JP2013001214A - Control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle suppressing an increase in consumption of fuel and improving a running cost while maintaining exhaustion performance.SOLUTION: The control device of a hybrid vehicle is used for a hybrid vehicle which includes: an engine 1 which has a catalyst 15 for cleaning exhaust gas on an exhaust system and is driven by a fuel supply from a fuel tank 14; a driving motor 3 which drives driving wheels 6, 6 with power supply from a battery 4; and a vehicle integrated controller 24. The control device of hybrid vehicle includes an engine operation control means (Fig.2) which controls the operation of the engine 1 based on an engine work done Eengine shown by a difference obtained by removing an electric energy amount Ebat consumed to a target place from an energy amount Edrive required from a present place to the target place when starting the engine according to the requirement besides the catalytic warm-up and a thermal energy amount Ecat of which is required to be input to the catalyst 15 in order to keep the catalyst temperature enabling the cleaning treatment ability to be maintained until reaching the target place from the present place.

Description

  The present invention relates to a control apparatus for a hybrid vehicle equipped with an engine having a catalyst for purifying exhaust gas in an exhaust system, and a motor for driving drive wheels by at least power supply from a battery.

  2. Description of the Related Art In recent years, plug-in hybrid vehicles that include a drive motor and a power storage device (battery) that can be charged from the outside in addition to an engine that is a conventional internal combustion engine have been studied as environmentally friendly automobiles.

  In this plug-in hybrid vehicle, when the battery capacity (hereinafter referred to as “battery SOC”) is large (hereinafter referred to as “CD mode”), the engine is stopped or the engine driving rate is decreased to drive the motor (hereinafter referred to as “CD mode”). , “EV driving”). The state after the battery SOC is lowered to a certain point (hereinafter referred to as “CS mode”), the engine is started, and the operation of maintaining the battery SOC by increasing the engine operation or the engine drive rate is generally performed. is there.

  Incidentally, when the engine is started for the first time, since the engine and the catalyst are not sufficiently warmed up, the exhaust purification treatment capacity is low. At this time, in order to ensure the exhaust performance of the engine, it is common to promote warm-up by retarding the engine ignition timing. During this warm-up operation, the engine operating efficiency deteriorates due to the warm-up priority operation. That is, more fuel is consumed than in normal operation.

  In the main CD mode in which EV travel is performed, it is preferable to perform a catalyst warm-up operation in order to maintain exhaust performance when the engine is started for some requirement or when the engine is started for the first time when the catalyst is cold. However, after the catalyst warm-up operation is completed, by returning to the CD mode with EV driving as the main again, the catalyst temperature decreases again due to insufficient engine operation time or insufficient energy input to the engine exhaust heat to the catalyst. It is possible.

  Accordingly, the state of the purification catalyst at the time of intermittent engine stop is determined, and in response to the determination, the operation of the engine in the intermittent stop state is restarted and the catalyst warm-up operation is performed to maintain an appropriate purification processing capability. A control device for a hybrid vehicle is known (for example, see Patent Document 1).

JP 2010-83232 A

  However, in the conventional hybrid vehicle control device, even after the catalyst warm-up operation ends, if the engine or catalyst temperature decreases due to the intermittent engine stop state, the engine is started again before the catalyst purification processing capacity decreases. To perform warm-up control operation. For this reason, the catalyst warm-up operation is repeated a plurality of times, and there is a problem that a large amount of fuel is consumed due to deterioration in engine operation efficiency.

  In the case of a plug-in hybrid vehicle, the running cost should be reduced by using up the electric energy as much as possible when reaching the destination and using gasoline fuel for the shortage. On the other hand, in the case where the battery is charged by repeated catalyst warm-up operation, there is a concern that when the battery arrives at the destination, the battery SOC remains unusable and the running cost is likely to deteriorate. was there.

  The present invention has been made paying attention to the above-described problem, and an object of the present invention is to provide a hybrid vehicle control device capable of suppressing increase in fuel consumption and improving running cost while maintaining exhaust performance. To do.

In order to achieve the above object, the hybrid vehicle control apparatus of the present invention is a means including an engine, a motor, engine work amount calculating means, thermal energy amount calculating means, and engine operation control means.
The engine has a catalyst for purifying exhaust gas in an exhaust system, and is driven by fuel supply from a fuel tank.
The motor drives the driving wheels by at least power supply from a battery.
The engine work amount calculating means calculates the engine work amount necessary for traveling from the current location to the destination by a difference obtained by subtracting the amount of electric energy consumed from the current location to the destination from the amount of energy required from the current location to the destination. Estimate calculation.
The thermal energy amount calculating means estimates and calculates an amount of thermal energy that needs to be input to the catalyst in order to maintain the catalyst temperature at which the purification treatment capability can be maintained until the destination reaches the destination.
The engine operation control means controls the operation of the engine based on the estimated engine work amount and the thermal energy amount when the engine is started due to a request other than catalyst warm-up.

Therefore, when the engine is started due to a request other than the catalyst warm-up, engine operation control is performed by energy management based on the engine work amount and the heat energy amount. Therefore, for example, if the engine work and heat energy are satisfied by one catalyst warm-up operation, the engine does not have to be restarted until the destination is reached unless the engine is started due to a catalyst warm-up request. Good. Thus, by increasing the number of times of catalyst warm-up to one time or the minimum number of times, an increase in fuel consumption due to repeated warm-up control operation is suppressed.
Further, when the engine is started due to a request other than the catalyst warm-up, engine operation control is performed based on the engine work amount obtained by subtracting the amount of electric energy consumed up to the destination from the amount of energy required up to the destination. That is, engine operation control is performed so that the total engine work amount from the current location to the destination reaches the calculated engine work amount. Therefore, when the minimum electric energy amount that needs to be left at the destination is set as the target energy amount, the electric energy amount can be used up to the target energy amount when arriving at the destination.
In addition, when the engine is started due to a request other than catalyst warm-up, engine operation is based on the amount of thermal energy that must be input to the catalyst to maintain the catalyst temperature at which the purification treatment capacity can be maintained until the destination is reached from the current location. Control is performed. That is, engine operation control is performed so that the total amount of heat energy from the current location to the destination reaches the calculated amount of heat energy. Therefore, until reaching the destination from the present location, the catalyst temperature that can maintain the purification treatment capacity is maintained, and the exhaust performance is maintained.
As a result, it is possible to suppress the increase in fuel consumption and improve the running cost while maintaining the exhaust performance.

