reached a predetermined upper limit position due to the lifting of the basket 4 by the lifter 3. In this example, the basket 4 is set to determine that the height of the basket 4 has reached a predetermined upper limit position when the sensor 5 detects the ceiling (or a high-altitude structure / obstacle) CL. When the sensor 5 detects the ceiling CL, the basket 4 is located at a warning position WL that is a predetermined distance below the ceiling CL. The sensor 5 is preferably a non-contact sensor such as a proximity sensor (e.g., ultrasonic sensor / photoelectric switch / laser scanner) that detects the approach of an object or a distance sensor (distance sensor) (e.g., laser distance sensor) that measures the distance to an object.

[0028] As shown in Fig. 2, an operating device 6 for a worker to operate by hand and a foot switch (operation permission unit) 7 for a worker to operate by foot are provided inside the basket 4. The operating device 6 is attached to, for example, a pillar 41 inside the basket 4, and has one or more operating levers (or joysticks) (operation units) 60 for operating the lifter 3 by the worker holding and operating it with his or her hand, that is, for driving the actuator 31. The operating device 6 is also provided with a lever (not shown) for traveling the vehicle body 2 (Fig. 1) of the aerial work platform vehicle 1. The operating device 6 is also provided with an emergency stop switch 61.

[0029] The foot switch 7 is disposed or fixed on the floor plate portion 40 in the basket 4, and is provided so as to be interlocked with the operating lever 60 of the operating device 6. In other words, operation by the operating lever 60 is permitted and the operating lever 60 can be operated only when the worker is stepping on the foot switch 7 with his foot. In this example, a three-position type foot switch 7 is used, and when the worker is not stepping on it with his foot, the switch is in position 1 and in the OFF state, when the worker steps on it lightly with his foot, the switch moves to position 2 and is ON, and when the worker steps on it hard with his foot, the switch changes to position 3 and is OFF.

[0030] FIG. 3 shows a schematic configuration of the control system of the aerial work platform vehicle 1. The control system 100 has a control unit 110, to which the operation unit (operation lever) 60 of the operating device 6, the operation permission unit (foot switch) 7, and the position detection unit (sensor) 5 are connected. The control unit 110 has an operation signal processing unit 111 that processes an operation signal output from the operation lever 60, an operation permission signal processing unit 112 that processes an operation permission signal output from the foot switch 7, and a drive signal output unit 113. Both the output a of the operation signal processing unit 111 and the output b of the operation permission signal processing unit 112 are input to the drive signal output unit 113. The drive signal output unit 113 is composed of an AND circuit, and outputs an output c when both the output a of the operation signal processing unit 111 and the output b of the operation permission signal processing unit 112 are input. The output c is input to the lifting mechanism drive unit (actuator) 31.

[0031] The control unit 110 has a detection signal processing unit 114 that processes the detection signal output from the sensor 5, and a disabling signal output unit (disabling means) 115. An output d of the detection signal processing unit 114 is input to the disabling signal output unit 115. The disabling signal output unit 115 is for outputting a disabling signal e for disabling the foot switch 7 based on the detection result by the sensor 5. The disabling signal e is input to the operation permission signal processing unit 112. In addition, an output f of the detection signal processing unit 114 is input to a notification unit 117.

[0032] In addition, the invalidation signal output unit 115 is configured to receive external signals such as a detection signal that detects abnormalities in a worker based on vital data (e.g., heart rate data, pulse rate data, etc.) of the worker obtained by a vital sensor (not shown), a detection signal that detects unauthorized and dangerous behavior of a worker based on image data obtained by a surveillance camera (not shown), and a control signal from another system (not shown).

