KR101198467B1 - Gravity compensation control apparatus and gravity compensation control method for excavator - Google Patents

Abstract

The present invention relates to a gravity compensation control device and a gravity compensation control method of an excavator. The gravity compensation control device according to the present invention includes a compensation value determining unit for controlling an excavator having a swing body, a boom, an arm and a bucket, and determining a gravity compensation value for the distance between the swing body and the bucket; A boom controller for generating a boom control signal for controlling rotation of the boom with respect to the pivot body according to a preset boom control technique; A boom driver for rotating the boom according to the boom control signal; And a main control unit controlling the boom control unit so that the gravity compensation value is reflected in the boom control scheme when the boom control unit generates the boom control signal. Accordingly, by compensating for the error of the excavator posture, in particular, the distance between the swinging body and the bucket through gravity compensation, the operation of the boom can be stably controlled regardless of the excavator posture.

Description

Gravity Compensation Control Device and Gravity Compensation Control Method of Excavator {GRAVITY COMPENSATION CONTROL APPARATUS AND GRAVITY COMPENSATION CONTROL METHOD FOR EXCAVATOR}

The present invention relates to a gravity compensation control device and a gravity compensation control method of an excavator, and more particularly, gravity compensation of an excavator that can minimize the error of the boom control signal according to the location of the bucket through the gravity compensation according to the position of the bucket It relates to a control device and a gravity compensation control method.

Excavators that are widely used in construction sites are gradually increasing their roles due to high applicability and economical efficiency to various types of work. However, excavator driving is a difficult task, and the phenomenon of avoiding excavator driving occurs, which causes a lot of difficulties in the construction site due to the difficulty in finding skilled drivers. In order to compensate for this, research on the automation of excavators, in which the excavator itself performs automatic excavation work, rather than human work, is continuously conducted.

One of the most important parts of such an intelligent excavator is to move the bucket path of the excavator accurately and quickly to the desired position. In order to control the bucket accurately, the driving unit for driving the boom and the arm connecting the bucket, that is, the hydraulic cylinder, must be precisely controlled.

In general, as an input signal for driving the boom and the arm, a target angle value between the boom and the swinging body and between the boom and the arm is input. That is, the position of the bucket is finally determined by inputting the angle between the boom and the swinging body and the angle between the boom and the arm for connecting the bucket to determine the position of the bucket.

However, it is not easy to control this precisely because the force and voltage to be controlled depend on the position of the excavation, in particular the position of the bucket. That is, when the bucket is located close to the swinging body as shown in FIG. 1 (a), and when it is far away from the swinging body as shown in FIG. The load applied to the center is different, and when the same voltage value is applied to the drive unit to rotate the boom 5 ° in the vertical direction in each of the two postures, the bucket is as shown in FIG. The boom may not rotate in a position away from the pivot body.

Accordingly, the present invention has been made to solve the above problems, the stability of the boom irrespective of the position of the excavator, for example, the distance between the swing body and the bucket, while stably ensuring the operation of the boom control signal according to the position of the bucket It is an object of the present invention to provide a gravity compensation control device and a gravity compensation control method of an excavator that can minimize the.

In addition, the present invention generates a boom control signal suitable for the attitude of the bucket in the execution of the boom control technique for the control of the boom, the gravity compensation control device and gravity compensation control method of the excavator that can more stably control the operation of the boom There is another purpose to provide.

According to an aspect of the present invention, there is provided a gravity compensation control apparatus for an excavator having a swing body, a boom, an arm, and a bucket, comprising: a compensation value determiner configured to determine a gravity compensation value for a distance between the swing body and the bucket; A boom controller for generating a boom control signal for controlling rotation of the boom with respect to the pivot body according to a preset boom control technique; A boom driver for rotating the boom according to the boom control signal; When the boom control unit generates the boom control signal, it is achieved by the gravity compensation control device of the excavator comprising a main control unit for controlling the boom control unit to reflect the gravity compensation value in the boom control technique .

