JP3263217B2 - Work machine operation control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for a working machine such as a crane truck with a boom or an aerial work vehicle with a boom.

[0002]

2. Description of the Related Art For example, in an aerial work vehicle equipped with a telescopic boom, in addition to boom turning, up / down and telescopic boom operations, a bucket swing operation (horizontal turning) provided at the tip of the boom is performed. Operation) and the like are performed by dedicated hydraulic actuators.

[0003] Incidentally, even when each operation of these booms is operated independently or when a plurality of operations are performed in parallel, the state of the boom which is changed by the plurality of operations is subject to some restrictions. There is no problem when it is performed by the operator's free will, for example, so-called vertical control for moving the bucket vertically while maintaining a constant work radius, or keeping the height of the bucket constant. If so-called horizontal control is performed to move this in the same horizontal plane while maintaining it, a boom operation that changes the operating condition of the bucket to match the operating condition of the bucket (for example, in the case of vertical control, In such a case, it is necessary to perform the operation of raising and lowering the boom and the operation of expanding and contracting the boom in a mutually related manner.

In this case, for example, in vertical control,
Only when the operator operates the operation lever for vertical operation, the operation of each of the above-described hydraulic cylinders is controlled so that the bucket moves vertically in accordance with the set conditions (i.e., the set work radius) automatically. It is necessary to constantly monitor changes in the boom angle and boom length and control the operation of the hydraulic cylinders for raising and lowering the boom while correlating them with each other. Becomes In this case, as a method for detecting the operating state of the boom, that is, the elevation angle and the length, it has been customary to use a potentiometer for detecting a change in the operating state of the boom as position information.

However, the hydraulic cylinder for raising and lowering and the hydraulic cylinder for expansion and contraction having different operation characteristics (particularly speed characteristics) such as vertical control in an aerial work vehicle are operated in association with each other to meet predetermined set conditions. When the operation is performed, a control error is likely to increase with only the position information from the potentiometer, and it cannot be said that the control accuracy is sufficient. Therefore, in order to realize more accurate control, it is necessary to consider speed information. In this case, the position information detected by the potentiometer may be differentiated and taken in as speed information.However, this potentiometer has a mechanical characteristic that its information resolution is relatively low. Absent.

Under these circumstances, as means for detecting the boom undulation angle and the like, in addition to the above-described potentiometer, a change in the undulation angle and the like can be detected as speed information depending on the number of output pulses, and the information resolution is extremely high. Attempts have been made to provide a high rotary encoder and realize high-precision control based on position information from a potentiometer and speed information from a rotary encoder.

[0007]

However, as described above, a potentiometer and a rotary encoder are provided side by side as means for detecting the state of the working machine, and control is performed based on position information by the potentiometer and speed information by the rotary encoder. In this case, the rotary encoder has a very high information resolution as compared to the potentiometer, so it is possible to expect more precise control, but it is very sensitive and fragile. When the rotary encoder breaks down, there is a problem that the entire control stops even if the potentiometer is working normally. In particular, when the rotary encoder is mounted on a construction machine, such as a crane truck or an aerial work vehicle, in which work vibration is likely to occur, the above-mentioned problem becomes more remarkable.

In view of the above, the present invention relates to an apparatus for controlling a working machine using a potentiometer and a rotary encoder in combination, wherein an operation of a working machine with a boom which can avoid a stop of the control due to a failure of the rotary encoder. It was made as a proposal of a control device.