1 is an overall system configuration diagram illustrating a series-type plug-in hybrid vehicle to which a control device according to a first embodiment is applied. It is a flowchart which shows the flow of the engine operation control process by the request | requirements other than the catalyst warming-up performed in the vehicle integrated controller of Example 1. FIG. It is a graph explanatory drawing which shows how to obtain | require the engine work calculated by the vehicle integrated controller of Example 1. FIG. It is a thermal energy amount characteristic view which shows the example of a calculation which calculates | requires the heat energy amount calculated with the vehicle integrated controller of Example 1 by the travel time to the destination, and external temperature. It is a catalyst temperature characteristic figure which shows that the catalyst temperature fall gradient when it is an engine stop state when determining the thermal energy input schedule in the vehicle integrated controller of Example 1 is influenced by the outside air temperature and the vehicle speed. FIG. 3 is a catalyst temperature characteristic diagram illustrating an example in which an engine operation schedule is determined based on determination of a thermal energy input schedule to the catalyst based on a catalyst temperature change gradient in an engine stop state and an engine operation state in the vehicle integrated controller of the first embodiment. is there. 6 is a time chart showing battery SOC characteristics and engine operation / stop characteristics from the current position to the destination in Comparative Example 1; 6 is a time chart showing battery SOC characteristics and engine operation / stop characteristics from the current position to the destination in Comparative Example 2; It is an action explanatory view showing an example of engine operation control action when the amount of heat energy is larger than the engine work amount in Example 1, (a) shows an energy relation graph, (b) shows from the current position to the destination. The time chart of a battery SOC characteristic and an engine operation / stop characteristic is shown. It is an action explanatory view showing an example of an engine operation control action when the engine work amount is larger than the heat energy amount in Example 1, (a) shows an energy relation graph, (b) shows from the current position to the destination. The time chart of a battery SOC characteristic and an engine operation / stop characteristic is shown.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
The configuration of the control apparatus for the hybrid vehicle of the first embodiment will be described by dividing it into “an overall system configuration” and “an engine operation control configuration according to a request other than catalyst warm-up”.

[Overall system configuration]
FIG. 1 shows the overall system configuration of a series-type plug-in hybrid vehicle to which the control device of the first embodiment is applied. The overall system configuration will be described below with reference to FIG.

  As shown in FIG. 1, the drive system of the series-type plug-in hybrid vehicle includes an engine 1, a generator motor 2, a drive motor 3 (motor), a battery 4, a deceleration differential mechanism 5, and drive wheels 6. And a generator motor inverter 7, a drive motor inverter 8, a charge converter 9, a switch 10, a charge port 11, and a fuel tank 14.

  This plug-in hybrid vehicle has an electric vehicle travel mode (hereinafter referred to as “EV travel mode”) and a hybrid vehicle travel mode (hereinafter referred to as “HEV travel mode”) as travel modes. The “EV travel mode” is a mode in which the engine 1 is stopped while the drive motor 3 is driven by the electric power stored in the battery 4 and travels using only the drive motor 3 as a drive source. On the other hand, the “HEV traveling mode” is a mode in which the generator motor 2 is driven by the engine 1 for charging or the like while traveling using the drive motor 3 as a drive source.

  The engine 1 is started by a power generation motor 2 when a power generation request is made, and generates power by driving the power generation motor 2 after a complete explosion. Then, when the generation request is made and the generation request is not made, the engine 1 and the generator motor 2 are stopped. The exhaust system of the engine 1 has a catalyst 15 for purifying exhaust gas. As this catalyst 15, for example, a three-way catalyst is used, and the three-way catalyst removes hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), etc., which are harmful substances contained in the exhaust gas. Remove at the same time. This three-way catalyst has a low reducing ability at room temperature. For this reason, in order to operate the three-way catalyst appropriately, for example, temperature management is required such that the temperature is raised quickly by exhaust gas heat immediately after the engine is started, and then a temperature equal to or higher than a predetermined temperature is maintained.

  The generator motor 2 is a motor generator that is connected to the engine 1 and exhibits a starter motor function and a power generation function. The starter motor function is exhibited when the engine 1 is started by consuming the power of the battery 4 and igniting the cranking of the engine 1 when the engine 1 is stopped and a power generation request is made. The power generation function is exhibited when the engine 1 is in a driving operation state, receives rotational driving power from the engine 1, converts it into three-phase AC power, and charges the battery 4 with the generated power.

  The drive motor 3 is a motor generator that is connected to a drive wheel 6 of a vehicle via a speed-reducing differential mechanism 5 and that exhibits a motor function and a power generation function. The motor function is exhibited when the vehicle is driven by consuming electric power from the battery 4 at the time of start acceleration, constant speed traveling, or intermediate acceleration. The power generation function is exhibited when performing regenerative power generation that receives rotational drive power from the drive wheels 6 during deceleration, braking, etc., converts this into three-phase AC power, and charges the generated power to the battery 4. .

  The battery 4 uses a lithium ion secondary battery, a high-capacity capacitor, or the like, and stores the power generated by the power generation motor 2 or the power regenerated by the drive motor 3 and also stored in the drive motor 3 or the power generation motor 2. Supply power.

  The generator motor inverter 7 is arranged between the generator motor 2 and the battery 4 and mutually converts three-phase alternating current and direct current. The three-phase alternating current is used for driving / power generation of the generator motor 2, and the direct current is used for charging / discharging the battery 4.

  The drive motor inverter 8 is arranged between the drive motor 3 and the battery 4 and mutually converts three-phase alternating current and direct current. The three-phase alternating current is used for driving / power generation of the drive motor 3, and the direct current is used for charging / discharging the battery 4.

  The charging converter 9 is arranged between the battery 4 and the charging port 11 and converts AC external power supplied from the charging port 11 into DC power that can charge the battery 4 during plug-in charging. .

