KR102390847B1 - Autohold control system and method for vehicle - Google Patents

Abstract

An auto hold control system for a vehicle according to various embodiments of the present disclosure includes: a clutch unit including a forward clutch and a reverse clutch; and a control unit for controlling the pressure oil supplied to the clutch unit, wherein the control unit includes: a mode determination unit for determining whether to enter an auto hold mode; a pressure calculation unit for calculating a required pressure of the hydraulic oil supplied to the clutch unit; and a hydraulic pressure providing unit for simultaneously providing hydraulic oil to the forward clutch and the reverse clutch according to the calculated required pressure.

Description

Auto hold control system and method for vehicle

The present invention relates to an auto hold control system for a vehicle and a method therefor.

In general, the auto hold function of a vehicle is an additional function of the ESC (Electronic Stability Control) constituting the brake system. It refers to a kind of convenience function that keeps the vehicle stopped by maintaining the braking pressure of the four wheels using the

However, most forklifts consist of only a braking system that controls pressure in conjunction with the brake pedal, and in most cases there is no brake control valve for implementing additional safety functions. There was a problem that it was difficult to implement the function in the same way as the auto hold of a general car.

The present invention has been devised to solve the above problems, and an object of the present invention is to provide an auto hold control system and method of a vehicle for implementing an auto hold function of the vehicle without a brake control valve for a separate auto hold function.

An auto hold control system for a vehicle according to various embodiments of the present disclosure provides an auto hold control system for a vehicle, comprising: a clutch unit including a forward clutch and a reverse clutch; and a control unit controlling the pressure oil supplied to the clutch unit, wherein the control unit includes: a mode determination unit determining whether to enter an auto hold mode; a pressure calculation unit for calculating a required pressure of the hydraulic oil supplied to the clutch unit; and a hydraulic pressure providing unit for simultaneously providing hydraulic oil to the forward clutch and the reverse clutch according to the calculated required pressure.

Preferably, a sensing unit for detecting driving state information of the vehicle may be included, and the mode determining unit may determine whether to enter the auto hold mode according to a preset logic based on the detected driving state information.

Preferably, the control unit may include a pressure compensator configured to perform correction in a direction to increase the required pressure when the vehicle is pushed in a state in which the vehicle enters the auto hold mode.

Preferably, the required pressure may be calculated according to a current inclination angle and a load of the vehicle.

Preferably, the entry into the auto hold mode may be released when the driver operates the accelerator pedal while the auto hold mode is entered.

According to various embodiments of the present disclosure, there is provided a method for controlling an auto hold of a vehicle, the method comprising: determining whether to enter an auto hold mode; calculating a required pressure of hydraulic pressure to be supplied to the clutch unit according to an inclination and a load when the auto hold mode is entered; and simultaneously providing hydraulic pressure to the forward clutch and the reverse clutch of the clutch unit according to the calculated required pressure.

Preferably, according to the required pressure, it is determined whether or not the vehicle is pushed in a state in which hydraulic pressure is simultaneously provided to the forward clutch and the reverse clutch, and when the push occurs, the required pressure is increased in a direction It may include performing calibration.

In the present invention, the auto hold function can be implemented without a separate brake control valve by providing hydraulic pressure to the forward/reverse clutch assembly at the same time to offset the driving force in the forward/reverse direction.

In addition, by controlling the hydraulic pressure simultaneously provided to the forward/reverse clutch assembly by using the proportional control valve, it is possible to variably control the hydraulic pressure according to the inclination angle and the size of the load, thereby increasing efficiency.

In addition, even if the vehicle is pushed according to the working environment, the reliability of the auto hold system can be improved by correcting the required pressure provided to the clutch unit through the pressure compensating unit.

1 is a block diagram illustrating a control relationship between main components of an auto hold control system for a vehicle according to various embodiments of the present disclosure;
FIG. 2 is a block diagram showing the configuration of a vehicle control unit of FIG. 1 ;
3 is a flowchart illustrating a vehicle auto hold control method according to various embodiments of the present disclosure;

Hereinafter, some embodiments of the present invention will be described with reference to exemplary drawings for convenience of description. In describing the reference numerals for the components of each drawing, the same components are denoted by the same reference numerals as much as possible even if they are displayed on different drawings.