[0033] Furthermore, the output g of the timer 116 is input to the invalidation signal output unit 115. The set time of the timer 116 can be set to any appropriate time, but if it is set too short, for example, one minute, the work becomes very complicated because a release operation is required every minute, but it is safer because it increases the deterrent effect against the worker fixing the foot switch 7 with tape or the like. On the other hand, if it is set too long, for example, several tens of minutes, it is dangerous because it increases the possibility that the worker will fix the foot switch 7 with tape or the like within that time. In consideration of such points, the set time is set to about 10 minutes, for example, but it may be determined based on the standard time required for high-altitude work or the time required to reach the high-altitude work position. More specifically, when a worker ascends to perform work and then descends, if the time required for ascending and descending is usually five minutes, the set time of the timer 116 may be set to about two minutes more than that.

[0034] Next, FIG. 4 to FIG. 7 respectively exemplify the first to fifth patterns of the time chart of each element constituting the control system 100. In each figure, "POS.1", "POS.2", and "POS.3" in the operation permission unit (foot switch) indicate positions 1, 2, and 3, respectively, and indicate that the operation permission unit here is a three-position type. "Up", "Down", and "Stand" in the operation unit (operation lever) indicate the cases where the basket is raised, lowered, and stopped by the operation of the operation unit, respectively. "Detection" and "Non-detection" in the position detection unit (sensor) indicate that the position detection unit has detected or has not detected a high-altitude structure (obstacle), respectively. The "set time" of the timer refers to the time preset by the timer. The external signal (operation mode switching signal) is for switching between two operation modes, a normal operation mode (H) and an emergency stop mode (L). The "reference plane" and "warning position" of the controlled object (basket) indicate the real-time position of the controlled object in the height direction, and the "reference plane" indicates that the controlled object is placed on the body of the aerial work vehicle before the lifter is extended (i.e., before the controlled object rises), and the "warning position" indicates the position at which the controlled object rises and is detected by the position detection unit (sensor) slightly below the "ceiling." In each figure, the horizontal axis represents time T, and the timing of the rise and fall of each time chart is indicated by the dotted lines T 1 ~T n (n: natural number).

[0035] Next, the first to fifth patterns will be described using Figures 4 to 7 while referring to Figures 1 to 3. First, the outline of the characteristic parts of each pattern will be briefly described, and then the details of each pattern will be described separately.

[0036] The first, second and fourth patterns indicate patterns in which the operation permission unit (foot switch) 7 is disabled by detection by the position detection unit (sensor) 5, and the disabled state is released by depressing the foot switch 7 again (see the gray areas in Figs. 4, 4A and 6). The third pattern indicates a pattern in which the foot switch 7 is disabled when the timer 116 reaches a predetermined set time, and the disabled state is released by depressing the foot switch 7 again, and the timer 116 is restarted (see the gray area in Fig. 5). The fifth pattern indicates a pattern in which the foot switch 7 is disabled and an emergency stop is performed by depressing the foot switch 7 up to POS.3 (see the gray area in Fig. 7).

[0037] <First pattern> FIG. 4 shows a first pattern of the time chart. As shown in the figure, in the section T 0 ~T 1 (That is, T 0 ≦T <T 1 ), the foot switch 7 is at POS.1 and in the switched-off state (see FIG. 2), and at this time, even if the operating lever 60 is operated to the up position, the basket 4 does not move upward, and its height position remains at the reference level.

[0038] Explaining this with reference to Fig. 3, since no operation permission signal is output from the foot switch 7, output b is not output from the operation permission signal processing unit 112. On the other hand, since an operation signal is output from the operating lever 60 and input to the operation signal processing unit 111, output a is output from the operation signal processing unit 111 and input to the drive signal output unit 113. Here, since the drive signal output unit 113 is an AND circuit that receives as inputs the outputs a and b, when only the output a is input, drive signal c is not output from the drive signal output unit 113 and the actuator 31 is not driven. As a result, the basket 4 does not rise and remains stationary.

[0039] Returning to Figure 4, T 1 (That is, T = T 1), when the operator depresses the foot switch 7, the foot switch 7 switches from POS.1 to POS.2 and is switched ON. This allows operation of the operating lever 60, and the operation lever 60 is enabled.