The switch 10 is disposed between the generator motor 2, the generator motor inverter 7, and the charging port 11, and switches between a power generation path and a power supply path. The power generation path has a pattern in which the charging port 11 is disconnected and the power generation motor 2 and the power generation motor inverter 7 are connected. As the power supply path, one of the following three patterns is switched and selected.
A pattern in which the power of the battery 4 is used by disconnecting the charging port 11 and connecting the generator motor 2 and the generator motor inverter 7.
A pattern in which the electric power of both the charging port 11 and the battery 4 is used by connecting the generator motor 2, the generator motor inverter 7, and the charging port 11.
A pattern in which the power of the charging port 11 is used by disconnecting the inverter 7 for the generator motor and connecting the generator motor 2 and the charging port 11.

  The charging port 11 is set at any position on the outer periphery of the vehicle body. When the vehicle is stopped at the set position of the external charging facility 12, the lid is opened and the power plug 13 of the external charger 12 is inserted and connected. Then, the battery 4 is charged (plug-in charging) via the charge converter 9. Here, the external charging facility 12 refers to a home charging facility for performing low-speed charging using late-night power at home, a quick charging stand capable of rapid charging at a place away from the home, and the like.

  The fuel tank 14 is a container for storing fuel such as gasoline and light oil supplied to the engine 1. The fuel stored in the fuel tank 14 is supplied to the combustion chamber of the engine 1 via a fuel supply passage and a fuel injection device (not shown).

As shown in FIG. 1, the control system of the plug-in hybrid vehicle of the first embodiment includes an engine controller (ECM) 20, a generator controller (GC) 21, a motor controller (MC) 22, and a battery controller (LBC) 23. And a vehicle integrated controller (VCM) 24 and a navigation controller (NAVI / C) 25.
Each controller 20, 21, 22, 23, 24 is connected by a CAN communication line 30 capable of exchanging information so that various data can be shared. Each of the controllers 20, 21, 22, 23, 24 includes a processor that executes a program, a memory that stores a program executed by the processor, and an interface connected to the processor.

  The engine controller 20 controls the output torque by manipulating the intake air amount, ignition timing, and fuel injection amount of the engine 1 in accordance with a control command from the vehicle integrated controller 24.

  The generator controller 21 outputs an operation command to the generator motor inverter 7 in order to control the input / output torque of the generator motor 2 in accordance with a control command from the vehicle integrated controller 24.

  The motor controller 22 outputs an operation command to the drive motor inverter 8 in order to control the input / output torque of the drive motor 3 in accordance with a control command from the vehicle integrated controller 24.

  The battery controller 23 estimates the internal state quantity such as the charge capacity (remaining capacity) of the battery 4 and the power that can be input / output, and performs protection control of the battery 4. Hereinafter, the charge capacity (remaining capacity) of the battery 4 is referred to as a battery SOC (SOC is an abbreviation for “State Of Charge”).

  The vehicle integrated controller 24 controls the motor drive output in accordance with the driver's request while coordinating the plurality of controllers 20, 21, 22, and 23 based on various shared data. In addition, the power generation output is controlled in consideration of both drivability and fuel efficiency (economic efficiency). This vehicle integrated controller 24 inputs information from the navigation controller 25, an ignition key switch (IGN-SW) 26, a fuel tank sensor 27, a catalyst temperature sensor 31, an outside air temperature sensor 32, a vehicle speed sensor 33, and other sensors 28. To do. And the information which should be notified to the passenger | crew containing a driver | operator is output to the navigation controller 25 and the speaker 29. FIG.

  The navigation controller 25 detects the position of the host vehicle using a GPS signal from a satellite, and has a navigation system control function for searching for a route to a destination and guiding based on map data stored in a DVD or the like. Bear. The vehicle position information on the map obtained by the navigation controller 25 is supplied to the vehicle integrated controller 24 together with the home position information and the charging station position information. The navigation controller 25 includes an input device (input means) for the passenger to input various information. The occupant can input the destination and the planned travel distance using the input device.

  The ignition key switch 26 is a switch for an ignition device of the engine 1. The ignition key switch 26 also serves as a starter motor (cell motor) switch. The fuel tank sensor 27 is a sensor for detecting the remaining capacity of the fuel stored in the fuel tank 14, and for example, a fuel level gauge or the like is used.

[Engine operation control configuration based on requests other than catalyst warm-up]
FIG. 2 shows a flow of engine operation control processing according to a request other than catalyst warm-up in the vehicle integrated controller 24 of the first embodiment (engine operation control means). Hereinafter, each step of FIG. 2 showing the engine operation control configuration according to a request other than the catalyst warm-up will be described.

In step S1, it is determined whether or not the engine 1 has been started with requirements other than catalyst warm-up during the CD mode with a large number of battery SOCs. If YES (engine start with requirements other than warm-up), the process proceeds to step S2, and if NO (engine start or engine stop with warm-up requirements), the determination in step S1 is repeated.
Here, the “requirements other than catalyst warm-up” are, for example, when the driving force requirement is high, when the battery output cannot be output due to temperature or voltage limitation, when diagnosis that requires engine start is performed, and engine start When the operation is performed when there is a switch or the like.

In step S2, following the determination that the engine is started due to requirements other than the warm-up in step S1, it is determined whether the engine 1 and the catalyst 15 have secured their original exhaust purification processing capability. If YES (exhaust gas purification capacity is secured), the process proceeds to the end. If NO (exhaust gas purification capacity is not ensured), the process proceeds to step S3.
Here, the determination that the exhaust purification processing capacity cannot be ensured is made when the temperature of the engine 1 or the catalyst 15 is low. That is, when the temperature of the engine 1 or the catalyst 15 is lower than the set temperature, it is necessary to perform catalyst warm-up, and therefore the process proceeds to the flow after step S3.

In step S3, following the determination that the exhaust gas purification processing capacity in step S2 has not been secured, whether destination information (route to the destination and gradient information) or distance to the destination can be assumed. Judging. If YES (destination information and distance to the destination can be assumed), the process proceeds to step S4. If NO (destination information and distance to the destination cannot be assumed), the process proceeds to the end.
Here, the destination information and the distance to the destination can be assumed, for example, when the destination is set for the navigation system, or when the driving pattern of the driver can be estimated by a commuting pattern, etc. .