The principle that terms or words used in the present specification and claims should not be limited to their ordinary or dictionary meanings, and the inventor may appropriately define the concept of a term to best describe his/her invention It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. When it is described that a component is 'connected' or 'coupled' to another component, the component may be directly connected or coupled to the other component, but another component is between the component and the other component. It should be understood that elements may be 'connected' or 'coupled'.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical spirit of the present invention, so at the time of the present application, various equivalents that can replace them It should be understood that there may be water and variations. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

The auto hold control system for a vehicle proposed by the present invention is a system for controlling the vehicle to maintain a stopped state even when the driver takes his or her foot off the brake pedal as necessary when the vehicle is stopped.

The vehicle according to various embodiments of the present disclosure may be described as an industrial vehicle including a forklift, but is not limited thereto, and may include a vehicle to which a general transmission is applied.

The vehicle auto hold control system proposed by the present invention may be used in a transmission to which a positive clutch clutch is applied. The positive clutch method may refer to a method in which hydraulic pressure is released when neutral to separate the clutch, and hydraulic pressure is supplied when forward or backward to couple the clutch.

In the positive clutch method, when the shift is neutral, the hydraulic pressure to the forward and reverse clutch assembly 420 is released, and at the same time, the adhesion force of the clutch piston to the clutch disk is released by the elastic restoring force of the spring, so that the engine 1 power may be cut off. In addition, when shifting forward or backward, hydraulic pressure is supplied to the forward or reverse clutch assembly 420 and at the same time, the clutch piston presses the clutch disk by hydraulic pressure, so that the power of the engine 1 can be transmitted to the wheel 5 . .

Hereinafter, an auto hold control system for a vehicle according to various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a control relationship between main components of an auto hold control system for a vehicle according to various embodiments of the present disclosure, and FIG. 2 is a block diagram illustrating the configuration of the vehicle control unit 110 of FIG. 1 , FIG. 3 is a flowchart illustrating an auto hold control method of a vehicle according to various embodiments of the present disclosure.

Referring to FIG. 1 , an auto hold control system for a vehicle according to various embodiments of the present disclosure may include a sensing unit 50 , a control unit, a valve unit 300 , and a clutch unit 400 .

The auto hold control system of a vehicle according to various embodiments of the present disclosure may include a sensing unit 50 . The sensing unit 50 is for detecting the current driving state of the vehicle, and may include a plurality of sensors disposed in each part of the vehicle. In an embodiment, the sensor may include an inclination sensor capable of detecting a current inclination state of the vehicle, a vehicle speed sensor capable of detecting a current speed of the vehicle, and a load sensor detecting a load acting on the current vehicle.

In addition, the sensing unit 50 may detect the operation signal of the parking brake switch to detect whether a parking mode of the vehicle is set, and may detect the driver's brake pedal operation signal through the brake pedal switch. The sensing unit 50 may detect a driver's accelerator pedal operation signal through the accelerator pedal switch.

Also, the sensing unit 50 may sense a shift operation signal of the driver through the shift lever. In one embodiment, the shift lever is a lever capable of operating a forward, neutral, or reverse shift stage and may be disposed inside the cabin of the vehicle, and when the driver operates the shift lever, any one of forward, neutral, and reverse shift stage signals is detected can do.

It will be apparent that known sensors may be used for these sensors, and installation positions may vary according to a specific design.

Referring to FIG. 2 , the control unit 100 of the auto hold control system for a vehicle according to various embodiments of the present disclosure may include a vehicle control unit 110 and a shift control unit 120 .

The vehicle control unit 110 may be electrically connected to the above-described sensing unit 50 , and the current vehicle inclination angle, the current vehicle speed, and the load applied to the current vehicle detected through the inclination sensor, the vehicle speed sensor, and the load sensor. can be entered. Also, the vehicle control unit 110 may receive operation signals of each switch from the parking brake switch, the brake pedal switch, the accelerator pedal switch, and the shift lever.

In the present invention, the driver may control the setting of the auto hold mode. In an embodiment, an auto hold switch may be provided in the driver's seat, and the driver may set the auto hold mode by operating the auto hold switch. When the driver operates the auto hold switch to on, the vehicle is set to the auto hold mode and becomes a state capable of performing the auto hold function. In addition, the driver may control the auto hold mode to be released by operating the auto hold switch to off.

The vehicle control unit 110 may include a determination unit 111 , a pressure calculation unit 112 , and a pressure correction unit 113 .

