Hybrid vehicle and power determination method

Abstract

To inhibit discharge of ammonia.SOLUTION: A vehicle S includes: a first determination unit 223 that determines a fuel injection quantity of an engine 2 and a motor torque generated by a motor 5 on the basis of an opening degree of an accelerator; a second determination unit 224 that determines a correction coefficient for correcting the fuel injection quantity and the motor torque on the basis of a temperature of a catalyst 3 that purifies NOx contained in exhaust gas of the engine 2 by reacting the NOx with ammonia which is contained in urea water injected into the exhaust gas, and an SOC of a battery 6 that supplies electricity to the motor 5; and a calculation unit 226 that calculates a corrected fuel injection quantity that is smaller than the fuel injection quantity and a corrected motor torque that is larger than the motor torque on the basis of the correction coefficient.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a hybrid vehicle and a power determination method for determining the power of a drive source provided in the hybrid vehicle. [Background technology]

[0002] The hybrid electric vehicle of Patent Document 1 improves the NOx purification rate of the catalyst by controlling the magnitude of the motor and engine output based on the temperature of the catalyst that purifies the NOx contained in the exhaust and the load required of the hybrid electric vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-227888 Summary of the Invention [Problem to be solved by the invention]

[0004] The catalyst in Patent Document 1 adsorbs ammonia contained in urea water injected into the exhaust gas, and reacts the ammonia with NOx contained in the exhaust gas to reduce it to nitrogen and water, thereby suppressing NOx emissions. The amount of ammonia that the catalyst can adsorb decreases as the catalyst temperature increases. Therefore, when the amount of output change is large when increasing the engine output, the catalyst temperature also rises sharply as the exhaust temperature rises, causing a sudden decrease in the amount of ammonia that the catalyst can adsorb, resulting in ammonia being desorbed from the catalyst and emitted.

[0005] The present invention has been made in view of these points, and has an object to suppress the emission of ammonia. [Means for solving the problem]

[0006] A hybrid vehicle according to a first aspect of the present invention has a first determination unit that determines the amount of fuel injection for the engine and the motor torque generated by the motor based on the degree of accelerator opening; a second determination unit that determines a correction coefficient for correcting the fuel injection amount and the motor torque based on the temperature of a catalyst that purifies NOx contained in the exhaust of the engine by reacting it with ammonia contained in urea water injected into the exhaust and the charging rate of a battery that supplies electricity to the motor; and a calculation unit that calculates a corrected fuel injection amount that is smaller than the fuel injection amount and a corrected motor torque that is greater than the motor torque based on the correction coefficient.

[0007] The second determination unit may increase the correction coefficient as the temperature of the catalyst decreases, and the calculation unit may decrease the correction fuel injection amount and increase the correction motor torque as the correction coefficient increases.

[0008] The second determination unit may increase the correction coefficient as the charging rate of the battery increases.

[0009] The second determination unit may determine, as the correction coefficients, a first correction coefficient for correcting the fuel injection amount and a second correction coefficient for correcting the motor torque, and the calculation unit may calculate the corrected fuel injection amount based on the first correction coefficient and calculate the corrected motor torque based on the second correction coefficient.

[0010] The calculation unit may calculate the corrected fuel injection amount by subtracting a first correction amount, which is obtained by multiplying the fuel injection amount by the correction coefficient, from the fuel injection amount, and the corrected motor torque by adding a second correction amount, which is obtained by multiplying the motor torque by the correction coefficient, to the motor torque.

[0011] The engine may further include a third determination unit that determines a fuel injection amount correction term for correcting the fuel injection amount and a motor torque correction term for correcting the motor torque based on the accelerator opening and the engine speed, and the calculation unit may calculate the corrected fuel injection amount by subtracting a first correction amount, which is obtained by multiplying the fuel injection amount correction term by the correction coefficient, from the fuel injection amount, and the corrected motor torque by adding a second correction amount, which is obtained by multiplying the motor torque correction term by the correction coefficient, to the motor torque.

[0012] The exhaust gas control device may further include an estimation unit that estimates the temperature of the catalyst based on the temperature of an inlet through which the exhaust flows into the catalyst and the flow rate of the exhaust.