[0040] Next, in section T 1 ~T 6 (That is, T 1 ≦T <T 6 ) is when operation by the operating lever 60 is permitted and the operating lever 60 is operable, so when the operating lever 60 is switched to the up position, the basket 4 rises (T 2 ≦T <T 3 and T 5 ≦T <T 6 ), and when the operating lever 60 is switched to the lowering side, the basket 4 is lowered (T 3 ≦T <T 4 ). Also, if the operating lever 60 is stationary, the bucket 4 maintains its position at that time (T 4 ≦T <T 5 ).

[0041] 3, the operation permission signal output from the foot switch 7 is input to the operation permission signal processing unit 112, which outputs output b, which is input to the drive signal output unit 113. Also, the operation signal output from the operating lever 60 is input to the operation signal processing unit 111, which outputs output a, which is input to the drive signal output unit 113. Since the drive signal output unit 113 is an AND circuit that receives the outputs a and b as inputs, the drive signal output unit 113 outputs drive signal c when the outputs a and b are input, which is input to the actuator 31. This drives the actuator 31, causing the basket 4 to move up and down.

[0042] Returning to Figure 4, T 6 (That is, T = T 6), the sensor 5 detects the ceiling CL (see FIG. 1). Then, the foot switch 7 is disabled (see the left end of the gray colored area in FIG. 4). At this time, in FIG. 3, the detection signal of the sensor 5 is input to the detection signal processing unit 114, and the output d from the detection signal processing unit 114 is input to the disabling signal output unit 115, which outputs the disabling signal e. When the disabling signal e is input, the operation permission signal processing unit 112 does not output the output b even if an operation permission signal is input from the operation permission unit 7. As a result, even if the output a is input from the operation signal processing unit 111, that is, even if the operation lever 60 is operated (in the interval T 7 ≦T≦T 8 3), the drive signal output unit 113 does not output an output c, and the actuator 31 is not driven (therefore, the operating lever 60 is in an inoperable state). This causes the basket 4 to maintain the position of the warning position WL (FIG. 1) that is slightly below the ceiling CL. For example, the worker performs a predetermined high-altitude work while the basket 4 is in the warning position WL. When the detection signal of the sensor 5 is input to the detection signal processing unit 114, the detection signal processing unit 114 outputs an output f and inputs it to the notification unit 117. The notification unit 117 notifies the user of the invalidation section (i.e., section T 6 ≦T <T 9 ) an alarm (warning sound such as a warning sound / buzzer sound / beep sound or warning lamp lighting / flashing) will alert the worker and those in the vicinity.

[0043] Next, in the time chart of foot switch 7, T=T 9 and T=T 10 As shown in the rising part of FIG. 4, the worker returns the foot switch 7 from POS.2 to POS.1 once (i.e., from ON to OFF), and then depresses it again to POS.2 (i.e., to ON). Then, the foot switch 7 is released from being disabled (see the right end of the gray colored area in FIG. 4).

[0044] 3, the output from the foot switch 7 turns OFF once, then turns ON again and is input to the operation permission signal processing unit 112. Then, even if the output e from the invalidation signal output unit 115 is input, the operation permission signal processing unit 112 outputs the output b, and the output b is input to the drive signal output unit 113. Therefore, if the output a from the operation signal processing unit 111 is input to the drive signal output unit 113, the output c is output from the drive signal output unit 113, and the actuator 31 is driven (as shown by (T) in FIG. 4). 11 ≦T≦T 12 In this way, the cancellation of the invalidation by the invalidation signal output unit 115 is performed by the operator operating the foot switch 7, that is, as described above, by temporarily returning the foot switch 7 from the state when the operation was permitted to the state before the operation was permitted (i.e., returning it from POS.2 to POS.1).

[0045] Thus, according to the first pattern, the foot switch 7 permits operation by the operating lever 60, whereby the actuator 31 is operated by the operating lever 60 to raise and lower the basket 4, the foot switch 7 is disabled by the disabling signal output unit 115, and the disabling by the disabling signal output unit 115 is released by the worker operating the foot switch 7. In other words, the disabling cannot be released unless the worker operates the foot switch 7.