[0009]

According to the present invention, as a specific means for solving this problem, as shown in FIG.
A plurality of hydraulic machines A1, A2,... Are operated based on the operating conditions set by the operating condition setting means G. In the operation control device of the working machine, which controls the hydraulic actuators A1, A2 so that the hydraulic actuators A1, A2,..., The hydraulic actuators A1, A2,.
, Comprising first potentiometers B1, B2,... Comprising potentiometers for detecting the operational states of the working machines corresponding to the motors A1, A2,.
The operation state detection means C1, C2,... And the failure determination means D1, D2,... Which determine the failure of the second operation state detection means C1, C2,. Receiving output signals from the first operating state detecting means B1, B2,..., The second operating state detecting means C1, C2,... And the failure determining means D1, D2,. , The output signals from the first operating state detecting means B1, B2,... And the output signals from the second operating state detecting means C1, C2,. Output selecting means E1, E2,... For respectively selecting and outputting the output, and the output selecting means E1, E2,... Corresponding to the hydraulic actuators A1, A2,. A plurality of operating state detecting means (B Or C1), (B2 or C2),
.. Receiving a plurality of output signals from the working machine and comparing the current operating condition of the working machine with the operating condition set by the operating condition setting device G to calculate a deviation thereof; An operation amount calculation means H for calculating the required operation amounts of the hydraulic actuators A1, A2,... In response to an output signal from the operation state deviation calculation means F, and an output from the operation amount calculation means H Each of the above hydraulic actuators A1,
A2,... For driving the actuator.

[0010]

According to the present invention, the following effects are achieved by adopting such a configuration.

That is, when a plurality of hydraulic actuators A1, A2,... Perform a plurality of different operations in order to operate the work machine in accordance with the operating conditions set by the operating condition setting means G, the failure determining means When a failure determination signal indicating a failure of the second operating state detecting means C1, C2,... Is not input from D1, D2,... (That is, when the second operating state detecting means C1, C2,. (If activated)
The first operating state detecting means B1, B2,... And the second operating state detecting means C1,
, The second operating state detecting means C1, C2,... Constituted by a rotary encoder having a high information resolution.
Output from is selected. Therefore, in this case, the deviation between the operating condition and the actual operating state is calculated by the operating state deviation detecting means F based on the outputs of the second operating state detecting means C1, C2,. Each of the hydraulic actuators A1,
A2,... Are calculated, and the hydraulic actuators A1, A2,... Are driven and controlled by the actuator driving means I based on the required operation amounts. Accuracy control will be realized.

On the other hand, output selection means E1, E2,.
When a failure determination signal is input to the second operating state detecting means C1, C2,... (That is, when normal operation is not ensured), the second operating state detecting means C1, C2,.
Instead of the first operation state, the output from the first operation state detection means B1, B2,... Constituted by a potentiometer and having a lower information resolution than the rotary encoder but capable of detecting a stable state is selected. State detecting means B1, B
Each of the above hydraulic actuators based on the output from
, The control accuracy is relatively lower than the control based on the output of the second operating state detecting means B1, B2,..., But the second operating state detecting means B
The operation of the working machine can be continued despite the failures of 1, B2,....

[0013]

Therefore, according to the operation control device of the working machine of the present invention, the first potentiometer composed of a highly reliable potentiometer capable of stably outputting information although the information resolution is low.
The operating state detecting means and the second operating state detecting means constituted by a rotary encoder having a higher information resolution than the potentiometer and capable of controlling with high accuracy are juxtaposed, and the second operating state detecting means operates normally. In the case of operating, while achieving high-precision control based on the output of the second operating state detecting means, while the second operating state of the detecting means fails, it becomes difficult to secure normal operation. Instead, the control is performed based on the output of the first operating state detecting means. Therefore, even if the second operating state detecting means fails, the control of the work implement itself is stopped. In addition, although the control accuracy is relatively inferior, the control of the work machine can be continued based on the output of the first operating state detecting means, and the work reliability of the work machine is improved accordingly.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an operation control device for a working machine according to the present invention; FIG. Have been. The aerial work vehicle 1 pivotally supports a base end portion of a telescopic boom 4 on a swivel 3 mounted on a vehicle body 2 so as to be rotatable so as to be able to move up and down.
An operator's boarding bucket 5 is attached to the tip of the robot so as to be swingable in the vertical direction. The swivel 3 is swung (ie, the telescopic boom 4 is swung) by a turning hydraulic motor 8 provided on the swivel 3 side. Further, the telescopic boom 4 is expanded and contracted by a telescopic hydraulic cylinder 7 disposed therein, and the undulation is performed by an undulating hydraulic cylinder 6 disposed between the telescopic boom 4 and the swivel 3. The bucket 5 is swinged by a bucket swing hydraulic motor 9.