[0013] A power determination method according to a second aspect of the present invention includes a first determination step of determining a fuel injection amount for an engine and a motor torque generated by a motor based on an accelerator opening degree; a second determination step of determining a correction coefficient for correcting the fuel injection amount and the motor torque based on the temperature of a catalyst that purifies NOx contained in the exhaust of the engine by reacting it with ammonia contained in urea water injected into the exhaust and the charging rate of a battery that supplies electricity to the motor; and a calculation step of calculating a corrected fuel injection amount that is smaller than the fuel injection amount and a corrected motor torque that is greater than the motor torque based on the correction coefficient. [Effects of the Invention]

[0014] According to the present invention, an effect of suppressing the emission of ammonia is achieved. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram for explaining an overview of a hybrid vehicle S according to the present embodiment. [Figure 2] 1 is a diagram showing the configuration of a vehicle S. FIG. [Figure 3] FIG. 10 is a diagram for explaining a corrected fuel injection amount and a corrected motor torque. [Figure 4]4 is a diagram showing an example of a processing sequence in the power determination device 20. FIG. [Figure 5] 10A and 10B are diagrams illustrating the operation of a vehicle S according to a first modified example. [Figure 6] 10A and 10B are diagrams illustrating the operation of a vehicle S according to a second modified example. [Figure 7] 10A and 10B are diagrams illustrating the operation of a vehicle S according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] <Overview of the Hybrid Vehicle S> FIG. 1 is a diagram illustrating an overview of a hybrid vehicle S (hereinafter referred to as "vehicle S") according to this embodiment. The vehicle S has an engine and a motor as drive sources, and has the function of determining the amount of fuel injected into the engine and the torque generated by the motor. For example, the vehicle S determines a corrected fuel injection amount obtained by correcting the amount of fuel injected based on the accelerator opening, and a corrected motor torque obtained by correcting the torque of the motor based on the accelerator opening, based on the charging rate of a battery that supplies electricity to the motor and the temperature of the catalyst. The vehicle S then injects fuel into the engine at the determined corrected fuel injection amount, and causes the motor to generate the determined corrected motor torque.

[0017] The accelerator opening is the amount of depression of the accelerator pedal by the driver of the vehicle S. In the following description, the amount of fuel injected based on the accelerator opening is referred to as the "fuel injection amount," the motor torque based on the accelerator opening is referred to as the "motor torque," the battery charging rate is referred to as the "SOC (State Of Charge)," and the catalyst temperature is referred to as the "catalyst temperature."

[0018] The vehicle S is equipped with a catalyst (so-called SCR; Selective Catalytic Reduction) for purifying NOx contained in the engine exhaust. The catalyst purifies the NOx by, for example, adsorbing ammonia contained in urea water injected into the exhaust and causing the NOx contained in the exhaust to react with the ammonia and reduce it to nitrogen and water. The amount of ammonia that the catalyst can adsorb decreases as the temperature of the catalyst increases.

[0019] Therefore, for example, when the road on which the vehicle S is traveling changes from a flat road to an uphill road, if the engine output suddenly increases in response to the driver's operation, the catalyst temperature also rises suddenly as the exhaust temperature rises, and the amount of ammonia that the catalyst can adsorb suddenly decreases. As a result, the amount of ammonia adsorbed in the catalyst before the catalyst temperature rises may exceed the amount of ammonia that the catalyst can adsorb after the catalyst temperature rises, causing the adsorbed ammonia to be discharged (so-called ammonia slip). To address this, when traveling uphill, one measure can be taken to increase the motor output instead of the engine output, but this measure cannot be used when the SOC is low.

[0020] Therefore, the vehicle S determines a correction coefficient based on the catalyst temperature and the SOC. Then, based on the determined correction coefficient, the vehicle S determines a correction fuel injection amount that is smaller than the fuel injection amount corresponding to the accelerator opening degree and a correction motor torque that is larger than the motor torque corresponding to the accelerator opening degree. For example, the vehicle S determines the correction fuel injection amount and the correction motor torque so that the sum of the engine output corresponding to the fuel injection amount and the motor output that generates the motor torque matches or is close to the sum of the engine output corresponding to the correction fuel injection amount and the motor output that generates the correction motor torque.

[0021] First, the vehicle S determines the fuel injection amount corresponding to the accelerator opening by referring to the fuel injection amount map M1 (shown in FIG. 1 as (1)). The fuel injection amount map M1 is a map that indicates a larger fuel injection amount as the accelerator opening increases. The vehicle S determines the motor torque corresponding to the accelerator opening by referring to the motor torque map M2 (shown in FIG. 1 as (2)). The motor torque map M2 is a map that indicates a larger motor torque as the accelerator opening increases.

