KR102252916B1 - Hybrid vehicle and method of controlling engine - Google Patents

Abstract

The present invention relates to a hybrid vehicle and an engine control method therefor, and more particularly, to a hybrid vehicle capable of using energy recovered during shifting to start an engine, and a control method thereof. A method for controlling a hybrid vehicle according to an embodiment of the present invention includes determining a first torque that is a current required torque; Determining a second torque or a predicted acceleration that is a predicted required torque that is expected to occur at a time point in the near future from the present; Determining a predicted speed predicted at the near future point in time using the second torque or the predicted acceleration and current speed; When any one of an engine starting condition and a shift occurrence condition is satisfied at a current time by using at least one of the requested torque and the current speed, at least one of the predicted speed, the second torque, and the predicted acceleration is used. Determining whether the remaining one of the engine starting condition and the shift generation condition is satisfied at the near future point in time; And when the other condition is satisfied, delaying an event corresponding to the condition satisfied at the current point in time or performing a control for advancing an event corresponding to the condition satisfied at the near future point in time. .

Description

Hybrid vehicle and engine control method therefor {HYBRID VEHICLE AND METHOD OF CONTROLLING ENGINE}

The present invention relates to a hybrid vehicle and an engine control method therefor, and more particularly, to a hybrid vehicle capable of directly using a part of kinetic energy recovered during shifting to start an engine, and a control method thereof.

The demand for eco-friendly vehicles is increasing due to the continuous demand for fuel efficiency improvement for vehicles and the strengthening of emission regulations in each country, and a realistic alternative to this is a hybrid electric vehicle (Hybrid Electric Vehicle/Plug-in Hybrid Electric Vehicle, HEV). /PHEV) is being provided.

Such a hybrid vehicle can provide optimum power and torque depending on how the engine and motor are harmoniously operated in the process of driving with two power sources composed of an engine and a motor. In particular, in a hybrid vehicle employing a parallel type (or TMED: Transmission Mounted Electric Device method) hybrid system equipped with an electric motor and an engine clutch (EC) between the engine and transmission, the output of the engine and the motor It can be transmitted to the drive shaft at the same time.

In the general situation of a hybrid vehicle, electric energy is used during initial acceleration (ie, EV mode). However, since there is a limit to satisfying the driver's required power with only electric energy, there is a moment when the engine must be used as the main power source (ie, HEV mode). In this case, in the hybrid vehicle, when the difference between the rotation speed of the motor and the rotation speed of the engine is within a predetermined range, the engine clutch is engaged so that the motor and the engine rotate together. The structure of such a hybrid vehicle will be described with reference to FIG. 1.

1 shows an example of a power train structure of a general hybrid vehicle.

Referring to FIG. 1, a parallel type hybrid system in which an electric motor (or driving motor 40) and an engine clutch 30 are mounted between an internal combustion engine (ICE, 10) and a transmission 50 is adopted. The power train of one hybrid car is shown.

In such a vehicle, in general, when the driver steps on the accelerator after starting (that is, the accelerator pedal sensor is on), the motor 40 is first driven using the power of the battery while the engine clutch 30 is open, and the motor power The wheels are moved through the transmission 50 and the final drive 16 (FD) (that is, in the EV mode). When the vehicle is gradually accelerated and gradually greater driving force is required, the auxiliary motor (or starter generator motor 20) may be operated to drive the engine 10.

Accordingly, when the rotational speeds of the engine 10 and the motor 40 become the same, the engine clutch 30 engages and the engine 10 and the motor 40 drive the vehicle together (that is, transition from EV mode to HEV mode. ). When a preset engine off condition such as a vehicle deceleration is satisfied, the engine clutch 30 is opened and the engine 10 is stopped (ie, transition from HEV mode to EV mode). At this time, the vehicle charges the battery 70 through the motor 40 using the driving force of the wheel, and this is referred to as braking energy regeneration or regenerative braking. Therefore, the starting power generation motor 12 plays the role of a start motor when the engine is started, and operates as a generator when the rotational energy of the engine is recovered after starting or when the engine is turned off. Start Generator).

In general, the transmission 50 is a stepped transmission or a multi-plate clutch, for example, a dual clutch transmission (DCT) is used, and after starting from the first stage in the EV mode, the upper shift is made to the second stage according to the speed and torque. At this time, for smooth shifting and clutch protection during the upper shifting process, the vehicle performs control to reduce the kinetic energy of the transmission input shaft, that is, speed, such as reducing the torque of the drive source. Such control may be referred to as "intervention control". .

For example, a reverse torque may be applied to the electric motor 40 as a driving source torque reduction means, and in this case, power generation may be performed in the electric motor 40. This will be described with reference to FIG. 2.

2 shows an example of an intervention process for an upper shift in a typical hybrid vehicle.

Referring to FIG. 2, three graphs are displayed, and the vertical axis represents the intervention, the torque of the electric motor, and the speed of the transmission input shaft from top to bottom.

The shifting process can be largely divided into a torque phase and an inertia phase, and in the torque phase, it can mean a phase in which the speed of the input shaft increases due to the positive torque generated by the electric motor. have. In addition, the inertia phase may mean a phase in which the torque of the motor decreases and the speed of the input shaft decreases. In addition, applying a reverse (-) torque to the electric motor means power generation. Therefore, the electric power produced through power generation in the electric motor can be used to charge the battery.

