KR102347756B1 - Engine control method for heating of hybrid electric vehicle - Google Patents

Abstract

The present invention relates to a method for controlling an engine during heating of a hybrid vehicle, and the main object of the present invention is to provide a method for controlling an engine during heating of a hybrid vehicle, which can improve a problem of fuel efficiency degradation caused by forced driving of an engine for indoor heating. will be. In order to achieve the above object, the method comprising: receiving, by a controller, vehicle location information and information on a road ahead based on the vehicle location from a navigation device in which a route to a destination is set during heating in a hybrid vehicle; calculating, by the controller, driving energy when the vehicle travels on the road ahead for a predetermined time based on the received vehicle location information, information on the road ahead, and pre-stored setting information; determining, by the controller, an engine control mode during heating by using the calculated driving energy, a current indoor temperature and a target indoor temperature of the vehicle; and performing, by the controller, engine control according to the determined engine control mode.

Description

Engine control method for heating of hybrid electric vehicle

The present invention relates to a method for controlling an engine during heating of a hybrid vehicle, and more particularly, to a method for controlling an engine during heating of a hybrid vehicle, which can improve fuel efficiency degradation caused by forced driving of an engine for indoor heating. .

Cars are equipped with HVAC (Heating, Ventilation, and Air Conditioning) to control the indoor temperature and create a comfortable indoor environment.

Recently, the FATC (Full Automatic Temperature Control) system that maintains a comfortable environment by automatically adjusting the indoor temperature according to the temperature set by the driver or passenger has been applied to most vehicles.

In this FATC system, when the user sets the temperature, in order to control the indoor temperature, sensor detection signals such as an insolation sensor for detecting the amount of insolation, an outdoor temperature sensor for detecting the outdoor temperature, and an indoor temperature sensor for detecting the indoor temperature of the vehicle are air-conditioned. The controller (FATC controller) receives the input and calculates the heat load in the room based on the detection value of each sensor, and determines the discharge mode, discharge temperature, discharge direction, and discharge air volume in consideration of the corresponding air conditioning load.

In addition, the air conditioning controller includes a discharge temperature sensor that detects a discharge temperature that is the temperature of the discharged air (that is, the air temperature at the discharge port), a water temperature sensor that detects the temperature of the engine coolant, and an evaporator to control the room temperature and system operation. A detection value such as an evaporator temperature sensor that detects a temperature may be input.

In addition, the air conditioning controller operates mode actuators, temp door (temperature control door) actuators, wind direction control door actuators, air conditioning blowers, compressors, etc. so that the supply of air conditioning air is controlled by the determined discharge mode, discharge temperature, discharge direction, and discharge air volume. elements are controlled.

On the other hand, a hybrid vehicle is a vehicle that runs using an engine and a motor as driving sources, and is an eco-friendly vehicle that can reduce exhaust gas and improve fuel efficiency by using both fossil fuel energy and electric energy for driving.

A typical hybrid vehicle has a driving mode selected according to driving conditions. It is driven in an EV (Electric Vehicle) mode that uses only the power of the motor, or is driven in an HEV (Hybrid Electric Vehicle) mode that uses both the power of the engine and the power of the motor. .

During braking of the vehicle or coasting due to inertia, a regenerative mode in which the kinetic energy of the vehicle is recovered as electric energy through motor power generation to charge the battery is performed.

In addition, the hybrid vehicle may stop the engine when the vehicle is stopped, and it is possible to drive the EV by the motor during low-speed driving or low-torque driving.

Compared to general internal combustion engine (engine) vehicles, high-efficiency driving point driving of the engine and driving at the optimal efficiency of the entire hybrid system are possible through the optimal torque distribution of the engine and motor under the vehicle driving conditions such as in HEV mode. fuel consumption is high

In the case of a hybrid vehicle, since an engine that can be used as a heat source for heating is mounted, high-temperature engine coolant is passed inside the heater core, and cold air (inside air, outside air) is passed around the heater core through which the engine coolant flows. Heating may be achieved by supplying air heated by heat exchange with engine coolant in the core to the interior of the vehicle.

