KR100992809B1 - Idle stop and start control method of hybrid vehicle - Google Patents

Abstract

When controlling the idle stop / start in the hybrid electric vehicle equipped with ISG, if the conditions of fuel cutoff control are satisfied, the acceleration stop is reduced by preventing the idling stop through the deceleration direct control when driving in four or more stages. It is to prevent the generation of Nox due to prevention and lean burning.

The present invention is a process for determining whether the fuel injection stop condition is satisfied in the driving state of the engine mode, and if the fuel injection stop condition is satisfied, the process of determining whether the four or more gears are combined by determining the gear shift stage and the gear shift stage is four or more gears. If the state is to combine the step of performing the deceleration direct control and then maintaining the idle control of the engine mode.

Idle stop, ISG, fuel injection stop, gearshift

Description

Idle stop and start control method of hybrid vehicle {IDLE STOP AND START CONTROL METHOD OF HYBRID VEHICLE}

1 is a schematic configuration diagram of an idle stop / start control apparatus of a hybrid vehicle according to the present invention;

2 is a flow diagram of one embodiment for performing idle stop / start control in a hybrid vehicle in accordance with the present invention.

<Description of the symbols for the main parts of the drawings>

10: operation request detection unit 20: ECU

30: TCU 40: battery

50: BMS 60: HCU / MCU

70: engine 80: motor

90: transmission

The present invention relates to a hybrid vehicle, and more particularly, to control the idle stop and start (Idle Stop And Start) in a hybrid electric vehicle equipped with an integrated generator starter (ISG) in direct deceleration when driving in more than four stages. The present invention relates to an idle stop / start control method of a hybrid vehicle that prevents generation of an acceleration stop and eliminates generation of Nox due to lean combustion by preventing an idle stop from being generated.

The hybrid electric vehicle uses an engine and a battery as a power source, and uses the power of the engine to charge the battery.

Therefore, a starter for starting the engine and a generator, which is a 14V power generation system for voltage generation, are provided.

However, when the starter and the generator are applied to each other, the limited space of the engine room cannot be efficiently used, and the cost increases and various problems are caused by the installation of the independent devices.

Therefore, the ISG is applied to simultaneously perform the functions of a starter for starting the engine and a generator for voltage generation, and provides fuel economy improvement through idle stop control when driving in the city or in a traffic jam.

Idle stop control is a function to turn off the engine when the vehicle stops detected according to the driver's brake pedal driving while driving the vehicle, and to start the engine again when the brake pedal is released.

The entry condition of the idle stop control is entered when the condition of Table 1 below is satisfied.

common One APS opening 0 2 After shifting operation 1 second or more 3 Vehicle speed 0km / h 4 Engine speed 1000 RPM or less 5 Ramp Grade / Vehicle Left and Right Grade 8 degrees or less / within 20 degrees 6 After ignition 5 seconds or more 7 Engine water temperature / AT oil temperature 25 ℃ or more and 105 ℃ or less
More than / 25 degrees Celsius and less than 110 degrees Celsius 8 Outside temperature -25 ℃ or more 9 Room temperature after air conditioning 20 ℃ or more and 36 ℃ or less 10 SOC in 36V battery More than 60% 11 36V battery temperature -10 ℃ or more and 75 ℃ or less 12 P / S pump load 0.9 MPa or less D range 13 Steering angle Within 90 degrees 14 Elapsed time since last restart 5 seconds or more 15 Vehicle speed history 2KPH or more 16 Gear stage 3 steps or less 17 brake pedal On 18 Brake M / CYL input 0.55 MPa or more P, N range 19 Elapsed time since last restart 20 seconds or more 20 After shifting the D range More than 2 seconds

However, the idle stop in a specific area may lower the oscillation performance and cause a problem of excessive discharge of Nox, a harmful exhaust gas.

In particular, in the area of fuel cut (Fuel Cut) there is a drawback of excessive discharge of Nox due to lean combustion.

The present invention has been invented to solve the above problems, the purpose is to control the idle stop / start in the hybrid electric automatic equipped with ISG in the state of traveling in four or more stages when the conditions of fuel cut control is satisfied In order to prevent the generation of idle stop through deceleration direct control, it is to prevent the deterioration of acceleration performance and to eliminate the generation of Nox due to lean combustion.

The present invention for realizing the above object comprises the steps of determining whether the fuel injection stop condition in the running state of the engine mode; If the fuel injection stop condition is satisfied, determining a shift stage and determining whether four or more stages are combined; When the shift stage is in a state in which four or more stages are coupled, the idle stop / start control method of the hybrid vehicle comprising the step of performing the deceleration direct control and then maintaining the idle mode of the engine mode.

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

As shown in FIG. 1, the idle stop / start control apparatus of the hybrid vehicle according to the present invention includes a driving request detector 10, an ECU 20, a TCU 30, a battery 40, a BMS 50, and an HCU /. MCU 60, engine 70, motor 80, CVT 90, and drive wheel 100.

