KR102046183B1

KR102046183B1 - Method and Apparatus for Controlling Vehicle of Construction Machine

Info

Publication number: KR102046183B1
Application number: KR1020130040405A
Authority: KR
Inventors: 김동목; 김낙인; 현용탁; 김득상; 강병일; 고민석; 김정호; 박경민; 조이형
Original assignee: 두산인프라코어 주식회사
Priority date: 2013-04-12
Filing date: 2013-04-12
Publication date: 2019-11-18
Also published as: KR20140123636A

Abstract

The present invention relates to a method and apparatus for controlling a vehicle of a construction machine, the method comprising: determining whether a sudden load occurs using an increase rate of a discharge pressure of a hydraulic pump; Calculating a required hydraulic pump torque using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the hydraulic pump has a sudden load; And performing torque compensation control of the engine using the calculated hydraulic pump required torque.

Description

Method and Apparatus for Controlling Construction Machines

The present invention relates to a vehicle control method and apparatus for a construction machine.

Construction machinery such as a hydraulic excavator generally includes a diesel engine as a prime mover, and drives at least one variable displacement hydraulic pump using a diesel engine to drive the hydraulic actuator by pressure oil discharged from the hydraulic pump. Perform the necessary work. The diesel engine has an input means for commanding a target engine speed, such as an accelerator lever, and controls the fuel injection amount and the engine speed according to the target engine speed.

The construction machine obtains the difference between the original target engine speed and the actual engine speed (speed deviation) using the speed sensor in relation to the control of the engine and the hydraulic pump, and inputs the hydraulic pump using the obtained speed deviation. The so-called speed sensing control for controlling torque is performed. The purpose of this control is to effectively reduce the load torque (input torque) of the hydraulic pump to prevent engine shutdown when the actual engine speed detected relative to the target engine speed decreases, thereby effectively utilizing the engine output.

Here, the output of the engine varies greatly depending on the environment around the engine. For example, when the place used is in the highlands, the engine output torque may be lowered due to the decrease in atmospheric pressure. In order to reduce the engine rotation speed even when the engine output is reduced in response to such a change in the environment, there is a European Patent Publication No. 01533524.

In this patent, the engine controller calculates a coefficient that can compensate the target engine speed using the sensor value related to the operating environment of the engine and the hydraulic oil temperature sensor value used in the hydraulic system of the construction machine, and calculates the target engine speed and the actual engine speed. The engine is controlled by calculating the fuel injection amount, injection timing, injection pressure, and injection rate based on the engine speed.

However, conventionally, only the actual engine speed is available for the engine controller to control the engine in response to the sudden load transmitted from the hydraulic pump to the engine. For example, in the non-operational state of the manipulator in which the hydraulic pump and the engine maintain the low load state, when the operation is made, the hydraulic pump generates a sudden load while the discharge flow rate and discharge pressure of the hydraulic pump rise rapidly. The payload generated from the hydraulic pump is delivered to the engine directly connected to the hydraulic pump, thereby lowering the actual engine speed by the insufficient generated torque of the engine. Therefore, the engine controller can cope with sudden load only after the actual engine speed decreases.

The present specification has been made to solve the problems as described above, to provide a vehicle control method and apparatus for a construction machine that can control the engine quickly and accurately when the sudden load generated from the hydraulic pump is transmitted to the engine. There is this.

In order to achieve the above object, according to the first embodiment of the present disclosure, a vehicle control method of a construction machine according to the present specification, the step of determining whether or not the sudden load using the increase rate of the discharge pressure of the hydraulic pump; Calculating a required hydraulic pump torque using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the hydraulic pump has a sudden load; And performing torque compensation control of the engine using the calculated hydraulic pump required torque.

According to a second embodiment of the present disclosure, a vehicle control apparatus for a construction machine according to the present disclosure includes a supply load determining unit determining whether a supply load occurs using an increase rate of a discharge pressure of a hydraulic pump; A hydraulic pump torque calculation unit that calculates a hydraulic pump required torque by using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the sudden load occurs in the hydraulic pump; And an engine controller configured to perform torque compensation control of the engine using the hydraulic pump required torque calculated by the hydraulic pump torque calculator.

As described above, according to the present specification, by providing a vehicle control method and apparatus for a construction machine that transmits torque information generated from a hydraulic pump to an engine controller, engine control can be performed quickly and accurately in response to a sudden load of the hydraulic pump. have.

1 is a view showing the configuration of a vehicle control apparatus for a construction machine according to an embodiment of the present invention;
2 is a flowchart illustrating a vehicle control method of a construction machine according to an embodiment of the present invention.

It is to be noted that the technical terms used herein are merely used to describe particular embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined otherwise, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately express the spirit of the present invention, it should be replaced with technical terms that can be properly understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.

Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components, or various steps described in the specification, wherein some of the components or some of the steps It should be construed that it may not be included or may further include additional components or steps.

In addition, the suffixes "module" and "unit" for the components used herein are given or mixed in consideration of ease of specification, and do not have meanings or roles that are distinguished from each other.

In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

1 is a view showing the configuration of a vehicle control apparatus of a construction machine according to an embodiment of the present invention.

Referring to FIG. 1, the vehicle control apparatus according to the present invention includes a quick load determining unit 110, a hydraulic pump torque calculating unit 120, a torque information transmitting unit 130, an engine control unit 140, and the like.

The supply load determination unit 110 determines whether the supply load is generated by using an increase rate of the discharge pressure of the hydraulic pump. In detail, the sudden load determiner 110 has a first increase in the increase rate of the discharge pressure of the hydraulic pump equal to or greater than a preset increase rate DELTA P / ΔT and a duration of the increase rate of the discharge pressure of the hydraulic pump. If ΔT1) or more, it is determined that sudden load has occurred in the hydraulic pump.

In addition, the sudden load determination unit 110 determines whether the sudden load ends by using the sudden load duration or the difference between the target engine speed and the actual engine speed. In detail, the sudden load discrimination unit 110 has a sudden sudden load duration greater than or equal to a preset second duration ΔT2 or a difference between the target engine speed and the actual engine speed is less than or equal to the predetermined reference value ΔN. In this case, it is determined that the sudden load is finished.

The hydraulic pump torque calculating unit 120 according to the determination result of the rapid load determining unit 110, when the hydraulic pump has a sudden load, the hydraulic pressure using the discharge pressure of the hydraulic pump, the power shift control pressure and the actual engine speed Calculate the required torque of the pump. At this time, the hydraulic pump torque calculation unit 120 may cause a delay in the required hydraulic pump torque increased according to an increase in the discharge pressure of the hydraulic pump, thereby compensating time delay due to the swash plate angle of the hydraulic pump. In addition, the hydraulic pump torque calculator 120 uses the hydraulic oil temperature together with the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed in order to prevent the torque error from occurring according to the hydraulic oil state. The required torque can be calculated.

In addition, the hydraulic pump torque calculation unit 120 may add a weight to the calculated hydraulic pump required torque in a quick load section in which torque rise is faster. In detail, the hydraulic pump torque calculating unit 120 extracts a high frequency component from the calculated hydraulic pump required torque, multiplies the extracted high frequency component by a weight, and then adds the high frequency component multiplied by the weight to the calculated hydraulic pump required torque. Can be.

The torque information transmitter 130 transmits the hydraulic pump required torque calculated by the hydraulic pump torque calculator 120 to the engine controller 140 using a CAN protocol.

The engine controller 140 performs torque compensation control of the engine by using the required hydraulic pump torque transmitted through the torque information transmitter 130. Accordingly, the engine control unit 140 according to the present invention can reduce excessive fuel injection of the engine and allow the engine to perform the correct amount of fuel injection at the correct time.

2 is a flowchart illustrating a vehicle control method of a construction machine according to an embodiment of the present invention.

Referring to FIG. 2, it is determined whether the increase rate of the discharge pressure of the hydraulic pump is equal to or greater than the preset increase rate ΔP / ΔT (S210).

When the increase rate of the discharge pressure of the hydraulic pump is equal to or greater than the preset increase rate ΔP / ΔT, it is determined whether the duration of the increase rate of the discharge pressure of the hydraulic pump is equal to or greater than the first preset duration ΔT1 (S220). ).

When the duration of the increase rate of the discharge pressure of the hydraulic pump is equal to or larger than the first preset duration ΔT1, it is determined that sudden load has occurred in the hydraulic pump, and the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed are determined. Calculate the required hydraulic pump torque using (S230). At this time, a delay occurs in the required hydraulic pump torque that increases with the increase in the discharge pressure of the hydraulic pump, thereby compensating for time delay due to the swash plate angle of the hydraulic pump. In addition, in order to prevent a torque error from occurring according to the hydraulic oil state, the hydraulic pump required torque may be calculated using the hydraulic oil temperature together with the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed.

Thereafter, torque compensation control of the engine is performed using the calculated hydraulic pump required torque (S240).

Subsequently, it is determined whether the sudden loading duration is greater than or equal to the preset second duration ΔT2 (S250), and when the sudden loading duration is greater than or equal to the preset second duration ΔT2, the sudden loading is terminated. It is determined that the torque compensation control of the engine is terminated (S260).

