KR20040056712A - Controlling apparatus for acceleration linearity of vehicle and method thereof - Google Patents

Abstract

PURPOSE: A control device of acceleration linearity for a vehicle and a method thereof are provided to improve torque efficiency of an engine and responsiveness by obtaining the acceleration linearity through feedback control according to the present vehicle speed with setting the expected value corresponding to acceleration response into the one-dimensional function in operating an accelerator pedal. CONSTITUTION: An acceleration linearity control device of a vehicle comprise a vehicle speed detecting unit(10) detecting speed of the vehicle; an engine rpm detecting unit(20) detecting rpm of the engine; an acceleration pedal detecting unit(30) detecting driving displacement of the accelerator pedal; a control unit(40) controlling acceleration linearity within the predetermined range according to driving displacement of the accelerator pedal by purpose of a driver; and an injector(50) injecting fuel to the combustion chamber according to the control signal from the control unit to keep output of the engine. The control unit divides the operational range into the starting acceleration range, the overtaking acceleration range and the auto-cruise range corresponding to torque of the engine.

Description

CONTROLLING APPARATUS FOR ACCELERATION LINEARITY OF VEHICLE AND METHOD THEREOF}

The present invention relates to the control of the acceleration response of the vehicle, and more particularly, to grasp the driver's intention according to the driver's acceleration pedal operation, and to set the optimum acceleration model by setting the expectation of the acceleration response as a one-dimensional or two-dimensional function. In addition, the present invention relates to a vehicle acceleration linearity control apparatus and method for securing acceleration linearity by feedback control (Feed Back Control) for a current vehicle speed based on an acceleration model value.

In general, the acceleration mechanism of the vehicle (Mechanism) is to control the fuel amount in accordance with the driver's simple acceleration pedal operation, in the case of gasoline engine further includes the control of the ignition timing, in the case of diesel engine only simple fuel amount control It is supposed to run.

In the case of the gasoline engine, traction control and electronic throttle control are performed to secure the linearity of the vehicle's acceleration response during the initial acceleration according to the tendency of high output. It is mainly applied to a vehicle with a specification, and it is not applied to a low-end type vehicle. As a result, it is impossible to secure stable acceleration linearity.

In addition, most diesel diesel engines are equipped with turbo chargers. Turbocharged engines do not have acceleration linearity due to turbo racks, and sudden acceleration from the point of boosting starts. It creates a problem that makes the driver embarrassed.

That is, the acceleration / deceleration distribution characteristic of the conventional vehicle is, as shown in the accompanying Figure 7a, the acceleration response value is caused to lack the acceleration in the state of the LTI or less, the acceleration expected value is less than the expected acceleration value, acceleration in the LTI area or more than the MTI area Acceleration increases rapidly as the response exceeds the expected acceleration, and the acceleration response indicates a transient phenomenon in which the acceleration is saturated above the MTI region.

In addition, the oscillation acceleration feeling in the LTI region, as can be seen in Figure 7b, acceleration response response is too slow even during the fast tip-in (fast tip-In) that drives the accelerator pedal rapidly, it does not significantly meet the acceleration expectations The acceleration of oscillation in the region of MTI abnormality results in the occurrence of shock at the quick tip in which quickly drives the accelerator pedal as shown in FIG. 7C, and the acceleration at the slow tip in occurs more than expected. The problem arises.

That is, in the case of a conventional gasoline diesel engine, the driver's intention is simply controlled by passive control according to the opening degree of the accelerator pedal, and thus the target for acceleration is not set so that the driver's expectation of acceleration cannot be met.

The present invention has been invented to solve the above problems, the object is to grasp the driver's intention according to the driver's accelerator pedal operation, and to set the expectation for the acceleration response to one-dimensional or two-dimensional functional formula to create an optimal acceleration model It is to set acceleration linearity by feedback control (Feed Back Control) on the current vehicle speed based on the acceleration model value.

That is, to maximize the efficiency by using the maximum output and torque of the engine mounted on the vehicle appropriately, to improve the merchandise of the vehicle with a response that meets the driver's acceleration expectations.

1 is a schematic configuration diagram of a linearity control apparatus for a vehicle according to the present invention.

Figure 2 is a state diagram of the division of each driving region based on the torque that the engine has for linearity control in the vehicle according to the present invention.

3 is a graph showing an oscillation model for each driving region for linearity control in a vehicle according to the present invention.