On the other hand, when it is determined to switch from the EV mode to the HEV mode when starting acceleration in the hybrid vehicle, the engine is started. As mentioned above, starting the engine involves cranking using the power of the HSG. This will be described with reference to FIG. 3.

3 shows an example of an engine starting process in a typical hybrid vehicle.

In FIG. 3, the vertical axis of the upper graph represents the torque of HSG, and the vertical axis of the lower graph represents the engine speed, respectively. Referring to FIG. 3, the engine is cranking due to the torque generated by the HSG and the engine is started.

,

<1)를 곱한 값(

E)이 전기 에너지로 변환되며, 그에 입력 효율 팩터(

,

<1)를 곱한 값(

E)만 배터리(70)에 저장된다. 또한, 배터리(70)에 저장된 전력(

E)이 배터리(70)로부터 출력될 때 다시 출력 효율 팩터(

,

<1) 를 곱하게 된다. 결국, 변속시 회수된 운동 에너지(E)는 경로 손실로 E*

*

*

만큼만 HSG에 전달되며, 여기서 다시 HSG의 에너지 효율(

,

<1)을 곱합 값(

E)이 결국 실제 엔진(10)의 크랭킹에 운동 에너지로 직접 작용하는 문제점이 있다.However, the EV->HEV mode switching condition is determined by various factors such as battery charge status (SOC), auxiliary load, and required torque. Occurs at a similar point in time. However, in a conventional hybrid vehicle, as shown by the arrow shown in FIG. 1, kinetic energy E recovered in the shifting process is first converted into energy from the electric motor 40 to charge the battery 70, and the battery 70 The power stored in) starts the HSG 20 again. Therefore, the power generation efficiency factor of the electric motor (

,

Multiplied by <1) (

E) is converted into electrical energy, and the input efficiency factor (

,

Multiplied by <1) (

Only E) is stored in the battery 70. In addition, the power stored in the battery 70 (

When E) is output from the battery 70, the output efficiency factor (

,

It is multiplied by <1). Eventually, the kinetic energy (E) recovered during shifting is E*

*

*

Only as much is passed to HSG, where again the energy efficiency of HSG (

,

<1) times the value (

E) has a problem in that the kinetic energy directly acts on the cranking of the actual engine 10 in the end.

An object of the present invention is to provide a method capable of using energy recovered during shifting more efficiently in a hybrid vehicle to start an engine and a vehicle performing the same.

In particular, the present invention is to provide a method capable of improving the loss of energy recovered during shifting in a hybrid vehicle via a battery and a vehicle performing the same.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. I will be able to.

In order to solve the above technical problem, a method for controlling a hybrid vehicle according to an embodiment of the present invention includes: determining a first torque that is a current required torque; Determining a second torque or a predicted acceleration that is a predicted required torque that is expected to occur at a time point in the near future from the present; Determining a predicted speed predicted at the near future point in time using the second torque or the predicted acceleration and current speed; When any one of an engine starting condition and a shift occurrence condition is satisfied at a current time by using at least one of the requested torque and the current speed, at least one of the predicted speed, the second torque, and the predicted acceleration is used. Determining whether the remaining one of the engine starting condition and the shift generation condition is satisfied at the near future point in time; And when the other condition is satisfied, delaying an event corresponding to the condition satisfied at the current point in time or performing a control for advancing an event corresponding to the condition satisfied at the near future point in time. .

In addition, a hybrid vehicle according to an embodiment of the present invention includes: a driving information detector configured to detect driving information according to vehicle operation by interlocking with various sensors of the hybrid vehicle; A driver acceleration/deceleration predictor for generating a predicted value of a driver's near future acceleration/deceleration will by using the information transmitted from the driving information detection unit using an acceleration/deceleration prediction model; And a second torque or prediction that is a required torque that is expected to occur at a point in time from the present to the near future by using the information transmitted from the driving information detector to determine the current required torque, the first torque, and the near-future acceleration/deceleration will predicted value. It may include a hybrid controller that determines acceleration, and determines a predicted velocity predicted at the near future point in time using the second torque or the predicted acceleration and the current velocity. Here, the hybrid controller uses at least one of the requested torque and the current speed, when any one of an engine starting condition and a shift generation condition is satisfied at a current time point, the predicted speed, the second torque, and the predicted It is determined whether the remaining one of the engine starting condition and the shift occurrence condition is satisfied at the near future point in time using at least one of acceleration, and if the other condition is satisfied, the condition satisfied at the present time point It is possible to perform a control to delay a first event corresponding to a or to advance a second event corresponding to a condition satisfied at the near future point in time.

The hybrid vehicle according to at least one embodiment of the present invention configured as described above can perform engine start control more efficiently.

In particular, since the electric energy recovered during the shift is directly transferred to the starting power generation motor without passing through the battery by controlling the shift timing and the engine starting timing within a predetermined range, efficiency is improved.

The effects that can be obtained in the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the following description. will be.

