JPH0457599B2 - - Google Patents

Description

[Detailed Description of the Invention] Object of the Invention (Industrial Application Field) The present invention relates to a control method for an aerial work vehicle, and more specifically, a control lever for raising/lowering/extending/swinging a boom;
When the control signal set based on the operation of the travel control lever etc. changes suddenly, boom operation or travel operation is delayed to improve boom operability and travel performance and improve safety. The present invention relates to a method for controlling an aerial work vehicle.

(Prior Art) In general, in an aerial work vehicle, when the boom's hoisting operation lever is suddenly operated, for example, the boom is prevented from being synchronously and suddenly hoisted.
By appropriately delaying the timing at which the drive voltage as a drive amount instruction signal to the control valve of the luffing hydraulic cylinder reaches its maximum or minimum, the boom is gradually operated and vibrations generated in the boom are reduced. There is. Conventionally, as this delay control method, the seventh
As shown in the figure, the driving voltage is increased or decreased based on the delay line A during a predetermined delay time τ, and the drive voltage is driven based on the delay curve B that is convex upward than the delay line A. There was a control method to increase or decrease the voltage.

(Problem to be Solved by the Invention) However, in the above two conventional delay control methods, the increase rate of the initial drive voltage is large especially in the case of a starting operation in the B type, so it is difficult to start the boom from a stationary state. There were problems in that the impact was strong and the machine easily vibrated when the machine was moved, resulting in a decrease in operating feeling and safety. or,
Even in the case of a stop operation, the reduction rate of the drive voltage at the end is large, so the boom suddenly comes to a standstill, causing intense vibrations, and if the boom collides with an obstacle due to inadvertence, the impact will be large, resulting in a lack of safety. There was a problem. On the other hand, in order to reduce boom vibration as much as possible for both types A and B to improve operational feeling and integrity, it is necessary to increase the delay time There was also the problem that the time required for movement or running became longer, reducing work efficiency.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention aims to prevent the control signal set based on the operation of the operating means for boom operation or traveling action of the aerial work vehicle to suddenly increases or decreases, the drive amount instruction signal for the boom drive means or travel drive means of the aerial work vehicle is increased or decreased with a delay from the time when the control signal is set, and the boom operation or travel operation is gradually controlled. In the control method of the aerial work vehicle, when the control signal increases rapidly, the increase rate of the drive amount instruction signal is changed stepwise or continuously from the beginning of the boom operation or traveling operation to the end of the movement. and when the control signal suddenly decreases, the reduction rate of the drive amount instruction signal is decreased stepwise or continuously from the beginning of the boom operation or travel operation to the end of the travel operation. There is.

(Function) Since the present invention employs the above means, it functions as follows.

That is, even if the control signal increases rapidly, the increase rate of the drive amount instruction signal is small at the beginning of the operation of the boom or the like, so the operation of the boom or the start of the traveling operation is performed slowly. Since the increase rate of the drive amount instruction signal increases at the end of the movement of the boom, etc., compared to the conventional case where the increase rate is constant (A type) or where the increase rate decreases towards the end (B type). This will shorten the delay time.

On the other hand, when the control signal suddenly decreases, the reduction rate of the drive amount instruction signal is large at the beginning of the movement of the boom, etc., so that the movement of the boom, etc. is carried out quickly and the delay time is shortened. Then, at the end of the operation of the boom, etc., the rate of decrease of the drive amount instruction signal becomes small, so the operation of the boom or the stop of the traveling operation is performed slowly.

(Embodiment) Hereinafter, an embodiment embodying the method of controlling an aerial work vehicle of the present invention will be described based on FIGS. 1 to 5.

As shown in FIG. 4, a turntable 2 is supported on a body frame 1 of the aerial work vehicle, and a telescoping boom 3 is mounted on the turntable 2 so as to be able to be raised and lowered by a raising and lowering cylinder 4. A platform 5 is attached to the tip of the boom 3, and an operation panel 6 is attached to the platform 5. As shown in FIG. 3, this operation panel 6 is provided with an operation lever 7 for raising and lowering the telescopic boom 3, an operation lever 8 for extending and retracting, and an operation lever 9 for turning, and an operation lever 10 for traveling the aerial work vehicle. are also located. Each of the operating levers 7 to 10 as operating means operates a potentiometer PM according to its inclination angle θ, and generates a control voltage Vc as a control signal that changes in proportion to the inclination angle θ. ing. For example, as shown in FIGS. 3 and 5, the hoisting operation lever 7 is moved from the neutral position (inclination angle θ is zero) to the front (positive upright direction) or backward (minus downhill direction) by a predetermined angle, that is, as shown in FIGS. There is a dead zone until the tilting angle reaches the minimum effective tilt angle θmin, and the control voltage Vc increases linearly and proportionally until the tilt angle θ reaches the maximum value θmax.