4A-4C are graphs of linearity control through fuel amount correction in a vehicle according to the present invention.

5 is a diagram illustrating the linearity control relationship for each model according to the accelerator pedal displacement in the vehicle according to the present invention.

6A and 6B are flow charts for performing linearity control in a vehicle in accordance with the present invention.

7A and 7C are graphs illustrating acceleration response relationships in a conventional vehicle.

The present invention for realizing the above object is a vehicle speed detection unit for detecting a vehicle speed; An engine speed detection unit detecting an engine speed; An accelerator pedal detection unit detecting a drive displacement of the accelerator pedal; A control unit for controlling acceleration linearity in each area set according to a driving change amount of the accelerator pedal which is the driver's will; Injector for maintaining the engine output by injecting the amount of fuel calculated in each combustion chamber corresponding to the control signal applied from the control unit,

The controller divides the driving region into an oscillation acceleration region (a), an overtaking acceleration region (b), and a constant speed driving region (c) based on the torque characteristics of the engine, and sets the driving region in the memory region. The one-dimensional or two-dimensional functional oscillation modeling value according to the rate of change (dθ / dt) is set.

In addition, the present invention comprises the steps of classifying the driving region based on the torque of the engine and modeling the driver's acceleration expectation according to the acceleration pedal drive change rate as a one-dimensional or two-dimensional function; When the driving change rate of the accelerator pedal by the driver's driving is detected, determining the current driving region and then controlling acceleration linearity by controlling the engine output by controlling the fuel amount and the air amount based on the modeling value.

The acceleration linearity control may include oscillation acceleration control in a stationary state, overtaking acceleration control during driving, and feedback control in a constant speed state.

The oscillation acceleration control may include determining an engine acceleration condition in a stationary state by detecting an engine speed, a vehicle speed, and an acceleration pedal change rate; If the oscillation acceleration condition is set, injecting a constant amount of fuel into the fixed region for a predetermined time after setting the mode entry flag to secure oscillation in the stationary state; Determining whether the injection to the fixed area is completed and whether the vehicle speed is greater than or equal to a set speed; If the injection to the fixed area is not completed or the vehicle speed is less than the set speed, the fixed injection is continued, if the injection to the fixed area is completed, and if the vehicle speed is above the set speed includes the step of ending the oscillation acceleration mode. .

The overtaking acceleration control may include determining whether vehicle state information such as a vehicle speed, an engine speed, and an acceleration pedal change rate detected after the oscillation acceleration mode ends is a condition of the overtaking acceleration control mode; Determining an acceleration model value of a one-dimensional or two-dimensional function according to the detected vehicle state information when it is determined as the overtaking acceleration control mode, and then storing the current vehicle speed; Determining an acceleration model inclination according to the acceleration pedal change rate and determining a vehicle speed to secure acceleration linearity with respect to overtaking acceleration through engine output control; In the process of performing the overtaking acceleration control, if the slope of the deceleration model satisfies a reset condition of the overtaking acceleration control, releasing the overtaking acceleration control.

In addition, the feedback control may include determining whether the detected vehicle speed change amount is greater than or equal to the reference speed; Determining whether there is a change in vehicle speed when the reference speed is equal to or greater than the reference speed; If the change in the vehicle speed is an increase speed, the control of reducing the fuel amount and the amount of air is applied to the model value according to the change amount of the accelerator pedal. The process of maintaining linearity.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As can be seen in Figure 1, the vehicle acceleration linearity control apparatus according to the present invention is a vehicle speed detection unit 10, the engine speed detection unit 20, the accelerator pedal detection unit 30, the control unit 40 and the injector 50 The vehicle speed detection unit 10 detects a current vehicle speed by detecting rotation speed of a transfer driven gear and outputs information on the current vehicle speed.

The engine speed detection unit 20 detects the current engine speed through the detection of the speed of the crank shaft and outputs information thereof.

The accelerator pedal detection unit 30 detects a driving displacement of the accelerator pedal and outputs information about the accelerator displacement.

Although various detection sensors related to fuel amount control are required as the input elements in the above, FIG. 1 assumes that only the minimum input elements are shown which are directly related to the present invention.

The control unit 40 performs acceleration linearity control in the area set according to the driving change amount of the accelerator pedal which is the driver's will.

The injector 50 controls the opening and closing of the nozzle according to the control signal applied from the control unit 40 to perform the injection of the fuel amount calculated for each combustion chamber to ensure acceleration linearity in each operating region.