In step S4, following the determination that the destination information and the distance to the destination can be assumed in step S3, the energy amount Edrive, the electric energy amount Ebat, the engine work amount Eengine (= Edrive−Ebat), and the heat The energy amount Ecat is estimated and calculated, and the process proceeds to step S5.
“Energy amount Edrive” refers to the amount of energy required for traveling from the current location to the destination, and is calculated based on route information to the destination, the use of electrical loads of air conditioners and auxiliary equipment, and the like.
“Electric energy amount Ebat” refers to the amount of electric energy that is desired to be consumed from the current location to the destination so that the target battery SOC targeted at the destination is reached. The difference between the current battery SOC and the target battery SOC. Is calculated by
“Engine work Eengine” means the amount of work that should be done with the engine 1 that is the minimum necessary to travel from the current location to the destination. As shown in FIG. 3, the electric energy Ebat is subtracted from the energy Edrive. Calculated by the difference (engine work amount calculation means).
“The amount of heat energy Ecat” means the amount of heat energy necessary to be input to the catalyst 15 in order to maintain the minimum catalyst temperature at which the purification treatment capacity can be secured until reaching the destination from the current location. As shown in FIG. 4, it is calculated from the travel time to the destination and the outside air temperature (thermal energy calculation means).

In step S5, following the calculation of each energy amount in step S4, catalyst warm-up control by the engine 1 is performed for a predetermined time, and the process proceeds to step S6.
Here, the catalyst warm-up control refers to control that promotes warm-up of the engine 1 by, for example, retarding the engine ignition timing.

In step S6, following the execution of catalyst warm-up control by the engine 1, the catalyst warm-up control by the engine 1 is terminated when a predetermined time required for catalyst warm-up at the time of engine start has elapsed, and the process proceeds to step S7.
That is, after the catalyst warm-up control in step S6 is completed, the engine operation control (step S7 to step S13) in the first embodiment is switched.

  In step S7, following the end of the catalyst warm-up control in step S6, it is determined whether the engine work amount Eengine estimated in step S4 is greater than the thermal energy amount Ecat, and YES (Eengine> Ecat) If YES in step S8, the process advances to step S8. If NO (Eengine ≦ Ecat), the process advances to step S12.

In step S8, following the determination that Eengine> Ecat in step S7, a heat energy input schedule and an engine operation schedule for the catalyst 15 are determined, and the process proceeds to step S9.
Here, when determining the thermal energy input schedule, as shown in FIG. 5, the current catalyst temperature is taken into account that the catalyst temperature decrease gradient when the engine is stopped is affected by the outside air temperature and the vehicle speed. Then, the time t1 or the time t2 during which the temperature is lowered to the minimum temperature at which the catalyst purification function is maintained is determined. Then, as shown in FIG. 6, a heat energy input schedule to the catalyst is determined based on the catalyst temperature change gradient in the engine stop state (downward gradient) and the engine operation state (upward gradient). Based on this thermal energy input schedule, an engine operating schedule is determined in which the thermal energy input area to the catalyst is the engine operating area and the EV travelable area that does not require the thermal energy input to the catalyst is the engine stop area.

  In step S9, following the determination of the engine operation schedule in step S8 or the determination that the destination has not been reached in step S11, the engine operation range and the engine stop region in the determined or corrected engine operation schedule In accordance with the switching control for switching, engine operation control is performed, and the process proceeds to step S10.

In step S10, following the engine operation control corresponding to the switching control in step S9, the gap between the intermediate target and the current performance is calculated, the engine operation schedule is corrected according to the gap, and the process proceeds to step S11.
Here, when the gap between the intermediate target and the current performance is calculated, the engine start timing is changed or the engine drive load during engine operation is changed so that the gap is eliminated or the gap is reduced. Correction is performed.

  In step S11, it is determined whether or not the vehicle has arrived at the destination following the execution of the correction of the engine operation schedule corresponding to the gap in step S10. If YES (arriving at the destination), the process proceeds to the end. If NO (not arriving at the destination), the process returns to step S9.

  In step S12, following the determination that Eengine ≦ Ecat in step S7, the work of the engine 1 becomes the calculated minimum required engine work Eengine following the end of the catalyst warm-up control. The engine power generation operation is continued, and the process proceeds to step S13.

  In step S13, following the end of the continuous operation of the engine power generation operation in step S12, the engine 1 is stopped and the process proceeds to the end.

Next, the operation will be described.
First, “the problem of the comparative example” will be described. Subsequently, the effects of the control device for the plug-in hybrid vehicle of the first embodiment are as follows: “Estimation calculation action of each energy amount”, “Engine operation control action by energy management”, “Engine operation control action when Eengine ≦ Ecat” , “Engine operation control action when Eengine> Ecat”.

[Problems of comparative example]
When the plug-in hybrid vehicle is in the CD mode with a large amount of battery SOC, the engine is stopped or the drive rate of the engine is lowered and EV driving is mainly performed. When the CS mode is reached after the battery SOC has been lowered to a certain point, it is common to perform an operation of maintaining the battery SOC by starting the engine and increasing the engine operation or the engine drive rate.

  Incidentally, when the engine is started for the first time, since the engine and the catalyst are not sufficiently warmed up, the exhaust purification treatment capacity is low. At this time, in order to ensure the exhaust performance of the engine, it is common to promote warm-up by retarding the engine ignition timing. During this warm-up operation, the engine operating efficiency deteriorates due to the warm-up priority operation. That is, more fuel is consumed than in normal operation.

  When the engine is started for the first time when the engine or the catalyst is cooled in the CD mode where EV driving is the main, it is preferable to warm up the catalyst in order to maintain the exhaust performance. However, after the catalyst warm-up operation is completed, returning to the CD mode mainly for EV driving may cause the catalyst temperature to drop again due to engine intermittent time and insufficient engine exhaust heat input to the catalyst. Conceivable.

  Therefore, the state of the purification catalyst at the time of intermittent engine stop is determined, and in response to the determination, the operation of the engine in the intermittent stop state is restarted and the catalyst is warmed up so as to maintain an appropriate purification processing capacity. This is referred to as Comparative Example 1 (JP 2010-83232 A, etc.).