1 shows an example of a power train structure of a general hybrid vehicle.
2 shows an example of an intervention process for an upper shift in a typical hybrid vehicle.
3 shows an example of an engine starting process in a typical hybrid vehicle.
4A shows an example of a situation in which kinetic energy can be directly transferred to an engine during a shift according to an embodiment of the present invention.
4B shows an example of an energy flow according to an overlap between a shift point and a mode change point according to an embodiment of the present invention.
5 is a block diagram schematically showing a control system of a hybrid vehicle according to an embodiment of the present invention.
6A and 6B illustrate an example of a driver acceleration/deceleration will prediction process that can be applied to embodiments of the present invention.
7 shows a method of determining a charging mode using a near-future acceleration/deceleration prediction model according to an embodiment of the present invention.
8 is a flowchart illustrating an example of a method for controlling a hybrid vehicle according to an embodiment of the present invention.
9 is a flowchart illustrating an example of a method for controlling a hybrid vehicle according to another aspect of the present invention.
10 shows an example of a matching line using proximity according to another aspect of an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, parts denoted by the same reference numerals throughout the specification refer to the same components.

In one embodiment of the present invention, when the shift point and the HEV mode switching point (that is, the engine start point) overlap, at least part of the kinetic energy to be recovered through the shift intervention control is immediately used to start the engine, so that the HSG is used. A method capable of reducing energy loss occurring on a path compared to the used start-up and a hybrid vehicle for performing the same are provided. The basic principle for this will be described with reference to FIGS. 4A and 4B.

4A is an example of a situation in which kinetic energy can be directly transferred to an engine during a shift according to an embodiment of the present invention, and FIG. 4B is an energy according to an overlap between a shift point and a mode change point according to an embodiment of the present invention. Each example of the flow is shown.

In order for the kinetic energy to be recovered through the intervention control during shifting to be used for cranking the engine without passing through the battery, the shift timing and engine start timing must be close within a predetermined time range. For example, as shown in FIG. 4A, when the section in which reverse torque is applied to the motor to generate power and the inertia phase of the transmission overlap each other on the time axis, some kinetic energy is generated instead of recovering all kinetic energy for the intervention through the motor. It can be delivered directly to the engine via the engine clutch. In other words, the rotation speed of the electric motor (ie, the rotation speed of the transmission input stage) may be reduced by the reverse torque (ie, the engine clutch load) according to engine cranking for starting the engine.

To this end, the engine clutch may be controlled to slip during the above-described overlapping section (ie, the engine clutch load rising section). In this case, since cranking using HSG becomes unnecessary, energy does not need to be transferred along an inefficient path in which kinetic energy is converted into electrical energy and converted from HSG back to kinetic energy through a battery.

As a result, the electric energy consumption of HSG for engine cranking is not generated, and the intervention torque can also be partially covered by the cranking torque, thereby improving the efficiency.

라 하면, 결국 엔진 크랭킹에 사용되는 에너지는

가 되며, 이는 도 1의 HSG를 이용할 때 전달되는 에너지인

대비 크게 효율이 향상될 수 있다.For example, referring to FIG. 4B, if the kinetic energy of the transmission input end is referred to as E, and the ratio of the kinetic energy transmitted to the engine clutch among E is k (k<1), the energy transmitted to the engine clutch becomes kE, The energy recovered through power generation in the motor becomes (1-k)E. The energy transfer efficiency factor of the engine clutch

In the end, the energy used for engine cranking is

Is, which is the energy transmitted when using the HSG of FIG. 1

In contrast, efficiency can be greatly improved.

Of course, the graph shown in FIG. 4 is the most ideal situation, and even if energy recovery is started first, if only overlapping, at least part of the kinetic energy can be transferred to the engine without passing through the battery in the shifting process. In the embodiment, it is not limited by the degree of overlap between the section in which the shift intervention control occurs and the section in which the engine starts.

Therefore, in the present embodiment, when a condition in which any one of the shift event and the engine start event occurs is satisfied, the time point at which the other one occurs is predicted, and the event in which the occurrence condition is satisfied is delayed or the time point is predicted. It is suggested to advance the event so that at least a part of the section in which the two events are held overlap.

The engine starting condition and the (upper) shift occurrence condition may be set to at least one of vehicle speed, battery charge state, accelerator pedal position, required drive torque, or required drive power. This will be described in more detail later.

According to an aspect of the present embodiment, in order to determine the time point of shifting and the time point of starting the engine, whether or not the shift has occurred and whether the engine is started may be determined at each of the present time point and the near future time point.

According to an aspect of the present embodiment, a shift point and an engine start point may be predicted using a near-future prediction model using a machine learning technique.

According to another aspect of the present embodiment, the time point of shift and the time point of engine start may be predicted by setting a prediction criterion based on at least one of time, torque, and speed through efficiency analysis according to the degree of overlap.

First, a hybrid vehicle structure to which embodiments of the present invention can be applied will be described with reference to FIG. 5.

5 is a block diagram schematically showing a control system of a hybrid vehicle according to an embodiment of the present invention.

