JPH06313326A - Actuator control device - Google Patents

Abstract

PURPOSE:To slowly compensate the dispersion of the output characteristic of an operation lever to obtain natural operating ability in an actuator control device used for a machine such as a power shovel or the like. CONSTITUTION:In the case where an output value (V) from an operation lever 4 is larger than the maximum set up value (Vmax) at a full stroke point held in a maximum set up value holding section 6, a comparison and renewal section 7 renews V as new Vmax. When a computing section 9 learns that a control signal moves to a deadband at a stroke neutral point from a deadband judging section 8, the section 9 carrys out computation for gradually approaching a value (VMAX) where a lever output signal is recognized as a lever full stroke point to Vmax.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator control device used in a machine such as a power shovel.

[0002]

2. Description of the Related Art In a machine such as a power shovel equipped with an actuator driven by an operating lever, the speed, force and position of the actuator increase and decrease as the lever stroke of the operating lever increases and decreases. FIG. 3 is a characteristic diagram showing the relationship between the lever stroke and the actuator speed, where the horizontal axis represents the lever stroke (S) and the vertical axis represents the actuator speed (Av). In the operating relationship between the lever stroke and the actuator speed, the dead zone (a, b) in which the actuator does not react to the lever operation
Exists. This dead zone is around 20% when the lever stroke is near the neutral point, and is 2-5% at the full stroke point.

By the way, the characteristic line of the lever may be different as shown in FIGS. 3A and 3B due to variations in the accuracy of the operating lever. In FIG. 3, A shows the characteristic of the standard lever A, and B shows the specification of the lever B with a large output. The width of the dead zone is larger in lever B than in lever A. In this case, since the lever B has more lever play near the full stroke point than the lever A, it is difficult to operate the lever in detail and the operability is deteriorated. This can occur even with the same operating lever, depending on the operating conditions and changes over time. As described above, the dead zone at the full stroke point has a great influence on the operability, so that the operating lever is required to have a high precision, resulting in a high cost.

On the other hand, in Japanese Patent Laid-Open No. 2-144706, when the output value from the operating lever exceeds the preset minimum guaranteed value, the latest maximum output value is made to match the minimum guaranteed value. While calculating the coefficient of, the coefficient is compared with the coefficient previously stored in the memory, and if the new coefficient is smaller than the previous coefficient, the new coefficient is replaced with the previous coefficient and stored in the memory, By outputting a control signal corresponding to a value obtained by multiplying the output value from the operation lever by the stored coefficient, the idle stroke not involved in the actuator control is reduced and the poor operability is improved. A method has been proposed.

[0005]

However, in the actuator control method proposed in Japanese Unexamined Patent Publication No. 2-144706 mentioned above, since the variation in the output characteristic of the operating lever is corrected at once, the lever operation is performed. The sensation suddenly changed, and the operability of the lever became unnatural.

According to the present invention, the variation in the output characteristic of the operating lever is corrected gradually and when the lever is in neutral.
An object of the present invention is to provide an actuator control device that can obtain natural operability.

[0007]

In order to solve the above problems, an actuator control device according to the present invention has an operation amount input having an operation lever and a measuring means for generating an electric signal according to a lever stroke of the operation lever. In an actuator control device including a device and a controller that outputs a control signal for driving an actuator based on an output value from the operation amount input device, a maximum set value at a full stroke point of the operation lever is held. Comparing the output value from the operation lever with the maximum set value, and if the output value is larger than the maximum set value, the output value is replaced with the maximum set value. The comparison / update means for updating and storing in the set value holding means and the control signal to the actuator are in the dead zone of the stroke neutral point. A dead band judging means for judging whether or not the maximum value held in the maximum set value holding means is a value for recognizing the lever output signal as a lever full stroke point each time the control signal shifts to the dead band. And a calculation means for performing calculation for gradually approaching the value.

In addition to the arithmetic function, the arithmetic means has a maximum output value from the operating lever which is larger than an initial set value at the full lever stroke and which is held by the maximum set value holding means. When it is smaller than the set value, the maximum set value held in the maximum set value holding means is calculated so as to gradually approach the lower limit set value at the full lever stroke.

