KR101732383B1 - Method for controlling reduction engine torque of hybrid vehicle - Google Patents

Abstract

The present invention discloses a method for controlling engine torque reduction of a hybrid vehicle. When the shift start time point in the shift control unit (TCU) satisfies the engine torque reduction control condition after the start of the shift, the engine torque reduction control is executed. When the engine torque reduction control condition is satisfied before the end of the shift, And the engine torque reduction control is continued when the calculated value for the difference between the output torque measurement value and the output torque prediction value is equal to or greater than a predetermined operation reference value When the engine torque reduction control is terminated at the end of the shift according to the existing engine torque reduction control pattern as the engine torque reduction control is canceled when reaching the next shift start point, the output torque change with respect to the variation of the input side torque of the speed change drive portion The vibration generated by the vibration is fundamentally eliminated, And can further improve the transmission feel of the vehicle.

Description

TECHNICAL FIELD [0001] The present invention relates to a control method for reducing engine torque of a hybrid vehicle,

More particularly, the present invention relates to an engine torque reduction control method for preventing a shift shock caused when engine torque reduction control is terminated at the end of a shift, To a torque reduction control method for a hybrid vehicle in which reduction control can be maintained.

These hybrid vehicles are future vehicles that use exhaust gas as well as electric motors as auxiliary power sources to improve exhaust gas and improve fuel efficiency. In response to the demand for improving fuel efficiency and developing environmentally friendly products, more active research is being conducted .

The hybrid vehicle includes an EV (Electric Vehicle) mode, which is a pure electric vehicle mode using only the power of an electric motor (drive motor), an HEV (Hybrid Electric Vehicle) mode, which uses the rotational power of the engine as the main power, And a regenerative braking (RB) mode in which braking and inertia energy is recovered through power generation of the drive motor to charge the battery when the vehicle is braked or driven by inertia.

In this hybrid vehicle, the mechanical energy of the engine and the electric energy of the battery are used together, and the optimum operation region of the engine and the driving motor is utilized. In addition, energy can be recovered by the driving motor during the braking operation.

A hybrid vehicle is equipped with a hybrid control unit (HCU), and a controller is provided for each device constituting the system.

For example, the HCU includes an engine control unit (ECU) that controls the entire engine operation, a motor control unit (MCU) (including an inverter) that controls the entire operation of the drive motor, a transmission controller Transmission Control Unit (TCU), Battery Management System (BMS) for monitoring and managing the battery status, and Full Auto Temperature Controller (FATC) for controlling the room temperature. Mode setting, and overall control of the vehicle. Each of the controllers is connected to a high-speed CAN communication line around the HCU as a top-level controller, and the information is exchanged between the controllers, .

That is, in the ECU or the MCU, if there is information necessary for the shift control, information is transmitted to the transmission controller (TCU) so that the shift control is performed. At this time, in the TCU, information transmitted from the ECU and the MCU, Is compared with previously input data to control the transmission, thereby achieving optimum shift control.

However, the TCU of such a hybrid vehicle generates and transmits an engine torque reduction command to the ECU when a change in torque on the output side with respect to a torque variation of the input side of the transmission is sensed from the shift control sensing unit, and the ECU receives the engine torque reduction command, The engine torque reduction control is executed in accordance with the illustrated engine torque reduction control pattern.

According to the engine torque reduction control pattern, the engine torque reduction control is canceled at the end of the shift, and the engine or motor torque increases sharply. As the engine torque suddenly rises, the output side torque to the input side torque sharply fluctuates Therefore, it was caused by the shock due to the shift shock due to the abrupt fluctuation of the output torque.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object to be achieved in the present invention is to provide an engine torque reduction control system, which is capable of performing engine torque reduction control when a shift start time point in a shift control unit ; Calculating a difference between an output torque prediction value calculated on the basis of an output torque measurement value of the transmission measured by the shift control sensing unit and an engine torque reduction amount of the ECU when the engine torque reduction control condition before the end of the shift is satisfied; And a step of continuously executing the engine torque reduction control when the difference between the output torque measurement value and the output side torque prediction value is equal to or greater than a predetermined operation reference value, thereby providing an engine torque reduction control method for a hybrid vehicle, The vibration generated by the change in the output side torque with respect to the variation of the input side torque of the transmission according to the change of the output torque of the transmission can be fundamentally eliminated to eliminate the shift shock and further improve the transmission feel of the vehicle.

