KR100559392B1 - Abrupt start prevention method for parallel hybrid electric vehicles - Google Patents

Abstract

By monitoring the engine's speed, APS signal, and motor power to support the start-up of the hybrid hybrid electric vehicle by controlling the accelerator pedal in the engine stop state or idle state, it is possible to prevent sudden start and stop with optimal power control. By suppressing the discharge of gas, to ensure the optimum acceleration performance,

Determining whether the driver's request is capable of controlling the rapid start in the engine stop / idle stop state, and calculating the required torque of the driver and the output power of the vehicle in the case of the sudden starting control, and determining whether the sudden start control is necessary, If necessary, initialize the engine speed and throttle control values, then set control flags; control engine cranking through motor speed and torque control; Calculating the throttle change rate in consideration of the torque change amount and the vehicle speed, controlling the engine output by the process and the calculated throttle change rate by limiting the motor torque output and the change rate and the gear ratio of the CVT, and limiting the motor torque output to stop the engine. / Perform a start control in the idle state.

Hybrid Electric Vehicles, Parallel, Motor Torque, Power Control

Description

Prevention of sudden start of parallel hybrid electric vehicle {ABRUPT START PREVENTION METHOD FOR PARALLEL HYBRID ELECTRIC VEHICLES}

1 is a schematic configuration diagram of a sudden start prevention device of a parallel hybrid electric vehicle according to the present invention.

Figure 2 is a flow diagram of an embodiment for performing a sudden start prevention control in a parallel hybrid electric vehicle according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel hybrid electric vehicle, and more particularly, to a vehicle speed, an acceleration position sensor (APS) signal, and a motor power during start control by an accelerator pedal operation in an idle state or idle state of an engine. The present invention relates to a method of preventing sudden start and departure of a parallel hybrid electric vehicle that monitors an engine output supporting an optimum power control to prevent a rapid start, to suppress harmful gas emission, and to ensure an optimum acceleration performance.

The parallel hybrid electric vehicle directly connects an electric motor to a gasoline engine and transmits power to the wheels through continuously variable transmission (CVT).

In a vehicle equipped with a conventional gasoline engine, since the motor is not mounted, power support by the motor cannot be performed. However, in a hybrid hybrid electric vehicle, power can be supplied to the motor at the driver's will. It simply responds to commands.

In other words, when the APS is developed through the driving of the accelerator pedal, the throttle valve is opened as much as possible according to the OOL (Optimal Operating Line) of the engine and the power is driven by the motor driven by the voltage supplied from the battery for the insufficient torque. Support.

In general, fuel consumption is lowered and a lot of harmful emissions are discharged in a vehicle equipped with a gasoline engine, which is a section in which the engine transitions from an unstable state to a stable state due to initial cold start, vehicle start, and rapid acceleration.

In a parallel hybrid electric vehicle, when the vehicle starts, the vehicle driver can drive the wheels simultaneously with the engine and the motor. The control of the motor drive is based on the determination of the remaining state of charge (SOC) of the battery and finally the motor output from the driver's APS. The reference value of torque and the engine throttle opening amount are calculated.

If the vehicle is stationary while driving or if the engine is warmed up enough and all systems, including batteries, are normal, the parallel hybrid vehicle will stop the engine and enter the driver's APS input standby state.

When the driver's willingness to drive the vehicle suddenly enters the APS, the engine is started by the motor, and upon completion of the start, the motor supports power and the engine generates power according to the throttle opening.

However, when excessive power demand is input by the driver due to the momentary operation of the motor and engine, the vehicle may start suddenly and there is a risk of an accident, the vehicle shift shock occurs severely, and the wheel slips, The problem that the acceleration force is lowered occurs.

In addition, due to excessive output demand, a rich mixing ratio is formed due to excessive opening of the throttle, resulting in a decrease in fuel economy, and a problem that causes harmful emissions by discharging harmful exhaust gases due to unstable combustion.

The present invention has been invented to solve the above problems, the object is to properly distribute the driving power of the electric motor and the engine when the vehicle starts by the driver's APS operation in the engine stop state or idle state, the wheels do not slip smoothly Starting from the vehicle, the vehicle is driven at the optimum point by using the fast response of the motor to improve the fuel efficiency characteristics according to the rapid acceleration of the engine, and to improve the emission of harmful emissions.

In other words, when controlling vehicle departure according to APS under normal condition, the vehicle speed, APS operation amount, motor power support and engine output are monitored for a certain period of time, and then the engine throttle opening change rate is adjusted to suppress the sudden increase or decrease of engine output and the motor. In order to support insufficient engine power by applying a low torque command, the motor may reduce the power or generate excessive power to generate the torque generated by the engine in a situation where a vehicle acceleration shock or vehicle slip may occur. By adjusting the amount of torque generated throughout the vehicle, such as reducing it, the optimal control to prevent vehicle shocks and slippage is carried out to prevent sudden start-up, reduce harmful emissions, and achieve stable acceleration and greater acceleration performance. It would be.

