Vehicle control system

Abstract

To inhibit an internal combustion engine from starting before finishing warming-up of a catalyst device.SOLUTION: A vehicle control device 4 for controlling a hybrid vehicle 100 is configured to perform the following: warming up a catalyst device 15 when a battery charge amount becomes less than a second charge amount larger than a predetermined first charge amount; on the basis of the first charge amount, a first electric energy amount which is an estimate value for an electric energy amount used to run the hybrid vehicle 100 during warming-up of the catalyst device 15, and a second electric energy amount which is an estimate value for an electric energy amount used to heat a conductivity base material 151, setting the second charge amount; on the basis of a change amount per unit time for a battery charge amount, and a warming-up time required to finish warming-up of the catalyst device 15 when a resistance value of the conductivity base material 151 is a predetermined initial resistance value, calculating the first electric energy amount; and when the resistance value of the conductivity base material 151 is increased from the initial resistance value, increasing the warming-up time for correction on the basis of the increased resistance value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a vehicle control device. [Background technology]

[0002] Patent Document 1 discloses a control device for a hybrid vehicle that starts energizing a conductive substrate when the battery charge level drops to a predetermined warm-up start charge level, and sets the warm-up start charge level so that the catalytic converter can be electrically heated prior to starting the internal combustion engine. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-196408 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, as the resistance of the conductive substrate increases due to aging or other factors, the power supplied to the conductive substrate decreases by the same amount as the increase in resistance. This increases the time required to complete the warm-up of the catalytic converter, i.e., the heating time during which the catalytic converter is electrically heated. Therefore, if the warm-up start charge amount is set without considering the resistance of the conductive substrate, even if the heating of the catalytic converter is started prior to the start of the internal combustion engine, the battery charge may drop more than expected before the catalytic converter is fully warmed up, potentially requiring the internal combustion engine to be started.

[0005] This invention addresses these problems and aims to prevent the internal combustion engine from starting before the catalytic converter has finished warming up. [Means for solving the problem]

[0006] In order to solve the above problems, a hybrid vehicle according to an aspect of the present invention includes an internal combustion engine, an electric heating type catalyst device in which a catalyst is supported on a conductive base material provided in an exhaust passage of the internal combustion engine and heated by being energized, a rechargeable battery, and a rotating electric machine driven by the power of the battery. And a vehicle control device for controlling this hybrid vehicle supplies power to the conductive base material to warm up the catalyst device when the charge amount of the battery becomes less than a second charge amount greater than a predetermined first charge amount when traveling by the power of the rotating electric machine with the internal combustion engine stopped. The second charge amount is set based on the first charge amount, a first power amount which is an estimated value of the power amount used to drive the hybrid vehicle during warm-up of the catalyst device, and a second power amount which is an estimated value of the power amount used to heat the conductive base material. The first power amount is calculated based on the change amount of the charge amount of the battery per unit time and the warm-up time required to complete the warm-up of the catalyst device when the resistance value of the conductive base material is a predetermined initial resistance value. When the resistance value of the conductive base material increases from the initial resistance value, the warm-up time is increased and corrected based on the increased resistance value.

Effect of the Invention

[0007] According to this aspect of the present invention, since the warm-up time can be increased and corrected and the second charge amount can be increased by the amount by which the resistance value of the conductive base material increases from the initial resistance value, it is possible to suppress the battery charge amount from decreasing to the first charge amount before the warm-up of the catalyst device is completed. Therefore, it is possible to suppress the internal combustion engine from starting before the warm-up of the catalyst device is completed.