  In Comparative Example 1, as shown in FIG. 7, even after the catalyst warm-up operation is completed, the engine and the catalyst temperature are lowered due to the engine intermittent state, and the engine is restarted and warmed before the purification capacity of the catalyst is lowered. Perform machine controlled operation. That is, as the catalyst warm-up is controlled in accordance with the decrease in the catalyst temperature, a large amount of fuel is consumed due to the deterioration of the engine operation efficiency associated with the warm-up operation (Problem 1).

On the other hand, when the catalyst is warmed up, a control method is known in which the exhaust component purification performance is further stabilized by an operation in which the air-fuel ratio is constant, that is, the engine output is kept as constant as possible. However, in this case, the excess engine output with respect to the driver's required driving force is directly charged to the battery or taken out of the battery.
For example, in a case such as a traffic jam in which driving with low load is repeated, it is assumed that the battery is charged with surplus power by repeated catalyst warm-up operation of the engine.
If this case continues, as shown in FIG. 7, the catalyst warm-up is repeated, so that a large amount of power is generated, and there is a possibility that even the battery SOC where the electric energy is to be used up cannot be used.
In other words, when you want to reach your destination, you want to lower the running cost by using electric energy as much as possible, and using the shortage of gasoline as fuel, while increasing the gasoline driving rate increases the running cost. (Problem 2).

  Comparative Example 2 that can be realized by monitoring the transition of the battery SOC so that the power can be efficiently used up to the target remaining battery level at the destination and adjusting the drive ratio of the motor and the engine. For example, JP-A-9-163506.

  However, in Comparative Example 2, since the relationship between the catalyst temperature transition is not considered in the engine drive rate, the engine must be started in order to warm up the catalyst due to a decrease in the catalyst temperature depending on the actual driving scene. A scene that cannot be generated occurs (Problem 3).

  That is, as shown in FIG. 8, even when the engine sharing ratio is 0, there are actually scenes where the engine is started and the catalyst is warmed up depending on the exhaust performance. In this case, in order to use up the battery SOC at the destination, it is necessary to readjust the drive ratio between the motor and the engine. If the readjustment is not done, a large amount of power will be generated by starting the engine or warming up the catalyst. There is a possibility that the target battery SOC cannot be used on the ground.

[Estimated calculation of each energy amount]
In step S4 of FIG. 2, each energy amount necessary for executing the engine operation control by the energy management of the first embodiment is estimated and calculated. In this calculation, it is necessary to increase the estimation accuracy of each energy amount in order to appropriately manage energy. Hereinafter, the estimation calculation operation of each energy amount reflecting this will be described.

(1) Amount of energy required to travel to the destination (Edrive)
The theoretical energy amount required to travel is calculated from the travel distance to the destination, estimated vehicle speed profile, and gradient information. In addition to this value, the energy required for the electrical equipment consumption of the air conditioner and auxiliary equipment, which is a function of time, is added to the loss that may actually occur, such as gear loss inherent to the vehicle, motor / inverter loss, and brake loss. Thus, the total amount of energy required to reach the destination is calculated.

(2) Amount of electric energy from the battery 4 that you want to use to your destination (Ebat)
In terms of fuel costs and electrical costs, electricity costs are cheaper, so when you get to your destination, it is preferable to use up to your target battery SOC from the viewpoint of running cost. Therefore, the amount of electric energy Ebat (= battery energy) that you want to use to your destination
(Current battery SOC−target battery SOC at the destination) × Battery capacity is calculated.

(3) Minimum engine work required for Engine 1 (Eengine)
The remainder after subtracting the amount of electric energy Ebat (= battery energy amount) that you want to use to the destination from the amount of energy Edrive required to travel to the destination is the minimum amount of work that the engine 1 must work. This value is calculated.

(4) Amount of thermal energy that needs to be input to the catalyst 15 (Ecat)
As for the input energy to the catalyst 15 required for one catalyst warm-up, the energy required for ensuring the catalyst purification performance may be obtained in advance by experiments or the like according to the vehicle and the catalyst 15.
Actually, after the catalyst warm-up is completed, the catalyst temperature is lowered by stopping the engine. This catalyst temperature decrease is predicted by main parameters such as elapsed time, vehicle speed, and outside air temperature, and the timing and amount of energy to be input to the catalyst 15 are calculated again (FIG. 5). By repeating this, the total amount of energy to be input to the catalyst 15 until the destination is calculated (FIG. 6).
More preferably, when the vehicle is stopped or at a low vehicle speed, it is desirable to produce an EV feeling by stopping the engine 1 as much as possible or reducing the load. The engine 1 may be driven actively in the background noise with a lot of traffic. In consideration of these requirements and environmental conditions, it is preferable to create a plurality of patterns of the energy input profile to the catalyst 15.

[Engine operation control by energy management]
As described above, in hybrid vehicles, if engine operation control giving priority to maintaining exhaust performance increases fuel consumption and running costs, exhaust performance cannot be maintained if engine operation control giving priority to improving running costs. . In other words, it is necessary to devise a trade-off between maintaining exhaust performance and improving running costs. Hereinafter, the engine operation control action by energy management reflecting this will be described.

  During the CD mode, a condition that the engine is started with requirements other than the catalyst warm-up, a condition that the engine 1 and the catalyst 15 are not able to secure the original purification processing capacity, and a condition that necessary information to the destination can be assumed. Suppose all are satisfied. When these three start conditions are satisfied, the process proceeds from step S1, step S2, step S3, step S4, step S5, step S6, step S7 and the subsequent steps in the flowchart of FIG. That is, each energy amount is calculated in step S4, and catalyst warm-up control is performed in step S5 and step S6. After step S7, the engine start timing and the driving load of the engine 1 are set based on the engine work amount Eengine and the heat energy amount Ecat so that the thermal energy of the engine 1 is distributed and input to the catalyst 15. Operation is controlled.

That is, engine operation control by energy management including catalyst warm-up is characterized by the following three points.
(a) When engine operation control is started with a requirement other than catalyst warm-up during the CD mode, energy management is performed after catalyst warm-up control is completed.
(b) The engine operation control is performed based on the engine work amount Eengine obtained by subtracting the electric energy amount Ebat from the energy amount Edrive.
(c) Engine operation control is performed based on the thermal energy amount Ecat.

