KR20160142727A - Method and device for controlling start time of engine in hybrid vehicle - Google Patents

Abstract

A method for controlling the start time of an engine in a hybrid vehicle comprises: a step of allowing a controller to calculate the coupling RPM of a motor coupled to an engine through an engine clutch based on the RPM rising gradient of the engine and the RPM rising gradient of the motor; and a step of allowing the controller to start the engine before the minimum time where the engine reaches the coupling RPM according to the RPM rising gradient of the engine, wherein the coupling RPM of the motor can be the same as the target rom of the engine. Therefore, the present invention determines the start time of the engine by considering the RPM of the motor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hybrid vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hybrid vehicle (hybrid electric vehicle) related technology, and more particularly, to a method of controlling an engine starting time of a hybrid vehicle and a control apparatus therefor.

The eco-friendly automobile encompasses a fuel cell automobile, an electric automobile, a plug-in electric automobile, and a hybrid automobile, and usually has a motor for generating a driving force.

An example of such an environment-friendly automobile is a hybrid vehicle, which uses an internal combustion engine and battery power. That is, the hybrid vehicle efficiently combines the power of the internal combustion engine and the power of the motor.

The hybrid vehicle may be comprised of an engine, a motor, an engine clutch that powers the engine between the engine and the motor, a transmission, a differential gear device, a battery, a starting generator that starts the engine or generates power by the output of the engine, have.

The hybrid vehicle includes a hybrid control unit for controlling the overall operation of the hybrid vehicle, an engine control unit for controlling the operation of the engine, a motor control unit for controlling the operation of the motor, A transmission control unit for controlling the operation of the transmission, and a battery control unit for controlling and managing the battery.

The battery controller may be referred to as a battery management system. The starter generator may also be referred to as an integrated starter & generator (ISG) or a hybrid starter & generator (HSG).

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

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

An object of the present invention is to provide an engine starting time control method for a hybrid vehicle capable of determining a driving time point (starting point or starting point) of an engine in consideration of revolutions per minute (RPM) And a control device.

In order to solve the above problems, a method of controlling an engine start time of a hybrid vehicle according to an embodiment of the present invention is a method for controlling an engine starting time of a hybrid vehicle, Calculating an engagement rotational speed of the motor coupled to the engine; And controlling the engine to start the engine before a minimum time for the engine to reach the engagement rotational speed in accordance with a speed increasing slope of the engine, wherein the combined rotational speed of the motor is controlled by a target rotation May be the same as the number.

The method of controlling an engine start time of the hybrid vehicle may further include the step of the controller generating an engine start command before the start control of the engine in response to an acceleration signal output from an accelerator pedal sensor (APS).

The method of controlling an engine starting time of the hybrid vehicle may further include the step of the controller controlling the motor to have the combined RPM in response to an acceleration signal output from an accelerator pedal sensor (APS) .

The controller may include a motor controller for controlling the motor, and a hybrid controller for controlling the motor controller and the engine.

The controller can control the engine to start through a hybrid start-up generator.

According to an aspect of the present invention, there is provided an apparatus for controlling an engine start time of a hybrid vehicle, comprising: an accelerator pedal sensor (APS) for detecting an operation of an accelerator pedal; And a controller for generating an engine start command prior to engine start control in response to an acceleration signal output from the accelerator pedal sensor, wherein the controller is configured to control the engine based on the engine speed up slope and the motor speed up slope Wherein the controller controls the engine to start the engine at a minimum time before the engine reaches the engagement speed according to the engine speed increase slope, The combined rotational speed of the motor may be equal to the target rotational speed of the engine.

The controller may control the motor to have the engagement rotational speed in response to an acceleration signal output from an accelerator pedal sensor (APS).

The controller may include a motor controller for controlling the motor, and a hybrid controller for controlling the motor controller and the engine.

The controller can control the engine to start through a hybrid start-up generator.