The present invention for realizing the above object is a process of determining whether the driver's request in the engine stop / idle state is a sudden start control possible situation; Determining whether the sudden start control is necessary by calculating the required torque of the driver and the output power of the vehicle when the sudden start control is possible; Initializing the engine speed and the throttle control value if it is determined that sudden start is necessary, and then setting a control flag; Controlling engine cranking through motor speed and torque control; Calculating a throttle change rate in consideration of the maximum torque and the torque change amount and the vehicle speed which can be started and stopped according to engine cranking; Process by limiting the motor torque output and rate of change and gear ratio of CVT; And controlling the engine output at the calculated throttle change rate, and limiting the motor torque output to perform start control in the engine stop / idle stop state. to provide.

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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 is a sudden start prevention device for a parallel hybrid electric vehicle according to the present invention according to the present invention, the driving request detection unit 10 and ECU 20, TCU 30, battery 40, BMS 50, the HCU / MCU 60, the engine 70, the motor 80, the CVT 90, and the driving wheel 100.

The driving request detection unit 10 detects a vehicle driving request of the driver, detects an APS signal for starting and acceleration requests, a brake pedal signal for controlling braking, an signal of an inhibitor switch for selecting a shift stage, and the like. Output electrical information.

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

The TCU 30 detects information such as the current vehicle speed, gear ratio, clutch state, and the like to control the overall operation of the output torque adjustment of the CVT 90.

The battery 40 supports the output power of the motor by supplying a voltage to the motor in the hybrid driving mode, and recovers and regenerates the regenerative braking energy of the motor 80 that operates as a generator during the engine mode and the braking control.

The BMS 50 manages and controls the SOC state of the battery by comprehensively detecting information such as voltage, current, and temperature of the battery 40, and controls the amount of current output when the motor power is supported.

The HCU / MCU 60 controls the overall behavior of the vehicle by integrating and controlling each controller according to the driver's oscillation control request, controlling the output torque and speed of the motor 80, and turning the motor 80 into an electric motor or a generator. Control to operate.

The output of the engine 70 is controlled by the control of the ECU 20 under the control of the HCU, which is the host controller, and the amount of intake air is adjusted through the electric throttle control (ETC).

The motor 80 is typically applied to a BLDC motor, and when the initial driving request is detected, the motor 80 is driven by the voltage of the battery 40 to start the engine 70, and to turn on the power when driving by the output of the engine 70. Support.

The CVT 90 adjusts the speed 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.

Referring to FIG. 2, an operation of controlling sudden start and optimal combustion through optimal power distribution in the parallel hybrid electric vehicle as described above will be described.

The HCU / MCU 60 detects the driver's driving request and various state information of the vehicle when the engine of the parallel hybrid electric vehicle is in an idle stop state or when the vehicle speed and the APS signal remain below a certain level. (S100).

Thereafter, it is determined whether the driver's driving request signal detected is a sudden start control of the vehicle (S110).

If it is determined that the vehicle is capable of controlling the rapid start and departure, the required torque and power of the driver are calculated from the signal of the APS, the information of the vehicle speed, and the engine speed (S111).

It is determined whether or not the calculated required torque and power of the driver is equal to or less than the predetermined value and the change rate is equal to or less than a predetermined value, so that normal control is possible in controlling the start of the vehicle (S112).

If it is determined that the normal control is possible in the above state, the driver's request is transmitted to each controller to control the motor torque and engine throttle control on the OOL (S113).

However, if it is determined that the required torque and power of the driver are in a state in which normal control is impossible, the engine speed control value and the throttle opening degree control value of the ETC are set to initialization (S114).

Thereafter, after setting the engine speed control and cranking control flag (S115), the engine cranking is controlled through the speed and torque control of the motor 80 through the MCU (S116).

It is determined whether the engine cranking is completed through the above control (S117). If the completion of the engine cranking is not detected, the process returns to the process of S116. When the completion of the engine cranking is detected, the maximum torque capable of starting the vehicle can be started. Calculate (S118).

Subsequently, it is determined whether the average value of the driver's driving torque demand is equal to or greater than the maximum torque capable of sudden start calculated in S118 (S119).

If it is determined in S119 that the average value of the required driving torque is less than or equal to the maximum starting torque, after calculating the front and rear wheel speed difference, the engine output and the motor power support without slip are performed, and then the sudden starting control flag is reset (S120). The throttle is calculated at the optimum point on the OOL, and the power support of the motor is provided by subtracting the engine torque by the throttle from the driving demand (S200).