Here, a boom angle detector for detecting a boom angle value between the swing body and the boom, an arm angle detector for detecting an arm angle value between the boom and the arm, a bucket for detecting a bucket angle value between the arm and the bucket Further comprising an angle detector; The compensation value determiner may determine the gravity compensation value according to a kinematic model between the boom, the arm, and the bucket based on the boom angle value, the arm angle value, and the bucket angle value.

The boom control unit receives the boom target rotation value for the rotation of the boom, receives the boom angle value, and performs the boom control technique; The main control unit may control the boom control unit so that the gravity compensation value is fed forward to the boom control technique and reflected.

On the other hand, according to another embodiment of the present invention, in the gravity compensation control method of an excavator having a swing body, a boom, an arm and a bucket, (a) a gravity compensation value for the distance between the swing body and the bucket Determining; (b) generating a boom control signal for controlling the boom by reflecting the gravity compensation value in a preset boom control technique for controlling the rotation of the boom with respect to the pivoting body; (C) it can also be achieved by the gravity compensation control method of the excavator comprising the step of rotating the boom in accordance with the boom control signal.

Here, the step (a) is the step of detecting the boom angle value between the pivot body and the boom; Detecting an arm angle value between the boom and the arm; Detecting a bucket angle value between the arm and the bucket; The gravity compensation value may be determined based on a kinematic model between the boom, the arm, and the bucket, based on the boom angle value, the arm angle value, and the bucket angle value.

And, step (b) (b1) is a step of inputting a boom target rotation value for the rotation of the boom; (b2) receiving the boom angle value and executing the boom control technique using the boom target rotational value as an input value; (b3) The gravity compensation value may be fed forward to the boom control technique and reflected.

Here, the boom control technique may include a PI control technique consisting of a P control technique and an I control technique.

The compensation value determiner is configured to act on the center of gravity of the boom, the arm, and the entire bucket about the rotation axis of the pivoting body and the boom, which are calculated according to the boom angle value, the arm angle value, and the bucket angle value. The gravity compensation value can be determined based on the force.

According to the present invention according to the configuration, by compensating for the error according to the attitude of the excavator, in particular the distance between the swing body and the bucket through gravity compensation, the gravity of the excavator that can stably control the operation of the boom irrespective of the attitude of the excavator Compensation control apparatus and gravity compensation control method are provided.

1 is a view showing examples of the posture of a conventional excavator,
2 is a view showing the configuration of an intelligent excavator system according to the present invention,
3 is a view showing the configuration of the gravity compensation control device of the intelligent excavator system according to the present invention,
4 shows an example of a kinematic model for calculating the gravity compensation value in the gravity compensation control device according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment according to the present invention. Here, in describing the present invention, the posture of the excavator 100 will be described with reference to FIG. 1.

2 is a view showing the configuration of an intelligent excavator system according to the present invention. As shown in FIG. 2, the intelligent excavator system according to the present invention includes an excavator 100 and a gravity compensation control device 300.

The excavator 100 is rotatably installed on the traveling body 120, the pivoting body 110 that is pivotally coupled to the traveling body 120 on an upper portion of the traveling body 120, and the pivoting body 110. The boom 130 includes a boom, an arm 140 that is rotatably installed at the boom 130, and a bucket 150 that is rotatably installed at the end of the arm 140. do. Here, the configuration of the excavator 100 may be provided in various forms known in the art, the detailed description thereof will be omitted.

Meanwhile, the gravity compensation control device 300 according to the present invention includes a compensation value determining unit 313, a boom controller 311, a boom driver 312 and a main controller 314, as shown in FIG. 3. do. In addition, the gravity compensation control device 300 is a boom angle detection unit 310, arm 140 angle detection unit, bucket angle detection unit 330, arm control unit 321, bucket control unit 331, arm drive unit 322 and Bucket drive unit 332 may be included.