The method of controlling an engine start time of a hybrid vehicle according to an embodiment of the present invention and the apparatus thereof are capable of preventing unnecessary driving energy loss and balancing state of charge (SOC) using engine power by optimizing an engine start- ) Can be secured and the fuel consumption can be effectively improved.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the drawings used in the detailed description of the present invention, a brief description of each drawing is provided.
1 is a view for explaining an example of engine startup in a hybrid vehicle (hybrid electric vehicle).
2 is a graph illustrating a method of controlling an engine start time of a hybrid vehicle according to an embodiment of the present invention.
3 is a block diagram illustrating a hybrid vehicle including an engine start-time control apparatus for a hybrid vehicle according to an embodiment of the present invention.
FIG. 4 is a graph illustrating a simulation result of the engine start time control method of the hybrid vehicle shown in FIG. 2. FIG.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, and the objects attained by the practice of the invention, reference should be made to the accompanying drawings, which illustrate embodiments of the invention, and to the description in the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Like reference numerals in the drawings denote like elements.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having", etc., are used to specify that a feature, a number, a step, an operation, an element, a component, or a combination thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Throughout the specification, when a part is referred to as being "connected" to another part, it is not necessarily the case that it is "directly connected", but also "electrically or mechanically connected" .

Unless defined otherwise, terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and, unless expressly defined herein, are to be construed as either ideal or overly formal Do not.

The TMED hybrid vehicle, which is a TMED (Transmission Mounted Electric Device) system, travels on the basis of the electric power of the battery during the initial oscillation and drives the electric motor. When a larger demand force (vehicle acceleration operation by the driver) After that, the clutch between the motor and the engine is coupled to transmit the driving force of the engine to the driving part.

Unlike conventional gasoline vehicles, hybrid vehicles apply a high level of torque in consideration of efficiency (fuel economy) and state of charge (SOC) balance after starting the engine. However, due to the nature of the engine, the torque accuracy degrades at low revolutions per minute (RPM), and high torque at low RPM degrades NVH (noise, vibration, harshness) performance.

Considering the torque accuracy and the NVH performance, the TMED hybrid vehicle does not perform the clutch engagement control in the region where the motor RPM is too low. In other words, the clutch is engaged with reference to the motor RPM regardless of whether the engine is started (started) or not. If the motor is at low velocity and the engine RPM increases during engine start-up, the engine will remain idle, which will adversely affect fuel economy.

1 is a diagram (graph) for explaining an example of engine startup in a hybrid vehicle (hybrid electric vehicle).

In the hybrid vehicle, the engine start timing can be determined only by the driver's request or the state of the vehicle without considering the characteristics of the engine. For example, when the accelerator pedal connected to the acceleration position sensor (APS) shown in FIG. 1 is stepped on, the driver shows acceleration or the SOC of the battery is low, The engine is started.

However, in a general engine, the power (torque) available according to the number of revolutions of the engine is limited, and the accuracy of the power may also be deteriorated. And high power at low rpm will adversely affect NVH performance.

Furthermore, in the case of an engine that is used for various purposes such as charging a SOC, such as a hybrid engine, the engine speed is a very important factor because a high torque is applied after the engine is started.

Therefore, in the TMED system, the engine is started due to the driver's intention or vehicle condition, but the clutch can not be engaged in a region where the number of revolutions of the motor is too low. As a result, until the engine RPM (16 in FIG. 1) capable of engaging the clutch after the engine is started, the engine maintains the idle state 18 as shown in FIG. 1, which adversely affects the fuel consumption. To be more specific, the accelerator pedal is depressed by the driver and non-drive energy can be generated in the engine as indicated by reference numeral 18. 1, reference numeral 12 denotes an RPM of the motor, and reference numeral 14 denotes an RPM of the engine.

If the engine can be started (engine starting time) by referring to the timing when the clutch engageable time point is determined in consideration of the accuracy of the engine power and the NVH performance in the TMED system as in the embodiment of the present invention described below , Which can be a great help in improving fuel efficiency.