Brief Description of the Drawings

[0008] [Figure 1] It is a schematic perspective view of a hybrid vehicle according to a first embodiment of the present invention. [Figure 2] It is a diagram showing the relationship between the battery charge amount and the switching load. [Figure 3] It is a flowchart for explaining the setting process of the warm-up start charge amount SOC2 according to the first embodiment of the present invention. [Figure 4] This figure shows a table for calculating the additional heating time tad based on the actual resistance value Rc. [Figure 5] This is a time chart showing the operation of catalyst warm-up control according to the first embodiment of the present invention. [Figure 6] This is a flowchart illustrating the process for setting the warm-up start charge amount (SOC2) according to a second embodiment of the present invention. [Figure 7] This figure shows a table for calculating the correction coefficient α based on vehicle speed. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, similar components will be given the same reference numerals.

[0010] (First Embodiment) Figure 1 is a schematic diagram of a hybrid vehicle (HEV (Hybrid Electric Vehicle) or PHEV (Plug-in Hybrid Electric Vehicle)) 100 according to a first embodiment of the present invention.

[0011] The hybrid vehicle 100 comprises an internal combustion engine 1, a battery 3, a drive motor 2 which is driven by either or both of the power generated using the power of the internal combustion engine 1 and the power stored in the battery 3, and an electronic control unit 4, and is configured to be able to move by transmitting the power of at least one of the internal combustion engine 1 and the drive motor 2 to a wheel drive shaft (not shown).

[0012] The internal combustion engine 1 includes an exhaust passage 12 for discharging exhaust gas (combustion gas) generated inside the engine body 11 to the outside, and an electrically heated catalyst (EHC) 15 for purifying the exhaust gas.

[0013] The electrically heated catalyst device 15 comprises a conductive substrate 151, a pair of electrodes 152, a voltage adjustment circuit 153, a voltage sensor 154, and a current sensor 155.

[0014] The conductive substrate 151 is formed from a material that generates heat when an electric current is passed through it, such as silicon carbide (SiC) or molybdenum disilicide (MoSi2). The conductive substrate 151 has multiple passages (hereinafter referred to as "unit cells") with a lattice-shaped (or honeycomb-shaped) cross-section formed along the direction of exhaust gas flow, and a catalyst (for example, an oxidation catalyst (two-way catalyst) or a three-way catalyst) is supported on the surface of each unit cell.

[0015] The pair of electrodes 152 are components for applying voltage to the conductive substrate 151. Each electrode 152 is electrically connected to the conductive substrate 151 and is also connected to the battery 3 via a voltage adjustment circuit 153. By applying voltage to the conductive substrate 151 through the pair of electrodes 152, current flows through the conductive substrate 151, causing the conductive substrate 151 to heat up and the catalyst supported on the conductive substrate 151 to be heated.

[0016] The voltage applied to the conductive substrate 151 by the pair of electrodes 152 (hereinafter referred to as "substrate applied voltage") can be adjusted by controlling the voltage adjustment circuit 153 with the electronic control unit 4. For example, it is possible to apply the voltage of the battery 3 directly, or to apply the voltage of the battery 3 after boosting or bucking it to an arbitrary voltage. Thus, in this embodiment, the power supplied to the conductive substrate 151 can be controlled to any desired power by controlling the voltage adjustment circuit 153 with the electronic control unit 4.

[0017] The voltage sensor 154 detects the substrate applied voltage. In this embodiment, the substrate applied voltage detected by the voltage sensor 154 is adjusted so that the substrate applied voltage becomes a predetermined rated voltage. 、 The voltage regulation circuit 153 is controlled.

[0018] The current sensor 155 detects the value of the current flowing through the conductive substrate 151 when a voltage is applied to the conductive substrate 151.

[0019] The electronic control unit 4 is a microcomputer equipped with a central processing unit (CPU), memory such as read-only memory (ROM) and random access memory (RAM), input ports, and output ports, all interconnected by a bidirectional bus.

[0020] In addition to the voltage sensor 154 and current sensor 155 mentioned above, the electronic control unit 4 receives output signals from various sensors, including a load sensor 41 that generates an output voltage proportional to the amount the accelerator pedal is pressed, a SOC sensor 42 for detecting the battery charge level (hereinafter referred to as "battery charge level") (SOC), and a speed sensor 43 for detecting the speed of the hybrid vehicle 100 (hereinafter referred to as "vehicle speed").