[0046] This can prevent the worker from using tape or the like to fix the foot switch 7 in an operation permitted state (i.e., in the operation permitted position of POS.2) when trying to move away from the foot switch 7. As a result, it is possible to prevent accidents during work at height, such as the worker colliding with a high-altitude structure (obstacle) or being pinched between the structure (obstacle), and thus improve work safety.

[0047] <Second pattern> 4A shows a second pattern of the time chart. In this second pattern, the foot switch 7 is disabled by the detection of the sensor 5 (see the left end of the gray colored area in the figure), which is the same as the first pattern. However, the method of control in the disabled section of the foot switch 7 is different from that of the first pattern.

[0048] In the first pattern, the invalidation section T 7 ≦T≦T 8 As shown in FIG. 4A, during this section, even if the operating lever 60 is operated to the lowering side, the basket 4 does not react to the operation of the operating lever 60, and the basket 4 remains stationary. In contrast, in the second pattern, during the section T 7 ≦T <T 8 In the figure, when the operating lever 60 is switched to the lowering side, the basket 4 moves downward in response to the operation of the operating lever 60. 8 ≦T <T 9 In this case, even if the operating lever 60 is switched to the upward direction, the basket 4 does not respond to the operation of the operating lever 60 (i.e., the operating lever 60 is inoperable), and the basket 4 maintains its current height position.

[0049] Thus, in the second pattern, when the foot switch 7 is disabled, the operation of lowering the basket 4 by the lifter 3 (FIG. 1) is permitted, but the operation of lifting is not permitted. In other words, the operating lever 60 is inoperable only for the operation of lifting (in other words, the operating lever 60 is operable only for the operation of lowering), so that the worker can move the basket 4 below the warning position WL, and work at height can be performed more safely. In contrast, in the first pattern shown in FIG. 4, the basket 4 is not moved beyond the disabled section (T 6 ≦T <T 9 ) remains in the warning position WL throughout the entire time from the beginning to the end of the

[0050] <Third pattern> 5 shows a third pattern of the time chart. This third pattern is different from the first and second patterns in that a timer 116 is used in addition to the position detection unit (sensor) 5. That is, in this case, T=T 1 At this point (that is, when permission for operation by the foot switch 7 begins), the timer 116 starts and begins counting.

[0051] Next, T 6 (That is, T = T 6 ), the timer 116 reaches a predetermined set time. Then, the foot switch 7 is disabled (see the left end of the gray colored area in FIG. 5). In this case, the timer 116 reaches a predetermined set time before the sensor 5 detects the ceiling CL (see the time chart of the sensor 5), and the operation lever 60 is in a stationary position for a long time with the foot switch 7 at POS.2 (see the time chart of the operation lever 60), so there is a possibility that an operator has committed fraud by fixing the foot switch 7 with packing tape or the like while the operation lever 60 is stationary.

[0052] Invalidation interval (i.e., interval T 6 ≦T <T 9 During the period T ), the operation of lowering the basket 4 is permitted as in the case of the second pattern shown in FIG. 7 ≦T <T 8 ), the worker can move the basket 4 below the warning position WL, making it safer to work at height.

[0053] Next, in the time chart of foot switch 7, T=T 9 and T=T 10As shown in the rising part of T, if the worker returns the foot switch 7 from POS.2 to POS.1 once (i.e., from ON to OFF) and then presses it back down to POS.2 (i.e., to ON), there is no possibility that the worker has committed an illegal act of fixing the foot switch 7 with packing tape or the like, so the invalidation of the foot switch 7 is released (see the right end of the gray colored part in FIG. 5), and T=T 10 In this case, the timer 116 is restarted. In this case, the invalidation is also released by the operator operating the foot switch 7, that is, by temporarily returning the foot switch 7 from the state when the operation was permitted to the state before the operation was permitted (i.e., returning it from POS.2 to POS.1). As a result, the foot switch 7 permits the operation by the operating lever 60, and when the operating lever 60 is operated, the basket 4 is raised or lowered (section T 11 ≦T <T 12 reference).