The boom angle detector 310 detects an angle value of the boom 130 corresponding to the angle between the pivoting body 110 and the boom 130. The arm angle detector 320 detects an arm 140 angle value corresponding to the angle between the boom 130 and the arm 140. Similarly, the bucket angle detector 330 detects the bucket 150 angle value corresponding to the angle between the arm 140 and the bucket 150. Here, the boom angle detector 310, the arm angle detector 320, and the bucket angle detector 330 may be provided in various forms that can calculate the rotation angle, for example, a resolver or an angle encoder. Can be.

The compensation value determiner 313 calculates a gravity compensation value for the distance between the pivot body 110 and the bucket 150. That is, as shown in FIG. 1, a distance difference between the pivot body 110 and the bucket 150 occurs according to the working posture of the excavator 100. Due to the distance difference between the pivot body 110 and the bucket 150, the center of gravity of the boom 130, the arm 140, and the bucket 150 with respect to the rotation axis between the pivot body 110 and the boom 130 ( Hereinafter, the force applied to the joint center of gravity (ie, the center of gravity of the joint), that is, the torque and the moment will be different, and the compensation value determiner 313 calculates the gravity compensation value to compensate for the difference in the force applied to the center of gravity of the joint. Calculate.

Here, the compensation value determiner 313 according to the present invention is the angle of the boom 130, the arm 140, respectively detected by the boom angle detector 310, the arm angle detector 320 and the bucket angle detector 330 An example of calculating the gravity compensation value according to the kinematic model between the boom 130, the arm 140, and the bucket 150 is based on the angle value and the bucket 150 angle value.

4 shows an example of a kinematic model for calculating the gravity compensation value in the gravity compensation control device 300 according to the present invention. In FIG. 4, an example of applying a D-H notation (Denavit-Hartenberg parameter notation) model is used as a kinematic model for calculating a gravity compensation value.

The compensation value determiner 313 determines the gravity compensation value based on the force applied to the joint center of gravity. Here, the force acting on the center of gravity of the boom 130, the arm 140, and the bucket 150 as a whole is calculated based on the boom 130 angle value, the arm 140 angle value, and the bucket 150 angle value. .

When described with reference to Figure 4, according to the attitude of the excavator 100, the force (G ₂ ) is applied to the center of gravity of the joint around the axis of rotation (O ₁ ) between the pivot body 110 and the bucket 150 is a boom ( 130 (M ₁ ), the weight of the arm 140 (M ₂ ), the weight of the bucket 150 (M ₃ ), the length of the rotation axis of the boom 130 and the rotation axis of the arm 140 (L _O1O2 ) and a length between the end of the rotating shaft and the bucket 150 of the length (L _O2O3), the bucket 150, the rotation axis between the rotating shaft and the bucket 150, the arm (140) (L _O3G4), the boom 130, the angle value (θ ₁ ), The arm 140 angle value θ ₂ and the bucket 150 angle value θ ₃ .

The force (G ₂ ) applied to the center of gravity of the joint may be expressed as Equation 1 below.

[Equation 1]

Here, in [Equation 1] and [Equation 2], θ _1mc , θ _2mc and θ _3mc are angles formed by the centers of gravity (G ₁ , G ₂ , G ₃ ) of the x-axis. The weight M ₁ of the boom 130, the weight M ₂ of the arm 140, the weight M ₃ of the bucket 150, the length between the axis of rotation of the boom 130 and the axis of rotation of the arm 140. (L _O1O2), because the length (L _O3G4) between the end of the rotating shaft and the bucket 150 of the length (L _O2O3), the bucket 150, the rotation axis between the rotating shaft and the bucket 150, the arm 140 is constant, the compensation value The determination unit 313 is the boom 130 angle value θ ₁ and the arm 140 angle value θ detected by the boom angle detector 310, the arm angle detector 320, and the bucket angle detector 330, respectively. ₂ ) and the load value G ₂ , G ₃ according to the gravity applied to the center of gravity of the arm 140 and the center of gravity of the bucket 150 using the angle value (θ ₃ ) of the bucket 150.