5, the control system 100 of a hybrid vehicle according to an embodiment of the present invention includes a driving information detection unit 110, a driving tendency determination unit 120, a driver acceleration/deceleration prediction unit 130, and a hybrid controller 140. ). Of course, this is an example, and it goes without saying that the shift control system may be configured with fewer or more components than this (eg, omission of the driving propensity determination unit).

The driving information detection unit 110 includes a vehicle speed sensor 111, an accelerator position sensor (APS) 112, a brake pedal sensor (BPS) 113, and an advanced driver assistance system (ADAS: Advanced Driver). In conjunction with at least one of the assistance system 114 and the navigation 115, driving information according to the operation of the vehicle is detected.

The driving information detection unit 110 detects the driver's accelerator pedal operation state through the APS 112 and detects the brake operation state through the BPS 113.

The driving information detection unit 110 detects the vehicle speed through the vehicle speed sensor 111, and forward behavior information including the relative distance and acceleration with the vehicle in front through a radar sensor of the ADAS 114, a (stereo) camera, etc. To detect. Of course, in addition to radar or camera, various sensors such as ultrasonic waves and lasers may be used depending on the configuration of ADAS.

The driving information detection unit 110 provides navigation information such as GPS/GIS based vehicle location information, road type, congestion, speed limit, intersection, toll gate, turn and slope information through the navigation 115 (road environment Information). Here, the navigation 115 may refer to a built-in navigation map for providing the above information and traffic information collected through external wireless communication (eg, telematics, TPEG, etc.).

The driving propensity determination unit 120 determines the driver's driving propensity based on a driving pattern such as an average speed, APS change amount (dAPS), and BPS change amount (dBPS) according to the driver's vehicle driving operation.

For example, the driving propensity determination unit 120 configures a fuzzy membership function as an input variable using measurement factors such as APS change amount, BPS change amount, vehicle speed, and gradient detected by the driving information detection unit 110 for short-term driving. Calculate the propensity index (SI = 0 ~ 100%).

In addition, the driving propensity determination unit 120 may determine the driving propensity of the driver as a plurality of levels by dividing the calculated short-term driving propensity index (SI = 0 to 100%) by a predetermined reference ratio according to the driving propensity intensity.

The driver acceleration/deceleration prediction unit 130 learns an acceleration/deceleration prediction model for each driving tendency by using a machine learning technique, and the driving environment of the vehicle and the driver's driving tendency are reflected by using the acceleration/deceleration prediction model. Generate a predicted value of the will of acceleration/deceleration in the near future. That is, the driver acceleration/deceleration prediction unit 130 uses the vehicle speed, radar information, navigation information, and driver's driving tendency detected through the driving information detection unit 110 as input information to determine a form of driving operation that appears in a relatively short time unit. By quantitatively quantifying the driver's momentary acceleration/deceleration will, the driver's near-future acceleration/deceleration prediction value can be generated through this. The acceleration/deceleration predicted value may be composed of the strength and probability of depressing the accelerator pedal or the brake pedal in a predetermined time unit in the near future.

The specific prediction algorithm of the acceleration/deceleration prediction unit 130 may include a neural network that supplements a previously constructed prediction model using a machine learning technique, which will be described in more detail later.

The hybrid controller 140 controls the operation of each unit for switching the driving mode of the hybrid vehicle according to an embodiment of the present invention, and integrally controls an engine controller and a motor controller connected to a network as a top level controller.

The hybrid controller 140 may analyze the current requested torque of the driver according to the APS or BPS detected by the driving information detection unit 110, and transmit itself (ie, the current requested torque) or a command according thereto to another controller. In addition, the hybrid controller 140 may receive the near-future acceleration/deceleration prediction value, predict a required torque or acceleration at a specific point in the near future, and determine whether a shift has occurred and/or whether the engine is started using the same. In addition, the hybrid controller 140 may advance or delay at least one of the engine start and shift times in order to overlap the shift time and the engine start time based on a result of determining whether the shift/engine is started.

For example, the transmission controller may obtain information on the current demand torque and the near future demand torque predicted value from the hybrid controller 140 to determine whether to final shift, and transmit a shift command corresponding to the determination result to the transmission.

Of course, according to an embodiment, when the acceleration/deceleration predictor 130 predicts up to the near-future required torque using the near-future acceleration/deceleration predicted value, the acceleration/deceleration predictor 130 immediately performs related control using the corresponding value, or Values can also be passed to other controllers.

In addition, in the above-described embodiment, the driving tendency determination unit 120 may be omitted depending on the configuration, and in this case, the driver acceleration/deceleration prediction unit 130 may perform acceleration/deceleration prediction excluding input values related to the driving tendency. have.

Hereinafter, a method of predicting the driver's acceleration/deceleration will by the driver acceleration/deceleration prediction unit 130 will be described with reference to FIGS. 6A and 6B.

6A and 6B illustrate an example of a driver acceleration/deceleration will prediction process that can be applied to embodiments of the present invention.

First, referring to FIG. 6A, a process of predicting the will of the driver acceleration/deceleration by the driver acceleration/deceleration predictor 130 can be roughly divided into three steps. Specifically, first, it may be determined whether or not which parameters are to be used as input values for prediction (S61). The determined input value may be calculated by correcting the prediction model through machine learning (S62), and classifying acceleration and deceleration through the input value and the modified model (S63).