As shown in FIG. 3, each of the operating levers 7 to 10
is connected to an A/D converter 11 for converting the control voltage Vc as an analog quantity into a digital quantity, and the A/D converter 11 is connected to a control circuit 12 consisting of a microcomputer. Further, a drive amplifier 13 is connected to the control circuit 12, and the amplifier 13 controls a control valve 14 that controls a hydraulic cylinder for luffing (not shown) as a boom drive means, and a hydraulic cylinder for telescoping (also a boom drive means). A control valve 15 that controls a swing hydraulic motor (not shown) as a boom driving means, and a control valve 1 that controls a traveling hydraulic motor (not shown) as a traveling drive means.
7 is connected.

The control circuit 12 is connected to the potentiometer PM.
Based on the respective control voltages Vc output from the control voltages Vc and the preset exponential drive amount setting curve L shown in FIG. 10 is suddenly connected, the drive voltage as the drive amount instruction signal
Delay operation is performed by outputting Vd, and if the operation is not sudden, the control voltage Vc is used as the drive voltage.
It is converted to Vd to avoid delayed operation.

On the other hand, on the frame 1 side, there are provided an elevation operation switch 18, a telescopic operation switch 19, and a turning operation switch 20, which are connected to the I/O port 2.
1 to the control circuit 12.
When the operating switches 18 to 20 are OFF, the control voltage Vc is the minimum (zero), and when they are ON, the control voltage Vc is the minimum (zero).
Although Vc is the maximum fixed value, it may be a value somewhere between the minimum and maximum, and it is also possible to operate multiple operation switches digitally.

Next, a control method based on the control device configured as described above will be explained with reference to the flowcharts of FIGS. 1 and 2.

Now, when each of the operating levers 7 to 10 is in the neutral position (the inclination angle θ is zero), the turning operation of the turntable 2 has stopped, and the extending and retracting operation of the boom 3 has also been stopped, for example, when the operating lever 7 for luffing forward (θ
is tilted in the positive direction), the current tilt angle θ
(k) is calculated, and the control circuit 12 calculates the current drive amount δθk corresponding to this inclination angle θ(k). When the operating lever is tilted rapidly, a predetermined delay time τk is given until the current drive amount δθk, that is, the current value is reached, based on the flowchart in FIG. This operation will be explained in detail below.

After the current value δθk is calculated, the drive amount is zero when the operating lever is in the neutral position, and is replaced with a value greater than zero and smaller than the current value δθk when the operating lever is in the operating position; In other words, a preset variable drive amount δθc is added to the previous value δθ(k-1) based on the drive amount setting curve L shown in FIG.
1) + δθc], the current value δθk is replaced with the total value [δθ(k-1) + δθc], and based on this replaced current value δθk', the drive voltage Vd is output from the control circuit 12. is calculated, and the drive voltage Vd is amplified and output from the drive amplifier 13.
Also, the replaced current value δθk′ is the previous value δθ(k−
1), and if the current value δθk is equal to or less than the above-mentioned total value [δθ(k-1) + δθc], the current value δθk remains valid,
The drive voltage Vd is calculated based on the current value δθk,
Boom delay operation ends.

As described above, in this embodiment, this process is repeated at regular intervals based on the flowchart shown in FIG. 2, and the drive voltage Vd is output along the drive amount setting curve L shown in FIG. is carried out smoothly. In other words, since the rate of increase in the drive Vd is lower in the initial stage of startup than in the middle and final stages, the stationary boom 3 starts to move smoothly, its vibrations are suppressed, and safety is improved.

The delay time τk is determined by the drive amount setting curve L and the setting time of a constant cycle, but it is desirable to set it to be as small as possible.