As shown in FIG. 2, the control unit 40 includes an oscillation acceleration region (a), an overtaking acceleration region (b), and a constant speed driving region (B) based on the torque characteristics of each engine. c) is set in the memory area.

In addition, by modeling the driver's acceleration will according to the drive change rate (dθ / dt) of the accelerator pedal is set for each region as shown in Figure 3, the set time (t1) for securing the acceleration initialization in the stop state, for example For example, a fixed zone that corrects a constant amount of fuel for 0.3 sec is set in the memory area.

That is, in FIG. 3, fuel is constantly injected for a predetermined time t1 for forming a fixed area at the initial stage of acceleration in the stationary state, and subsequently, fuel injection amount is controlled based on a model, and model-based control is performed after the start-up. It is limited within the set time, approximately 6sec.

The modeling of each area of the driver's acceleration will is set to the area of the oscillation model 1 when the acceleration pedal drive change rate is 0 ≤ Th_change ≤ C1, and the area of the oscillation model 2 when the acceleration pedal drive change rate is C1 ≤ Th_change ≤ C2. If the acceleration pedal drive change rate is C2 ≤ Th_change ≤ C3, the oscillation model 3 is set.

In the above description, C1, C2, and C3 are arbitrary set reference values, and Th_change means acceleration pedal drive change rate.

In addition, in the case of the overtaking acceleration area, the model-based control reflects the driver's intention according to the acceleration pedal drive change rate, similarly to the control in the oscillation acceleration area, and the optimum feeling of acceleration in which linearity is maintained by feedback control according to the vehicle speed Should be secured.

An operation of controlling acceleration linearity in the present invention including the above function will be described with reference to FIGS. 6A and 6B.

First, the control unit 40 is divided into an oscillation acceleration region (a), an overtaking acceleration region (b), and a constant speed driving region (c) based on the torque of the engine as shown in FIG. In the case of the region a, the oscillation model reference value shown in FIG. 3 reflecting the driver's will is set according to the rate of change of the accelerator pedal, and the overtaking acceleration model reference value is set as shown in FIG. 5 in the overtaking acceleration region b.

The model value is a value extracted through repetitive learning for each condition of the engine.

In the state where the reference model value reflecting the driver's will is set for each driving region as described above, when the engine start of the vehicle is kept on, the controller 40 may determine the state information of the vehicle, that is, the current engine speed and The driving displacement of the accelerator pedal, the vehicle speed, and the like, which are the driver's acceleration intention, are detected and analyzed (S101) to determine the driver's acceleration condition (S102).

In the above acceleration condition determination, it is determined whether the vehicle speed is at a stop state or at a set speed, preferably 3 KHP or less, and whether the change rate of the accelerator pedal drive is a condition of the oscillation acceleration of more than the first set value (Th_changer? C1) (S103). ).

When it is determined that the acceleration condition according to the driver's acceleration pedal driving is the oscillation acceleration condition, the controller enters the oscillation acceleration control mode (S104), and then determines whether the flag (flag) of the oscillation acceleration control is currently set (S105). ).

If the current oscillation acceleration flag is set (Flag = 1) and the control mode is in progress, the process returns to step S103, and if the oscillation acceleration flag is not set, the fixed for the initial oscillation control in the stop state. After setting the injection region, a counter for a set time t1, for example, 3 sec is started (S106), and a constant fuel amount is injected at a fixed value at all times during the set time t1 (S107).

Subsequently, the vehicle speed is detected at a reference speed, for example, 3 KPH or more, and it is determined whether the oscillation acceleration control in the stationary state after the set time t1 of the fixed injection region has elapsed is completed (S108).

If it is determined that the oscillation acceleration control in the stationary state is not completed, the process returns to step S107. When the oscillation acceleration control in the stationary state is determined to be completed, the oscillation acceleration control flag and the fixed area injection control flag in the stationary state are completed. After the reset (S109) to enter the acceleration condition control mode based on the model value (S110).

When the acceleration condition control mode based on the model value is entered as described above, the controller 40 reads the vehicle state information, that is, the current vehicle speed Veh_speed, the engine speed, and the rate of change of the accelerator pedal [Th_change (dθ / dt). )] To determine the acceleration model vehicle speed including the driver's will (S112).