Here, the process of determining the input value (S61) is again 1) a process of extracting candidates of the input value, 2) a process of pre-processing data by integrating the input signal, and 3) using the pre-processed candidate value. It may include the process of selecting the final variable. Meanwhile, as a machine learning technique, a time series model-based technique may be used, or a deep learning-based technique may be used. Here, examples of the time-series model-based technique include the ARIMA (Autoregressive integrated moving average) technique that explains the change in behavior over time as a stochastic, and the MLP (Multi-Purpose) technique that uses a nonparametric regression method as a general-purpose approximator. layer Perceprton) technique. In addition, deep learning-based techniques include stacked autoencoder (SAE) techniques that make input/output data similar through dimensionality reduction, recurrent neural networks (RNNs) techniques, which are neural network algorithms that process sequential information, and are suitable for long-term dependency learning. LSTM (Long Short Term Memory) technique, etc. are mentioned. Among these, an example of a process of predicting a driver's acceleration/deceleration will in the near future by the driver acceleration/deceleration prediction unit using a neural network algorithm is shown in FIG. 6B.

Referring to FIG. 6B, the driver acceleration/deceleration prediction unit 130 according to an embodiment of the present invention includes a neural network that learns an acceleration/deceleration prediction model for each driver's driving tendency by using a machine learning technique.

It is preferable that the driver acceleration/deceleration prediction unit 130 has a near-future acceleration/deceleration prediction model for each driving tendency based on big data accumulated through test driving before leaving the vehicle using a neural network.

In addition, the driver acceleration/deceleration prediction unit 130 further reflects vehicle behavior data learned through actual driver's vehicle driving after delivery to the near-future acceleration/deceleration prediction model for each driving tendency built using a neural network to provide personalized driving to the driver. Near future acceleration/deceleration prediction models can be generated according to propensity. In this case, the driver acceleration/deceleration predictor 130 may apply the learned behavior data according to the driver's propensity determination to a near-future acceleration/deceleration prediction model of the corresponding driving propensity.

The driver acceleration/deceleration prediction unit 130 can calculate a near future acceleration/deceleration will prediction value according to the driver's driving tendency by using the driving environment in which the vehicle speed, radar information, and navigation information are combined and the driver's driving tendency as input information. have. Here, the driving propensity may be classified into a plurality of propensity types as shown in FIG. 6B, and may be composed of numerical values such as an average speed, an accelerator pedal change rate (dAPS), and a brake pedal change rate (dBPS).

In addition, the driver acceleration/deceleration prediction unit 130 may perform model correction according to the driver acceleration/deceleration model learning in real time through machine learning while being mounted on the vehicle, or receive the modified model from the outside to predict without learning. Can also be used only.

In other words, when the model is modified from outside, parameters that are input values for training are transmitted to the telematics center or cloud server, so that only the final model is transmitted to the vehicle after the model modification through training is performed outside. have.

7 shows a method of determining a charging mode using a near-future acceleration/deceleration prediction model according to an embodiment of the present invention.

Referring to FIG. 7, the hybrid controller 140 according to an embodiment of the present invention analyzes a current driving request according to a driver's APS or BPS operation, and calculates a required torque (S1). The hybrid controller 140 determines a current event (ie, whether a shift/engine start has occurred) according to the current requested torque (S2).

Meanwhile, the driver acceleration/deceleration prediction unit 130 outputs driver acceleration/deceleration will prediction information using the near-future acceleration/deceleration prediction model, and through this, the hybrid controller 140 can predict the vehicle behavior at the near future point in time (S3).

The hybrid controller 140 determines an event that will occur in the near future (whether a near-future shift/engine is started) by combining the determination results of each of the S2 and S3 steps (S4), and finally delays the current event or generates a near-future event. Can advance. Of course, the hybrid controller 140 may perform general control in which the timing change control is not applied when it is determined that the overlapping of the shift timing and the engine starting timing is difficult to occur over a certain range even through event delay/advancement.

Here, the required torque predicted value may be calculated by the driver acceleration/deceleration predictor 130, or may be calculated by the hybrid controller 140 as described above, and although not shown, it can be calculated by a separate controller for generating the required torque predicted value. May be.

Next, a method of switching a driving mode of a hybrid vehicle according to an embodiment of the present invention will be described in more detail with reference to FIG. 8 below, with the above-described hybrid vehicle control system 100 as a main body.

8 is a flowchart illustrating an example of a method for controlling a hybrid vehicle according to an embodiment of the present invention.

Referring to FIG. 8, first, the hybrid controller 140 detects an APS change amount or a BPS change amount through the driving information detection unit 110 and calculates the current required torque of the driver (S810).

Here, the required torque may be obtained as a function of the pedal position value Pedal(n) detected by the current pedal sensors APS and BPS. In more detail, the'(n)' value may have a positive (+) value when the accelerator pedal APS is manipulated, and may have a negative (-) value when the brake pedal BPS is manipulated.

In this case, when the APS and BPS are simultaneously detected due to a driver's wrong manipulation, the hybrid controller 140 may ignore the APS change and calculate the required torque only with the BPS change by applying a brake override function.