[0054] <Fourth pattern> 6 shows a fourth pattern of the time chart. This fourth pattern is similar to the third pattern in that a timer 116 is used in addition to the position detection unit (sensor) 5. However, in this fourth pattern, the foot switch 7 is disabled by the detection of the sensor 5, similar to the second pattern.

[0055] That is, as shown in FIG. 6 (That is, T = T 6 ), when the sensor 5 detects the ceiling CL, the foot switch 7 is disabled (see the left end of the gray colored area in the figure). At this time, the timer 116 has not yet reached the predetermined set time and is not cleared.

[0056] Invalidation interval (i.e., interval T 6 ≦T <T 9 During the period T ), the operation of lowering the basket 4 is permitted as in the case of the second pattern shown in FIG. 7 ≦T <T 8), the worker can move the basket 4 below the warning position WL, making it safer to work at height.

[0057] Next, in the time chart of foot switch 7, T=T 9 and T=T 10 As shown in the rising part of T, the worker returns the foot switch 7 from POS.2 to POS.1 (i.e., turns it from ON to OFF), and then presses it back down to POS.2 (i.e., turns it ON). Then, T=T 9 At T, the timer 116 is cleared, the invalidation of the foot switch 7 is released (see the right end of the gray colored portion in FIG. 6), and T=T 10 At , the timer 116 is restarted.

[0058] Even in this case, the invalidation is released by the operator operating the foot switch 7, that is, by temporarily returning the foot switch 7 from the state when the operation was permitted to the state before the operation was permitted (i.e., returning it from POS.2 to POS.1). As a result, the foot switch 7 permits the operation by the operating lever 60, so that when the operating lever 60 is operated, the basket 4 moves up and down (section T 11 ≦T <T 12 reference).

[0059] In addition, in FIG. 6, the time chart of the foot switch 7 indicates the point where the foot switch 7 is depressed again for the second time (section T 13 ≦T≦T 14 (See Reference 1.) Such re-depression outside the invalidation section is the result of an intentional operation by the worker, and it is presumed that the worker has not engaged in any fraudulent act such as fixing the foot switch 7 with tape or the like through such an intentional operation, so that the timer 116 is cleared even when the foot switch 7 is re-depressed a second time.

[0060] <The fifth pattern> FIG. 7 shows a fifth pattern of the time chart. In the first to fourth patterns, the foot switch 7 is switched only between POS.1 and POS.2, and is not switched to the position POS.3. In the fifth pattern, the foot switch 7 is pressed down to POS.3. In addition, in the fifth pattern, a time chart of an external signal (operation mode switching signal) is shown instead of the time chart of the position detection unit (sensor) 5 and the timer 116 shown in the first to fourth patterns. In this case, in the control of the basket 4 by the lifter 3, there are two operation modes, a normal operation mode (H) and an emergency stop mode (L), and these two modes are switched by the operation mode switching signal.

[0061] As shown in FIG. 7, in the section T 0 ~T 6 (That is, T 0 ≦T <T 6 ) is operating in normal operating mode, and T 6 (That is, T = T 6 ) the foot switch 7 is switched from POS.2 to POS.3. At this time, the worker, sensing danger, etc., presses the foot switch 7 hard, and the foot switch 7 is in a switch OFF state different from POS.1. This causes a transition to the emergency stop mode (L) (i.e., H→L), and the foot switch 7 is disabled (see the left end of the gray colored area in FIG. 7), and the basket 4 is brought to an emergency stop.

[0062] When the control of basket 4 is shifted to the emergency stop mode (L), the section T 6 ≦T≦T 10-11 As shown in the shaded area in FIG. 1, an emergency stop process is performed in which the lifter 3 gradually lowers the basket 4. That is, in this case, after the basket 4 is brought to an emergency stop, the basket 4 gradually lowers from its position at that time, returns to the reference surface position at the start, and stops. During this emergency stop mode, the foot switch 7 is disabled, so the basket 4 is not operated by the operating lever 60 (section T7 ≦T <T 10 reference).