[0022] The vehicle S determines a correction coefficient corresponding to the catalyst temperature and SOC by referring to a correction coefficient map M3 ((3) shown in FIG. 1). The correction coefficient is a coefficient for correcting the fuel injection amount and the motor torque, and the correction coefficient map M3 is a map showing the correction coefficient corresponding to the catalyst temperature and SOC. The correction coefficient and the correction coefficient map M3 will be described later.

[0023] The vehicle S determines the fuel injection amount correction term corresponding to the accelerator opening and engine speed by referring to the fuel injection amount correction term map M4 ((4) in FIG. 1). The vehicle S determines the motor torque correction term corresponding to the accelerator opening and engine speed by referring to the motor torque correction term map M5 ((5) in FIG. 1). The fuel injection amount correction term, the motor torque correction term, the fuel injection amount correction term map M4, and the motor torque correction term map M5 will be described later.

[0024] Next, vehicle S calculates the product obtained by multiplying the fuel injection amount correction term by the correction coefficient as the first correction amount ((6) in FIG. 1), and determines the subtraction value obtained by subtracting the first correction amount from the fuel injection amount as the corrected fuel injection amount ((7) in FIG. 1). Vehicle S calculates the product obtained by multiplying the motor torque correction term by the correction coefficient as the second correction amount ((8) in FIG. 1), and determines the addition value obtained by adding the second correction amount to the motor torque as the corrected motor torque ((9) in FIG. 1).

[0025] By operating as described above, the vehicle S can increase the engine output when the catalyst temperature is low to prevent a sudden rise in catalyst temperature. As a result, the vehicle S can suppress a decrease in SOC and also suppress the occurrence of ammonia slip. By suppressing a decrease in SOC, the vehicle S can easily increase the motor output when there is a possibility of ammonia slip occurring, thereby suppressing ammonia slip. Furthermore, when the catalyst temperature and SOC are high, the vehicle S can suppress a rise in catalyst temperature by increasing the motor output more than the engine output, thereby suppressing ammonia slip. The configuration and operation of the vehicle S will be described in detail below.

[0026] <Vehicle S Configuration> Fig. 2 is a diagram showing the configuration of a vehicle S. The vehicle S shown in Fig. 2 includes an accelerator device 1, an engine 2, a catalyst 3, an exhaust passage 4, a motor 5, a battery 6, a temperature sensor 11, a flow rate sensor 12, a rotation speed sensor 13, a cruise control device 14, and a power determination device 20. Fig. 2 shows, as an example, a case where the accelerator opening is the depression amount of the accelerator pedal.

[0027] The accelerator device 1 is a device for controlling the acceleration of the vehicle S. The accelerator device 1 includes, for example, an accelerator pedal and a pedal sensor, and the pedal sensor detects the depression amount indicating the amount of depression of the accelerator pedal by the driver of the vehicle S. The accelerator device 1 outputs the detected depression amount to the power determination device 20 as an accelerator opening degree.

[0028] The engine 2 is the driving source of the vehicle S, and is an internal combustion engine that generates power by burning and expanding a mixture of fuel and intake air (air). The catalyst 3 is a purification device provided downstream of the engine 2 in the exhaust path 4 for purifying the exhaust gas from the engine 2 that flows through the exhaust path 4, and includes, for example, an SCR. The catalyst 3 purifies the NOx contained in the exhaust gas from the engine 2 by causing it to react with ammonia contained in urea water injected into the exhaust gas. The exhaust path 4 is a flow path through which the exhaust gas from the engine 2 flows.

[0029] The motor 5 is a drive source for the vehicle S, and is an electric motor that generates power using electricity supplied from the battery 6 via an inverter (not shown). When braking the vehicle S, the motor 5 may operate as a generator (performing so-called regenerative braking) to generate electricity and store the generated electricity in the battery 6. The battery 6 is a rechargeable storage battery that supplies electricity to the motor 5. The battery 6 stores, for example, electricity supplied from outside the vehicle S, electricity generated by the motor 5, and electricity generated by a solar panel (not shown) provided on the vehicle S.

[0030] The temperature sensor 11 is provided upstream of the catalyst 3 in the exhaust passage 4, and is a sensor for detecting the temperature at the inlet where the exhaust flows into the catalyst 3, and outputting this temperature to the power determination device 20. The flow rate sensor 12 is a sensor for detecting the flow rate of the exhaust flowing through the exhaust passage 4 (hereinafter referred to as the "exhaust flow rate"), and outputting this flow rate to the power determination device 20. The rotation speed sensor 13 is a sensor for detecting the rotation speed of the engine 2, and outputting this rotation speed to the power determination device 20.