The driving request detection unit 10 detects a driver's vehicle driving request, and receives an acceleration position sensor (APS) signal, a brake pedal signal for controlling braking, and a shift stage selection for a driver's start request, a start, and an acceleration request. It detects the signal of the inhibitor switch and outputs electrical information about it.

The ECU 20 controls overall operations of the engine according to the vehicle driving request signal of the driver from the driving request detection unit 10 and engine state information such as coolant temperature and engine torque.

The TCU 30 controls the overall operation of adjusting the output torque of the transmission 90 by detecting information such as current vehicle speed, gear ratio, clutch state, oil temperature, and the like.

The battery 40 supports the output power of the motor by supplying a voltage to the motor 80 in the hybrid driving mode, and supplies a voltage at the start of the engine by the motor 80, and operates as a generator during engine mode and braking control. The regenerative braking energy of 80 is recovered and charged.

The BMS 50 manages and controls the SOC state of the battery 40 by comprehensively detecting information such as voltage, current, and temperature of the battery 40, and supports the power of the motor 80 and at the start of the engine 70. Control the amount of current output to

The HCU / MCU 60 controls each controller in accordance with the driver's oscillation control request to control the overall behavior of the vehicle and the output torque and speed of the motor 80.

In addition, when the condition of the fuel cutoff control is satisfied in the engine mode, when the shift stage combines four or more stages, the idle stop control is not executed and the current engine operation is continuously maintained.

In addition, to output the speed command to the motor 80 at the start of the engine through the ISG to allow the motor 80 to follow the speed command with a constant torque, and to prevent the speed of the vehicle from increasing rapidly during engine ignition. The motor 80 is controlled with negative torque.

In addition, when the speed of the motor 80 reaches the idle RPM after ignition of the engine, it is determined that the cranking is completed, and the motor speed command mode is switched to the torque command mode of the motor and the engine, and the load size is maintained to maintain the idle speed. In applying proportional torque, the negative torque is applied at a set decreasing slope to provide stability of the engine and provide a stable ride.

The output of the engine 70 is controlled by the control of the ECU 20 under the control of the HCU, which is an upper controller, and the amount of intake air is adjusted through an electric threshold control (ETC) not shown.

The motor 80 is driven by the voltage of the battery 40, and supports power when traveling by the output of the engine 70.

The transmission 90 adjusts the transmission ratio under the control of the TCU 30 to transmit the power transmitted from the motor 80 to the driving wheel 100 through the differential gear so that the vehicle can be driven.

An operation of performing idle stop / start control in the hybrid vehicle according to the present invention including the above-described function will be described with reference to FIG. 2.

In a state in which the hybrid vehicle equipped with the ISG is driven in the engine mode, the ECU 20 may determine the fuel injection stop condition based on the information of the driving request detection unit 10 and the state information of the engine 70 detected through the HCU / MCU 60. It is determined whether to satisfy (S102).

If the fuel injection stop condition is not satisfied in step S102, it is determined whether an idle stop entry condition that satisfies the above-described condition of Table 1 (S107).

If the idle stop entry condition is not satisfied in step S107, the idle control is maintained in the engine mode (S106). If the idle stop entry condition is satisfied, the idle stop control is performed (S108).

In addition, if the fuel injection stop condition is satisfied in the determination of S102, the current shift stage is determined by analyzing the information detected by the TCU 30 (S103) to determine whether the shift stage combines four or more stages. (S104).

If it is determined in the determination of S104 that four stages or less are coupled, it is determined whether the idle stop entry condition is satisfied (S107). If the idle stop entry condition is not satisfied, the idle control is maintained in the engine mode (S106). When the stop entry condition is satisfied, the idle stop control is performed (S108).

However, if it is determined in the determination of S104 that the shift stage combines four or more stages, the deceleration direct control is performed (S105), and the idle control is continuously maintained in the engine mode (S106).

As described above, in the present invention, when the idle stop / start is controlled in the hybrid electric vehicle equipped with the ISG, the idle stop occurs through the deceleration direct control in the state where the fuel stop control is satisfied in the state of driving in four or more stages. By avoiding this, the effect of preventing the deterioration of acceleration performance and eliminating the generation of Nox due to lean combustion is provided.

Claims (3)

Determining whether the fuel injection stop condition is satisfied in the driving state of the engine mode; If the fuel injection stop condition is satisfied, determining a shift stage and determining whether four or more stages are combined; If the shift stage is in a state that combines four or more stages, the idle stop / start control method of the hybrid vehicle, characterized in that for performing the deceleration direct-connected control and maintaining the idle mode of the engine mode. The method of claim 1,  An idle stop / start control method of a hybrid vehicle, characterized in that the idle stop control is performed when the fuel injection stop condition is not satisfied or when the idle stage entry condition is satisfied while the shift stage is combined with four gears or less. The method of claim 1, Idle stop / start control method of a hybrid vehicle, characterized in that the idle stop control is performed if the idle stop entry condition is met while the shift stage is engaged with four gears or less while satisfying the fuel injection stop condition.

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