According to a first aspect of the present invention, there is provided a method for controlling engine torque reduction of a hybrid vehicle,

Executing engine torque reduction control when the shift start time point in the shift control unit (TCU) satisfies the engine torque reduction control condition;

Calculating a difference between an output torque prediction value calculated based on an output torque measurement value of the transmission measured by the shift control sensing unit and an engine torque reduction demand amount of the ECU when the engine torque reduction control condition immediately before the gearshift end is satisfied; And

And continuously executing the engine torque reduction control when the difference between the output torque measurement value and the output torque prediction value is equal to or greater than a predetermined operation reference value.

The method comprises:

It is preferable to determine whether the TCU has started the next shift and release the engine torque reduction control at the next shift start time.

The method comprises:

And canceling the engine torque reduction control when the difference between the output torque measurement value and the output torque prediction value is not equal to or greater than the operation reference value.

Here, the engine torque reduction control condition includes:

It is preferable that the current gear range information, the oil temperature, the engine revolution speed, the turbine revolution speed, the throttle opening variation amount, and the turbine rotation speed variation amount satisfy the set value condition and there is no failure in the communication and sensor system will be.

Thus, according to the engine torque reduction control method of the hybrid vehicle of the present invention, the engine torque reduction control is executed when the shift start point in the shift control unit (TCU) satisfies the post-engine torque reduction control condition, Calculating a difference between an output torque prediction value calculated based on an output torque measurement value of the transmission measured by the sensing unit and an engine torque reduction amount of the ECU and calculating a difference between the output torque measurement value and the output torque prediction value by a predetermined operation reference value or more The vibration generated by the output torque change with respect to the variation of the input side torque of the transmission due to the termination of the engine torque reduction control at the end of the shift can be fundamentally eliminated to eliminate the shift shock, The effect of further improving the transmission feeling is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further understand the technical idea of the invention. And should not be construed as limiting.
1 is a waveform diagram showing an engine torque reduction control pattern of a general hybrid vehicle.
2 is a flowchart illustrating an engine torque reduction control process of a hybrid vehicle according to the present invention.
3 is a waveform diagram showing the engine torque reduction control pattern shown in Fig.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 2 is a flowchart for explaining an engine torque reduction control process of a hybrid vehicle according to an embodiment of the present invention, and FIG. 3 is a waveform diagram showing the engine torque reduction control pattern shown in FIG.

Before describing the method of controlling the engine torque reduction of the hybrid vehicle according to the embodiment of the present invention, the hybrid vehicle sets a target shift stage on the basis of information input from the shift lever, the vehicle speed and the brake pedal, A transmission control unit (TCU) for generating and transmitting a transmission signal for controlling the transmission drive section in accordance with a shift pattern having a hydraulic duty value of the engagement side element and a hydraulic duty value of the release side element, The optimum shift control is performed.

The transmission control unit (TCU) is provided with a transmission correction coefficient and various threshold values for the current gear stage for correcting the hydraulic duty values of the friction elements including the engagement-side element and the release-side element as an interpolation table And the speed change drive unit means all the solenoid valves applied to the hydraulic control means of the friction element including the engagement side element and the release side element.

That is, the shift control is performed through such input information in the shift control unit (TCU). In the case of the hybrid vehicle, the transmission drive portion receiving the input side torque of the engine or the motor changes the output side torque according to the variation of the input side torque Shift shock occurs during shifting due to such fluctuation of the output side torque.

Therefore, in order to reduce the input side torque and the output side torque fluctuation of the speed change drive portion during such shifting, the TCU requests the engine control unit (ECU) for engine torque reduction control, and the ECU executes engine torque reduction control do.

That is, in order to prevent a shift shock caused when the engine torque reduction control is terminated at the time of the end of the shift, the embodiment of the present invention is configured such that the output torque measurement value and the output side torque prediction value after the end of the shift The engine torque reduction control is continuously executed through a series of processes as shown in FIG.

As shown in Fig. 2, the shift control unit (TCU) determines whether the engine torque reduction control condition is satisfied through step 103 when the shift start point has been reached through step 101, The engine torque reduction control is requested when the torque reduction control condition is satisfied, and the engine torque reduction control is executed in the ECU that has received the engine torque request control (step 105).