The acceleration model vehicle speed is calculated through Equation 1 below.

y = Veh_speed + INC * X

Where y; Model vehicle speed, Veh_speed; Current vehicle speed, INC (tilt); f [Th_change (dθ / dt)], X; It's time.

When the vehicle speed of the acceleration model is determined as described above, the timer is driven to determine the normal driving switching, and a counter of 3 sec, for example, is started (S113), and the current vehicle speed (Veh_speed_C) at which the acceleration is started is stored. (S114).

Thereafter, the current control condition determines whether the acceleration flag (INC_flag) is set (S115). If the acceleration flag is not set, the acceleration flag is set (S116). Then, the acceleration model is determined by a one-dimensional or two-dimensional function. The slope (ref_INC = Const * dθ / td) is determined (S117).

In the above Const; The set constant value.

When the inclination of the acceleration model is determined, the oscillation acceleration vehicle speed value is determined by multiplying the slope and the time value of the acceleration pedal drive change rate with the current vehicle speed, as shown in FIG. According to C), the acceleration response (A, B, C) is controlled to have a linearity (S118).

At this time, as can be seen in Figure 4, in order to reduce the difference between the acceleration model value and the current acceleration control value by applying a virtual value of the feedback control result to maintain the linearity in the acceleration response by the control of the additional fuel amount.

As described above, if control is performed for a predetermined time set in the state in which the oscillation acceleration is controlled by applying the model value according to the acceleration pedal drive change rate, the reference slope of the acceleration model and the current slope are calculated differently. The absolute value is determined by calculating the slope of the deceleration model (S119).

Thereafter, it is determined whether the determined deceleration model slope satisfies the reset condition of the oscillation acceleration control (S120). If the reset condition of the oscillation acceleration control is not satisfied, the process returns to the process of S111 to repeatedly perform the above-described process. When the reset condition is satisfied, the vehicle speed feedback control mode is entered (S121).

When the vehicle speed feedback control mode is entered, the vehicle speed change amount is detected through a calculation of subtracting the current vehicle speed from the vehicle speed of the oscillation acceleration to which the model value is applied (S122), and it is determined whether the detected vehicle speed change amount is greater than or equal to the set reference speed (S123). .

If it is determined that the current vehicle speed change amount is less than or equal to the set reference speed (S127), and if it is determined that the current vehicle speed change amount is equal to or greater than the set reference speed, it is determined whether a vehicle speed change is detected (S123).

If it is determined that the vehicle speed change is a condition of the increase speed, the vehicle speed is controlled to follow the model value according to the accelerator pedal drive change rate through the fuel amount and air amount reduction control (S125), and when it is detected that the vehicle speed change is the condition of the deceleration speed The vehicle speed is controlled to follow the model value according to the acceleration pedal drive change rate through the increase control of the fuel amount and the air amount (S126).

In the above, in the case of a diesel engine for the acceleration linearity control, as shown in FIG. 4, only the fuel amount control is performed without the air amount control, and in the case of the gasoline engine, the ETC is controlled by the PI gain, and the ETC is mounted. If not, perform air volume control by duty control of ISA (Idle Speed Actuator).

As described above, the present invention sets a model in one-dimensional formula for the acceleration response according to the driver's acceleration pedal operation for each driving region based on the torque of each engine, and based on the model value By securing the acceleration linearity by feedback control on the vehicle speed, the maximum output and torque of the engine mounted on the vehicle are properly used to maximize efficiency, and the vehicle's merchandise is improved with responsiveness that meets the driver's expectation of acceleration.

Claims (15)