The determination unit 111 may determine whether the auto hold function is operated. The operating conditions of the auto hold function may be preset according to the type of vehicle, such as a forklift, a passenger car, or an excavator. The determination unit 111 may determine whether to operate the auto hold function by determining whether the operating conditions of the auto hold function are satisfied in the state set in the auto hold mode. The determination unit 111 may determine whether the operating condition of the auto hold function is satisfied through the signal sensed by the above-described sensing unit 50 . In an embodiment, the determination unit 111 may determine whether to implement the auto hold function through detection signals of the inclination sensor and the vehicle speed sensor and operation signals of the shift lever and the parking brake switch. [Table 1] is an exemplary embodiment in which the auto hold operation condition is determined through the determination unit 111 according to the detection result of the sensing unit 50 .

Condition One 2 3 4 5 6 7 8 9 slope ascent O O downhill O O flat O O selector Advance O O O junior O O O neutrality O parking
switch parking O release O O O O O O vehicle speed Okm/h O O O O O O over Okm/h O Whether it works X X X O X O X O O

In one embodiment, as in condition 4, when the vehicle is currently on an uphill road through the inclination sensor and the vehicle speed is Okm/h in the forward shift stage when the shift lever is in the forward shift stage, as in condition 4, the auto hold function It can be judged that the operating conditions of In an embodiment, the determination unit 111 determines through the inclination sensor of the auto hold function when the vehicle speed is Okm/h in the forward or reverse gear stage or the parking switch is released, even when the current vehicle is on a flat ground. It can be judged that the operating conditions are satisfied. In the present invention, the auto hold function can be operated even when the vehicle is not only on a slope but also on a flat ground. This is because, in the case of industrial vehicles such as forklifts, it is necessary to implement the auto hold function according to the load of the work piece even on flat ground.

When the determination unit 111 determines that the operating condition of the auto hold function is satisfied according to the current vehicle state, the pressure calculation unit 112 controls the hydraulic pressure to be applied to the forward clutch assembly 410 and the reverse clutch assembly 420 . The required pressure can be calculated. In this case, the required pressure may be a minimum pressure for maintaining a stopped state of the vehicle. The pressure calculator 112 may calculate a required pressure according to the signal sensed by the sensing unit 50 . In an embodiment, the pressure calculator 112 may calculate the required pressure according to the current inclination angle of the vehicle by the inclination sensor and the load value acting on the vehicle by the load sensor. That is, in the present invention, it is possible to control the braking force according to the inclination angle and the load of the vehicle.

In addition, the vehicle control unit 110 according to various embodiments of the present disclosure may include a pressure compensator 113 . The pressure compensating unit 113 may correct the above-described necessary pressure by detecting whether the vehicle is pushed while the vehicle is stopped. In one embodiment, the pressure compensating unit 113 is configured to simultaneously provide hydraulic pressure of the same magnitude to the forward clutch assembly 410 and the reverse clutch assembly 420 by the shift control unit 120 according to the required pressure calculated above. , it is possible to detect whether the vehicle is pushed through the sensing unit 50 . If the pushing occurs, the pressure correcting unit 113 may correct the required pressure in a direction to increase the calculated required pressure. In an embodiment, the pressure corrector 113 may perform the correction by adding a pressure of a preset size to the required pressure calculated above.

However, in one embodiment, when the pressure correcting unit 113 determines whether the vehicle is pushed and sends a correction signal to the pressure correcting unit 113, the above-described pressure calculating unit 112 continuously receives the correction signal to determine the required pressure. Calibration can be performed.

The shift controller 120 may control the proportional control valve according to the required pressure calculated by the pressure calculator 112 . The shift control unit 120 may simultaneously transmit a voltage value signal corresponding to the calculated required pressure to the forward proportional control valve 310 and the reverse proportional control valve 320 . The shift control unit 120 may control the hydraulic pressure provided to the clutch unit 400 by controlling displacement amounts of the forward proportional control valve 310 and the reverse proportional control valve 320 according to the calculated required pressure.

The shift control unit 120 may simultaneously provide hydraulic pressure to the forward clutch assembly 410 and the reverse clutch assembly 420 through the control of the proportional control valve. At this time, since the hydraulic pressure of the same pressure is simultaneously provided to the forward clutch assembly 410 and the reverse clutch assembly 420 , the forward power and the reverse power transmitted to the wheel 5 are offset, and as a result, braking force may be generated. .