Regarding (a) First, in hybrid vehicles and plug-in hybrid vehicles that aim to run as much EV as possible during the CD mode, the engine is started immediately after starting the vehicle by basic, engine warm-up or catalyst warm-up. Don't do that.
However, when the driving force requirement is high, the battery output cannot be output due to temperature or voltage limitation, the diagnosis requiring the engine start is performed, or the operation is performed when there is an engine start switch etc. In such a case, the engine is started even in the CD mode.
As described above, when the engine is started with a condition other than the warm-up requirement, catalyst warm-up control or the like is performed to increase the catalyst temperature in order to maintain the exhaust performance. Thereafter, when idling stop is performed, as the engine stops, the catalyst temperature decreases and the purification processing capacity of the catalyst deteriorates. Therefore, as described in the problems of Comparative Examples 1 and 2, the engine is restarted to warm the catalyst. The machine was repeated.
On the other hand, in the first embodiment, when the engine is started with a requirement other than the catalyst warm-up requirement during the CD mode, after the catalyst warm-up control is finished, the engine is managed by energy management based on the engine work amount Eengine and the thermal energy amount Ecat. Operation control is performed.
Therefore, for example, if the engine work Eengine and the thermal energy Ecat are satisfied by one catalyst warm-up operation, the engine is not restarted until the destination is reached unless the engine is started due to a catalyst warm-up request. May be.
Thus, by increasing the number of times of catalyst warm-up to one time or the minimum number of times, an increase in fuel consumption due to repeated warm-up control operation is suppressed.

With regard to (b), for example, in a case of traffic jams where low load driving is repeated, surplus power is charged to the battery by repeated catalyst warm-up operation of the engine. In this case, when the battery reaches the destination, the battery SOC that the electric energy that it wants to use up is left unusable, increasing the running cost.
On the other hand, in the first embodiment, when the engine is started due to a request other than the catalyst warm-up, the engine work amount Eengine is obtained by subtracting the electric energy amount Ebat consumed to the destination from the energy amount Edrive required to the destination. Based on this, operation control of the engine 1 is performed.
That is, the operation control of the engine 1 is performed so that the total engine work amount from the current position to the destination reaches the calculated engine work amount Eengine.
Therefore, when the minimum electric energy amount that needs to be left at the destination is set as the target energy amount, the electric energy amount can be used up to the target energy amount when arriving at the destination.

For (c), for example, when monitoring the transition of the battery SOC so that the power can be used efficiently up to the target remaining battery level at the destination, and adjusting the motor-to-engine drive ratio, the engine drive rate and the catalyst temperature transition Therefore, depending on the actual driving scene, the catalyst temperature decreases and the exhaust performance is impaired.
In contrast, in the first embodiment, when the engine is started due to a request other than the catalyst warm-up, the heat that needs to be input to the catalyst 15 to maintain the catalyst temperature at which the purification treatment capacity can be maintained until the destination is reached from the current location. Operation control of the engine 1 is performed based on the energy amount Ecat.
That is, the operation control of the engine 1 is performed so that the total amount of thermal energy from the current location to the destination reaches the calculated thermal energy amount Ecat.
Therefore, until reaching the destination from the present location, the catalyst temperature that can maintain the purification treatment capacity is maintained, and the exhaust performance is maintained.

[Engine operation control when Eengine ≤ Ecat]
In the first embodiment, the engine operation control is divided according to Eengine ≦ Ecat and Eengine> Ecat. Hereinafter, based on FIGS. 2 and 9, the engine operation control action when Eengine ≦ Ecat where the amount of energy input to the catalyst 15 is equal to or greater than the minimum required engine work amount will be described.

In the flowchart of FIG. 2, when the catalyst warm-up control by the engine 1 is completed in step S6 and it is determined in step S7 that Eengine ≦ Ecat, the process proceeds from step S7 to step S12 → step S13 → end. . In step S12, following the end of the catalyst warm-up control, the engine power generation operation is continued until the work amount of the engine 1 reaches the calculated minimum required engine work amount Eengine. Stop.
That is, as shown in FIG. 9 (a), when Eengine ≦ Ecat, the amount of energy that is deficient to the destination is collectively obtained by the engine power generation operation. The aim is to stop the engine after the warm-up of the catalyst, thereby minimizing energy loss due to engine start due to a decrease in the catalyst temperature and annoyance as much as possible.

  Therefore, in the time chart of FIG. 9B, when the catalyst warm-up control started at time t1 ends at time t2, the engine power generation operation is started without stopping the engine 1. Then, the engine power generation operation is continued until the time t3 when the total work amount of the engine 1 becomes the minimum required engine work amount Eengine, and the engine 1 is kept stopped from the time t3 until the time t4 arriving at the destination. That is, as shown by arrow A in FIG. 9 (b), during the CD mode, the engine is started with requirements other than warm-up, and when entering the warm-up mode, until the engine is stopped, The amount of energy that is insufficient is generated together.

  In this way, until the destination is reached, the amount of energy taken out from the battery 4 can be used to cover all of the basics. After that, even if the catalyst temperature decreases due to engine shutdown, the engine can be started with warm-up requirements. Except for this, the engine 1 is not started. For this reason, the number of times of catalyst warm-up can be limited to one time so that engine restart due to other than the warm-up requirement may not be performed. Then, the total work amount of the engine 1 performed between time t1 and time t3 matches the minimum required engine work amount Eengine, so that the destination as shown by the arrow B in FIG. The battery SOC at the time of arriving at has been used up to the target battery SOC.

  As described above, the EV travel section can be secured thereafter by combining the minimum required engine work Eengine into one engine operation. For example, a high-speed road, a place with a lot of background noise, a noisy area other than an EV, and a single engine operation in front of a prohibited area except for an EV. You can run on EV.

[Engine operation control when Eengine> Ecat]
In the first embodiment, the engine operation control is divided according to Eengine ≦ Ecat and Eengine> Ecat. The engine operation control operation when Eengine> Ecat where the minimum required engine work amount is larger than the amount of energy input to the catalyst 15 will be described below with reference to FIGS.