At this time, a temp door may be used to control the room temperature, and the discharge temperature may be adjusted by controlling the position and the opening amount (heater core-side opening amount) of the temp door.

However, it is necessary to operate and maintain the engine in an idle state in order to secure heating performance even in the EV driving state, which can improve fuel efficiency by stopping the engine during driving under low-temperature conditions in winter, braking, or other driving. Therefore, fuel efficiency may be lower than under normal driving conditions.

The biggest cause of fuel economy deterioration during winter driving is the loss caused by engine idling to cope with the heating load.

Since a hybrid vehicle can drive an EV, the engine temperature can be kept lower than that of a general internal combustion engine vehicle. forced drive).

However, engine on control that unnecessarily increases the temperature of the engine coolant may be intermittently performed, and unnecessary engine driving leads to deterioration of fuel efficiency.

1 is a flowchart schematically illustrating a method for controlling heating of a hybrid vehicle according to the related art.

As shown, the controller determines whether it is necessary to drive the engine for heating (S1), and if necessary, performs engine-on control for driving the engine (S2).

In this case, if the engine coolant temperature is below the reference temperature, the engine operation is induced to increase the coolant temperature, and the reference temperature for determining the engine operation may be determined by the outside air temperature, the indoor temperature, the driver's set temperature, and the like.

In addition, a control for determining a high engine power to increase the coolant temperature in the engine idling state during heating may be performed (S3), and a dedicated junction time may be applied when determining the engine on by the coolant temperature in the engine clutch junction. (S4).

In this case, the engine clutch bonding time may increase the engine coolant temperature by making the engine clutch bonding faster than the general engine clutch bonding time.

However, if heating is unnecessary and engine driving is unnecessary, such as when driving an EV or in a stationary state, the engine should be stopped (engine off). In order to raise the coolant temperature during heating), the engine is driven in an idle state (engine on).

As described above, due to the engine on section for simple heating only, fuel loss in non-driving conditions (a condition in which the engine is not used to drive a vehicle, a condition in which the engine is used for heating) occurs significantly, which is a factor of deterioration of fuel economy in winter. it's working

Accordingly, the present invention was created to solve the above problems, and it is an object of the present invention to provide a method for controlling an engine during heating of a hybrid vehicle, which can improve the problem of fuel efficiency degradation caused by forced driving of the engine for indoor heating. There is this.

In order to achieve the above object, according to an embodiment of the present invention, when heating in a hybrid vehicle, the control unit receives vehicle location information and information on the road ahead based on the vehicle location from the navigation device in which the route to the destination is set. ; calculating, by the controller, driving energy when the vehicle travels on the road ahead for a predetermined time based on the received vehicle location information, information on the road ahead, and pre-stored setting information; determining, by the controller, an engine control mode during heating by using the calculated driving energy, a current indoor temperature and a target indoor temperature of the vehicle; and performing, by the controller, engine control according to the determined engine control mode.

Accordingly, according to the method for controlling the engine during heating of a hybrid vehicle according to the present invention, unnecessary forced engine driving can be reduced, thereby vehicle fuel efficiency can be improved, and discomfort felt by a driver can be minimized by minimizing unnecessary engine forced driving. Of course, the problem of excessive generation of engine noise can be improved.

1 is a flowchart illustrating a conventional method for controlling an engine during heating.
2 is a flowchart illustrating an engine control process during heating according to an embodiment of the present invention.
3 is a view for explaining an example of a method of calculating driving energy in a control process according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the embodiments of the present invention. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

As is known, the heat source for winter heating in a vehicle can be called an engine, and after being heated in the engine, high-temperature engine coolant that exchanges heat with air for air conditioning (inside air, outside air) while passing through the heater core is used for vehicle heating do.

When the air for air conditioning passes around the heater core, it is heated by heat exchange with engine coolant in the heater core, and the heated air for air conditioning is discharged into the interior of the vehicle, thereby heating the room.