The compensation value determiner 313 determines the gravity compensation value by using the force G _{2 applied} to the center of gravity of the joint and outputs it to the boom controller 311. In more detail, the force G _{2 applied} to the center of gravity of the joint calculated by the compensation value determiner 313 means the minimum force required for the boom 130 to overcome the gravity and rotate, and the compensation The value determiner 313 determines the gravity compensation value based on the force G _{2 applied} to the joint center of gravity.

Here, the method of determining the gravity compensation value stores the gravity compensation value corresponding to the force (G ₂ ) applied to the center of gravity of the joint in a table form, and extracts the gravity compensation value corresponding to the force (G ₂ ) calculated from the table. Can be output to the boom control unit 311. In addition, the compensation value determiner 313 defines a relation between the force (G ₂ ) and the gravity compensation value applied to the center of gravity of the joint, and calculates the gravity compensation value according to the calculated force (G ₂ ) through the relational boom. It can be output to the control unit 311. In addition, the determination of the gravity compensation value according to the force G _{2 applied} to the center of gravity of the joint is determined by the size of the excavator 100, for example, the weight of the pivot body 110, the boom 130, the arm 140, and the bucket ( Of course, those skilled in the art can apply the modification according to the length or weight of 150).

As described above, when the gravity compensation value is determined by the compensation value determining unit 313 and transmitted to the boom control unit 311, the boom control unit 311 may rotate the main body 110 according to a preset control method of the boom 130. Produces a boom control signal for controlling the rotation of the boom 130 with respect to). Here, in the present invention, the boom control unit 311 uses the PI control technique as a boom 130 control technique, and receives a target rotation value (Input) of the boom 130 for the rotation of the boom 130, and is a spring. For example, the PI control technique is performed by receiving an angle feedback.

The main controller 314 controls the boom controller 311 to reflect the gravity compensation value in the boom 130 control technique, that is, the PI control technique, when the boom controller 311 generates the boom control signal. For example, the boom control unit 311 is controlled so that the compensation value is fed forward to the boom 130 control technique.

Referring to FIG. 3, the boom control unit 311 may be configured to drive the boom driving unit 312 based on a result of the PI control execution unit 311a and the PI control execution unit 311a performing the PI control technique. It may include a control signal output unit 311b for generating and outputting the required boom control signal.

As such, the boom control signal output from the boom control unit 311 is transmitted to the boom driving unit 312 so that the boom driving unit 312 is driven so that the pivoting body 110 can be rotated with respect to the boom 130. Here, the boom drive unit 312 is provided in the form of a hydraulic cylinder (hydraulic cylinder), the operation and force of the hydraulic cylinder is controlled according to the opening and the degree of opening of the cylinder valve according to the boom control signal from the boom control unit 311. . In this case, the boom control signal generated and output by the control signal output unit 311b of the boom control unit 311 may be output in the form of a voltage value for determining whether the cylinder valve is open or not.

Meanwhile, the arm controller 321 controls the arm driver 322 based on the arm 140 angle value detected by the arm angle detector 320, and the bucket controller 331 is controlled by the bucket angle detector 330. The bucket driver 332 may be controlled based on the detected angle of the bucket 150. Here, the arm controller 321 and the bucket controller 331 may generate and output an arm control signal and a bucket control signal for controlling the arm driver 322 and the bucket driver 332 through the PI control technique. In addition, the configurations of the arm driver 322 and the bucket driver 332 may be provided corresponding to the shape of the boom driver 312 described above.