[0021] The electronic control unit 4 controls the hybrid vehicle 100 by driving various control components based on the output signals from various sensors that are input to it. The control of the hybrid vehicle 100 performed by the electronic control unit 4 will be described below.

[0022] The electronic control unit 4 operates the hybrid vehicle 100 by switching the driving mode to either CD (Charge Depleting) mode or CS (Charge Sustaining) mode based on the battery charge amount (SOC). Specifically, if the battery charge amount is equal to or greater than a predetermined mode switching charge amount (SOC1, for example, 10% of the full charge), the electronic control unit 4 sets the driving mode of the hybrid vehicle 100 to CD mode, and if it is less than the mode switching charge amount (SOC1), it sets the driving mode of the hybrid vehicle 100 to CS mode. The mode switching charge amount (SOC1) may be the lower limit of the acceptable battery charge amount (SOC), or it may be a value higher than the lower limit.

[0023] CD mode is a mode in which the charging power of the battery 3 is preferentially used to power the drive motor 2, and at least the power of the drive motor 2 is transmitted to the wheel drive shaft to drive the hybrid vehicle 100.

[0024] When the driving mode is CD mode, the electronic control unit 4 stops the internal combustion engine 1 and uses the power charged by the battery 3 to drive the drive motor 2, thereby propelling the hybrid vehicle 100. In other words, when the driving mode is CD mode, the electronic control unit 4 stops the internal combustion engine 1 and controls the output of the drive motor 2 based on the driving load so that the output corresponds to the required output according to the driving load, thereby propelling the hybrid vehicle 100.

[0025] CS mode is a mode in which the hybrid vehicle 100 is driven so that the battery charge level (SOC) is maintained at the battery charge level at the time the system switches to CS mode (hereinafter referred to as "maintenance charge level").

[0026] When the driving mode is CS mode, the electronic control unit 4 drives the hybrid vehicle 100 using the power of the drive motor 2 with the internal combustion engine 1 stopped if the driving load is less than the switching load. On the other hand, if the driving load is greater than or equal to the switching load, the electronic control unit 4 drives the hybrid vehicle 100 using the power of both the internal combustion engine 1 and the drive motor 2. As shown in Figure 2, the electronic control unit 4 changes the switching load according to the battery charge amount SOC such that the switching load becomes smaller when the battery charge amount SOC is low.

[0027] In this way, when the driving mode is CS mode, the electronic control unit 4 controls the output of the internal combustion engine 1 and the drive motor 2 based on the battery charge amount SOC and the driving load to drive the hybrid vehicle 100 so that the output corresponds to the required output according to the driving load. Since the switching load is low when the battery charge amount SOC is at the mode switching charge amount SOC1, after the battery charge amount SOC drops to the mode switching charge amount SOC1 during vehicle operation and the driving mode switches from CD mode to CS mode, the internal combustion engine 1 will basically be started. Therefore, CS mode can be described as a driving mode that is basically based on the premise of operating the internal combustion engine 1, but allows the hybrid vehicle 100 to be driven using only the output of the drive motor 2 when the thermal efficiency of the internal combustion engine 1 is poor.

[0028] Thus, CS mode is a driving mode that is basically based on the premise of operating the internal combustion engine 1, and after the driving mode switches from CD mode to CS mode, the internal combustion engine 1 will basically be started. The switch from CD mode to CS mode depends on the battery charge level (SOC). When the internal combustion engine 1 is started after switching from CD mode to CS mode, the exhaust gas emitted from the engine body 11 flows through the exhaust passage 12 and is discharged into the atmosphere.