As such, a hybrid vehicle among eco-friendly vehicles is equipped with an engine, so it is possible to heat the interior by using the heat of the engine.

In addition, when the engine coolant temperature (coolant temperature) is lower than the temperature required for heating in the hybrid vehicle, the air conditioning controller (FATC controller) requests forcible operation of the engine, and according to the request of the air conditioning controller, the engine controller (ECU:Engine Control Unit) ) forcibly drives the engine.

The engine coolant temperature is detected by the water temperature sensor, and in the following description, the engine coolant temperature will be abbreviated as coolant temperature.

In addition, in order to satisfy the driver's heating demand, the coolant temperature must be maintained above a certain level.

Since the engine is forcibly driven only for heating, not for driving the vehicle, fuel consumption by the engine occurs, and fuel consumption for heating decreases fuel efficiency of the vehicle.

Therefore, minimizing unnecessary engine forced driving is very important for improving vehicle fuel efficiency, and an object of the present invention is to provide an engine control method capable of improving fuel efficiency degradation caused by forced engine driving for heating. .

In the following description, engine on means that the engine is driven by combustion in the state of fuel supply and fuel injection, and engine off means that the engine is not combusted by cutting off fuel and combustion is not performed. This means that it is not running.

2 is a flowchart illustrating a control process according to an embodiment of the present invention, and FIG. 3 is a diagram for explaining an example of a method of calculating driving energy in the control process according to an embodiment of the present invention.

The engine control process during heating according to the present invention, that is, the engine driving and control process for heating may be performed under the cooperative control of the air conditioning controller (FATC controller) and the engine controller (ECU).

For example, when the air conditioning controller determines engine on/off based on the coolant temperature detected by the water temperature sensor, and determines that the engine is on, that is, when it determines that engine on is necessary, the Requests engine on, so that the engine controller can be set to drive and control the engine.

In addition, the engine controller performs at least some steps included in the control process, such as calculating the forward driving energy and calculating the driving energy applied value, among the entire control process of FIG. 2 , and sets the current indoor temperature to the set temperature. In the remaining steps, such as the step of comparing, the step of comparing the difference between the target indoor temperature and the current indoor temperature with a set temperature difference, the air conditioning controller may be set to perform.

However, the result determined by one controller in the step of comparing and determining during the entire control process of FIG. 2, for example, steps S14, S15, S17, S18, S20, S21, is also shared with another controller through communication and information exchange between the controllers. can make it

Alternatively, as described above, one integrated electronic control unit may be configured to perform the control process according to the embodiment of the present invention without distinguishing between the air conditioning controller and the engine controller.

In the following description, the integrated one electronic control unit for performing the control process of the present invention, or a plurality of controllers (eg, air conditioning controller and engine controller) that cooperatively control to perform the control process of the present invention are controlled. to be referred to as

First, the control process of the present invention may be started by a user (eg, a driver) setting a route from a current location of the hybrid vehicle to a destination.

At this time, when the user selects a destination through the navigation device, the navigation device checks the current location of the vehicle from the GPS signal received through the GPS receiver, and then, based on the 3D map data and real-time traffic information received from the outside, A route from the current location to the destination selected by the user may be calculated.

The real-time traffic information may be, for example, Transport Protocol Expert Group (TPEG) data.

In addition, since the navigation device includes a GPS receiver, vehicle location information, that is, current location information of the vehicle, is acquired from a GPS signal received through the GPS receiver and transmitted to the control unit, route information to the set destination, and current vehicle location information Based on the location, information on the road ahead along the route is transmitted to the controller.

Here, the information on the front road may include a road inclination angle and a traffic vehicle speed that is real-time traffic information.

Accordingly, the control unit receives necessary information such as vehicle location information, route information, and information on the road ahead from the navigation device (S11), and as will be described later, the vehicle location information received from the navigation device, information on the road ahead, and the Based on the stored setting information, it is possible to calculate the forward driving energy of the vehicle in which the forward road conditions and traffic conditions are reflected (S12).