When the sudden load duration is less than the preset second duration ΔT2, it is determined whether the difference between the target engine speed and the actual engine speed is equal to or less than the predetermined reference value ΔN (S252), and the target engine rotation. When the difference between the number and the actual engine speed is equal to or less than the preset reference value? N, it is determined that the sudden load is finished, and the torque compensation control of the engine is terminated (S260).

In addition, although not shown in the figure, it is possible to add a weight to the calculated hydraulic pump required torque in a quick load section in which the torque rise is faster. In detail, the high frequency component may be extracted from the calculated hydraulic pump required torque, multiplied by the extracted high frequency component, and the high frequency component multiplied by the weight may be added to the calculated hydraulic pump required torque.

The aforementioned method can be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

For implementation in hardware, a method according to embodiments of the present invention may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), and Programmable Logic Devices (PLDs). It may be implemented by field programmable gate arrays (FPGAs), processors, controllers, microcontrollers and microprocessors.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, a procedure, or a function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

Embodiments disclosed herein have been described with reference to the accompanying drawings. As described above, the embodiments shown in each drawing should not be construed as limiting, but may be combined with each other by those skilled in the art, and some components may be omitted.

Here, the terms or words used in the present specification and claims should not be construed as being limited to the ordinary or dictionary meanings, but should be interpreted as meanings and concepts corresponding to the technical spirit disclosed in the present specification.

Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only one embodiment disclosed in the present specification, and do not represent all the technical ideas disclosed in the present specification. It should be understood that there may be equivalents and variations.

110: emergency load determination unit 120: hydraulic pump torque calculation unit
130: torque information transmitting unit 140: engine control unit

Claims

Determining whether a sudden load occurs using an increase rate of the discharge pressure of the hydraulic pump;
Calculating a required hydraulic pump torque using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the hydraulic pump has a sudden load; And
Performing torque compensation control of the engine using the calculated hydraulic pump required torque;
Including,
Determining whether the sudden load occurs,
When the increase rate of the discharge pressure of the hydraulic pump is greater than the predetermined increase rate, the duration of the increase rate of the discharge pressure of the hydraulic pump is more than the first predetermined time period, characterized in that it is determined that the emergency load has occurred in the hydraulic pump Vehicle control method of construction machinery.

delete

The method of claim 1, wherein in calculating the hydraulic pump required torque,
A method of controlling a vehicle of a construction machine, characterized by compensating for the time delay of the swash plate angle of the hydraulic pump by causing a delay in the required torque of the hydraulic pump which increases with the increase in the discharge pressure of the hydraulic pump.

The method of claim 1, wherein in calculating the hydraulic pump required torque,
A method for controlling a vehicle of a construction machine, comprising calculating a required torque of a hydraulic pump in consideration of a hydraulic oil temperature.

Determining whether a sudden load occurs using an increase rate of the discharge pressure of the hydraulic pump;
Calculating a required hydraulic pump torque using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the hydraulic pump has a sudden load; And
Performing torque compensation control of the engine using the calculated hydraulic pump required torque;
Including
After calculating the required hydraulic pump torque,
Extracting high frequency components from the calculated hydraulic pump required torque;
Multiplying the extracted high frequency components by weights; And
Adding a high frequency component multiplied by a weight to the calculated hydraulic pump required torque;
Vehicle control method of a construction machine further comprising a.

The method according to any one of claims 1, 3, 4 and 5, after the step of performing the torque compensation control,
Determining whether or not the sudden end of the load is determined as the sudden end of the load when the difference between the target engine speed and the actual engine speed is equal to or less than a preset reference value; And
Terminating the torque compensation control when the sudden load of the hydraulic pump is terminated;
Vehicle control method of a construction machine further comprising a.

The method according to any one of claims 1, 3, 4 and 5, after the step of performing the torque compensation control,
Determining whether the sudden loading ends when the sudden loading ends when the sudden loading duration is greater than or equal to the second predetermined duration; And
Terminating the torque compensation control when the sudden load of the hydraulic pump is terminated;
Vehicle control method of a construction machine further comprising a.

A supply load determining unit for determining whether a supply load occurs using an increase rate of the discharge pressure of the hydraulic pump;
A hydraulic pump torque calculation unit that calculates a hydraulic pump required torque by using the discharge pressure of the hydraulic pump, the power shift control pressure, and the actual engine speed when the sudden load occurs in the hydraulic pump; And
An engine controller configured to perform torque compensation control of the engine by using the required hydraulic pump torque calculated by the hydraulic pump torque calculator;
Including,
The sudden load determination unit,
When the increase rate of the discharge pressure of the hydraulic pump is greater than the predetermined increase rate, the duration of the increase rate of the discharge pressure of the hydraulic pump is more than the first predetermined time period, characterized in that it is determined that the emergency load has occurred in the hydraulic pump Vehicle control unit of construction machinery.