[0029] Harmful substances in the exhaust gas can be purified by the catalyst device 15 when the catalyst device 15 has finished warming up, that is, when the temperature of the conductive substrate 151 (hereinafter referred to as "catalyst bed temperature") TEHC [°C] is above a predetermined activation temperature TEHC2 (for example, 500 [°C]) at which the exhaust gas purification function of the catalyst supported on the conductive substrate 151 is activated.

[0030] On the other hand, immediately after starting the internal combustion engine 1, before the catalyst device 15 has finished warming up, the exhaust gas purification function of the catalyst supported on the conductive substrate 151 begins when the catalyst bed temperature TEHC rises above a predetermined activation start temperature TEHC1 (e.g., 300°C), which is lower than the activation temperature TEHC2. However, the catalyst device 15 cannot sufficiently purify harmful substances in the exhaust gas, resulting in a deterioration of exhaust emissions. Therefore, in order to suppress the deterioration of exhaust emissions after engine start-up, it is desirable to start energizing the conductive substrate 151 during CD mode to start warming up the catalyst device 15, and to complete the warm-up of the catalyst device 15 before switching to CS mode.

[0031] For example, if the battery charge amount SOC decreases to a warm-up start charge amount SOC2, which is greater than the mode switching charge amount SOC1, during CD mode, it is conceivable to start energizing the conductive substrate 151 to warm up the catalyst device 15, and complete the warm-up of the catalyst device 15 during the time when the battery charge amount SOC decreases from the warm-up start charge amount SOC2 to the mode switching charge amount SOC1, that is, during CD mode until switching from CD mode to CS mode.

[0032] However, if the warm-up start charge amount SOC2 is not set to an appropriate value, the battery charge amount SOC may drop to the mode switching charge amount SOC1 before the catalytic converter 15 has finished warming up. In that case, the internal combustion engine 1 may start before the catalytic converter 15 has finished warming up, which may result in a deterioration of exhaust emissions after the internal combustion engine 1 starts up.

[0033] Conversely, there is a risk that the time from when the catalyst device 15 has finished warming up until the battery charge level (SOC) drops to the mode switching charge level (SOC1) may become too long.

[0034] If, after the catalyst device 15 has finished warming up, power is supplied to the conductive substrate 151 to continue heating it until the battery charge level (SOC) drops to the mode switching charge level (SOC1), power will be wasted, and the distance that can be driven in CD mode (hereinafter referred to as "EV driving distance") will be shortened. In addition, the conductive substrate 151 may be overheated, which could accelerate the deterioration of the conductive substrate 151.

[0035] Furthermore, if the driving mode is switched to CS mode when the catalytic converter 15 has finished warming up, the driving mode will be switched to CS mode before the battery charge amount SOC falls below the mode switching charge amount SOC1, resulting in a shorter EV driving range. Also, if the power supply to the conductive substrate 151 is stopped when the catalytic converter 15 has finished warming up, the temperature of the conductive substrate 151 will decrease before the battery charge amount SOC falls below the mode switching charge amount SOC1, which may worsen exhaust emissions after the internal combustion engine 1 is started.

[0036] Here, the amount of heat Q [J], or electrical energy (hereinafter referred to as "electrical energy for substrate heating") W, required to raise the catalyst bed temperature TEHC from an initial temperature TEHC0 to the activation temperature TEHC2 is given. h [Ws] can be expressed by the following equation (1), where C is the heat capacity of the conductive substrate 151.

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[0037] Furthermore, as in this embodiment, the substrate applied voltage V h a constant rated voltage V max When heating the conductive substrate 151 is controlled as follows: Substrate supply power P h This can be expressed by equation (2) below, using the substrate resistance value R.

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[0038] Therefore, when the base material applied voltage V h is controlled to a constant rated voltage V max and the conductive base material 151 is heated, the heating time t h [s] required to raise the catalyst bed temperature TEHC from the initial temperature TEHC0 to the activation temperature TEHC2 can be expressed by the following formula (3). [Equation]

[0039] When starting to energize the conductive base material 151 during the CD mode to warm up the catalyst device 15, in addition to the base material supply power P h supplied to the conductive base material 151 to heat it, the power for driving the driving motor 2 for power running and the power for driving various auxiliary machines such as an air conditioner, that is, the running power P p required to run the hybrid vehicle 100 is also needed.