In the present invention, after a route from the navigation device to a destination is set, the controller calculates forward driving energy using vehicle location information transmitted from the navigation device, information on a road ahead on the route, and pre-stored setting information.

Here, the vehicle location information may be information indicating the current location of the vehicle, and the information on the road ahead may include a road inclination angle on a route and a traffic vehicle speed that is real-time traffic information.

In addition, the setting information is information previously input and stored in the control unit for use in calculating the driving resistance as described below, for example, the air density (ρ), the air resistance coefficient (C _d ), the area of the front of the vehicle (A), It may include the vehicle weight (A), gravitational acceleration (g), tire radius (or companion diameter) (r), and road surface friction coefficient (or tire friction coefficient) (μ).

Various methods are known for calculating driving energy while a vehicle moves along a predetermined route, including a hybrid vehicle. For example, in the present invention, for a predetermined time (eg, 10 minutes or 20 minutes), the vehicle When it is assumed that the vehicle is driven on the road of , the forward driving energy E corresponding to the driving resistance in consideration of the road condition and the traffic situation in front may be obtained and used in real time by Equation 1 below.

In the present invention, the forward driving energy (E) refers to the driving energy required when the vehicle drives the road ahead for a predetermined time along the driving route set through the navigation device, and It is a value calculated by predicting and estimating energy, and may be calculated as a value corresponding to driving resistance in consideration of road conditions and traffic conditions ahead.

Here, the running resistance may be defined as the sum of the air resistance according to the vehicle speed, the rolling resistance according to the friction between the tire and the road surface, and the inclination resistance according to the inclination angle of the road.

Equation 1 below is an equation capable of calculating driving energy in the present invention.

[Equation 1]

Here, t is the end time, t _o is the start time, R _a is air resistance, R _r is rolling resistance, and R _g is inclination resistance.

Also, in calculating the air resistance, ρ is the air density, C _d is the air resistance coefficient, A is the area of the front of the hybrid vehicle, and v is the vehicle speed.

Here, the vehicle speed v may be a traffic vehicle speed, which is real-time traffic information indicating the traffic condition of the road ahead, and the controller receives information on the traffic vehicle speed included in the TPEG data from the navigation device, and sets the traffic vehicle speed to the vehicle speed ( v) can be used to calculate the driving energy.

In calculating the rolling resistance and inclination resistance, μ denotes the road surface friction coefficient (or tire friction coefficient) of the road, m denotes the weight of the hybrid vehicle, g denotes the gravitational acceleration, and θ denotes the road inclination angle.

Also, by multiplying the running resistance by the tire radius, a value corresponding to the torque can be obtained. In Equation 1, r denotes the tire radius (or companion diameter), and ω denotes the tire (wheel) rotation angular velocity.

The tire rotation angular speed may be obtained as a value corresponding to the vehicle speed v, and may be obtained from the vehicle speed v.

The ρ and C _d , A, μ, m, g, and r are setting information that is input and stored in advance in the control unit, and is information that is previously input and stored as a specific value in the control unit and is used.

In addition, the road inclination angle θ refers to the inclination angle of the road located in front of the vehicle along the route based on the current location of the vehicle, and the driving energy ( E) is used to calculate

In the present invention, the method using Equation 1 in calculating the driving energy of the hybrid vehicle is exemplary, the present invention is not limited thereto, and known methods known to those skilled in the art as a method of calculating the driving energy. One of them may be adopted and used.

In the present invention, assuming that the vehicle drives the road ahead on the route from the current location for a predetermined time (eg, 10 minutes or 20 minutes), the control unit calculates the traffic vehicle speed, which is real-time traffic information of the front road transmitted from the navigation device. Based on the predetermined time (eg, 1 minute), an expected vehicle position at which the vehicle is located may be determined every time elapses, and the driving energy while the vehicle moves to each expected position may be calculated using Equation 1 above.