2 is a graph illustrating a method of controlling an engine start time of a hybrid vehicle according to an embodiment of the present invention.

The engine start time control method of the hybrid vehicle (or hybrid electric vehicle) is an engine start control considering the possibility of clutch engagement (engine clutch lockup) of a TMED (Transmission Mounted Electric Device) system, It can be a control that determines the driving point of the engine in consideration of the RPM level of the motor.

The TMED system (or the TMED hybrid system) has a clutch between the engine and the motor as shown in Fig. 3, and travels only by the motor force without engaging the clutch in the low speed / constant speed section. In the high-speed / high-load region, the vehicle can be driven by the force of the engine and the motor by engaging the clutch.

Referring to FIG. 2, the present invention can optimize the engine start-up time 110 based on the engageable RPM 106 of the clutch included in the TMED system.

)를 참조하여 엔진의 기동시점을 차별화할 수 있다.The present invention relates to a vehicle speed at an EV line (an electric vehicle line) 108 at the time of an engine start command for switching a hybrid electric vehicle (HEV) mode or a rising speed (or a rising slope) of the RPM 102 of a motor

The starting point of the engine can be differentiated.

In the case of a hybrid engine, it takes about 200 to 300 ms until the engine is sufficiently supplied with normal air and fuel after the first start attempt.

Further, due to the characteristics of the TMED system, the number of revolutions of the engine and the motors 104 and 102 must be controlled equally for the clutch engagement. When the engine and the motor are coupled through the clutch when the difference in the number of revolutions occurs, shock and jerk are generated and the drivability is greatly deteriorated. Since the motor is connected to the drive system through the transmission, the rotation speed of the motor is closely related to the speed of the vehicle.

Therefore, in order to engage the clutch, the target revolution speed 104 of the engine must be set to the motor revolution speed 102 (synchronized) after the engine is started, which may also take about 200 to 300 ms. That is, after the engine start command, it takes about 500 to 700 ms or more to prepare for clutch engagement. Therefore, as the upward slope of the rotational speed 102 of the motor is increased, the engine starting time 110 must be increased so that the clutch can be engaged at the correct engageable rotational speed.

The best condition is to take the engine start time 110 precisely in all operating conditions, but there may be a disadvantage in that the starting point of the engine can not be optimized due to various operation patterns and road conditions under actual conditions. In the present invention, it is possible to determine the final engine start time 110 by referring to the number of revolutions of the motor, which is the secondary control, after applying the engine start command on the EV line 108 on a first step. With this control, the clutch engagement timing can be optimized.

3 is a block diagram illustrating a hybrid vehicle including an engine start-time control apparatus for a hybrid vehicle according to an embodiment of the present invention.

3, the hybrid vehicle 200 includes an acceleration position sensor or an acceleration pedal position sensor (APS) 205, a hybrid control unit (HCU) 210, a motor controller unit, an MCU) 215, an engine 225, a hybrid starter & generator (HSG) 227, an engine clutch 230, a battery 235, 240, a transmission 245, and a driving wheel 250, which is a wheel. In another embodiment of the present invention, the hybrid vehicle 200 may further include an engine control unit (ECU) that controls the operation of the engine 225. The engine controller (ECU) can control the operating point of the engine (225) according to the control signal applied from the hybrid controller (HCU) (210) through the network so that the optimum torque can be outputted. The engine controller (ECU) may be included in the hybrid controller (HCU)

The hybrid vehicle 200 may include a power train of a transmission mounted electric device (TMED) type having a motor 240 and a transmission 245 attached thereto. The hybrid vehicle 200 may include an engine 225 and a motor 240 An EV mode (electric vehicle mode) or an engine 225 (an electric vehicle mode) which is a pure electric vehicle mode using only the power of the motor 240 depending on whether the engine clutch 230 exists between the power sources (HEV) mode (hybrid electric vehicle mode) in which the rotational force of the motor 240 is used as the main power while the rotational force of the motor 240 is used as the auxiliary power. In more detail, in the hybrid vehicle 200 having the structure in which the motor 240 is directly connected to the transmission 245, the engine RPM is pulled up through the start of the hybrid start generator (HSG) 227, The power transmission and interruption of the clutches 230 and 225 is performed through the coupling and disconnection of the clutch 230 and a driving force is generated in the wheel 250 through the power transmission system that may include the transmission 245, The engine torque can be transmitted through the engagement of the clutch 230 when the torque transmission of the engine 225 is requested.