[0031] The driving control device 14 is a device including, for example, one or more processors such as a CPU (Central Processing Unit) or an ECU (Electronic Control Unit) and a storage unit. The driving control device 14 injects fuel into the engine 2 at the corrected fuel injection amount determined by the power determination device 20, and causes the motor 5 to generate the corrected motor torque determined by the power determination device 20, by causing the processor to execute a program stored in the storage unit. The driving control device 14 obtains the charging rate of the battery 6 and notifies the power determination device 20 of the charging rate.

[0032] The power determination device 20 is a device including, for example, one or more processors such as a CPU or an ECU. The power determination device 20 determines a corrected fuel injection amount and a corrected motor torque based on, for example, the accelerator opening obtained from the accelerator device 1, the temperature obtained from the temperature sensor 11, and the SOC obtained from the cruise control device 14. The power determination device 20 notifies the cruise control device 14 of the determined corrected fuel injection amount and corrected motor torque, thereby causing the engine 2 to inject fuel at the corrected fuel injection amount and the motor 5 to generate the corrected motor torque. The power determination device 20 may have a housing including electronic components, or may be a printed circuit board on which electronic components are mounted. The power determination device 20 may include the cruise control device 14. The configuration and operation of the power determination device 20 will be described in detail below.

[0033] <Configuration of power determining device 20> 2, the power determination device 20 has a storage unit 21 and a control unit 22. The control unit 22 has an acquisition unit 221, an estimation unit 222, a first determination unit 223, a second determination unit 224, a third determination unit 225, and a calculation unit 226.

[0034] The storage unit 21 has a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a solid state drive (SSD). The storage unit 21 stores programs executed by the control unit 22 and various information for determining the corrected fuel injection amount and the corrected motor torque. As an example, the storage unit 21 stores a fuel injection amount map M1, a motor torque map M2, a correction coefficient map M3, a fuel injection amount correction term map M4, and a motor torque correction term map M5 shown in FIG. 1.

[0035] The control unit 22 is, for example, a processor such as a CPU or an ECU. The control unit 22 executes a program stored in the storage unit 21 to function as an acquisition unit 221, an estimation unit 222, a first determination unit 223, a second determination unit 224, a third determination unit 225, and a calculation unit 226. The control unit 22 may be configured with one processor, or may be configured with multiple processors or a combination of one or more processors and an electronic circuit. The configuration of each unit realized by the control unit 22 will be described below.

[0036] The acquisition unit 221 acquires various types of information from outside the power determination device 20 at a predetermined control period. The control period is, for example, 0.1 seconds. The acquisition unit 221 acquires, for example, the accelerator opening from the accelerator device 1, the temperature of the inlet of the catalyst 3 from the temperature sensor 11, the flow rate of the exhaust gas flowing through the exhaust passage 4 from the flow rate sensor 12, the rotation speed of the engine 2 from the rotation speed sensor 13, and the SOC of the battery 6 from the driving control device 14. The acquisition unit 221 stores the acquired various types of information in the storage unit 21, for example.

[0037] The estimation unit 222 estimates the temperature (catalyst temperature) of the catalyst 3. The estimation unit 222 estimates the catalyst temperature based on, for example, the temperature of the inlet through which the exhaust gas flows into the catalyst 3 and the flow rate of the exhaust gas. Specifically, the estimation unit 222 acquires, for example, the temperature detected by the temperature sensor 11 and the flow rate of the exhaust gas detected by the flow rate sensor 12 from the acquisition unit 221, and estimates the catalyst temperature resulting from the exhaust gas at the acquired temperature and flow rate coming into contact with the catalyst 3. The estimation unit 222 may estimate the temperature detected by the temperature sensor 11 as the catalyst temperature.

[0038] The first determination unit 223 determines the fuel injection amount of the engine 2 and the motor torque generated by the motor 5 based on the accelerator opening. The first determination unit 223 determines the fuel injection amount of the engine 2 corresponding to the accelerator opening acquired by the acquisition unit 221, for example, by referring to a fuel injection amount map M1 stored in the storage unit 21 (shown in (1) in FIG. 1). The first determination unit 223 determines the motor torque corresponding to the accelerator opening acquired by the acquisition unit 221, for example, by referring to a motor torque map M2 stored in the storage unit 21 (shown in (2) in FIG. 1).

[0039] The second determination unit 224 determines a correction coefficient for correcting the fuel injection amount and the motor torque based on the catalyst temperature and the SOC of the battery 6. The correction coefficient is a coefficient for calculating a first correction amount for the fuel injection amount and a second correction amount for the motor torque, and is, for example, a coefficient indicating a value equal to or greater than 0. The second determination unit 224 determines a correction coefficient corresponding to the catalyst temperature estimated by the estimation unit 222 and the SOC of the battery 6 acquired by the acquisition unit 221 from the driving control device 14, for example, by referring to a correction coefficient map M3 stored in the storage unit 21 ((3) shown in FIG. 1).