The hydraulic cylinder 6 for raising and lowering, the hydraulic cylinder 7 for extending and retracting, the hydraulic motor 8 for turning and the hydraulic motor 9 for bucket swing are connected to the operating panel 11 on the turning table 3 side or the operating lever on the bucket 5 side. The operation of each control valve in the hydraulic unit 10 is controlled by a control signal output from a control unit 13 described below based on an operation signal output from the operation signal output unit 12 in response to the operation. In this embodiment, each of the hydraulic cylinders 6 to 9 corresponds to a hydraulic actuator in the claims.

In order to detect the state of the aerial work vehicle 1 that changes in connection with the operation of the hydraulic cylinders 6 to 9, the swivel 3 is provided with the aerial work vehicle 1. A potentiometer 14 for detecting a turning position and a rotary encoder 18 are provided on the telescopic boom 4, and a potentiometer 15 for detecting an undulation angle of the telescopic boom 4 and a rotary encoder are provided.
19 and a potentiometer 16 for detecting the boom length and a rotary encoder 20, and a potentiometer 17 for detecting the swing position of the bucket 5 and a rotary encoder 21 are arranged on the bucket 5 side. In this embodiment, the potentiometers 14 to 17 correspond to the first operating state detecting means (B1, B2) in the claims, and the rotary encoders 18 to 21 correspond to the claims in the claims. This corresponds to the second operating state detecting means (C1, C2). Information corresponding to the state of the boom and the like detected by the potentiometers 14 to 17 and the rotary encoders 18 to 21 is input to a control unit 13 described later as control elements of the hydraulic cylinders 6 to 9 and the like. .

The aerial work vehicle 1 can be operated individually or simultaneously by an operator's operation. Of course, the hydraulic cylinders 6 and 7 and the hydraulic motor 8 can be operated during the simultaneous operation. May be operated freely based on no operating conditions or may be operated under specific operating conditions. The latter operation is the above-described vertical control operation or horizontal control operation.

When performing such a vertical or horizontal control operation, it is necessary to simultaneously operate a plurality of hydraulic actuators while associating them with each other in accordance with a set specific operating condition. Potentiometers 14 to 17 and rotary encoders 18 to 2
One output signal is used.

Hereinafter, the vertical control and the horizontal control in the aerial work vehicle 1 will be specifically described by taking the case of the vertical control as an example. Prior to that, the technical background of the operation control device of this embodiment will be described. The operation control device of this embodiment is provided with rotary encoders 18 to 21 which detect a state change of a detection target as speed information and realize an extremely high information resolution in order to realize more accurate control. In addition, potentiometers 14 to 17 for detecting a change in the state of the detection target as position information are provided for the following reasons. That is, first, the rotary encoders 18 to 21 used in this embodiment are incremental type rotary encoders, and although position information can be obtained from the speed information thereof, an absolute position cannot be obtained. From the rotary encoders 18 to 2 using the absolute values of the position information detected by the potentiometers 14 to 17.
1 preset, so that the rotary encoders 18 to 2
This is for realizing higher-precision control by obtaining the position information in addition to the speed information from No. 1. Second, the rotary encoders 18 to 21 have an advantage that they are very sensitive and have a high information resolution because of their structure, but have a disadvantage that they are easily broken.
In the case where the control by only 1 is performed, if the rotary encoders 18 to 21 fail and a normal operation cannot be secured, the control itself is stopped. In such a case, the rotary encoders 18 to 21 are stopped. Although control accuracy is relatively inferior to that of the control unit 21, control is performed based on output signals of the potentiometers 14 to 17 with stable operation and high reliability, thereby stopping the control itself due to a failure of the rotary encoders 18 to 21. This is to avoid it (this is the original purpose of the present invention).