The accelerator pedal sensor (APS) 205 can sense the operation of the accelerator pedal by the driver and can provide a signal to the hybrid controller (HCU) 210 according to the operation force applied to the accelerator pedal.

The hybrid controller (HCU) 210 can integrally control controllers such as a motor controller (MCU) 215 connected to a network such as a CAN (Controller Area Network) as a top level controller, It is possible to control the entire operation of the mobile terminal 200.

The hybrid controller (HCU) 210 calculates the driver's requested power in response to the acceleration signal (or the operation signal of the accelerator pedal) output (transmitted) from the accelerator pedal sensor (APS) The engine start command can be generated internally before the start control of the engine 225. [

The hybrid controller (HCU) 210 controls the engine clutch (HCU) 210 based on the upward slope of the engine revolution (RPM) and the upward slope of the motor revolution (RPM) transmitted from the motor controller (Or estimate) the combined rotational speed RPM of the motor 240 coupled to the engine 225 (or the clutch engageable RPM 106 of FIG. 2) via the output shaft 230. The combined rotational speed RPM of the motor 240 that provides the driving force to the wheel 250 may be equal to the target rotational speed of the engine 225. [ The RPM rise slope of the engine may be sensed by an engine speed sensor (not shown) that may be connected (attached) to the engine 225 and provided to the hybrid controller (HCU)

The hybrid controller (HCU) 210 calculates the minimum time (the engine ON time 110 in FIG. 2) at which the engine 225 reaches the engagement speed RPM in accordance with the engine RPM gradient, ) Through the hybrid start-up generator (HSG) 227 before the start of the engine. That is, the hybrid controller (HCU) 210 may apply the final engine start command to the engine 225 at the engine ON time 110 shown in FIG. The hybrid start generator (HSG) 227 can start the engine or operate as a generator by the engine power (engine output) to charge the battery 235. The hybrid start generator (HSG) 227 may also be referred to as an integrated starter & generator (ISG).

The motor controller (MCU) 215 controls the motor 240 to have the combined RPM in response to the acceleration signal (operation signal of the accelerator pedal) output from the accelerator pedal sensor (APS) 205 .

The motor controller (MCU) 215 can calculate (or calculate) the slope of the rotation speed (RPM) of the motor and can control the operation of the motor 240. The upward slope of the RPM of the motor may be sensed by a motor rotational speed sensor (not shown) that may be connected (attached) to the motor 240 and provided to the motor controller (MCU)

The motor controller (MCU) 215 controls the output torque of the driving motor 240 according to a control signal applied from the hybrid controller (HCU) 210 through the network so as to be driven to the region having the maximum efficiency . The motor controller (MCU) 215 includes an inverter composed of a plurality of power switching elements. The power switching elements constituting the inverter include an insulated gate bipolar transistor (IGBT), a MOSFET, an FET, a transistor TR, Relay. ≪ / RTI > A motor controller (MCU) 215 may be disposed between the battery 235 and the motor 240.

The engine 225 may include any one of a diesel engine, an LPG engine, and an LNG engine. The engine 225 may output a torque to an operating point corresponding to a control signal applied from the engine controller, The combination can be appropriately maintained.