[0040] Therefore, if the running power amount W h required to run the hybrid vehicle 100 in the CD mode for the heating time t p is used, it is considered that the warm-up start charge amount SOC2 can be set according to, for example, the following formula (4), and when the battery charge amount SOC decreases to the warm-up start charge amount SOC2 during the CD mode, starting to energize the conductive base material 151 to start warming up the catalyst device 15 can appropriately complete the warm-up of the catalyst device 15 during the CD mode until the battery charge amount SOC decreases from the warm-up start charge amount SOC2 to the mode switching charge amount SOC1. [Equation]

[0041] Note that the running power amount W pThis can be calculated, for example, based on equation (5) below. If ΔSOC is the rate of change of the battery charge amount SOC per unit time (hereinafter referred to as "battery change"), then the battery change ΔSOC when the internal combustion engine 1 is not started can be considered as the current driving load of the hybrid vehicle 100. Therefore, the heating time t required to raise the catalyst bed temperature TEHC from the initial temperature TEHC0 to the activation temperature TEHC2 is added to the battery change ΔSOC. h By multiplying these together, we can determine the amount of power used for driving, W, assuming that the driving load remains at the current level. p It is possible to calculate this.

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[0042] However, the conductive substrate 151 may develop microcracks due to aging or other factors, and as a result, the substrate resistance R may increase from the initial resistance R0 at the time of product shipment. In that case, as is clear from equations (2) and (3) above, the substrate power P supplied will increase by the amount by which the substrate resistance R has increased from the initial resistance R0. h The resistance decreases, and as a result, the heating time t increases by the amount that the substrate resistance R rises from the initial resistance R0. h It will be longer.

[0043] heating time t h As the heating time t increases, as is clear from equations (4) and (5) above, h The longer the length, the more power (W) is used for driving. p This increases, and as a result, the warm-up start charge amount SOC2 also increases. In other words, as the substrate resistance value R increases, the amount of electricity required to complete the warm-up of the catalyst device 15 increases.

[0044] Thus, the appropriate value of the warm-up start charge amount SOC2, which is the threshold for initiating current flow to the conductive substrate 151, changes depending on the substrate resistance value R. If the substrate resistance value R is large, the warm-up start charge amount SOC2 must be larger compared to when the substrate resistance value R is small; otherwise, the battery charge amount SOC may drop to the mode switching charge amount SOC1 before the catalyst device 15 is fully warmed up. Therefore, in this embodiment, the warm-up start charge amount SOC2 is set according to the substrate resistance value R, and the catalyst device 15 is warmed up accordingly.

[0045] Figure 3 is a flowchart illustrating the process for setting the warm-up start charge amount (SOC2) according to this embodiment. The electronic control unit 4 repeatedly executes this routine at predetermined calculation cycles.

[0046] In step S1, the electronic control unit 4 determines whether or not the catalyst device 15 requires warming up. In this embodiment, if the catalyst bed temperature TEHC is less than the activation start temperature TEHC1 described above, the electronic control unit 4 determines that the catalyst device 15 requires warming up and proceeds to step S2. On the other hand, if the catalyst bed temperature TEHC is equal to or greater than the activation start temperature TEHC1, the electronic control unit 4 determines that the catalyst device 15 does not require warming up and terminates the current process.

[0047] In step S2, the electronic control unit 4 reads the current substrate resistance value (hereinafter referred to as "actual resistance value") Rc stored in memory. In this embodiment, the electronic control unit 4 temporarily energizes the conductive substrate 151 each time the hybrid vehicle 100 is started, and stores the substrate resistance value R detected at that time in memory as the actual resistance value Rc.