[0040] For example, the second determination unit 224 increases the correction coefficient as the catalyst temperature decreases. That is, the correction coefficient map M3 includes a correction coefficient that increases as the catalyst temperature decreases. By the second determination unit 224 determining the correction coefficient in this manner, the vehicle S can decrease the correction fuel injection amount and increase the correction motor torque as the catalyst temperature decreases. As a result, it is possible to prevent ammonia slip from occurring due to a sudden increase in the catalyst temperature caused by a sudden increase in the output of the engine 2 when the catalyst temperature is low.

[0041] For example, the second determination unit 224 increases the correction coefficient as the SOC of the battery 6 increases. That is, the correction coefficient map M3 includes a correction coefficient that increases as the SOC increases. By the second determination unit 224 determining the correction coefficient in this manner, the vehicle S can decrease the correction fuel injection amount and increase the correction motor torque as the SOC of the battery 6 increases. As a result, when the SOC of the battery 6 is high, the increase in catalyst temperature can be suppressed by reducing the output of the engine 2, and therefore the occurrence of ammonia slip can be suppressed.

[0042] The third determination unit 225 determines a fuel injection amount correction term for correcting the fuel injection amount and a motor torque correction term for correcting the motor torque, based on the rotation speed and accelerator opening of the engine 2. The fuel injection amount correction term is a term for calculating a first correction amount for the fuel injection amount, and the motor torque correction term is a term for calculating a second correction amount for the motor torque.

[0043] The third determination unit 225 determines the fuel injection amount correction term corresponding to the rotation speed of the engine 2 and the accelerator opening degree acquired by the acquisition unit 221, for example, by referring to a fuel injection amount correction term map M4 stored in the storage unit 21 (shown in (4) in FIG. 1). The fuel injection amount correction term map M4 is a map that includes the fuel injection amount correction term corresponding to the rotation speed and the accelerator opening degree of the engine 2, and indicates a fuel injection amount correction term for increasing the first correction amount as the rotation speed of the engine 2 increases and as the accelerator opening degree increases.

[0044] The third determination unit 225 determines the motor torque correction term corresponding to the rotation speed of the engine 2 and the accelerator opening degree acquired by the acquisition unit 221, for example, by referring to a motor torque correction term map M5 stored in the storage unit 21 (shown as (5) in FIG. 1). The motor torque correction term map M5 is a map that includes the motor torque correction term corresponding to the rotation speed and the accelerator opening degree of the engine 2, and indicates a motor torque correction term for increasing the second correction amount as the rotation speed of the engine 2 increases and as the accelerator opening degree increases.

[0045] The rotation speed of the engine 2 corresponds to the amount of exhaust gas flow at the current time, and the degree of accelerator opening corresponds to the amount of exhaust gas flow at a time a predetermined time has elapsed from the current time. The higher the exhaust gas flow rate, the higher the catalyst temperature. Therefore, the fuel injection amount correction term map M4 can include a fuel injection amount correction term that corresponds to the amount of change in catalyst temperature after a predetermined time from the current time and the catalyst temperature at the current time. The motor torque correction term map M5 can include a motor torque correction term that corresponds to the amount of change in catalyst temperature after a predetermined time from the current time and the catalyst temperature at the current time. Therefore, the third determination unit 225 can determine the fuel injection amount correction term and the motor torque correction term that correspond to the amount of change in catalyst temperature after a predetermined time from the current time and the catalyst temperature at the current time.

[0046] The calculation unit 226 calculates a correction fuel injection amount that is smaller than the fuel injection amount and a correction motor torque that is larger than the motor torque, based on the correction coefficient determined by the second determination unit 224. For example, the calculation unit 226 reduces the correction fuel injection amount and increases the correction motor torque as the correction coefficient increases.

[0047] Fig. 3 is a diagram for explaining the corrected fuel injection amount and the corrected motor torque. The horizontal axis of Fig. 3 represents time, and the vertical axis of Fig. 3 represents the "catalyst temperature" of the catalyst 3, the "SOC" of the battery 6, the "correction coefficient" determined by the second determination unit 224, the "injection amount," and the "torque." In the "injection amount" shown in Fig. 3, the solid line represents the corrected fuel injection amount, and the dashed line represents the fuel injection amount. In the "torque" shown in Fig. 3, the solid line represents the corrected motor torque, and the dashed line represents the motor torque.