[0009]

When the output value from the operation lever satisfies the condition of being larger than the maximum set value, the controller updates and stores the output value as a new maximum set value. Then, when the control signal to the actuator shifts to the dead zone of the stroke neutral point, the value that the controller recognizes the lever output signal as the lever full stroke point is the maximum set value held in the maximum set value holding means. The calculation for gradually approaching to is performed. As a result, it is possible to eliminate the error between the point that is recognized as the lever full stroke in the controller and the actual lever full stroke point of the operation lever. For example, looking at levers A and B in FIG. 3,
Since the lever output signal V for the same lever stroke is different as shown by A1 and B1 in FIG. 4, the actuator speed Av for the lever output signal is as shown in FIG. 5C for the levers A and B before correction. It becomes a characteristic.
On the other hand, in the corrected levers A and B, A2 and B in FIG.
2, the dead zone amount b at the full stroke point of the lever B can be made equal to the dead zone amount a of the lever A.

If the output value from the operating lever is larger than the initial set value at the time of lever full stroke and smaller than the maximum set value held in the maximum set value holding means, the maximum value is set. By performing a calculation to gradually bring the set value closer to the lower limit set value at full lever stroke, an appropriate dead zone can be secured even if the dead zone on the lever full stroke side is too small, and operability can be improved. it can. According to this, the calculation processing for correction is performed every time the lever shifts to the dead zone of the stroke neutral point, so that the variation in accuracy of the operation lever is gradually corrected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an actuator control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of an actuator control system to which the actuator control device according to the present invention is applied. This actuator control system includes a manipulated variable input device 1, a controller 2,
And an actuator 3.

The operation amount input device 1 receives an operation for controlling an actuator. This manipulated variable input device 1
The operating lever 4 and the measuring means 5 for generating an output signal according to the lever stroke of the operating lever 4 are provided. An output signal (hereinafter referred to as a lever output signal) from the manipulated variable input device 1 is sent to the controller 2.

The controller 2 is the operation amount input device 1
Is a control circuit that executes a later-described calculation process based on the output value of the lever output signal from the controller and outputs a control signal for driving the actuator. The maximum setting value holding unit 6, the comparison / update unit 7, the dead band It is composed of a judgment unit 8 and a calculation unit 9.

The maximum set value holding portion 6 is the operation lever 4
Holds the maximum set value (Vmax) at the full stroke point. This value is updated as needed.

The comparing / updating unit 7 includes the manipulated variable input device 1
The output value (V) of the lever output signal from V is compared with the maximum set value held in the maximum set value holding unit 6, and V
If> Vmax, the output value of the lever output signal is replaced with the maximum set value before the maximum set value holding unit 6 and updated and stored. However, the range that can be updated is set within a range that does not pose a safety concern. Here, the abnormal voltage determination threshold value (VEM
G) is set and the output value of the lever output signal exceeds this value, abnormal voltage input processing is performed. In addition, the safety can be ensured by performing the update when the control signal of the controller is in the dead zone of the lever neutral point.

The dead zone judging section 8 monitors the control signal to the actuator 3 to judge whether or not the control signal is in the dead zone at the neutral point of the stroke. When shifting to the band, this is notified to the calculation unit 9.

When the dead band judgment unit 8 judges that the control signal has shifted to the dead band, the calculation unit 9 sets the value (VMAX) at which the lever output signal is recognized as the lever full stroke point to the maximum value. The calculation for gradually approaching the maximum set value (Vmax) held in the set value holding unit 6 is performed. Further, the output value (V) of the lever output signal,
The initial set value (Vimax) at the lever full stroke is compared with the value (VMAX) recognized as the lever full stroke point. When Vimax <V <VMAX, the maximum set value holding unit 6 holds the value. The maximum set value (Vmax) that is present is gradually calculated to approach the lower limit set value (Vmin) when the lever is fully stroked.

Here, the calculation for gradually approaching VMAX to Vmax is such that, when the speed of approaching VMAX to Vmax is ΔV +, VMAX = VMAX each time the operating signal of the actuator shifts to the dead zone at the neutral point. + (ΔV +)
The calculation process of is executed once. As a result, VMAX gradually approaches Vmax at a constant rate. However,
VMAX is not corrected beyond the value of Vmax.