At this time, the driving energy is the driving energy while the vehicle moves from the previous expected position to the next expected position, which is the predetermined time (eg, 1 minute) during which the vehicle is moved from the previous expected position to the next expected position. driving energy during

In addition, the driving energy in each section, that is, the driving energy E for each predetermined time, is the vehicle speed v on the front road, that is, the above-described traffic vehicle speed and the forward road, when the vehicle moves along the front road. It is calculated by Equation 1 with the road inclination angle θ, etc. of

Since this driving energy (E) is calculated using the traffic vehicle speed (V) and the road inclination angle (θ) on the road ahead as variables, it can be said that it corresponds to the driving resistance in consideration of the road conditions and traffic conditions ahead. .

As described above, the driving energy (E) corresponding to the driving resistance in consideration of the road and traffic conditions in front is calculated as a value when the vehicle is driven for a divided time (eg, 1 minute), as shown in FIG. The driving energy is calculated and obtained for each set unit of time.

For example, assuming that the vehicle travels on the road ahead on the route from the current location for a total of 10 minutes, assuming that the vehicle moves on the road ahead for every minute, the traffic vehicle speed ( v) and the driving energy using the road inclination angle θ as variables are calculated, and in this case, driving energy for a total of 10 sections may be calculated.

3 shows an example in which driving energy of a total of 10 sections is calculated, the number (n) of the divided sections can be variously changed, and the present invention is not limited to 10 sections.

As described above, while the vehicle is driving, the driving energy (E) on the road ahead to be driven is continuously predicted and estimated in real time, and the engine control process as shown in FIG. 2 using the driving energy (E) calculated for each section This is done.

In a preferred embodiment of the present invention, after the driving energy (E) for each section is calculated, the control unit calculates the energy change amount corresponding to the difference in running energy between two consecutive sections before and after in the entire section, respectively, and After calculating the summed driving energy applied value by applying the weight ( S13 ), the driving energy applied value at this time is used in real time in the control process of FIG. 2 .

In this case, the weight may be set to a larger value in a time section closer to the current location and time of the vehicle, and set to a gradually smaller value in a time section further away from the vehicle.

For example, the weight for each time interval may be n/n, (n-1)/n, (n-2)/n,..., (nm)/n (where n is the number of intervals and , n and m are all natural numbers, nm > 0).

That is, if the number of sections is 10, the weights applied to a total of 10 sections are 10/10 (=1), 9/10, 8/10, 7/10,..., 1/10 (where m=9) ), and the weights of larger values are sequentially applied from the temporally closest section to the current location.

In this way, the driving energy applied value to be applied to the engine control process according to the present invention is obtained in this way by multiplying each variation by a weight and adding the weight. Since uncertainty is high and there is a relatively large possibility of fluctuations due to changes in traffic conditions, greater weight is applied to closer data than to distant data.

In the example of FIG. 3 , when a total of 10 variations from a to j are calculated, it can be said that a has the highest importance and j has the lowest importance, so the greatest weight is applied to a, b, c, and d , e, f, g, h, i, j are applied with progressively smaller weights.

The above-described driving energy application value K may be defined as in Equation 2 below.

[Equation 2]

Of course, when the vehicle passes through section a and comes to section b, the largest weight (n/n) applied to section a before in this section b is applied, and similarly, smaller weights are sequentially applied to sections further away from the subsequent section. do.

As described above, the process of obtaining the driving energy value to be used in the heating engine control process of the present invention, and more specifically, the driving energy application value calculated by applying the weight for each section as described above has been described in detail.

As described above, in the present invention, the driving energy (ie, forward driving energy) refers to the total driving energy required for driving for the predetermined time when it is assumed that the vehicle travels on the road ahead for a predetermined time along the set route. can

In this case, the driving energy is a predicted and estimated value of energy required for driving on the road ahead, and is calculated in consideration of information transmitted from the navigation device, that is, information on the road and traffic conditions ahead.