The valve unit 300 may include a forward proportional control valve 310 and a reverse proportional control valve 320 to control hydraulic pressure provided to the forward clutch assembly 410 and the reverse clutch assembly 420 . In the present invention, the displacement amount of the valve may be variably controlled according to a voltage value signal corresponding to the required pressure through the proportional control valves 310 and 320 . Through this, it is possible to control the magnitude of the hydraulic pressure provided to the forward clutch assembly 410 and the reverse clutch assembly 420 , thereby controlling the magnitude of the braking force implemented through the auto hold function.

The clutch unit 400 is provided in the transmission of the vehicle, and may serve to transmit the power of the engine 1 to the axle in order to perform a forward or reverse driving function of the vehicle. The clutch unit 400 may include a forward clutch assembly 410 for forward driving and a reverse clutch assembly 420 for backward driving.

The clutch unit 400 may be implemented in a positive manner, and hydraulic pressure may be provided to the clutch assembly and adhesion may be generated to the clutch disk, so that power may be transmitted to the wheel 5 . Such a positive type clutch is well-known, and detailed description of the specific structure will be omitted.

According to various embodiments of the present disclosure, when the auto hold function is activated, hydraulic pressure is simultaneously provided to the forward clutch assembly 410 and the reverse clutch assembly 420 , thereby canceling the driving force of the wheel 5 in the forward/reverse direction to cancel the vehicle. A standstill may be maintained.

Specifically, in the positive clutch unit 400 , the output gear of the forward clutch assembly 410 and the output gear of the reverse clutch assembly 420 are engaged with the reduction gear of the axle. As the clutch disk of the clutch assembly to which hydraulic pressure is provided among the clutch assemblies 420 is pressed, the driving force is transmitted to the reduction gear of the axle through the corresponding clutch assembly.

When the auto hold function according to various embodiments of the present disclosure is activated, hydraulic pressure is simultaneously provided to the forward clutch assembly 410 and the reverse clutch assembly 420 , thereby outputting the forward clutch assembly 410 and the reverse clutch assembly 420 . The gear can transmit driving force to the reduction gear of the axle at the same time. In this case, since the rotation direction of the reduction gear of the axle by the forward clutch assembly 410 and the rotation direction of the reduction gear of the axle by the reverse clutch assembly 420 are opposite to each other, the rotational force in the opposite direction is simultaneously applied to the reduction gear of the axle Therefore, the reduction gear of the axle cannot rotate and can be fixed.

In addition, since the hydraulic pressure provided to the forward clutch assembly 410 and the reverse clutch assembly 420 can be variably controlled through the above-described valve unit 300 , when the vehicle is pushed, the required pressure is corrected automatically. It is possible to continuously implement the hold function. For example, if the auto hold function is activated and the vehicle is pushed due to its own weight on an uphill slope, the hydraulic pressure provided to the forward clutch assembly 410 and/or the reverse clutch assembly 420 is increased through correction of the required pressure. By increasing the driving force transmitted to the axle, the auto hold function can be continuously implemented.

The vehicle auto hold control system according to various embodiments of the present disclosure may further include a display unit (not shown). The display unit may display whether the auto hold mode is set. In an embodiment, when the driver turns on the auto hold switch, the display unit may display that the auto hold mode is on, indicating that the current auto hold function is in a state in which the auto hold function can be operated.

In addition, the display unit may display the operating state of the auto hold function. When it is determined by the determination unit 111 that the operating condition of the auto hold function is satisfied, the display unit may notify the driver that the auto hold function is currently operating.

Hereinafter, an auto-hold control method through the above-described auto-hold control system will be described in detail with reference to FIG. 3 .

Referring to FIG. 3 , the auto hold control method according to various embodiments of the present disclosure includes a step of determining an operating condition of the auto hold function ( 510 ), a step of calculating a required pressure ( 520 ), and a forward clutch assembly ( 410 ). and simultaneously providing hydraulic oil to the reverse clutch assembly 420 ( 530 ), confirming that the vehicle is pushed ( 540 ), and correcting the required pressure ( 550 ).

First, in the step 510 of determining the operating condition of the auto hold function, when the auto hold mode is set by the driver, the determining unit 111 of the vehicle control unit 110 drives the vehicle sensed by the sensing unit 50 . It may be determined whether the state corresponds to an operating condition for implementing the auto-hold function.

In the step 520 of calculating the required pressure, if it is determined that the current vehicle state satisfies the operating conditions of the auto hold function, the pressure calculator 112 for stopping the vehicle according to the current inclination angle and load of the vehicle. The required pressure of hydraulic pressure to be provided to the clutch unit 400 may be calculated.