A vehicle speed detector for detecting a vehicle speed; An engine speed detection unit detecting an engine speed; An accelerator pedal detection unit detecting a drive displacement of the accelerator pedal; A control unit for controlling acceleration linearity in each area set according to a driving change amount of the accelerator pedal which is the driver's will; And an injector configured to maintain the output of the engine by injecting the amount of fuel calculated in each combustion chamber corresponding to the control signal applied from the control unit. The method of claim 1, The control unit divides the driving region into an oscillation acceleration region (a), an overtaking acceleration region (b), and a constant speed driving region (c) based on the torque characteristics of the engine, and sets the acceleration linearity of the vehicle. Control unit. The method of claim 1, Wherein the control unit acceleration linearity control apparatus for a vehicle, characterized in that the oscillation modeling value of the one-dimensional or two-dimensional function according to the drive change rate (dθ / dt) of the accelerator pedal is set. The method of claim 1, The control unit acceleration linearity control device of a vehicle, characterized in that the fixed area for injecting a constant amount of fuel for a predetermined time (t1) in order to ensure the initialization of the oscillation acceleration in the stationary state is set. The method of claim 1, The control unit continuously injects fuel in the fixed region at the initial stage of the oscillation acceleration in the stop state, and controls the fuel injection amount based on the acceleration model value after the fixed region, and the control based on the model value is limited to within a predetermined time set after the oscillation. Acceleration linearity control device for a vehicle, characterized in that. The method of claim 3, The oscillation acceleration model value of the one-dimensional or two-dimensional function equation of each driving region is set to the region of the oscillation model 1 when the acceleration pedal drive change rate is 0 ≦ Th_change ≦ C1, and the oscillation model when the acceleration pedal drive change rate is C1 ≦ Th_change ≦ C2 If the acceleration pedal drive change rate is C2 ≤ Th_change ≤ C3, set it to the area of the oscillation model 3, and C1, C2, C3 are arbitrary set reference values, and Th_change means the acceleration pedal drive change rate. An acceleration linearity control device of a vehicle. The method of claim 2, In the overtaking acceleration region, a model-based control according to an accelerator pedal change rate and a feedback control are simultaneously applied according to a vehicle speed. Classifying the driving region based on the torque of the engine and modeling the driver's acceleration expectation according to the acceleration pedal drive change rate as a one-dimensional or two-dimensional function; If the driving change rate of the accelerator pedal by the driver's drive is detected, determining the current driving region and then controlling the acceleration linearity by controlling the engine output by controlling the fuel amount and the air amount based on the modeling value. How to control acceleration linearity of a vehicle. The method of claim 8, The acceleration linearity control method includes acceleration oscillation control in a stationary state, overtaking acceleration control during driving, and feedback control in a constant speed state. The method of claim 9, The oscillation acceleration control may include determining an engine acceleration condition in a stopped state by detecting an engine speed, a vehicle speed, and an acceleration pedal change rate; If the oscillation acceleration condition is set, injecting a constant amount of fuel into the fixed region for a predetermined time after setting the mode entry flag to secure oscillation in the stationary state; Determining whether the injection to the fixed area is completed and whether the vehicle speed is greater than or equal to a set speed; If the injection to the fixed area is not completed or the vehicle speed is less than the set speed, the fixed injection is continued, if the injection to the fixed area is completed, if the vehicle speed is above the set speed comprising the step of ending the oscillation acceleration mode Acceleration linearity control method of a vehicle, characterized in that. The method of claim 9, The overtaking acceleration control may include determining whether vehicle state information such as a vehicle speed, an engine speed, and an accelerator pedal change rate detected after the oscillation acceleration mode is terminated is a condition of the overtaking acceleration control mode; Determining a one-dimensional acceleration model value according to the detected vehicle state information when the overtaking acceleration control mode is determined, and then storing the current vehicle speed; Determining an acceleration model inclination according to the acceleration pedal change rate and determining a vehicle speed to secure acceleration linearity with respect to overtaking acceleration through engine output control; And canceling the overtaking acceleration control when the inclination of the deceleration model satisfies the reset condition of the overtaking acceleration control in the process of performing the overtaking acceleration control. The method of claim 9, The feedback control includes determining whether the detected vehicle speed change amount is greater than or equal to a reference speed; Determining whether there is a change in vehicle speed when the reference speed is equal to or greater than the reference speed; If the change in the vehicle speed is an increase speed, the control of reducing the fuel amount and the amount of air is applied to the model value according to the change amount of the accelerator pedal. Acceleration linearity control method of a vehicle comprising the step of maintaining the linearity. The method of claim 10, The method for controlling the acceleration linearity of the vehicle, characterized in that for maintaining a certain amount of fuel injection to the fixed area for ensuring oscillation in the oscillation acceleration control for 3 seconds. The method of claim 10, The end condition of the oscillation acceleration control mode is the acceleration linearity control method of the vehicle, characterized in that the injection is completed in the fixed region, the vehicle speed is 3KHP or more. The method of claim 11, In the overtaking acceleration control mode, the acceleration model of the one-dimensional or two-dimensional function equation is calculated by multiplying the current vehicle speed and the slope of the acceleration pedal change rate and the holding time of the acceleration linearity control method of the vehicle.