[0063] After the basket 4 returns to the reference plane position, safety is confirmed. Then, the operation mode switching signal is T=T 11 At the timing, the normal operation mode (H) is entered, the foot switch 7 is released from being disabled, and the operation is switched from POS.1 to POS.2 (T=T 12 As a result, operation by the operating lever 60 becomes possible, and the basket 4 is raised by switching the operating lever 60 to the raising side (section T≧T 13 (See reference) Note that T=T 11 Regarding the transition from the emergency stop mode (L) to the normal operation mode (H) at the timing, a safety input from another device may be used.

[0064] Next, FIG. 8 shows an example of a flowchart of the control system (FIG. 3). Here, only the first pattern in FIG. 4 will be described, and the second to fifth patterns will not be described.

[0065] When the program starts, in step S1 of FIG. 8, the program waits for the foot switch 7 to be turned on (i.e., to switch from POS.1 to POS.2). If the foot switch 7 is not turned on, the basket 4 will not move even if the operating lever 60 is operated (the operating lever section T in FIG. 4). 0 ≦T <T 1 reference).

[0066] When the foot switch 7 is turned on (T = T in Figure 4), 1 ), the determination in step S1 becomes "yes", and the process proceeds to step S2. At this time, the operation of the control lever 60 is permitted by the foot switch 7, and the actuator 31 can be operated by the control lever 60.

[0067] In step S2, the worker operates the operation lever 60. In step S3, the basket 4 moves up and down (i.e., rises and falls) by operating the operation lever 60 (section T of the operation lever and basket in FIG. 4). 2 ≦T <T 6 Steps S1, S2 and S3 constitute the operation permission steps of this flowchart.

[0068] Next, in step S4, it is determined whether the sensor 5 detects the ceiling CL (FIG. 1). If the sensor 5 does not detect the ceiling CL, the process returns to step S2 and the processes of steps S2 to S4 are repeated. If the sensor 5 detects the ceiling CL (T of the sensor in FIG. 4=T 6 3), the determination in step S4 becomes "yes," and the process proceeds to step S5. In step S5, an alarm is generated by the notification unit 117 (FIG. 3).

[0069] Next, in step S6, the foot switch 7 is disabled. This disables the operation lever 60, and the actuator 31 cannot be operated by the operation lever 60 (the operation lever and basket section T in FIG. 4). 7 ≦T≦T 8 Step S6 constitutes the invalidation step of this flow chart. After the process in step S6, the basket 4 stops in step S7 (see basket section T in FIG. 4). 6 ≦T <T 9 At this time, the basket 4 is stopped at the warning position WL (see Fig. 1). 6 ≦T <T 9 During this time, specified work at height will be performed.

[0070] Next, in step S8, the process waits for the operator to depress the foot switch 7 again (i.e., after switching from POS.2 to POS.1, it returns to POS.2 again). When the operator depresses the foot switch 7 again (in the foot switch section T in FIG. 4), 9 ≦T≦T 10)), the determination in step S8 becomes "yes", and the process proceeds to step S9.

[0071] In step S9, the invalidation of the foot switch 7 is released, and in the following step S10, the alarm by the notification unit 117 is released. This allows the operation of the control lever 60 again by the foot switch 7, and the actuator 31 can be operated by the control lever 60. Thus, the basket 4 moves up and down (i.e., ascends and descends) by operating the control lever 60 (section T of the control lever and basket in FIG. 4). 11 ≦T≦T 12 Steps S8 to S10 constitute the invalidation cancellation step of this flowchart.

[0072] Next, in step S11, it is determined whether or not the process should be ended. If it is determined that the process should be ended, the process is ended, and if it is determined that the process should not be ended, the process returns to step S1 and the processes of steps S1 to S10 are repeated.