  In the flowchart of FIG. 2, when the catalyst warm-up control by the engine 1 is completed in step S6 and it is determined in step S7 that Eengine> Ecat, step S7 to step S8 → step S9 → step S10 → step Proceed to S11. Then, while it is determined that the destination has not been reached in step S11, the flow of going from step S9 to step S10 to step S11 is repeated, and it is determined that the destination has not been reached in step S11. Then, the process proceeds from step S11 to the end. In step S8, a heat energy input schedule and an engine operation schedule for the catalyst 15 are determined. In step S9, engine operation control is performed according to the switching control. In step S10, the gap between the intermediate target and the current performance is calculated, and the engine operation schedule is corrected according to the gap.

  That is, when Eengine> Ecat as shown in FIG. 10 (a), the engine total work to the destination is set to the minimum required engine work Eengine, triggered by the engine starting once in the CD mode. Control that repeats operation and stop of the engine 1 is performed. The aim is to switch from basic control with CD mode = EV running and CS mode = HEV running to consistent control with CD mode = CS mode = HEV running to suppress a decrease in catalyst temperature.

  Therefore, in the time chart of FIG. 10B, when the catalyst warm-up control started at time t1 ends at time t2, the engine 1 is stopped from time t2 to time t3. Thereafter, the engine operation and the engine stop are repeated until time t19 when the vehicle arrives at the destination, such as engine operation at time t3 to t4 and engine stop at time t4 to t5. That is, as shown by an arrow C in FIG. 10 (b), during the CD mode, when the engine is started with a requirement other than warm-up and enters the warm-up mode, the engine operation and the engine are required until the destination is reached. Repeat the stop. At this time, the total operation time of the engine 1 is determined to be the minimum required engine work amount Eengine, and the start timing of the engine operation is the timing before the catalyst temperature is lowered to the minimum temperature that maintains the purification function. To be.

  As described above, since the catalyst warm-up control is performed by starting the engine with the requirements other than the warm-up before the repeated catalyst warm-up, the catalyst temperature can be increased to the catalyst temperature at which the purification processing capability of the catalyst 15 can be maintained at an early stage. . Based on the thermal energy input schedule, the engine operation schedule is determined as to when the engine work amount Eengine that must be worked at least before the arrival at the destination is distributed and worked. For this reason, it is possible to suppress fuel deterioration due to repeated catalyst warm-up while ensuring exhaust performance. Then, the total work amount of the engine 1 performed between the time t1 and the time t19 coincides with the minimum required engine work amount Eengine, so that as shown by an arrow D in FIG. The battery SOC at the time of arriving at has been used up to the target battery SOC.

Further, in the first embodiment, when the engine is started due to a request other than the catalyst warm-up, each energy amount is calculated. However, even when engine operation control is started, each energy amount is always calculated, The situation is monitored. Then, the intermediate target and the current gap are grasped, and the engine operation schedule and the thermal energy input schedule to the catalyst 15 are corrected based on the contents of the gap (step S10).
Therefore, the deviation between the target and the current is always grasped, and the engine start timing and the engine driving load are corrected. For this reason, in the actual traffic environment which changes every moment, it becomes possible to exhibit the aim effect of suppressing the increase in fuel consumption and improving the running cost while maintaining the exhaust performance with higher accuracy.

Next, the effect will be described.
In the control device for the plug-in hybrid vehicle of the first embodiment, the following effects can be obtained.

(1) an engine 1 having a catalyst 15 for purifying exhaust gas in an exhaust system and driven by fuel supply from a fuel tank 14;
A drive motor 3 (motor) for driving the drive wheels 6 and 6 by at least power supply from the battery 4;
Engine work that estimates and calculates the engine work Eengine required for traveling from the current location to the destination based on the difference between the amount of energy Edrive required from the current location to the destination and the amount of electrical energy Ebat consumed to the destination. Quantity calculation means (step S4);
Thermal energy amount calculating means (step S4) for estimating and calculating a thermal energy amount Ecat that needs to be input to the catalyst 15 in order to maintain the catalyst temperature at which the purification treatment capacity can be maintained until the destination is reached from the current location;
An engine operation control means (FIG. 2) for controlling the operation of the engine 1 based on the estimated engine work amount Eengine and the thermal energy amount Ecat when the engine is started due to a request other than the catalyst warm-up;
Is provided.
For this reason, it is possible to suppress the increase in fuel consumption and improve the running cost while maintaining the exhaust performance.

(2) The engine operation control means (FIG. 2), when the thermal energy amount Ecat is equal to or greater than the engine work amount Eengine (NO in step S7), when the engine 1 is started due to a request other than catalyst warm-up, The operation of the engine 1 is continued to warm up the catalyst (step S12).
For this reason, in addition to the effect (1), when the thermal energy amount Ecat is equal to or greater than the engine work amount Eengine, it is possible to prevent the engine start from being repeated frequently for warming up the catalyst.

(3) The engine operation control means (FIG. 2) calculates the total engine work amount by the engine work amount estimation calculation means (step S4) without stopping the engine 1 even when the catalyst warm-up control is finished. The operation of the engine 1 is continued until the engine work amount Eengine is reached (step S12, step S13).
For this reason, in addition to the effect of the above (2), the EV travel section can be secured thereafter by combining the minimum required engine work Eengine including the catalyst warm-up into one engine operation.

(4) The engine operation control means (FIG. 2) uses the engine 1 as a trigger when the engine work amount Eengine is greater than the thermal energy amount Ecat and is triggered by a request other than catalyst warm-up. The engine on / off control is repeated until the engine is operated and stopped.
For this reason, in addition to the effects (2) and (3) above, when the engine work Eengine is larger than the thermal energy Ecat, the engine can be switched to a consistent engine on / off control after engine startup due to a request other than catalyst warm-up. Further, it is possible to suppress a decrease in the catalyst temperature.