In the above-described embodiment, the boom drive unit 312, the arm drive unit 322 and the bucket drive unit 332 has been described as being a component of the gravity compensation control device 300, which helps to understand the intelligent excavator system according to the present invention As an example, the intelligent excavator system according to the present invention does not mean that the excavator 100 and the gravity compensation control device 300 are physically or logically divided, and the gravity compensation in one physical excavator 100 It is a matter of course that the control device 300 is embedded or some components are provided outside the physical excavator 100 in the technical spirit of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

100: excavator 110: pivoting body
120: running body 130: boom
140: arm 150: bucket
300: gravity compensation control device 310: boom angle detection unit
311 boom control unit 312 boom drive unit
313: compensation value determiner 320: arm angle detector
321: arm control unit 322: arm drive unit
330: bucket angle detection unit 331: bucket control unit
332: bucket driving unit 314: main control unit

Claims (10)

In the gravity compensation control device of an excavator having a swing body, a boom, an arm and a bucket,
A compensation value determiner configured to determine a gravity compensation value for the distance between the pivot body and the bucket;
A boom controller for generating a boom control signal for controlling rotation of the boom with respect to the pivot body according to a preset boom control technique;
A boom driver for rotating the boom according to the boom control signal;
And a main control unit controlling the boom control unit so that the gravity compensation value is reflected in the boom control technique when the boom control unit generates the boom control signal. The method of claim 1,
A boom angle detector for detecting a boom angle value between the pivot body and the boom;
An arm angle detector for detecting an arm angle value between the boom and the arm;
A bucket angle detector for detecting a bucket angle value between the arm and the bucket;
The compensation value determiner determines the gravity compensation value according to the kinematic model between the boom, the arm and the bucket based on the boom angle value, the arm angle value and the bucket angle value. Compensation control. The method of claim 2,
The boom control unit receives a boom target rotational value for rotation of the boom, receives the boom angle value, and performs the boom control technique;
And the main control unit controls the boom control unit so that the gravity compensation value is fed forward and reflected in the boom control technique. The method of claim 3,
The boom control technique is a gravity compensation control device of the excavator, characterized in that it comprises a PI control technique consisting of P control technique and I control technique. 5. The method according to any one of claims 2 to 4,
The compensation value determiner,
Compensation for gravity based on the force acting on the center of gravity of the boom, the arm and the entire bucket relative to the pivot axis and the axis of rotation of the boom calculated in accordance with the boom angle value, the arm angle value and the bucket angle value Gravity compensation control device of the excavator, characterized in that the value is determined. In the gravity compensation control method of an excavator having a swing body, a boom, an arm and a bucket,
(a) determining a gravity compensation value for the distance between the pivot body and the bucket;
(b) generating a boom control signal for controlling the boom by reflecting the gravity compensation value in a preset boom control technique for controlling the rotation of the boom with respect to the pivoting body;
and (c) rotating the boom in response to the boom control signal. The method according to claim 6,
The step (a)
Detecting a boom angle value between the pivot body and the boom;
Detecting an arm angle value between the boom and the arm;
Detecting a bucket angle value between the arm and the bucket;
And based on the boom angle value, the arm angle value, and the bucket angle value, the gravity compensation value is determined according to a kinematic model between the boom, the arm, and the bucket. Compensation Control Method. The method of claim 7, wherein
The step (b)
(b1) inputting a boom target rotation value for the rotation of the boom;
(b2) receiving the boom angle value and executing the boom control technique using the boom target rotational value as an input value;
(b3) Gravity compensation control method of the excavator, characterized in that the feed-forward feed reflected to the boom control technique. 9. The method of claim 8,
The boom control technique is a gravity compensation control method of an excavator, characterized in that it comprises a PI control technique consisting of P control technique and I control technique. 10. The method according to any one of claims 7 to 9,
The gravity compensation value is applied to the force acting on the center of gravity of the boom, the arm and the entire bucket relative to the rotation axis of the boom body and the boom, which is calculated according to the boom angle value, the arm angle value and the bucket angle value. Gravity compensation control method of an excavator, characterized in that determined based on.

Images