In the driver acceleration/deceleration prediction unit 130, the driver's near future through a function (i.e., a function (Radar information, Navi information, driver propensity)) that uses vehicle speed, radar information, navigation information, and driver's driving propensity as input information. An acceleration/deceleration will predicted value Pedal(n+a) is generated (S820).

Here, Pedal(n+a) refers to the position of the accelerator/brake pedal after a second, and the a value may be a time reference for overlapping the engine starting time and the shifting time. For example, if a is 3 seconds, it may mean that when the difference between the engine start time and the shift time occurs within 3 seconds, the hybrid controller may delay or advance at least one of the two to control such that the two times are sufficiently overlapped. It is obvious to those skilled in the art that the value a may be variously set according to vehicle specifications, such as power generation efficiency of the electric motor, capacity, or operation characteristics of the starter power generation motor.

In addition, the near-future acceleration/deceleration will predicted value may mean the driver's willingness to accelerate (increase APS or decrease BPS) or will (increase APS or increase BPS) predicted in the near future after a predetermined time, and the amount of change or pedal position. Of course, information such as the will of acceleration/deceleration in the front, change range, and pedal position may be included as well as probability information about it.

Using the predicted acceleration/deceleration will predicted value (Pedal(n+a)) of the driver acceleration/deceleration predictor 130, the hybrid controller 140 determines the near-future required torque predicted value, that is, "predicted torque" and near-future speed, that is, "predicted speed. "Can be determined (S830).

In more detail, the hybrid controller 140 may obtain the predicted torque as a function of the acceleration/deceleration will predicted value, and obtain the predicted speed as a function of the current pedal sensor value, the acceleration/deceleration will predicted value, and the current speed. That is, the predicted speed may be obtained by adding the amount of speed change obtained by the difference between the pedal operation state in the future and the current pedal operation state to the current speed sensed by the vehicle speed sensor 111.

When the current speed, the current required torque, the predicted speed and the predicted torque are obtained, the hybrid controller 140 may determine the current event and the near future event.

Specifically, first, the hybrid controller 140 determines whether to switch the HEV mode, that is, whether to start the engine based on the current required torque (or required power) (required torque>=Threshold1?) (S840A). Here, "Threshold1" may be a torque that is determined by at least one of vehicle speed, maximum motor torque, available battery power, and current SOC as a reference for starting the engine.

If it is determined that engine start is necessary based on the current torque, the hybrid controller determines whether a shift occurs at a near future time based on the predicted speed (predicted speed >= Threshold2 (predicted torque)?) (S850A). Here, "Threshold2 (predicted torque)" may mean a reference speed at which a value is changed according to the predicted torque.

As a result of the determination, the hybrid controller 140 may determine to delay the engine start within a second range or to advance the shift intervention control if it is predicted that the current engine start occurs and the shift will occur at a near future point after a second. (S860A). At this time, when the engine is started, engine cranking is performed by slip control of the engine clutch.

Conversely, as a result of the determination in step S850, when the current engine starts, but the shift does not occur after a second, the start is simply performed using the engine HSG (S860B).

In addition, when it is determined in step S840A that the condition for engine start occurrence at the current time is not satisfied, the hybrid controller 140 determines whether the shift has occurred at the current time, the current required torque and the current speed (current speed >= Threshold2 (required torque)). ?) can be determined based on (S840B).

When a shift occurs, whether the engine is started at a near future point in time may be determined based on the predicted torque (predicted torque >= Threshold1?) (S850B).

As a result of the determination, when the current shift occurs and the engine start is predicted to occur at a near future point in time a second later, the hybrid controller 140 may determine to advance the engine start within a second range or to delay the shift intervention control. (S860C). At this time, when the engine is started, engine cranking is performed by slip control of the engine clutch.

Conversely, as a result of the determination of step S850, the current shift occurs, but if the engine does not start after a second, the shift can be performed simply (S860B), and if the engine does not start or the shift does not occur at the current time, it is again S810. You can go right back to the stage.

In FIG. 8 described so far, the required torque and speed of the near future are predicted using a near future prediction model through a machine learning technique. According to another aspect of the present embodiment, instead of using a near future prediction model, when a current operating point is close to a preset mapping line, a corresponding event may be predicted to occur in the near future.

This will be described with reference to FIGS. 9 to 10.

9 is a flowchart showing an example of a method for controlling a hybrid vehicle according to another aspect of the present invention, and FIG. 10 shows an example of a matching line using proximity according to another aspect of the present invention.

In FIG. 9, only differences from FIG. 8 will be described for clarity of the specification.

Referring to FIG. 9, unlike FIG. 8, the process of predicting the will of acceleration/deceleration of a driver in the near future (S820 to S830) is omitted, and a current event determination is performed (S840A and S840B).

In the case of near-future prediction, when the engine needs to be started in step S840A, it is possible to predict whether a near-future shift has occurred based on a mapping line for the current torque and the shift (current speed >= Threshold3 (required torque)?) (S850A'). The mapping line for the shift will be described with reference to FIG. 10A. Referring to (a) of FIG. 10, a mapping line having a vehicle speed slightly lower than the actual upper (N->N+1) shift line (corresponding to Threshold2) (ie, “shift prediction line”, corresponding to Threshold3) is It can be set in advance. In the end, the shift prediction line is the reference speed whose value changes according to the torque similar to Threshold2, while Threshold2 means the speed at which the actual shift occurs, whereas the shift prediction line predicts that shift will occur in the near future with respect to the current required torque. It means the speed at which you can become.