[0073] [First Modification] In the above embodiment, the sensor 5 detects the ceiling CL above (i.e., above the worker's head), but the application of the present invention is not limited to this. The sensor 5 may detect structures (obstacles) diagonally above or to the side depending on the shape and arrangement of high-altitude structures and obstacles. The sensor 5 may be fixed not only directly to the top of the basket 4, but also to the tip of a support that extends upward (or diagonally upward) from the top of the basket 4. When the sensor 5 is fixed to the tip of a support, it does not necessarily have to be a non-contact sensor, and may be a contact sensor having a contact that contacts the detection object. Furthermore, the sensor 5 may be configured to measure height using a barometer, GPS, or the like. In these cases, it is necessary to measure the height of the structures and obstacles above in advance.

[0074] [Second Modification] In the above embodiment, an example was shown in which a three-position type foot switch having a position 3 in addition to positions 1 and 2 was used as the foot switch 7 (see particularly the time chart in FIG. 7), but the application of the present invention is not limited to this. The foot switch 7 may not have position 3, and may simply turn ON / OFF between positions 1 and 2 (see, for example, the time charts in FIGS. 4 to 6).

[0075] [Third Modification] In the above embodiment, an example was shown in which a foot switch operated by an operator with his foot was used as the operation permission unit, but the application of the present invention is not limited to this. A one-handed (or two-handed) enabling switch that an operator grips and operates with his hand may also be adopted, and the enabling switch and the foot switch may be used in combination. By using the enabling switch and the foot switch in combination to provide a duplicated system, an even safer system can be constructed.

[0076] [Fourth Modification] The time charts based on the first to fifth patterns shown in FIGS. 4 to 7 are merely examples, and it goes without saying that control may be performed based on patterns other than these.

[0077] [Fifth Modification] In the above embodiment, the timer 116 is set to a fixed time as an example, but the timer 116 may be set to a random time.

[0078] [Sixth Modification] In the above embodiment, an example is shown in which the foot switch is disabled based on detection by a sensor and / or a time set by a timer, or based on an external signal, but the application of the present invention is not limited to this.

[0079] Generally, when working at height, workers are required to wear a safety belt (fall prevention device) as a safety measure, and therefore the hook of the safety belt needs to be hooked to the handrail of the basket of the vehicle for working at height during work. Therefore, a sensor that detects that the safety belt is hooked to the handrail (for example, an opening / closing switch that detects the opening and closing of the hook's release stopper) may be provided on the hook of the safety belt, and when the worker removes the hook from the handrail, the foot switch may be controlled to be disabled based on the detection signal from the hook sensor.

[0080] This prevents workers from locking the foot switch in the operation permitted state when they try to move away from the foot switch, which can prevent accidents during high-altitude work, such as workers colliding with or being pinned between high-altitude structures (obstacles) and structures (obstacles), improving work safety.

[0081] In addition, the foot switch may be controlled to be disabled based on vital data of the worker obtained from a vital sensor or image data of the worker and his / her surrounding environment obtained from a surveillance camera, and further, the vital sensor and surveillance camera may be used in conjunction with the sensor (position detection unit) and timer of the above-mentioned embodiment.

[0082] [Another application example 1] In the above embodiment, the vehicle for working at height to which the present invention is applied is a self-propelled vehicle having a power source such as an engine or a battery, but it does not necessarily have to be self-propelled, and may be a vehicle such as a truck that is made movable by mounting a basket lifter on the chassis of the vehicle. The lifting mechanism (lifter) is not limited to the scissor type with a pantograph structure as shown in the above embodiment, but may be a vertical mast type consisting of a multi-stage lifting mast, or a boom type consisting of a multi-stage boom, and any structure may be adopted. For example, in the case of a boom type, since the basket not only rises and falls but also rotates, it is preferable to install a sensor that detects obstacles on the side or below. In this case, the set time of the timer 116 (FIG. 3) may be set to a different time for each direction of basket movement (up and down / left and right), which allows for more detailed control.