[0048] 3, at times P0 and P1, the catalyst temperature decreases from temperature C0 to temperature C1, and the SOC increases from the charging rate B0 to the charging rate B2, so that the second determination unit 224 increases the correction coefficient from coefficient H0 to coefficient H2. Then, at time T2, for example, the calculation unit 226 determines a correction fuel injection amount E21 that is smaller than the fuel injection amount E22 determined by the first determination unit 223, and determines a correction motor torque M21 that is larger than the motor torque M22 determined by the first determination unit 223.

[0049] Subsequently, at time P2, the catalyst temperature rises from temperature C1 to temperature C3, and the SOC drops from the charging rate B2 to the charging rate B0, causing the second determination unit 224 to reduce the correction coefficient from coefficient H2 to coefficient H3. Then, at time T3, for example, the calculation unit 226 determines a correction fuel injection amount E31 that is smaller than the fuel injection amount E32 determined by the first determination unit 223, and determines a correction motor torque M31 that is larger than the motor torque M32 determined by the first determination unit 223.

[0050] At times P0, P1, and P2 shown in FIG. 3, the difference "E22-E21" between the fuel injection amount and the corrected fuel injection amount at time T2, when the correction coefficient is largest, is larger than the differences between the fuel injection amount and the corrected fuel injection amount at other times. That is, the larger the correction coefficient, the smaller the corrected fuel injection amount calculated by calculation unit 226 is. Also, the difference "M21-M22" between the corrected motor torque and the motor torque at time T2 is larger than the differences between the corrected motor torque and the motor torque at other times. That is, the larger the correction coefficient, the larger the corrected motor torque calculated by calculation unit 226 is.

[0051] By operating as described above, calculation unit 226 can reduce the correction fuel injection amount and increase the correction motor torque when the correction coefficient is large due to a drop in catalyst temperature (for example, time P0 shown in FIG. 3). As a result, calculation unit 226 can increase the output of engine 2 more than the output of motor 5 in a state where the catalyst temperature has dropped, thereby suppressing a drop in SOC. As a result, calculation unit 226 can suppress a drop in SOC in a state where ammonia slip is likely to occur, and therefore can suppress ammonia slip by increasing the motor output in that state.

[0052] Furthermore, when the correction coefficient is large due to a high SOC, the calculation unit 226 can reduce the correction fuel injection amount and increase the correction motor torque (for example, at time P1 shown in FIG. 3). As a result, even if a large output is required to travel on an uphill road, for example, the calculation unit 226 can drive the vehicle S by increasing the output of the motor 5 because the SOC is high, and can therefore suppress the output of the engine 2. As a result, the calculation unit 226 can suppress a rise in catalyst temperature and thereby suppress ammonia slip.

[0053] The calculation unit 226 calculates a corrected fuel injection amount ((7) shown in FIG. 1) by subtracting a first correction amount ((6) shown in FIG. 1) obtained by multiplying a fuel injection amount correction term by a correction coefficient from the fuel injection amount. The calculation unit 226 calculates the first correction amount by multiplying the fuel injection amount correction term by the correction coefficient, for example, by substituting the correction coefficient determined by the second determination unit 224 for the coefficient included in the fuel injection amount correction term, and calculates the corrected fuel injection amount by subtracting the first correction amount from the fuel injection amount.

[0054] Calculation unit 226 calculates a corrected motor torque ((9) in FIG. 1) by adding a second correction amount ((8) in FIG. 1) obtained by multiplying the motor torque correction term by a correction coefficient to the motor torque. Calculation unit 226 calculates the second correction amount by multiplying the motor torque correction term by the correction coefficient, for example, by substituting the correction coefficient determined by second determination unit 224 for the coefficient included in the motor torque correction term, and calculates a corrected motor torque by adding the second correction amount to the motor torque.

[0055] By operating as described above, calculation unit 226 can use the fuel injection amount correction term and motor torque correction term corresponding to the engine 2 rotation speed corresponding to the catalyst temperature at the current time and the accelerator opening degree corresponding to the catalyst temperature after a predetermined time from the current time. As a result, calculation unit 226 can calculate the corrected fuel injection amount and corrected motor torque corresponding to the catalyst temperature at the current time and the amount of change in catalyst temperature after a predetermined time from the current time, thereby improving the accuracy of suppressing ammonia slip.