Next, a specific description will be given of a case where the operation control device of this embodiment performs vertical control. FIG. 3 shows a functional block diagram when performing vertical control. Here, as the operating state detecting means of the aerial work vehicle 1, when the bucket 5 is moved vertically with a constant working radius (this is an operating condition), a boom length which causes a variation in the working radius is detected. The potentiometer 16 and the rotary encoder 20 for detecting the undulation angle correspond to the potentiometer 16 and the rotary encoder 20. The operation signal output unit 12 corresponds to the operating condition setting means of the aerial work vehicle 1.

The operation signal output unit 12 outputs a signal corresponding to an operation amount and an operation direction of a vertical operation lever (not shown) operated by an operator. The operation condition signal is a condition for starting the vertical control, the operation direction signal is a movement direction condition for moving the bucket 5 up or down, and the operation amount signal is a movement speed condition. Then, signals from the potentiometers 15, 16 and the rotary encoders 19, 20 and the operation signal output unit 12 are input to a control unit 13, which will be described later, to perform vertical control.

The control unit 13 includes an A / D converter 31, a boom length output selection circuit 32, an undulation angle output selection circuit 33, a boom length detector, a failure judgment circuit 34, and an undulation angle detector, as described later. Failure determination circuit 35, direction control circuit 36, direction control circuit 37, up / down counter 38, up / down counter 39, and working radius calculation circuit 4
0, deviation calculation circuit 41, valve operation amount calculation circuit 42, storage circuit 43, A / D converter 44, neutral determination circuit 45, D
/ A converter 46, D / A converter 47, and signal processing circuit 48
And a signal processing circuit 49.

The information on the absolute boom length from the potentiometer 16 is supplied to the A / D converter 31 by the A / D converter 31.
After being D-converted, it is input as position information to a signal processing circuit 48, a boom length detector failure determination circuit 34, and an up / down counter 38, which will be described below. In the signal processing circuit 48, in parallel with outputting the input boom length position information as it is to a boom length output selection circuit 32, which will be described later, the position information is differentiated and the boom length is selected. Is output to the boom length output selection circuit 32 as speed information on the change speed of the boom. Therefore, both the position information on the boom length and the speed information based on the position information are input to the boom length output selection circuit 32 from the potentiometer 16 side.

Similarly, information on the absolute undulation angle from the potentiometer 15 is also subjected to A / D conversion in the A / D converter 31 and then converted into position information to be processed by the signal processing circuit 49 described below and the undulation angle detection. Are input to the device failure determination circuit 35 and the up / down counter 39, respectively. And
In the signal processing circuit 49, in parallel with outputting the input position information as it is to the undulation angle output selection circuit 33, which will be described later, the position information is differentiated, and this is subjected to speed information relating to the change speed of the undulation angle. Undulation angle output selection circuit 3
Output to 3. Therefore, both the position information on the undulation angle and the speed information based on the position information are input to the undulation angle output selection circuit 33 from the potentiometer 15 side.

On the other hand, the rotary encoders 19, 2
The signal (pulse signal) from 0 is input to the direction control circuit 36 and the direction control circuit 37 as speed information on the boom length and the undulation angle, respectively. In each of the direction control circuits 36 and 37, whether the input signal is a change in the direction of extension or contraction of the telescopic boom 4, and in which direction the telescopic boom 4 is tilted or raised. Is determined, and the speed information on the actual direction of change is input to the up / down counters 38 and 39, respectively. In each of the up / down counters 38 and 39, if the input pulse is counted as it is, only the speed information of the boom expansion / contraction or the undulation can be obtained. Therefore, in this case, each potentiometer input through the A / D converter 31 is used. 15,1
6 is reset, the boom length or the undulation angle obtained by the potentiometer signal at that time is defined as the absolute boom length or the undulation angle, and counting is started from this point, and the absolute boom length or the undulation angle is used as the base point. And the position information is obtained by calculation from the speed information and the count time, and both the position information and the speed information are used as the boom length output selection circuit 32 and the boom length detector failure. Judgment circuit 3
4, and outputs to the undulation angle output selection circuit 33 and the undulation angle detector failure determination circuit 35.