Note that if the operating lever 7 is suddenly returned to the stop position while the boom 3 is erected at a predetermined position, a delayed operation will be performed according to the drive amount setting curve L' in Fig. 1. In this case, since the reduction rate of the drive voltage Vd at the end of the stopping operation is smaller than at the initial and middle stages, the boom 3 is stopped quietly, and even if the boom collides, the impact is suppressed, which is advantageous in terms of safety.

Furthermore, as is clear from the drive amount setting curves L and L', the rate of increase in the drive voltage Vd becomes larger towards the end of the start-up, while the rate of decrease in the drive voltage Vd becomes larger towards the beginning of the stop operation. In other words, at the end of startup or the beginning of stop operation, which have little effect on the vibration of boom 3, the drive voltage is
Change the rate of increase or decrease in Vd to conventional A type or B type.
It is larger than the type. Therefore,
Since the movement of the boom 3 is accelerated accordingly, the delay time τ can be made shorter than in the past.

Note that the present invention can also be embodied as follows.

(1) As shown in FIG. 6, instead of the drive amount setting curve L, a polygonal drive amount setting curve L may be used.

(2) In the embodiment described above, the driving amount setting curve L is stored in the control circuit 12 in advance, but instead of this, it may be calculated using a calculation formula. Alternatively, it may be defined (stored) as a map in the control circuit 12 and used.

(3) In the above embodiment, the case of starting and stopping has been described, but it may be implemented as a control method in which the control voltage Vc is rapidly raised or lowered during operation.

Effects of the Invention As detailed above, according to the present invention, when the control signal suddenly increases based on the operation of the operating means, the boom operation or traveling operation accompanying the increase in the drive amount instruction signal is changed to the corresponding operation. It can be performed slowly at the beginning of the movement, and even if the control signal decreases rapidly, the boom, etc. can be operated slowly at the end of the movement due to the decrease in the drive amount instruction signal, so vibrations of the boom and vehicle body can be suppressed. This makes it possible to improve the operating feeling and safety, and also to reduce the rate of increase or decrease of the drive amount indication signal during the boom operation or the progress stage of traveling operation, when the vibration of the boom or vehicle body is hardly affected. Since these are made larger, the operation of the boom etc. can be carried out quickly, delay time can be shortened, and work efficiency can also be improved, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a drive amount setting curve diagram showing an example of the control method for the aerial work vehicle of the present invention, FIG. 2 is a flowchart diagram for explaining the control method, and FIG. 3 is a schematic circuit diagram of the control device. Figure 4 is a front view of the aerial work vehicle.
Fig. 5 is a graph showing the relationship between the tilt angle of the operating lever and the control voltage, Fig. 6 is a graph showing another example of the drive amount setting line, and Fig. 7 is a graph for establishing the conventional control method. . Telescopic boom...3, Luffing operation lever...7,
Telescopic operation lever……8, Swivel operation lever……
9. Travel control lever...10. Control circuit...1
2. Drive amplifier...13. Control valves for undulating, telescoping, turning, and traveling...14,1
5, 16, 17, operation switch...18-20,
Delay time...τ, tilt angle of the operating lever...θ, amount of drive when the tilt angle of the operating lever is θ(k)...
δθk, drive amount calculated based on the drive amount setting curve L... δθc, control voltage as a control signal...
Vc, drive voltage as drive amount instruction signal...Vd.

Claims (1)

[Claims] 1. When the control signal set based on the operation of the operating means for boom operation or traveling operation of the aerial work vehicle suddenly increases or decreases, the boom drive means of the aerial work vehicle or In a control method for an aerial work vehicle, in which a drive amount instruction signal for a traveling drive means is increased or decreased with a delay from when the control signal is set, and the operation of the boom or the traveling operation is gradually advanced, wherein the control signal suddenly increases or decreases. If the control signal suddenly increases, the increase rate of the driving amount instruction signal is increased stepwise or continuously from the initial stage to the final stage of the boom operation or traveling operation, and if the control signal suddenly decreases, the driving amount instruction signal increases gradually or continuously. A control method for an aerial work vehicle in which a reduction rate of a volume indicating signal is reduced stepwise or continuously from the beginning of the boom operation or travel operation to the end of the movement. 2. When the drive amount instruction signal exceeds a variable drive amount set by a substantially exponential drive amount setting curve stored in the control circuit in advance, the variable drive amount is replaced with the actual drive amount and delayed. A method for controlling an aerial work vehicle according to claim 1, which operates.