In step 530 of simultaneously supplying hydraulic oil to the forward clutch assembly 410 and the reverse clutch assembly 420 , the shift control unit 120 sets the valve unit to a voltage value corresponding to the required pressure calculated by the pressure calculation unit 112 . By controlling 300 , hydraulic pressure may be simultaneously provided to the forward clutch assembly 410 and the reverse clutch assembly 420 . As a result, an adhesion force is simultaneously generated between the clutch disk of the forward clutch assembly 410 and the clutch disk of the reverse clutch assembly 420 , and the forward driving force and the reverse driving force are canceled to stop the vehicle.

In step 540 of confirming the vehicle's push, the pressure compensator 113 may check the vehicle's push through the detection signal of the vehicle speed sensor, and when the push is confirmed, the previously calculated required pressure may be corrected. In the present invention, the reliability of the auto hold function can be increased by continuously correcting the required pressure value through feedback control.

As described above, in the present invention, the auto hold function can be implemented without a separate brake control valve by providing hydraulic pressure to the forward/reverse clutch assembly 420 at the same time to offset the driving force in the forward/reverse direction. In addition, by controlling the hydraulic pressure simultaneously provided to the forward/reverse clutch assembly 420 using the proportional control valve, it is possible to minimize the impact and increase the efficiency. In addition, even if the vehicle is pushed according to the working environment, the reliability of the auto hold system can be improved by correcting the required pressure provided to the clutch unit 400 through the pressure correction unit 113 .

In the above, even though it has been described that all the components constituting the embodiment of the present invention operate by being combined or combined into one, the present invention is not necessarily limited to this embodiment. That is, within the scope of the object of the present invention, all the components may operate by selectively combining one or more. In addition, terms such as 'include', 'comprise', or 'have' described above mean that the component may be inherent unless otherwise stated, so other components are excluded. Rather, it should be construed as being able to further include other components. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless otherwise defined. Terms commonly used, such as those defined in the dictionary, should be construed as being consistent with the contextual meaning of the related art, and should not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

1: engine
5: wheel
50: sensing unit
100: control unit
110: vehicle control unit
111: judgment unit
112: pressure calculator
113: pressure compensation unit
120: shift control unit
300: valve unit
310: forward proportional control valve
320: reverse proportional control valve
400: clutch unit
410: forward clutch assembly
420: reverse clutch assembly

Claims (7)

In the auto hold control system of a vehicle,
a clutch unit having a forward clutch and a reverse clutch; and
A control unit for controlling the pressure oil supplied to the clutch unit,
The control unit is
a determination unit that determines whether an operating condition of the auto hold function is satisfied;
a pressure calculation unit for calculating a required pressure of the hydraulic oil supplied to the clutch unit; and
and a shift control unit configured to implement the auto hold function by generating a braking force by simultaneously supplying hydraulic oil to the forward clutch and the reverse clutch according to the calculated required pressure.

According to claim 1,
And a sensing unit for detecting the driving state information of the vehicle,
The determination unit is an auto hold control system for a vehicle that determines whether an operating condition of the auto hold function is satisfied according to a preset logic based on the detected driving state information.

3. The method of claim 2,
The control unit is
and a pressure corrector configured to correct the required pressure in a direction to increase the required pressure when the vehicle is pushed in a state in which the auto hold function is in operation.

The method of claim 1,
The auto hold control system of a vehicle wherein the required pressure is calculated according to a current inclination angle and a load of the vehicle.
According to claim 1,
An auto hold control system for a vehicle in which the auto hold function is canceled when the driver operates the accelerator pedal while the auto hold function is in operation.

determining whether an operating condition of the auto hold function is satisfied;
when it is determined that the operating condition of the auto hold function is satisfied, calculating a required pressure of hydraulic pressure to be supplied to the clutch unit according to an inclination and a load; and
According to the calculated required pressure, the forward clutch and reverse clutch of the clutch unit
A method of auto-hold control of a vehicle, comprising the step of simultaneously providing hydraulic pressure.

7. The method of claim 6,
According to the required pressure, it is determined whether the vehicle is pushed in a state where hydraulic pressure is simultaneously provided to the forward clutch and the reverse clutch, and when the push occurs, correction is performed in a direction to increase the required pressure A method of auto-hold control of a vehicle comprising the steps of:

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