The boom length detector failure determination circuit 34 and the undulation angle detector failure determination circuit 35 correspond to failure determination means (D1, D2) in the claims, respectively. The rotary encoder 20 determines the failure of the rotary encoder 20 as a detector and the rotary encoder 19 as an undulation angle detector. The position information input from the potentiometer 16 or the potentiometer 15 and the up / down counter 38 or The boom length output selection circuit compares the position information of the two pieces of information input from the up / down counter 39 with each other and, if the difference between these two pieces of position information is greater than or equal to a predetermined value, outputs the failure determination signal. 32 or the undulation angle output selection circuit 33.

The boom length output selection circuit 32 and the undulation angle output selection circuit 33 correspond to output selection means (E1, E2) in the claims. The position information and speed information from the potentiometer 16 and the position information and speed information from the rotary encoder 20 are simultaneously input to the boom length output selection circuit 32. Further, the position information and speed information from the potentiometer 15 and the position information and speed information from the rotary encoder 19 are simultaneously input to the undulation angle output selection circuit 33. Here, each of these output selection circuits 32, 33
In the case where no failure determination signal is input from the boom length detector failure determination circuit 34 or the undulation angle detector failure determination circuit 35, respectively, the position information and the speed from the rotary encoder 20 or the rotary encoder 19 are output. While the information is output, when the failure determination signal is input, the position information and the speed information from the potentiometer 16 or the potentiometer 15 are output.

Of the position information and the speed information from the output paths selected by the boom length output selection circuit 32 and the undulation angle output selection circuit 33, respectively, the work radius calculation circuit 40 described below has position information, Both the position information and the speed information are input to the valve operation amount calculation circuit 42, respectively. Then, the work radius calculation circuit 40 calculates the current work radius based on the position information on the boom length from the boom length output selection circuit 32 and the position information on the undulation angle from the undulation angle output selection circuit 33, The work radius information is output to a deviation calculation circuit 41 and a storage circuit 43 described later.

On the other hand, the output signal from the operation signal output unit 12 is A / D-converted by an A / D converter 44, and then input to a valve operation amount calculation circuit 42 and a neutral determination circuit 45 described later. . The neutral determination circuit 45 outputs a vertical control start signal to the storage circuit 43 described below only when the vertical operation lever is operated and is in a position other than the neutral position (ie, when a vertical control request is issued). . In the storage circuit 43, when a vertical control signal is input from the neutral determination circuit 45, the work radius at that time input from the work radius calculation circuit 40 is stored as a target control value. That is, the target value is set by the operation signal of the operation signal output unit 12, and in this embodiment, the operation signal output unit 1
2 and the storage circuit 43 constitute an operating condition setting means (G) in the claims.

The target value (work radius) stored in the storage circuit 43 is input to a deviation calculation circuit 41 described later. The deviation calculation circuit 41 calculates a deviation between the two based on the target value and the current work radius input from the work radius calculation circuit 40, and outputs the difference to a valve operation amount calculation circuit 42 described later. In this embodiment, the working radius calculating circuit 40 and the deviation calculating circuit 41 constitute an operating state deviation calculating means (F) in the claims.

In the valve operation amount calculation circuit 42, the current work obtained from the position information on the boom length input from the boom length output selection circuit 32 and the position information input from the elevation angle output selection circuit 33. To the radius and the deviation of the operating state input from the error calculation circuit 41,
Further, taking into account the speed information on the boom length from the boom length output selection circuit 32 and the speed information on the undulation angle from the undulation angle output selection circuit 33, the telescopic hydraulic cylinder 7, the undulating hydraulic cylinder 6, Is operated to calculate the operation amounts of the telescopic valve 22 and the up-and-down valve 23 necessary to make the deviation zero, and the respective operation amounts are expanded and contracted via the D / A converter 46 and the D / A converter 47. Valve 22
And output to the up / down valve 23. In this case, the operation direction is set based on input information from the operation signal output unit 12.