If it is determined in S119 that the average value of the required driving torque is more than the maximum possible starting torque, since the current driving required torque is capable of sudden starting, the rapid starting control flag is set to limit the engine output and the motor torque so that the sudden starting prevention control can be performed. It performs (S121).

Subsequently, it is determined whether the acceleration of the vehicle detected according to the sudden start prevention control is less than or equal to the set reference value (S122). When it is determined that the acceleration is less than or equal to the set reference value, it is determined whether the control threshold time exceeds the set reference time (S123).

When it is determined that the control threshold time exceeds the set reference time, the idle stop sudden start control flag is reset to release the sudden start control (S124), the throttle is calculated by the rate of change at the optimum point on the OOL, and the engine by the throttle in the driving demand amount The power support of the motor is provided by subtracting the torque (S200).

If it is determined in step S122 that the acceleration of the vehicle is equal to or greater than the set reference value, the counter increments the number of times of rapid start control execution (S125), and determines whether the counter of the number of sudden start control times exceeds the set reference value (S126).

If the counter of the number of rapid start and control times in step S126 does not exceed the set reference value, the change rate is calculated at the optimum point on the OOL by the throttle, and the power support of the motor is provided by subtracting the engine torque by the throttle from the operation demand (S200).

However, if it is determined in step S126 that the counter for the number of sudden oscillation control exceeds the set reference value, then the number of sudden oscillation control counted up to now is set as the reference value, and then learning recording of the sudden oscillation control information is performed (S127), and the throttle is the optimal point on the OOL. By calculating the rate of change in the power supply of the motor to the value obtained by subtracting the engine torque by the throttle from the driving demand amount (S200).

In addition, if it is determined in step S110 that the driving request signal is not in the state of rapid start control of the vehicle, it is detected whether there is a sudden start control history in the memory (S130). The data is written to the area (S131), the sudden start control flag and the sudden start counter flag are reset to an initial state (S132).

Then, when the driver's request is detected in the vehicle stop and idle state, the flag for the sudden start control can be set by the learned information, and the engine output torque and the power support of the motor are properly distributed through the above-described procedure. A stable start is maintained (S133).

As described above, the present invention provides an optimal distribution control by controlling the engine output torque and the power support of the motor when the operation demand in the parallel hybrid electric vehicle is an initial rapid acceleration control condition in which the start control is entered in a state where the system is unstable. Power control prevents sudden start-up, suppresses emissions of harmful gases, and improves fuel economy.

Claims (7)

delete Determining whether the driver's request is capable of sudden start control in the engine stop / child stop state; Determining whether the sudden start control is necessary by calculating the required torque of the driver and the output power of the vehicle when the sudden start control is possible; Initializing the engine speed and the throttle control value if it is determined that sudden start is necessary, and then setting a control flag; Controlling engine cranking through motor speed and torque control; Calculating a throttle change rate in consideration of the maximum torque and the torque change amount and the vehicle speed which can be started and stopped according to engine cranking; Process by limiting the motor torque output and rate of change and gear ratio of CVT; And controlling the engine output at the calculated throttle change rate, and limiting the motor torque output to perform start control in an engine stop / idle stop state. The method of claim 2, When the driver's required torque and the output power of the vehicle calculated as described above do not need the sudden start control, the sudden start prevention method of the parallel hybrid electric vehicle characterized in that the control of the torque of the motor and the throttle of the engine is controlled on the OOL. The method of claim 2, If the maximum possible starting torque calculated after the engine cranking is less than the driver's required torque average value, calculate the speed difference of the front and rear wheels, perform engine output and motor power support without slip, and then adjust the torque and throttle of the motor. Rapid start prevention method of a parallel hybrid electric vehicle, characterized in that the control on the OOL. The method of claim 2, When the vehicle acceleration is less than the set reference speed in the state of performing the rapid start prevention control through the engine output and the motor torque limit, the rapid start control is initialized, the number of the rapid start control is counted and recorded in the self-diagnosis memory, and the torque and throttle of the motor Prevention of sudden start of a parallel type hybrid electric vehicle, characterized in that the control on the OOL. The method of claim 2, When the set threshold time elapses in the state of performing the rapid start prevention control through the engine output and the motor torque limit, the rapid start control is initialized, and the rapid start of the parallel hybrid electric vehicle characterized in that the torque and the throttle of the motor are controlled on the OOL. Prevention method. The method of claim 2, When there is a history of execution of the sudden start prevention control through the engine output and the motor torque limit, when the driver's request is detected in the vehicle stop / idle state, the rapid start prevention method of the parallel hybrid electric vehicle, characterized in that to enter the control possible situation .

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