[0056] The calculation unit 226 outputs the calculated corrected fuel injection amount and corrected motor torque to the driving control device 14, thereby causing the engine 2 to inject fuel at the corrected fuel injection amount and causing the motor 5 to generate the corrected motor torque.

[0057] <Processing sequence in the power determination device 20> Fig. 4 is a diagram showing an example of a processing sequence in the power determining device 20. The processing sequence shown in Fig. 4 is a processing sequence showing the operation of the power determining device 20 to calculate a corrected fuel injection amount and a corrected motor torque by performing the operation shown in Fig. 1. The power determining device 20 executes the processing sequence shown in Fig. 4 at a predetermined control cycle.

[0058] The acquisition unit 221 acquires the accelerator opening from the accelerator device 1 and acquires the engine speed from the speed sensor 13 (S11). The first determination unit 223 determines the fuel injection amount ((1) in FIG. 1) corresponding to the accelerator opening acquired by the acquisition unit 221 and the motor torque ((2) in FIG. 1) corresponding to the accelerator opening (S12).

[0059] The acquisition unit 221 acquires the temperature of the catalyst 3 from the temperature sensor 11, and acquires the SOC of the battery 6 from the driving control device 14 (S13). The second determination unit 224 determines a correction coefficient ((3) shown in FIG. 1) based on the SOC acquired by the acquisition unit 221 and the catalyst temperature estimated by the estimation unit 222 based on the temperature of the catalyst 3 acquired by the acquisition unit 221 (S14). The third determination unit 225 determines a fuel injection amount correction term ((4) shown in FIG. 1) and a motor torque correction term ((5) shown in FIG. 1) based on the accelerator opening and engine speed acquired by the acquisition unit 221 (S15).

[0060] The calculation unit 226 calculates a first correction amount ((6) in FIG. 1 ) by substituting the correction coefficient determined by the second determination unit 224 for the coefficient included in the fuel injection amount correction term determined by the third determination unit 225 (S16). For example, the calculation unit 226 determines the first correction amount as a multiplied value obtained by multiplying the fuel injection amount correction term by the correction coefficient. The calculation unit 226 calculates a second correction amount ((8) in FIG. 1 ) by substituting the correction coefficient for the coefficient included in the motor torque correction term determined by the third determination unit 225 (S16). For example, the calculation unit 226 determines the second correction amount as a multiplied value obtained by multiplying the motor torque correction term by the correction coefficient. The calculation unit 226 calculates a corrected fuel injection amount ((7) in FIG. 1 ) by subtracting the first correction amount from the fuel injection amount, and a corrected motor torque ((9) in FIG. 1 ) by adding the second correction amount to the motor torque (S17), and ends the processing.

[0061] <First Modification> In the above description, the calculation unit 226 calculates the first correction amount by multiplying the fuel injection amount correction term by the correction coefficient, and the second correction amount by multiplying the motor torque correction term by the correction coefficient, but this is not limiting. The calculation unit 226 may calculate the first correction amount and the second correction amount without using the fuel injection amount correction term and the motor torque correction term. FIG. 5 is a diagram showing the operation of the vehicle S according to the first modified example. The vehicle S shown in FIG. 5 differs from the vehicle S shown in FIG. 1 in that it does not have the fuel injection amount correction term map M4 and the motor torque correction term map M5 and in that it has (4) and (6) shown in FIG. 5, but is the same in other respects.

[0062] The calculation unit 226 calculates, for example, a corrected fuel injection amount ((5) in FIG. 5) by subtracting a first correction amount ((4) in FIG. 5) obtained by multiplying the fuel injection amount by a correction coefficient from the fuel injection amount. The calculation unit 226 calculates, for example, a corrected motor torque ((7) in FIG. 5) by adding a second correction amount ((6) in FIG. 5) obtained by multiplying the motor torque by a correction coefficient to the motor torque. By the calculation unit 226 operating in this manner, the calculation unit 226 can reduce the amount of calculation required for calculating the corrected fuel injection amount and the corrected motor torque for the vehicle S.

[0063] <Second Modification> In the above description, the second determination unit 224 determines one correction coefficient for calculating the corrected fuel injection amount and the corrected motor torque, but the present invention is not limited to this. The second determination unit 224 may determine a first correction coefficient for correcting the fuel injection amount and a second correction coefficient for correcting the motor torque as the correction coefficients.