The hybrid start generator (HSG) 227 operates as an electric motor or a generator and is operated as an electric motor in accordance with a control signal applied from a motor controller (MCU) 215 to start up the engine 225, The engine 225 can be operated as a generator to generate a voltage in a state in which the engine 225 is maintained in a start-on state, and the generator voltage can be supplied to the battery 235 through the inverter as a charging voltage. The hybrid start generator (HSG) 227 may be connected to the engine 225 by a belt.

The engine clutch 230 is mounted between the engine 225 and the drive motor 240 so that power transmission (power connection) can be interrupted to allow the operation of the EV mode and the HEV mode to be provided.

The battery 235 is composed of a plurality of unit cells and a high voltage of, for example, DC 350 (Volt) to 450V for providing a voltage to the driving motor 240 may be stored.

The drive motor 240 is operated by the three-phase alternating voltage applied from the motor controller 215 to generate torque, and can operate as a generator in another run to supply the regenerative energy to the battery 235.

The transmission 245 may be implemented as an automatic transmission (multi-stage transmission) or a continuously variable transmission (CVT), and the engagement element and the release element may be operated by hydraulic operation under the control of a shift controller Can be combined. The transmission 245 may transmit or block the driving force of the engine 225 and / or the motor 240 to the wheel 250.

In another embodiment of the present invention, a hybrid controller (HCU) 210 and a motor controller (MCU) 215 (or hybrid controller (HCU) 210, motor controller (MCU) May be integrated into a single controller (controller or control unit). In this case, the controller can perform the operation (operation) of the hybrid controller (HCU) 210 and the motor controller (MCU) 215 described above. The engine start timing control apparatus of the hybrid vehicle may include the controller and the accelerator pedal sensor (APS)

The controller may be, for example, one or more microprocessors operated by a program or hardware including the microprocessor, and the program may perform an engine start time control method of a hybrid vehicle according to an embodiment of the present invention And the like.

Referring to FIGS. 2 and 3, the engine start time control method of the hybrid vehicle according to the embodiment of the present invention can be described as follows.

Engine Start Time Control Method The engine start time control method of the hybrid vehicle may include a calculation step and a control step.

2 and 3, in the calculation step, the controller controls the engine clutch 230 based on a rising slope of revolutions per minute (RPM) and an increasing slope of the rotation speed of the motor (RPM) (Estimates) the combined rotational speed RPM of the motor 240 coupled to the engine 225 via the output shaft 210. [ The combined rotational speed RPM of the motor 240 that provides the driving force to the wheel 250 and the target rotational speed of the engine 225 may be equal to each other. The controller can determine whether the RPM of the motor 240 is between the engine RPM 106 considering the rising slope and the startup time and the clutch engageable RPM 106. [ When the RPM of the motor 240 is between the engine RPM and the clutch engageable RPM in consideration of the rising slope and the startup time, the controller can inhibit the engine startup.

Next, according to the control step, as shown in FIG. 2, the controller sets the minimum time (time) at which the engine 225 reaches the engagement rotational speed RPM in accordance with the upward slope of the rotational speed RPM of the engine 225 It is possible to control the engine 225 to start before the engine 110 is started. That is, the controller may apply a final start command to the engine 225. [ The controller may internally generate an engine start command prior to the start control of the engine in response to an acceleration signal output from an accelerator pedal sensor (APS) The controller can control the motor 240 to have the engagement RPM in response to the acceleration signal output from the accelerator pedal sensor (APS) 205.

Next, the controller determines whether the RPM of the engine 240 is greater than the RPM of the RPM motor 240 (or the RPM of the motor and the RPM of the engine) Number of revolutions (RPM) is reached). When the rotation speed RPM of the motor is greater than the engagement rotation speed RPM of the motor 240 (or the rotation speed RPM of the motor and the rotation speed RPM of the engine are greater than the engagement rotation speed RPM of the motor 240) , The controller may control the pressure of the fluid supplied to the engine clutch 230 through the clutch controller (not shown) so that the engine 225 and the motor 240 are coupled.