(5) The engine operation control means (FIG. 2) is configured to calculate the engine work amount estimation calculation while maintaining the minimum temperature at which the purification function of the catalyst 15 is maintained as the catalyst temperature. The thermal energy input schedule to the catalyst 15 is determined so as to be the engine work amount Eengine calculated by the means (step S4), and the engine 1 is operated based on the thermal energy input schedule to the catalyst 15. Determine the engine operation schedule that repeatedly stops.
For this reason, in addition to the effect of (4) above, the engine on / off control is performed according to the engine operation schedule determined based on the catalyst purification function and the minimum required engine work, thereby ensuring high exhaust performance and running. It is possible to achieve both cost improvement.

(6) The engine operation control means (FIG. 2) predicts a decrease in the catalyst temperature when the engine is stopped by adding outside air temperature information and vehicle speed information to the elapsed time after the engine is stopped (FIG. 5), Determine the heat energy input schedule.
For this reason, in addition to the effect of (5) above, a highly accurate thermal energy input schedule can be determined by accurately estimating the temperature transition that can ensure the purification treatment capability of the catalyst 15.

(7) The engine operation control means (FIG. 2) monitors the current situation by repeatedly calculating the engine work amount Eengine and the thermal energy amount Ecat after starting the engine due to a request other than catalyst warm-up. Then, the intermediate target and the current gap are calculated, and the engine operation schedule is corrected according to the gap.
For this reason, in addition to the effects (4) to (6) above, in the actual traffic environment that changes every moment, the effect of aiming to increase the fuel consumption and improve the running cost while maintaining the exhaust performance Can be exhibited with higher accuracy.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

In the first embodiment, an example in which engine operation control by energy management including catalyst warm-up is started in the CD mode is shown. However, the engine operation control by energy management including catalyst warm-up may be started after waiting for the transition from the CD mode to the CS mode. Furthermore, when the condition is satisfied in at least one of the low vehicle speed range condition including the stop of the vehicle and the CD mode condition in which the battery SOC is large, the engine load in the engine operation control is reduced as compared with the case where these conditions are not satisfied. It is good also as an example which makes it low.
That is, basically, control is performed so that the catalyst temperature does not fall below a temperature at which the exhaust purification treatment capability can be maintained, and the total engine work does not exceed the minimum engine work. However, it is preferable to maintain EV driving as much as possible when the vehicle is at a stop or when the vehicle speed is low, or when it is equivalent to the CD mode, which is EV driving. Therefore, in such a case, control is performed to stop the engine or to reduce the engine load. Then, it is preferable to control the engine start timing and the engine driving load so that the engine can be operated as much as possible in the case of high-speed, high background noise that is not noticeable even when engine noise is generated, and high background traffic.

  In the first embodiment, an example is shown in which the control device of the present invention is applied to a series-type plug-in hybrid vehicle including a generator motor and a drive motor (two motors). However, the control device of the present invention is also applied to a parallel type plug-in hybrid vehicle having two motors, a parallel type plug-in hybrid vehicle having a motor generator (one motor) for both power generation and driving, and the like. be able to. Furthermore, even in a hybrid vehicle that cannot be plug-in charged, for example, a hybrid vehicle that requires measures for warming up the catalyst by frequently using EV driving, such as a parallel hybrid vehicle that cannot be plug-in charged. It can also be applied to. That is, all hybrid vehicles such as series, parallel, and plug-in are targeted.

1 Engine 2 Generator motor 3 Drive motor (motor)
4 Battery 5 Deceleration Differential Mechanism 6 Drive Wheel 7 Generator Motor Inverter 8 Drive Motor Inverter 9 Charge Converter 10 Switch 11 Charge Port 14 Fuel Tank 15 Catalyst 20 Engine Controller 21 Generator Controller 22 Motor Controller 23 Battery Controller 24 Vehicle Integration Controller 25 Navigation controller

Claims (7)

An engine having a catalyst for purifying exhaust gas in an exhaust system and driven by fuel supply from a fuel tank;
A motor that drives the drive wheels by supplying power from at least a battery;
Engine work calculation means that estimates and calculates the engine work required to travel from the current location to the destination based on the difference between the amount of energy required from the current location to the destination and the amount of electrical energy consumed by the destination. When,
Thermal energy amount calculation means for estimating and calculating the amount of thermal energy that needs to be input to the catalyst to maintain the purification treatment capacity from the current location until reaching the destination;
Engine operation control means for controlling the operation of the engine based on the estimated engine work amount and the thermal energy amount when starting the engine due to a request other than catalyst warm-up;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
The engine operation control means continues the operation of the engine for catalyst warm-up when the engine is started due to a request other than catalyst warm-up when the amount of heat energy is equal to or greater than the engine work. A control device for a hybrid vehicle. In the hybrid vehicle control device according to claim 2,
The engine operation control means does not stop the engine even when the catalyst warm-up control is finished, and until the total engine work reaches the engine work calculated by the engine work estimation calculation means. A control apparatus for a hybrid vehicle, characterized by continuing driving. In the hybrid vehicle control device according to claim 2 or 3,
The engine operation control means performs engine on / off control that repeats operation and stop of the engine, triggered by the start of the engine due to a request other than catalyst warm-up when the engine work amount is greater than the thermal energy amount A control apparatus for a hybrid vehicle characterized by the above. In the hybrid vehicle control device according to claim 4,
The engine operation control means maintains the minimum temperature at which the purification function of the catalyst is maintained as a catalyst temperature, and the engine work to the destination is calculated by the engine work estimation calculation means. A hybrid vehicle characterized in that a thermal energy input schedule to the catalyst is determined so as to be an amount, and an engine operation schedule that repeats operation and stop of the engine is determined based on the thermal energy input schedule to the catalyst. Control device. In the hybrid vehicle control device according to claim 5,
The engine operation control means predicts a decrease in catalyst temperature when the engine is stopped by adding outside air temperature information and vehicle speed information to an elapsed time after the engine is stopped, and determines the thermal energy input schedule. A control device for a hybrid vehicle. In the hybrid vehicle control device according to any one of claims 4 to 6,
The engine operation control means, after starting the engine due to a request other than the catalyst warm-up, monitors the current situation by repeatedly performing the estimation calculation of the engine work amount and the thermal energy amount, and sets the gap between the intermediate target and the current point of time. A control device for a hybrid vehicle, characterized by calculating and correcting an engine operation schedule according to a gap.