[0048] In step S3, the electronic control unit 4 determines the standard heating time t required to raise the catalyst bed temperature TEHC from the current temperature, i.e., the initial temperature TEHC0, to the activation temperature TEHC2, assuming that the substrate resistance value R is the initial resistance value R0. pre Calculate the standard heating time t. pre This can be calculated, for example, based on equations (1) to (3) above. Also, the standard heating time tpre Since this value changes depending on the initial temperature TEHC0 of the catalyst bed temperature TEHC, it may be calculated according to the initial temperature TEHC0 by referring to a table or the like that created in advance through experiments or other means. The current temperature of the catalyst bed temperature TEHC (initial temperature TEHC0) may be detected directly by a temperature sensor, for example, or it may be estimated based on ambient temperature, engine coolant temperature, engine lubricating oil noise, etc.

[0049] In step S4, the electronic control unit 4 refers to the table in Figure 4, which was prepared in advance through experiments, and determines the additional heating time t required to complete the warm-up of the catalyst device 15 (i.e., the time required to raise the catalyst bed temperature TEHC from the current temperature (initial temperature TEHC0) to the activation temperature TEHC2) based on the actual resistance value Rc. ad Calculate the additional heating time t. ad In other words, the standard heating time t pre This is the increase correction amount for . As shown in the table in Figure 4, the additional heating time t ad This value is 0 if the actual resistance Rc is the same as the initial resistance R0, and increases as the actual resistance Rc becomes higher than the initial resistance R0. Note that the shape of the table in Figure 4 is just one example, and its shape may be linear, nonlinear, or stepped.

[0050] In step S5, the electronic control unit 4 calculates the battery change amount ΔSOC and sets the warm-up start charge amount SOC2 based on equation (6) below. In equation (6), the second term on the right-hand side is the driving energy amount W. p It corresponds to this.

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[0051] Figure 5 is a time chart illustrating the operation of the warm-up control of the catalyst device 15 according to this embodiment. In Figure 5, the solid lines (C) and (D) show the operation when the warm-up start charge amount SOC2 is increased according to the actual resistance value Rc, that is, when the warm-up start charge amount SOC2 is set based on equation (6) above. On the other hand, the dashed lines (C) and (D) show the operation when the warm-up start charge amount SOC2 is set based on equations (1) to (5) above, without considering the change in the base material resistance value R, for example assuming that the base material resistance value R is the initial resistance value R0.

[0052] As shown in Figure 5, according to this embodiment, the additional heating time t is calculated by the amount by which the actual resistance value Rc becomes higher than the initial resistance value R0. ad This allows the warm-up start charge amount SOC2 to be increased. Therefore, it is possible to prevent the battery charge amount SOC from dropping to the mode switching charge amount SOC1 before the catalytic converter 15 has finished warming up. Consequently, it is possible to prevent the internal combustion engine 1 from starting before the catalytic converter 15 has finished warming up, thus suppressing the deterioration of exhaust emissions after the internal combustion engine 1 has started.

[0053] The hybrid vehicle 100 according to this embodiment, as described above, comprises an internal combustion engine 1, an electrically heated catalytic converter 15 in which a catalyst is supported on a conductive substrate 151 that generates heat when energized and is provided in the exhaust passage 12 of the internal combustion engine 1, a rechargeable battery 3, and a drive motor 2 (rotating electric machine) driven by the power of the battery 3. The electronic control unit 4 (vehicle control device) for controlling the hybrid vehicle 100 supplies power to the conductive substrate 151 to warm up the catalytic converter 15 when the battery charge amount SOC falls below the warm-up start charge amount SOC2 (second charge amount), which is greater than the mode switching charge amount SOC1 (first charge amount), while the vehicle is running on the power of the drive motor 2 with the internal combustion engine 1 stopped. The mode switching charge amount SOC1 and the estimated amount of electricity used to run the hybrid vehicle 100 during the warm-up of the catalytic converter 15 are the driving power amount W. p (First energy) and the estimated energy used to heat the conductive substrate 151, which is the energy W for substrate heating.h Based on (second energy), the warm-up start charge amount SOC2 is set, and the battery change amount ΔSOC and the standard heating time t required to complete the warm-up of the catalyst device 15 when the base material resistance value R is a predetermined initial resistance value R0 are used. pre Based on (warm-up time), the amount of power used for driving is W. p The standard heating time t is calculated based on the increased resistance value. When the substrate resistance R increases from the initial resistance R0, the standard heating time t is calculated based on the increased resistance value. pre It is configured to amplify and correct the value.