The use of the shift prediction line was conceived because if this trend continues when the current operating point (determined by vehicle speed and required torque) reaches the shift prediction line, it is likely that the operating point will reach the actual upper shift line in the near future. .

In addition, when engine start does not occur in step 840A, but shift occurs in step S840B, the hybrid controller 140 starts the engine at a near future time based on the required torque and the engine start prediction line (required torque >= Threshold4?). Prediction on whether or not occurrence is performed (S850B'). The engine start prediction line will be described with reference to FIG. 10B. Referring to FIG. 10B, an engine start prediction line (corresponding to Threshold4) having a required torque slightly lower than the engine start determination criterion (corresponding to Threshold1) may be set in advance. Similar to Threshold1, the engine start prediction line is a reference torque line whose value is changed according to the torque in at least one of the maximum motor torque, the available battery power, and the current SOC, but Threshold1 refers to the required torque to generate the actual engine start. On the other hand, the engine start prediction line means a required torque that can be predicted that engine start will occur in the near future with respect to the current required torque.

Operations (S860A to S860D) performed according to each prediction are the same as in FIG. 8, and redundant descriptions will be omitted.

Meanwhile, in the above-described embodiments, it has been described that the driver's will of acceleration/deceleration prediction model is constructed and modified through machine learning of the will of a future driver corresponding to the current driving condition based on data accumulated during actual vehicle operation. However, instead of using such a predictive model, a near future acceleration/deceleration will predicted value may be determined by setting a rule in advance. An example of these rules is shown in Table 1 below.

Input signal Analysis of driving conditions Expected result [Navi/Telematics]
Road type = Highway
Identity information = smooth
Forward event = none

[Radar]

Distance of vehicle ahead = proximity
Relative vehicle speed in front = -10 kph

[Driving propensity/history]
Driving at a constant speed for the past 5 minutes

[Lane departure prevention system]
Stay in the current lane During constant speed driving,
To maintain the distance between the vehicle and the vehicle in front.
For intermittent braking APS = 0, BPS = small [Navi/Telematics]
Road type = Highway
Identity information = smooth
Forward event = Tollgate/200m

[Radar]
Distance of vehicle ahead = None
Relative vehicle speed in front = N/A

[Driving propensity/history]
Average vehicle speed through past toll gate = 50 kph

[Lane departure prevention system]
Stay in the current lane Driving on the highway
To pass the toll gate
At current speed
Deceleration to 50kph APS = 0, BPS = medium

In addition, in the above description, the required torque in the future is predicted through near-future prediction, but the required future torque is replaced with other types of parameters or information such as the predicted future acceleration value (i.e., predicted acceleration) predicted by the acceleration/deceleration predictor. It is obvious to those skilled in the art that it may be.

The present invention described above can be implemented as a computer-readable code on a medium on which a program is recorded. The computer-readable medium includes all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAM, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc. There is this.

Therefore, the detailed description above should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all conversions within the equivalent scope of the present invention are included in the scope of the present invention.

Claims (21)