In addition, in the present invention, the driving energy is predicted, estimated, and calculated in real time while the vehicle moves along a set route using information transmitted from the navigation device and pre-stored setting information.

In addition, in the present invention, the driving energy is the total driving energy required for the vehicle to travel the road ahead for a predetermined time along the route. The driving energy for each section time is obtained by Equation 1, and then, the driving energy applied value is obtained by multiplying the amount of change in driving energy between sections by a weight for each section and adding them.

Hereinafter, an engine control process during heating using the driving energy applied value will be described in detail with reference to FIG. 2 .

In the embodiment of FIG. 2, the first set value (δ), the second set value (γ), the third set value (β), and the fourth set value (α) are ‘first set value (δ) > second set value (α) value (γ) > fourth set value (α) > third set value (β)'.

A user (eg, a driver) selects a destination through the navigation device while operating the air conditioner by setting the target indoor temperature for indoor air conditioning of the vehicle, and after a route from the navigation device to the destination is set, the control unit receives the necessary information from the navigation device (S11).

In addition, the controller calculates the driving energy using the information (S12) and calculates the driving energy application value using the driving energy for each section (S13).

Then, the control unit compares the current indoor temperature detected by the sensor with the set temperature (a) (S14), and if the current indoor temperature is higher than the set temperature (a) and the driving energy applied value is greater than the first set value (δ), , enters the engine-on limit mode (S15, S16).

After entering the engine-on limiting mode, the controller performs engine-on limiting control that maintains the engine in an off state even when the coolant temperature is below the reference temperature.

Here, the reference temperature is a temperature for determining whether it is necessary to increase the coolant temperature during heating, that is, a temperature for determining whether to turn on the engine for heating.

The reference temperature may be set by the control unit to be determined by the outside air temperature, the indoor temperature, the driver's set temperature, and the like.

Conventionally, if the coolant temperature is below the reference temperature, the engine is unconditionally turned on (engine forcibly driven) to increase the coolant temperature. off) the engine on limit control to keep the state is performed.

Even if the user requests heating as described above, even if the current indoor temperature is lower than the target indoor temperature, the driving energy applied value is the first set value in a situation where the engine can be turned off because the current indoor temperature is higher than the set temperature (a). If it is greater than (δ), it is difficult to improve fuel efficiency and ensure quietness by limiting engine on, that is, by maintaining the engine in an off state, when stopped, driving at low speed in EV mode, or when braking or coasting. make it possible

And, if the current indoor temperature is below the set temperature (a) in step S14, the difference between the target indoor temperature and the current indoor temperature is compared with the set temperature difference (b) (S17), where the difference between the target indoor temperature and the current indoor temperature is If it is less than the set temperature difference (b) and the driving energy applied value is greater than the second set value (γ), the engine on (on) standard down mode is entered (S18, S19).

After entering the engine-on reference-down mode, the control unit lowers the reference temperature by a predetermined temperature under the same conditions, determines whether engine-on is required according to the lowered reference temperature, and controls engine on/off according to the result. carry out

Here, since the reference temperature may be set to be determined by the outdoor temperature, the indoor temperature, the driver's set temperature, etc., in this case, the temperature determined as compared to the normal reference temperature during heating is compared to the same conditions of the outdoor temperature, the indoor temperature, and the driver's set temperature. The lower reference temperature is used to determine whether to turn the engine on or off.

That is, the normal engine on/off reference temperature line is lowered by a predetermined temperature, the coolant temperature detected by the water temperature sensor is compared with the lowered reference temperature, the engine is turned on if it is below the reference temperature, and the engine is turned off if it is higher than the reference temperature. is to keep

As such, if the difference between the target indoor temperature and the current indoor temperature is small, and the driving energy is greater than the second set value (γ) when the current indoor temperature is close to the target indoor temperature and the engine can be turned off, It lowers the temperature to induce the engine to be turned off as much as possible.