[0083] [Another application example 2] Although a vehicle for high-altitude work generally refers to a vehicle that is equipped with a running device (vehicle body) in addition to a lifting device (lifter) and can run, the present invention is also applicable to so-called high-altitude work platforms that are stationary and do not have a running device. Therefore, the vehicle for high-altitude work used in this specification is a concept that includes high-altitude work platforms.

[0084] [Other Modifications] The above-described embodiment and each modification should be considered in all respects as merely illustrative of the present invention, and not restrictive. Those skilled in the art to which the present invention pertains may, when considering the teachings above, construct various modifications and other embodiments that incorporate the principles of the present invention without departing from the spirit and essential characteristics of the present invention, even if not expressly described herein. [Industrial Applicability]

[0085] The present invention is useful in a control system and a control method for an aerial work platform. [Explanation of symbols]

[0086] 1: Aerial work platform 3: Lifter (lifting mechanism) 4: Basket (work floor) 5: Sensor (position detection section) 7: Foot switch (operation permission part) 60: Operating lever (operating part) 100: Control Systems 115: Invalidation signal output unit (invalidation means) 116: Timer [Prior art documents] [Patent documents]

[0087] [Patent Document 1] Patent No. 6274665 (see paragraphs

[0009] ,

[0015] to

[0017] ,

[0023] ,

[0029] , and Figures 1 to 3) [Patent Document 2] JP 2020-75769 A (see paragraphs

[0021] to

[0022] and Figure 2) [Patent Document 3] Patent No. 3479442 (see paragraphs

[0013] to

[0014] and Figure 3)

Claims

1. A control system for a vehicle for working at height, the vehicle having a work platform on which a worker boards and works, and a lifting mechanism for raising and lowering the work platform, An operation unit for operating the lifting mechanism; an operation permission unit for permitting an operation by the operation unit; a disabling means for disabling the operation permission unit, The cancellation of the invalidation by the invalidation means is performed by an operator operating the operation permission unit. A control system comprising:

2. In claim 1, A position detection unit detects when the height of the work platform reaches a predetermined upper limit position, The disabling means is configured to disable the operation permission unit based on a detection result by the position detection unit. A control system comprising:

3. In claim 2, When the position detection unit detects the position, the lifting mechanism is stopped and the operation unit is rendered inoperable by disabling the operation permission unit using the disabling means. A control system comprising:

4. In claim 2, When the position detection unit detects the position, the operation unit is inoperable only with respect to an operation of raising the work platform by the lifting mechanism. A control system comprising:

5. In claim 1, The cancellation of the disablement by the disablement means is performed by an operator temporarily returning the operation permission unit to a state before the operation permission was granted. A control system comprising:

6. In claim 1, the disabling means is configured to disable the operation permission unit when a predetermined time set in advance by a timer has elapsed from the start of operation permission by the operation permission unit, A control system comprising:

7. In claim 6, When the operation permission unit is disabled before the predetermined time has elapsed, the timer is cleared. A control system comprising:

8. In claim 1, The operation permission unit has an emergency stop function for emergency stopping the lifting mechanism. A control system comprising:

9. In claim 8, When the lifting mechanism is stopped in an emergency, an emergency stop process is performed in which the lifting mechanism gradually lowers the work platform. A control system comprising:

10. A control method according to the control system of claim 1, comprising: an operation permission step in which the operation permission unit permits the operation of the operation unit, thereby enabling the operation of the lifting mechanism by the operation unit; a disabling step in which the disabling means disables the operation permission unit; a disablement canceling step in which an operator operates the operation permission unit to cancel the disablement performed by the disablement means; A control method comprising:

11. In claim 10, In the disabling step, when it is detected that the height of the work platform has reached a predetermined upper limit position, or when a predetermined time preset by a timer has elapsed since the start of operation permission by the operation permission unit, the disabling means disables the operation permission unit. A control method comprising:

12. In claim 10, The cancellation of the invalidation in the canceling of the invalidation step is performed by an operator temporarily returning the operation permission unit to a state before the operation permission was granted. A control method comprising:

Images