In this embodiment, the valve operation amount calculating circuit 42 is provided with an operation amount calculating means in the claims.
(H), the telescopic valve 22 and the up / down valve 23 correspond to the actuator driving means (I) in the claims.

The specific configuration of the control unit 13 has been described above.

Next, the actual flow of the vertical control by the control unit 13 will be described with reference to the flow charts shown in FIGS.
Explanation will be made based on the

After the start of the vertical control (ie, after the operation signal output unit 12 is operated), first, a flag F indicating the setting of the operating condition (ie, the working radius required to be kept constant) is set. Set F = 0 (Step S
1). The flag F indicates that the operating condition has not been set when F = 0, and indicates that the operating condition has already been set when F = 1.

Next, in step S2, the output (L ₁ ) of the potentiometer 16 for detecting the boom length and the output (θ ₁ ) of the potentiometer 15 for detecting the undulation angle are read, respectively.
Based on (L ₁ ) and (θ ₂ ), the rotary encoder 20 for detecting the boom length and the rotary encoder 1 for detecting the elevation angle
9 are respectively reset to obtain the absolute boom length and the absolute undulation angle.

Further, in step S4, the output (L ₂ ) of the rotary encoder 20 relating to the boom length is obtained.
And output of the rotary encoder 20 regarding the undulation angle (θ ₂ )
And read respectively.

Next, in steps S5 to S10, each output is selected. That is, first, step S
5 is a potentiometer 16 for the boom length.
It is determined whether or not the absolute value of the output (L ₁ ) and the output (L ₂ ) of the rotary encoder 20 is larger than a predetermined value A. here,
If the absolute value is larger than the predetermined value A, the deviation between the position information (boom length information) based on the potentiometer 16 and that based on the rotary encoder 20 is large, so that either the potentiometer 16 or the rotary encoder 20 fails. However, since the rate of failure of the rotary encoder 20 is overwhelmingly large as a structural characteristic of the two, it is determined here that the rotary encoder 20 has failed, and the output of the potentiometer 16 (L ₁ ) is selected (step S6). On the other hand, when the absolute value is smaller than the predetermined value A, it is determined that both the potentiometer 16 and the rotary encoder 20 are operating normally, and in this case, information resolution is large and high-precision control is performed. Promising rotary encoder 20
Output (L ₂ ) is selected (step S7).

[0039] Further, in step S8, the absolute value of the output (theta ₂₎ of the output (theta ₁₎ and the rotary encoder 19 of the potentiometer 15 about hoisting angle to determine whether greater than a predetermined value B. Here, when the absolute value is larger than the predetermined value B, since the deviation between the position information (undulation angle information) based on the potentiometer 15 and that based on the rotary encoder 19 is large, one of the potentiometer 15 and the rotary encoder 19 Although it is considered that a failure has occurred, in this case, similarly to the case of selecting the boom length output, it is determined that the rotary encoder 19 has failed, and
Output of potentiometer 15 as control output signal
(θ ₁ ) is selected (step S9). On the other hand, when the absolute value is smaller than the predetermined value B, the potentiometer 1
5 and the rotary encoder 19 are determined to be operating normally, and in this case, the output (θ ₂ ) of the rotary encoder 19 is selected (step S10).

Subsequently, the output (L ₁ or L ₂ ) relating to the boom length and the output relating to the undulation angle selected as described above.
The current working radius (R) is calculated based on (θ ₁ or θ ₂ ). Further, in step S12, a flag determination is performed. First, since the flag F is 0, step S11 is performed.
The current working radius (R) calculated in is the target value for control.
This is stored as (R ₀ ) (Step S13), and the flag F is set to F = 1 (Step S14). Then, the process returns to the output reading control of Step S2.
After returning to step S2, reading of each output and selection of output are performed in the same manner as described above, and the current working radius (R) is further calculated, and the process proceeds to step S15.

In step S15, the operation amount of the vertical operation lever (ie, the required operation speed) is read, and in step S16, the operation direction of the vertical operation lever is read.
(That is, the requested movement direction of the bucket 5). In step S17, the operation amounts of the telescopic valve 22 and the up-and-down valve 23 are adjusted so that the current working radius (R) becomes the target value (R ₀ ) in consideration of the operating speed and the moving direction.
(V ₁ , V ₂ ) is calculated and output (step S1).
8).