The controller may include a motor controller (MCU) 215 for controlling the motor 240 and a hybrid controller (HCU) 210 for controlling the motor controller (MCU) 215 and the engine 225 . The controller can control the engine 225 to start through the hybrid start generator (HSG)

4 is a graph illustrating a simulation result (or a test result) of the engine start timing control method of the hybrid vehicle shown in FIG.

4, reference numeral 302 denotes an electric current of the battery 235, reference numeral 304 denotes an RPM of the motor 240, and reference numeral 306 denotes an RPM of the engine 225. In FIG. The battery current 302 should not exceed the maximum battery consumption current of 60 (A). This is because battery efficiency may deteriorate from 80A.

Reference numeral 308 denotes an engine starting allowable time 110 considering the motor RPM rising speed, and reference numeral 310 denotes an engine rotational speed time point at which clutch engagement is possible in consideration of the characteristics of the engine.

As described above, the present invention allows engine starting at an optimum point in consideration of the motor RPM rising speed, so that clutch engagement can be performed at an engine speed at which clutch engagement is possible. Therefore, the present invention can prevent unnecessary fuel consumption due to shortening of waiting time after engine startup, and can optimize the amount of battery usage by engaging the clutch at an engine speed at which clutch engagement is possible.

The components or " units " or blocks or modules used in the present embodiment may be implemented in software such as a task, a class, a subroutine, a process, an object, an execution thread, , A field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a combination of the above software and hardware. The components or parts may be included in a computer-readable storage medium, or a part of the components may be dispersed in a plurality of computers.

As described above, the embodiments have been disclosed in the drawings and specification. Although specific terms are used herein, they are used for the purpose of describing the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. It is therefore to be understood by those skilled in the art that various modifications and equivalent embodiments may be made without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

205: Accelerator pedal sensor (APS)
210: Hybrid controller (HCU)
215: Motor controller (MCU)
225: engine
230: Engine clutch
240: motor

Claims (9)

A method of controlling an engine start time of a hybrid vehicle,
Calculating a combined number of revolutions of the motor coupled to the engine via an engine clutch based on an increasing slope of the number of revolutions of the engine and an increasing number of revolutions of the motor; And
Controlling the engine to start before the minimum time the engine reaches the engagement speed in accordance with the engine speed rise slope
/ RTI >
Wherein the number of revolutions of the motor is equal to the target number of revolutions of the engine.
The method of controlling an engine starting time of a hybrid vehicle according to claim 1,
Further comprising the step of the controller generating an engine start command before the start control of the engine in response to an acceleration signal output from an accelerator pedal sensor (APS).
The method of controlling an engine starting time of a hybrid vehicle according to claim 1,
Further comprising the step of the controller controlling the motor to have the engagement RPM in response to an acceleration signal output from the accelerator pedal sensor APS.
The method according to claim 1,
Wherein the controller includes a motor controller for controlling the motor, and a hybrid controller for controlling the motor controller and the engine.
The method according to claim 1,
And the controller controls the engine to start by way of a hybrid start-up generator.
An engine starting time control apparatus for a hybrid vehicle,
An accelerator pedal sensor (APS) for sensing the operation of the accelerator pedal; And
A controller for generating an engine start command before starting control of the engine in response to an acceleration signal output from the acceleration pedal sensor;
/ RTI >
Wherein the controller calculates an engagement rotational speed of the motor coupled to the engine via an engine clutch based on an inclination of the rotational speed of the engine and an inclination of the rotational speed of the motor, Wherein the control means controls the engine to start before a minimum time for the engine to reach the engagement rotational speed, and the engagement rotational speed of the motor is equal to the target rotational speed of the engine.
The method according to claim 6,
Wherein the controller controls the motor to have the engagement rotational speed in response to an acceleration signal output from an accelerator pedal sensor (APS).
The method according to claim 6,
Wherein the controller includes: a motor controller for controlling the motor; and a hybrid controller for controlling the motor controller and the engine.
The method according to claim 6,
Wherein the controller controls the engine to start by way of a hybrid start-up generator.

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