Further, the calculation for gradually bringing Vmax closer to Vmin is carried out by changing the speed of bringing Vmax closer to Vmin by Δ.
When V- is set, the calculation process of Vmax = Vmax + (ΔV-) is executed once each time the operating lever shifts to the dead zone of the neutral point. As a result, Vmax gradually approaches Vmin at a constant rate. However, Vmax is not corrected beyond the value of Vmin.

As described above, since the values of VMAX and Vmax are not corrected beyond a predetermined value, the width of the dead zone at the full stroke of the operating lever should be kept within a substantially constant range. You can When the system starts up, Vimax is set as an initial value for each of VMAX and Vmax.

The controller 2 is composed of a control circuit having CPU (central processing unit), ROM, RAM and the like as main constituent elements, and executes a process of a flow chart described later by a predetermined control program.

Next, the flow of the set value correction process by the controller 2 will be described with reference to the flowchart of FIG.

First, Vmax = Vimax and VMAX = Vimax are set (step 101), and it is determined whether the output value V of the lever output signal is larger than the abnormal voltage determination threshold value (VEMG) (step 102). Here, when V> VEMG, it is an excessive voltage, so abnormal voltage input processing is performed (step 103). If V> VEMG is not satisfied in step 102, it is determined whether V is larger than Vmax (step 104). If V> Vmax, the output value V of the new lever output signal is replaced with Vmax and held (step 105). Then, it is judged whether or not the control signal of the actuator is in the dead zone of the stroke neutral point (step 106), and when the control signal shifts to the dead zone, VMAX is set by the speed ΔV +.
Is made to gradually approach Vmax (step 10).
7). Next, it is judged whether or not the output value V of the lever output signal is smaller than VMAX and larger than Vimax (step 108). If Vimax <V <VMAX, the speed Δ
A calculation is performed by V- to gradually bring Vmax closer to the lower limit set value Vmin at the lever full stroke (step 10).
9).

According to the arithmetic processing of the controller described above, the amount of the dead zone at the full stroke of the operating lever can be kept substantially constant, so that the poor operability due to the variation in the accuracy of the operating lever can be improved. it can. In addition, since calculation processing is performed each time the lever moves to the stroke neutral point, variations in the accuracy of the operating lever are gradually corrected. Therefore, the operation feeling of the lever does not suddenly change, and the operability of the lever can be made natural.

[0026]

As described above, in the actuator control device according to the present invention, the variation of the output characteristic of the operating lever is gradually corrected every time the control signal of the actuator shifts to the dead zone of the stroke neutral point. Therefore, the feeling of operating the lever is gradually improved over time, and the operator can obtain natural operability.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an actuator control system.

FIG. 2 is a flowchart showing a flow of setting value correction processing by a controller.

FIG. 3 is a characteristic diagram showing the relationship between lever stroke and actuator speed.

FIG. 4 is a characteristic diagram showing a relationship between a lever stroke and a lever output signal.

FIG. 5 is a characteristic diagram showing a relationship between a lever output signal and an actuator speed.

[Explanation of symbols]

 1 ... manipulated variable input device 2 ... controller 3 ... actuator 4 ... operating lever 6 ... maximum set value holding unit 7 ... comparison / update unit 8 ... dead band judgment unit 9 ... arithmetic unit

Claims (2)

[Claims] 1. An operation amount input device having an operation lever and a measuring means for generating an output signal according to a lever stroke of the operation lever, and for driving an actuator based on an output value from the operation amount input device. In an actuator control device comprising a controller for outputting a control signal of, a maximum set value holding means for holding a maximum set value at a full stroke point of the operation lever, an output value from the operation lever and the maximum set value. When the output value is larger than the maximum set value, the output value is replaced with the maximum set value and the comparison / update means for updating and storing in the maximum set value holding means, and the control signal to the actuator are Region determining means for determining whether or not the stroke neutral point is in a specific region, and each time the control signal shifts to the specific region, The controller further comprises a calculating means for calculating a value for recognizing the lever output signal as a lever full stroke point to gradually approach the maximum set value held in the maximum set value holding means. Actuator control device. 2. The calculation means, in addition to the calculation function,
When the output value from the operating lever is larger than the initial set value at the time of lever full stroke and smaller than the value held in the maximum set value holding means, it is held in the maximum set value holding means. 2. The actuator control device according to claim 1, wherein the maximum set value is calculated so as to gradually approach the lower limit set value at the time of lever full stroke.