[0054] Thus, according to this embodiment, the standard heating time t increases by the amount that the substrate resistance value R becomes higher than the initial resistance value R0. pre By increasing and correcting this, the warm-up start charge amount SOC2 can be made larger. Therefore, it is possible to suppress the battery charge amount SOC from dropping to the mode switching charge amount SOC1 before the catalytic converter 15 has finished warming up. Consequently, it is possible to suppress the internal combustion engine 1 from starting before the catalytic converter 15 has finished warming up, and thus the deterioration of exhaust emissions after the internal combustion engine 1 has started can be suppressed.

[0055] (Second Embodiment) Next, a second embodiment of the present invention will be described. In this embodiment, an additional heating time t is added depending on the vehicle speed of the hybrid vehicle 100. ad This differs from the first embodiment in that it adjusts the length. The following will focus on explaining these differences.

[0056] When the vehicle speed of the hybrid vehicle 100 is high, the driving load, i.e., the battery change amount ΔSOC, tends to fluctuate more easily compared to when the vehicle speed is low, and the battery charge amount SOC may drop more sharply than expected. Therefore, when the vehicle speed of the hybrid vehicle 100 is high, if the warm-up start charge amount SOC2 is not set higher than when the vehicle speed is low, the battery charge amount SOC may drop sharply during warm-up, falling below the mode switching charge amount SOC1, and there is a risk that the internal combustion engine 1 will have to be started.

[0057] Therefore, in this embodiment, an additional heating time t is given according to the vehicle speed of the hybrid vehicle 100. ad We decided to adjust the length. The process for setting the warm-up start charge amount SOC2 according to this embodiment will be explained below with reference to Figure 6.

[0058] Figure 6 is a flowchart illustrating the process for setting the warm-up start charge amount (SOC2) according to this embodiment.

[0059] In step S21, the electronic control unit 4 refers to the table in Figure 7 and determines the additional heating time based on the vehicle speed. ad A correction coefficient α is calculated to be multiplied by this. The correction coefficient α can take values ​​from 0 to 1. As shown in the table in Figure 7, in this embodiment, when the vehicle speed is less than a predetermined first vehicle speed, the correction coefficient α is set to 0, and the additional heating time ad This is set to 0. Then, while the vehicle speed is between the first vehicle speed and a predetermined second vehicle speed, the correction coefficient α is set to a value between 0 and 1 such that the correction coefficient α increases as the vehicle speed increases, and when the vehicle speed is the second vehicle speed or higher, the correction coefficient α is set to 0. Note that the vehicle speed may be the current value or the most recent average value.

[0060] In step S22, the electronic control unit 4 sets the warm-up start charge amount SOC2 based on equation (7) below.

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[0061] Thus, in this embodiment, when the vehicle speed is low, the standard heating time t is lower compared to when it is high. pre The additional heating time is the amount of correction for the increase. ad To reduce the size, the standard heating time t preThis is further corrected based on vehicle speed. As a result, at high vehicle speeds where the battery change amount ΔSOC is prone to fluctuations, the warm-up start charge amount SOC2 can be set to a higher value. Therefore, even if the battery charge amount SOC drops sharply during warm-up, it is possible to prevent the battery charge amount SOC from falling below the mode switching charge amount SOC1. This prevents the need to start the internal combustion engine 1 during warm-up, thereby suppressing the deterioration of exhaust emissions.