In the control method of a hybrid vehicle,
Determining a first torque that is a current required torque;
Determining a second torque or a predicted acceleration that is a predicted required torque that is expected to occur in a near future from the present;
Determining a predicted speed predicted at the near future point in time using the second torque or the predicted acceleration and current speed;
When any one of an engine starting condition and a shift occurrence condition is satisfied at a current time by using at least one of the requested torque and the current speed, at least one of the predicted speed, the second torque, and the predicted acceleration is used. Determining whether the remaining one of the engine starting condition and the shift generation condition is satisfied at the near future point in time; And
A hybrid vehicle comprising the step of performing a control for delaying an event corresponding to the condition satisfied at the current point in time or advancing an event corresponding to the condition satisfied at the near future point in time when the remaining one condition is satisfied Control method. The method of claim 1,
When the controlling step is performed,
Performing intervention control for shifting;
Transferring at least a portion of the kinetic energy to be recovered in the intervention control process to the engine through an engine clutch; And
Further comprising the step of performing cranking for starting the engine with the transmitted kinetic energy. The method of claim 1,
When the engine starting condition is satisfied at the current time point and the shift condition is satisfied at the near future time point,
The step of performing the control,
Delaying engine start; or
A method for controlling a hybrid vehicle, comprising the step of performing an early shift. The method of claim 1,
When the shift condition is satisfied at the current time point and the engine start condition is satisfied at the near future time point,
The step of performing the control,
Delaying the shift; or
A method of controlling a hybrid vehicle, comprising the step of performing an engine start early. The method of claim 1,
The step of determining the first torque,
A method of controlling a hybrid vehicle, performed using the positions of the accelerator pedal and the brake pedal. The method of claim 1,
The step of determining the second torque or the predicted acceleration,
Determining a predicted value of a driver's acceleration/deceleration will by using an acceleration/deceleration predictive model using at least one of driver propensity information, advanced driving assistance device (ADAS) information, navigation information, and vehicle speed information as input values; And
And determining the second torque or the predicted acceleration using the predicted acceleration/deceleration will predicted value. The method of claim 6,
The predicted value of acceleration/deceleration will is,
A control method of a hybrid vehicle comprising position information of the accelerator pedal and the brake pedal at the near future point in time. The method of claim 1,
The engine starting condition at the near future point in time,
A control method of a hybrid vehicle, which is satisfied when the second torque or the predicted acceleration is equal to or greater than a preset HEV mode change torque. The method of claim 1,
In the near future, the shifting condition,
A control method of a hybrid vehicle, which is satisfied when the predicted speed is greater than or equal to a shift generation reference speed that is variable according to the second torque. A computer-readable recording medium on which a program for executing the control method of a hybrid vehicle according to any one of claims 1 to 9 is recorded. In a hybrid vehicle,
A driving information detector configured to detect driving information according to vehicle operation by interlocking with various sensors of the hybrid vehicle;
A driver acceleration/deceleration predictor for generating a predicted value of a driver's near future acceleration/deceleration will by using the information transmitted from the driving information detection unit using an acceleration/deceleration prediction model; And
The first torque, which is the current required torque, is determined using the information transmitted from the driving information detection unit, and the second torque or predicted acceleration, which is the required torque that is expected to occur at a point in time from the present to the near future, using the predicted value of the will of acceleration and deceleration in the near future. And a hybrid controller configured to determine a predicted speed predicted at the near future time point using the second torque or the predicted acceleration and the current speed,
The hybrid controller,
When any one of an engine starting condition and a shift occurrence condition is satisfied at a current time by using at least one of the requested torque and the current speed, at least one of the predicted speed, the second torque, and the predicted acceleration is used. Thus, it is determined whether the other of the engine starting condition and the shift occurrence condition are satisfied at the near future point in time, and if the other condition is satisfied, a first event corresponding to the condition satisfied at the current point in time A hybrid vehicle for performing a control to delay or advance a second event corresponding to a condition satisfied at the near future point in time. The method of claim 11,
The hybrid controller,
When the first event is delayed or the second event is advanced, at least part of the kinetic energy recovered in the intervention control process for shifting is controlled to be transmitted to the engine through the engine clutch so as to be used for engine cranking. . The method of claim 11,
When the engine starting condition is satisfied at the current time point and the shift condition is satisfied at the near future time point,
The hybrid controller, for controlling to delay engine start or to perform a shift early. The method of claim 11,
When the shift condition is satisfied at the current time point and the engine start condition is satisfied at the near future time point,
The hybrid controller controls to delay a shift or to perform engine start early. The method of claim 11,
The hybrid controller,
A hybrid vehicle for determining the first torque using the positions of the accelerator pedal and the brake pedal detected by the driving information detection unit. The method of claim 11,
The driver acceleration/deceleration prediction unit,
Using an acceleration/deceleration prediction model that uses at least one of driver propensity information, advanced driving assistance (ADAS) information, navigation information, and vehicle speed information as an input value, the predicted value of the driver's acceleration/deceleration will is determined,
The hybrid controller,
And determining the second torque or the predicted acceleration using the predicted acceleration/deceleration will. The method of claim 16,
The predicted value of acceleration/deceleration will is,
A hybrid vehicle including position information of the accelerator pedal and the brake pedal at the near future point in time. The method of claim 11,
The engine starting condition at the near future point in time,
A hybrid vehicle that is satisfied when the second torque or the predicted acceleration is equal to or greater than a preset HEV mode change torque. The method of claim 11,
In the near future, the shifting condition,
A hybrid vehicle that is satisfied when the predicted speed is greater than or equal to a shift generation reference speed that is variable according to the second torque. In the control method of a hybrid vehicle,
Determining whether an engine starting condition set to at least one of a vehicle speed, a battery state of charge, an accelerator pedal position, a required torque, or a required power is satisfied;
Predicting whether an upper shift condition set to at least one of the vehicle speed, the battery charge state, the accelerator pedal position, the required torque, and the required power will be satisfied within a preset time from the present; And
During EV driving of the hybrid vehicle, if the engine start condition is satisfied and the shift condition is predicted to be satisfied within the preset time, the engine start time is delayed or the upper shift time is advanced and the upper shift is performed by engine cranking. Controlling to generate a motor deceleration for the; control method of a hybrid vehicle comprising a. In the control method of a hybrid vehicle,
Determining whether an upper shift condition set to at least one of a vehicle speed, a state of charge of a battery, an accelerator pedal position, a required torque, or a required power is satisfied;
Predicting whether an engine starting condition set to at least one of the vehicle speed, the battery state of charge, the accelerator pedal position, the required torque, and the required power will be satisfied within a preset time from the present; And
During EV driving of the hybrid vehicle, if the upper shift condition is satisfied and the engine start condition is predicted to be satisfied within the preset time, the upper shift point is delayed or the engine start point is advanced to the upper end by engine cranking. Controlling to generate a motor deceleration for shifting; control method of a hybrid vehicle comprising a.

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