The amount of operation of the telescopic valve 22 and the undulating valve 23
After outputting (V ₁ , V ₂ ), it is determined whether or not the vertical operation lever has been set to the neutral position (that is, whether or not the vertical control request has been canceled). Return, the above working radius (R) and target value
(R ₀ ) is repeated. On the contrary,
When the vertical operation lever is set to the neutral position, the control ends at that time.

By executing the control as described above, when the rotary encoders 19 and 20 are operating normally, high-precision control based on the position information and the speed information from them is realized. Encoder 19,2
If 0 is out of order, control is performed based on the position information and the speed information from the potentiometers 15 and 16. Therefore, even when the rotary encoders 19 and 20 fail, the control based on the outputs of the potentiometers 15 and 16 is continued although the control accuracy is relatively inferior due to the difference in resolution. The control itself is not stopped due to the failure of the vehicle 20, and the work reliability of the aerial work vehicle 1 is improved accordingly.

Although only the vertical control has been described here, it goes without saying that the present invention can be applied to other controls such as horizontal control. Here, as horizontal control,
A control for simply moving the bucket 5 horizontally at a constant height, and a control for horizontally moving the bucket 5 while maintaining the relative position of the bucket 5 to the vertical wall surface in a state where the bucket 5 is opposed to a vertical wall surface, for example. In particular, in the latter horizontal control, the position control of the bucket 5 is performed by expanding and contracting, raising and lowering and turning the telescopic boom 4 and swinging the bucket 5.
(So-called swinging motion) is involved as a control object. Therefore, as the operation state detecting means, the detectors shown in FIG. 2, that is, the potentiometer 14 and the rotary encoder 18 for detecting the turning angle, and the potentiometer 15 for detecting the elevation angle are used. , A rotary encoder 19, a potentiometer 16 and a rotary encoder 20 for detecting the length of the boom 4, and a potentiometer 17 and a rotary encoder 21 for detecting the swing angle. Therefore, in horizontal control,
The detection information from each of these detectors is taken into the control unit 13, and the same control as in the above-described vertical control is performed. Also in this case, by selecting the output of the potentiometer and the output from the rotary encoder depending on whether or not each of the rotary encoders 18 to 21 has a failure, high accuracy can be obtained when the rotary encoders 18 to 21 are operating normally. Control is realized,
Further, when these are out of order, the control itself is of course continued although the control accuracy is relatively inferior.

Also, in the above embodiment, the potentiometers 14 to 14 dedicated to vertical control or horizontal control are used.
17, the present invention is not limited to this. For each of the potentiometers 14 to 17, a potentiometer of an overload prevention device generally provided in the aerial work vehicle 1 is used. Can also.

That is, as shown in FIG. 6, the overload prevention device includes a moment sensor 51, a potentiometer 52 for detecting a boom length, a potentiometer 53 for detecting an up / down angle, and a potentiometer 53 for detecting a turning angle as working state detecting means. Potentiometer 54 and potentiometer 55 for detecting swing angle
And potentiometer 5 for detecting the overhang width of outrigger
And a work restriction setting switch 57 arbitrarily set by an operator. And
The information detected by the potentiometers 51 to 56 and the setting conditions set by the work restriction switch 57 are input to the control unit 50 to perform control.

The control unit 50 controls the rated moment (allowable moment) under the current working condition based on the information from the potentiometers 52 to 56.
And a real work state calculation circuit 60 for calculating an actual work state (for example, a work radius or a work head) based on information from the potentiometers 52 to 26). Have. The rated moment calculated by the rated moment calculation circuit 58 is compared with the actual moment detected by the moment sensor 51 in the comparison circuit 59. When the actual moment exceeds the rated moment, the operation is stopped by the comparison circuit 59. A moment excess signal is output to the determination circuit 63.