[0062] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0063] For example, in the second embodiment described above, additional heating time ad By multiplying this by a correction factor α, an additional heating time t is calculated according to the vehicle speed. ad The length was being adjusted, but simply put, when the vehicle speed is less than the first vehicle speed, an additional heating time t ad Set to 0, and when the vehicle speed is equal to or greater than the first vehicle speed, an additional heating time t ad Without correction, the warm-up start charge amount SOC2 may be set based on equation (6). That is, when the vehicle speed is less than the first vehicle speed, even if the base material resistance value R has increased from the initial resistance value R0, the standard heating time t pre The additional heating time is the amount of correction for the increase. ad The electronic control unit 4 may be configured to set this value to zero.

[0064] Furthermore, in each of the above embodiments, the computer program executed in the electronic control unit 4 may be provided in the form of a computer-readable portable recording medium, such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. [Explanation of Symbols]

[0065] 1. Internal combustion engine 2. Motor for driving (rotating electric machine) 3 Batteries 12 Exhaust passage 15 Catalyst device 100 Hybrid Vehicles 151 Conductive substrate

Claims

1. Internal combustion engines and An electrically heated catalyst device is provided in the exhaust passage of the internal combustion engine, and comprises a conductive substrate that generates heat when an electric current is passed through it, on which a catalyst is supported. A rechargeable battery, A rotating electric machine powered by the aforementioned battery, A vehicle control device for controlling a hybrid vehicle equipped with the following: When the internal combustion engine is stopped and the vehicle is being driven by the power of the rotating electric machine, if the charge level of the battery falls below a second charge level that is greater than a predetermined first charge level, power is supplied to the conductive substrate to warm up the catalyst device. Based on the first charge amount, the first energy amount which is an estimated value of the amount of energy used to run the hybrid vehicle while the catalyst device is warming up, and the second energy amount which is an estimated value of the amount of energy used to heat the conductive substrate, the second charge amount is set. Based on the change in the amount of charge of the battery per unit time and the warm-up time required to complete the warm-up of the catalyst device when the resistance value of the conductive substrate is a predetermined initial resistance value, the first amount of energy is calculated. When the resistance value of the conductive substrate increases from the initial resistance value, the warm-up time is corrected by increasing the value based on the increased resistance value. The system is configured to further correct the warm-up time based on the vehicle speed, such that when the vehicle speed is low, the amount of increase correction applied to the warm-up time is smaller compared to when the vehicle speed is high. Vehicle control device.

2. An internal combustion engine, An electrically heated catalyst device is provided in the exhaust passage of the internal combustion engine, and comprises a conductive substrate that generates heat when an electric current is passed through it, on which a catalyst is supported. A rechargeable battery, A rotating electric machine powered by the aforementioned battery, A vehicle control device for controlling a hybrid vehicle equipped with the following: When the internal combustion engine is stopped and the vehicle is being driven by the power of the rotating electric machine, if the charge level of the battery falls below a second charge level that is greater than a predetermined first charge level, power is supplied to the conductive substrate to warm up the catalyst device. Based on the first charge amount, the first energy amount which is an estimated value of the amount of energy used to run the hybrid vehicle while the catalyst device is warming up, and the second energy amount which is an estimated value of the amount of energy used to heat the conductive substrate, the second charge amount is set. Based on the change in the amount of charge of the battery per unit time and the warm-up time required to complete the warm-up of the catalyst device when the resistance value of the conductive substrate is a predetermined initial resistance value, the first amount of energy is calculated. When the resistance value of the conductive substrate increases from the initial resistance value, the warm-up time is corrected by increasing the value based on the increased resistance value. When the vehicle speed is below a predetermined vehicle speed, even if the resistance value of the conductive substrate has increased from the initial resistance value, the increase correction amount for the warm-up time is set to zero. Vehicle control device.

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