By increasing the number of engine-off states in this way, it is possible to improve fuel efficiency and secure quietness when the vehicle is stopped, driving at a low speed in the EV mode, or when braking or coasting.

In addition, even when the driving energy applied value is less than or equal to the first set value (δ) in step S15 and the driving energy applied value is greater than the second set value (γ), the engine-on reference down mode is entered.

That is, when the current indoor temperature is higher than the set temperature (a) and the driving energy applied value is less than or equal to the first set value (δ) but is greater than the second set value (γ), the engine-on reference downward control is performed. will be.

And, when the difference between the target indoor temperature and the current indoor temperature is greater than the set temperature difference (b) in step S17, or when the applied driving energy value is less than or equal to the second set value (γ) in step S18, the driving energy applied value is set to the third Comparing with the set value (β) and the fourth set value (α) (S20, S21), if the driving energy applied value is greater than the third set value (β) but less than or equal to the fourth set value (α), the engine idle It enters the idle speed downward mode for lowering the rotation speed (rpm) (S22).

The idle speed down mode is a control used when the engine needs to be turned on because the room temperature is currently low, but the driving energy is high. Downward control.

As described above, if the idle speed down control condition is satisfied, that is, if the driving energy applied value is greater than the third set value (β) but less than or equal to the fourth set value (α), the engine is inevitably turned on for heating, but the engine By lowering the idle rotation speed of the engine, it is possible to secure quietness and improve fuel efficiency.

On the other hand, by comparing the driving energy applied value with the third set value (β) and the fourth set value (α) in steps S20 and S21, the driving energy applied value is the third set value (β) and the fourth set value ( If both are greater than α), the idle operation point downward mode is entered in which the idle operation point of the engine is lowered (S23).

The idle operating point downward mode is a control used when the engine needs to be turned on due to the low indoor temperature, but the driving energy is very high. The idle operating point downward control is performed by lowering the idle operating point of the engine by a certain level based on the engine torque value.

At this time, an operating point at which the engine torque value corresponding to the idle speed is lowered by a set value is selected from the engine operating point map of the engine speed (rpm)-torque (Nm) in the normal idle operation operation point selected in this way, A method of controlling the idle operation of the engine at an operating point at which the torque value is lowered from the speed may be applied.

If the idle operating point downward control condition is satisfied, that is, if the driving energy applied value is both greater than the third set value β and the fourth set value α, the engine is inevitably turned on for heating. , by lowering the idle operating point of the engine to perform a control to slow down the rate of increase in the coolant temperature to improve fuel efficiency.

Although the embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention as defined in the following claims Also included in the scope of the present invention.

Claims (16)

receiving, by the controller, vehicle location information and information on a road ahead based on the vehicle location from a navigation device in which a route to a destination is set during heating in a hybrid vehicle;
calculating, by the controller, driving energy when the vehicle travels on the road ahead for a predetermined time based on the received vehicle location information, information on the road ahead, and pre-stored setting information;
determining, by the controller, an engine control mode during heating by using the calculated driving energy, a current indoor temperature and a target indoor temperature of the vehicle; and
Comprising the step of the control unit performing engine control according to the determined engine control mode,
The control unit is
Calculate the driving energy for each section time for each divided time section by dividing the predetermined time,
Calculates the amount of change in driving energy between consecutive sections,
Calculate the driving energy application value of the summed value by multiplying the driving energy change amount by the weight for each section,
In the step of determining the engine control mode for heating, the heating engine for a hybrid vehicle, wherein the heating engine control mode is determined using the calculated driving energy application value, the current indoor temperature of the vehicle, and the target indoor temperature. control method.
The method according to claim 1,
The information on the front road includes a road inclination angle of the front road along the set route and a traffic vehicle speed which is real-time traffic information.
The method according to claim 1 or 2,
The pre-stored setting information includes air density, air resistance coefficient, vehicle front area, road friction coefficient, vehicle weight, gravitational acceleration and tire radius of the vehicle.
4. The method according to claim 3,
The driving energy is an engine control method when heating a hybrid vehicle, characterized in that calculated by the following equation.
Formula:

where R _a is air resistance, R _r is rolling resistance, R _g is slope resistance, t is end time, t _o is start time, ρ is air density, C _d is air resistance coefficient, and A is the area of the front of the vehicle. where v is the real-time traffic information of the road ahead; It is the tire rotation angular velocity obtained as a value.
delete The method according to claim 1,
The method for controlling an engine for heating a hybrid vehicle, characterized in that the weight for each section is set to a larger value for a time section closer to the current location and current time of the vehicle, and to a smaller value for a time section further away from the vehicle.
7. The method of claim 6,
The weight for each section is n/n, (n-1)/n, (n-2)/n,..., (nm)/n (where n is the number of divided sections, and n and m are All of which are natural numbers, and nm > 0).
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
When the current indoor temperature is higher than the set temperature and the driving energy application value is greater than the first set value, the engine control method for heating a hybrid vehicle, characterized in that the engine on limit mode is determined for maintaining the engine in an off state during heating.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is less than the set temperature, the difference between the target indoor temperature and the current indoor temperature is less than or equal to the set temperature difference, and the driving energy applied value is greater than the second set value,
Lowering the reference temperature for turning on the engine by the set temperature,
The engine control method for heating a hybrid vehicle, characterized in that the lowered reference temperature is compared with the coolant temperature to determine an engine on reference down mode for controlling engine on/off.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is higher than the set temperature and the driving energy applied value is less than the first set value but is greater than the second set value,
Lowering the reference temperature for turning on the engine by the set temperature,
The engine control method for heating a hybrid vehicle, characterized in that the lowered reference temperature is compared with the coolant temperature to determine an engine on reference down mode for controlling engine on/off.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is below the set temperature, the difference between the target indoor temperature and the current indoor temperature is greater than the set temperature difference, and the driving energy applied value is greater than the third set value but less than or equal to the fourth set value,
An engine control method for heating a hybrid vehicle, comprising determining an idle speed lowering mode for lowering the idle rotation speed (rpm) of the engine to a set speed.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is higher than the set temperature, the driving energy applied value is less than the first set value and the second set value, and the running energy applied value is greater than the third set value but less than the fourth set value,
An engine control method for heating a hybrid vehicle, comprising determining an idle speed lowering mode for lowering the idle rotation speed (rpm) of the engine to a set speed.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
The current indoor temperature is less than or equal to the set temperature, the difference between the target indoor temperature and the current indoor temperature is less than or equal to the set temperature difference, the applied driving energy value is less than or equal to the second set value, and the applied running energy value is greater than the third set value but the fourth If it is below the set value,
An engine control method for heating a hybrid vehicle, comprising determining an idle speed lowering mode for lowering the idle rotation speed (rpm) of the engine to a set speed.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is below the set temperature, the difference between the target indoor temperature and the current indoor temperature is greater than the set temperature difference, and the driving energy applied value is greater than the third set value and the fourth set value,
An engine control method for heating a hybrid vehicle, comprising controlling the engine to an idle driving state, but determining an idle operating point downward mode for lowering the idle operating point of the engine by a predetermined level based on an engine torque value.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
If the current indoor temperature is higher than the set temperature, the driving energy applied value is less than the first set value and the second set value, and the driving energy applied value is greater than the third set value and the fourth set value,
An engine control method for heating a hybrid vehicle, comprising determining an idle operating point lowering mode for lowering the idle operating point of the engine.
The method according to claim 1,
In the step of determining the engine control mode during the heating,
The control unit is
The current indoor temperature is less than or equal to the set temperature, the difference between the target indoor temperature and the current indoor temperature is less than or equal to the set temperature difference, the applied driving energy value is less than or equal to the second set value, and the applied running energy value is the third set value and the fourth set value greater than,
An engine control method for heating a hybrid vehicle, comprising determining an idle operating point lowering mode for lowering the idle operating point of the engine.

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