Here, the engine torque reduction control condition is that the current gear range information, the oil temperature, the engine speed, the turbine speed, the throttle open amount, and the turbine speed change amount satisfy the set value conditions, Is not present.

Then, the TCU determines whether the TCU has reached the end of the shift (step 107). If the TCU has reached the predetermined time (T1) before the end of the shift, the TCU measures the output torque of the transmission and outputs an output torque measurement value ), And calculates the output torque prediction value of the shift drive section according to the engine torque reduction required amount of the ECU (step 111).

Then, the TCU calculates a difference between the output torque measurement value and the output torque prediction value (step 113), and compares the calculated value with a predetermined operating reference value (step 115).

For example, when the calculated value is equal to or greater than a predetermined operation reference value, the TCU continues the engine torque reduction control (step 117).

However, if the calculated value is not equal to or greater than the predetermined operation reference value, the TCU cancels the engine torque reduction control (step 119).

On the other hand, if the TCU has reached the next shift start point through step 121, the TCU proceeds to step 119 to cancel the engine torque reduction control.

That is, the engine torque reduction control pattern is as shown in FIG. 3 through the above-described series of processes. That is, the TCU continues to execute the engine torque reduction control when the calculated value of the difference between the output torque measurement value and the output torque prediction value after the end of the shift is equal to or greater than a predetermined operation reference value, and when the calculated value is not equal to or greater than the operation reference value The engine torque reduction control is canceled.

According to the present invention, when the shift start time in the shift control unit (TCU) satisfies the post-engine torque reduction control condition, the engine torque reduction control is executed. If the engine torque reduction control condition is satisfied before the end of the shift, Calculates a difference between an output torque estimation value calculated on the basis of an output torque measurement value of the transmission and an engine torque reduction amount of the ECU measured by the engine torque estimating means and an output torque estimation value calculated based on the engine torque reduction value, The torque reduction control is continuously executed and the engine torque reduction control is terminated when the next shift start point is reached.

Therefore, when the engine torque reduction control is terminated at the end of the shift according to the existing engine torque reduction control pattern, the vibration caused by the change in the output side torque with respect to the variation of the input side torque of the speed change drive unit is fundamentally eliminated, Thereby further improving the transmission feel of the vehicle.

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, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

When the shift start time point in the shift control unit (TCU) satisfies the engine torque reduction control condition after the start of the shift, the engine torque reduction control is executed. When the engine torque reduction control condition is satisfied before the end of the shift, And the engine torque reduction control is continued when the calculated value for the difference between the output torque measurement value and the output torque prediction value is equal to or greater than a predetermined operation reference value And when the engine torque reduction control is terminated at the end of the shift according to the existing engine torque reduction control pattern as the engine torque reduction control is terminated when the next shift start timing is reached, The vibration generated by the transmission The efficiency of the engine torque reduction control method of the hybrid vehicle which can eliminate the cost and improve the transmission feeling of the vehicle can be made very great and the possibility of the commercialization or sales of the applied vehicle is sufficient and realistic It can be practiced clearly.

Claims (4)

Executing engine torque reduction control when the shift start time point in the shift control unit (TCU) satisfies the engine torque reduction control condition;
Calculating a difference between an output torque estimated value of the shift drive portion measured by the shift control sensing portion and an output torque predicted value calculated based on an engine torque reduction required amount of the engine control unit when the engine torque reduction control condition immediately before the gearshift end is satisfied; And
And continuously executing the engine torque reduction control when the difference between the output torque measurement value and the output torque prediction value is equal to or greater than a predetermined operation reference value. The method of claim 1,
Further comprising determining whether the TCU has started the next shift and canceling the engine torque reduction control at the next shift start time. The method of claim 1,
Further comprising the step of canceling the engine torque reduction control when the difference between the output torque measurement value and the output torque prediction value is not equal to or greater than the operation reference value. The engine torque reduction control system according to one of claims 1 to 3,
Wherein the current gear range information, the oil temperature, the engine revolution speed, the turbine revolution speed, the throttle opening degree change amount, and the turbine rpm variation amount each satisfy the set value condition and there is no failure in the communication and sensor system A method for controlling engine torque reduction of a hybrid vehicle.

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