On the other hand, the actual work state calculated by the actual work state calculation circuit 60 and the work restriction switch 57
Value storage circuit 6 storing the setting conditions set by
2 is compared with the limit value output from the comparator 2, and when the actual work state exceeds the limit value, a work state excess signal is output from the comparison circuit 61 to the work stop determination circuit 63. The work stop judging circuit 63 judges that the work should be stopped when either or both of the moment excess signal and the work state excess signal are input, and the driving means of each hydraulic actuator (i.e., , Control valve) to output a stop signal to stop the work at that time.

The above is the outline of the overload prevention device. Here, as described above, since the overload prevention device is provided with the potentiometers 52 to 56 for detecting the working state, as shown in FIG.
By taking the output of 56 into the A / D converter 31 of the control unit 13 for vertical / horizontal control, the potentiometers 52 to 56 can be used for both overload prevention control and vertical / horizontal control. . Therefore, in such a case, it is not necessary to provide a dedicated potentiometer for vertical / horizontal control, so that the structure can be simplified or the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is a side view of a main part of an aerial work vehicle with a boom provided with the operation control device according to the embodiment of the present invention.

FIG. 3 is a functional block diagram of the operation control device shown in FIG. 2;

FIG. 4 is a control flowchart of the operation control device shown in FIG. 2;
It is.

FIG. 5 is a control flowchart of the operation control device shown in FIG. 2;
It is.

FIG. 6 is a control block diagram of the overload prevention device.

[Explanation of symbols]

1 is an aerial work vehicle, 2 is a car body, 3 is a swivel base, 4 is a telescopic boom, 5 is a bucket, 6 is a hydraulic cylinder for raising and lowering, 7 is a hydraulic cylinder for expanding and contracting, 8 is a hydraulic motor for turning, and 9 is a bucket swing. Hydraulic motor, 10 a hydraulic unit, 11 an operation panel, 12 an operation signal output unit, 13 a control unit, 14-17 a potentiometer, 18-2
1 is a rotary encoder, 22 is a telescopic valve, 23 is an up / down valve, 31 is an A / D converter, 32 is a boom length output selection circuit, 33 is an up / down angle output selection circuit, and 34 is a boom length detector failure judgment circuit. , 35 is an undulation angle detector failure judgment circuit, 36 is a direction control circuit, 37 is a direction control circuit, 38 and 39 are up-down counters, 40 is a working radius calculation circuit, 41 is a deviation calculation circuit, and 42 is a valve operation amount calculation. Circuit, 43 is a storage circuit, 44 is an A / D converter, 45 is a neutral determination circuit, and 46 and 47 are D / A converters.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B66F 9/24 B66C 23/90

Claims (1)

(57) [Claims] A work machine in which a plurality of operations of different forms are simultaneously associated with each other by a plurality of hydraulic actuators is operated based on an operating condition set by an operating condition setting means, and the operating condition is satisfied. An operation control device of a working machine for controlling each of the above-mentioned hydraulic actuators, comprising, for each hydraulic actuator, a potentiometer for detecting an operating state of the working machine corresponding to the hydraulic actuator. A second operating state detecting means comprising first operating state detecting means and a rotary encoder; a failure determining means for determining a failure of the second operating state detecting means and outputting a failure determination signal; Receiving output signals from the state detection means, the second operation state detection means, and the failure determination means, and receiving the failure determination signal; The output signal from the first operating state detecting means and an output signal from said second operating state detecting means when said fault signal is not input,
Output selecting means for selecting and outputting each of them, and receiving a plurality of output signals from a plurality of operating state detecting means respectively selected by the output selecting means corresponding to each of the hydraulic actuators. Operating state deviation calculating means for comparing the current operating state of the work implement with the operating condition set by the operating condition setting means and calculating a deviation thereof; and receiving an output signal from the operating state deviation calculating means, An operation amount calculation means for calculating a required operation amount of each hydraulic actuator, and an actuator drive means for receiving the output from the operation amount calculation means and driving each of the hydraulic actuators. Operation control device for working machine.