[0064] Fig. 6 is a diagram showing the operation of the vehicle S according to the second modified example. The vehicle S shown in Fig. 6 differs from the vehicle S shown in Fig. 5 in that it has a first correction coefficient map M3a and a second correction coefficient map M3b and in that it has (3a) and (3b) shown in Fig. 6, but is the same in other respects. The correction coefficient maps M3a and M3b, like the correction coefficient map M3, are maps that include correction coefficients corresponding to the SOC and catalyst temperature of the battery 6, and that include correction coefficients that become larger as the catalyst temperature becomes lower and the SOC becomes higher.

[0065] The second determination unit 224 determines the first correction coefficient corresponding to the catalyst temperature and the SOC (shown in FIG. 6(3a)) by, for example, referring to the first correction coefficient map M3a stored in the storage unit 21. The second determination unit 224 determines the second correction coefficient corresponding to the catalyst temperature and the SOC (shown in FIG. 6(3b)) by, for example, referring to the second correction coefficient map M3b stored in the storage unit 21.

[0066] Calculation unit 226 calculates the corrected fuel injection amount based on the first correction coefficient, and calculates the corrected motor torque based on the second correction coefficient. For example, calculation unit 226 calculates the first correction amount by multiplying the fuel injection amount by the first correction coefficient ((4) in FIG. 6), and calculates the corrected fuel injection amount by subtracting the first correction amount from the fuel injection amount ((5) in FIG. 6). For example, calculation unit 226 calculates the second correction amount by multiplying the motor torque by the second correction coefficient ((6) in FIG. 6), and calculates the corrected motor torque by adding the second correction amount to the motor torque ((7) in FIG. 6).

[0067] The second determination unit 224 determines the correction coefficient as described above, which allows the calculation unit 226 to multiply the fuel injection amount and the motor torque by different correction coefficients, making it easier for the calculation unit 226 to adjust the first correction amount in the corrected fuel injection amount and the second correction amount in the corrected motor torque.

[0068] <Third Modification> In the above description, the calculation unit 226 calculates the corrected fuel injection amount by subtracting the first correction amount from the fuel injection amount and the corrected motor torque by adding the second correction amount to the motor torque, but this is not limiting. The calculation unit 226 may calculate the corrected fuel injection amount by multiplying the fuel injection amount by a correction coefficient and the corrected motor torque by multiplying the motor torque by the correction coefficient.

[0069] 7 is a diagram showing the operation of the vehicle S according to the second modified example. The vehicle S shown in FIG. 7 differs from the vehicle S shown in FIG. 6 in that it has (4) and (5) shown in FIG. 7, but is the same in other respects. In FIG. 7, the second determination unit 224 determines, for example, a first correction coefficient ((3a) shown in FIG. 7) indicating a value greater than or equal to 0 and less than or equal to 1, and determines a second correction coefficient ((3b) shown in FIG. 7) indicating a value greater than or equal to 1.

[0070] The calculation unit 226 determines the product obtained by multiplying the fuel injection amount by the first correction coefficient as the corrected fuel injection amount ((4) in FIG. 7), and determines the product obtained by multiplying the motor torque by the second correction coefficient as the corrected motor torque ((5) in FIG. 7). By the second determination unit 224 and the calculation unit 226 operating in this manner, the vehicle S can reduce the amount of calculation required to calculate the corrected fuel injection amount and the corrected motor torque.

[0071] <Fourth Modification> In the above description, an example has been given of the operation in which second determination unit 224 determines a correction coefficient indicating a value equal to or greater than 0, but this is not limiting. Second determination unit 224 may determine a correction coefficient indicating a value less than 0. In this case, calculation unit 226 calculates, for example, a corrected fuel injection amount obtained by adding the first correction amount to the fuel injection amount, and a corrected motor torque obtained by subtracting the second correction amount from the motor torque.

[0072] <Effects of Vehicle S> As described above, the vehicle S has a first determination unit 223 that determines the fuel injection amount of the engine 2 and the motor torque generated by the motor 5 based on the accelerator opening, a second determination unit 224 that determines a correction coefficient for correcting the fuel injection amount and the motor torque based on the temperature of the catalyst 3 that purifies NOx contained in the exhaust of the engine 2 by reacting it with ammonia contained in the urea water injected into the exhaust and the SOC of the battery 6 that supplies electricity to the motor 5, and a calculation unit 226 that calculates a corrected fuel injection amount that is smaller than the fuel injection amount and a corrected motor torque that is larger than the motor torque based on the correction coefficient.

[0073] By configuring the vehicle S in this manner, the vehicle S can suppress a sudden rise in the output of the engine 2 when the catalyst temperature is low, thereby suppressing a sudden rise in the catalyst temperature. As a result, the vehicle S can suppress a sudden decrease in the amount of ammonia that can be adsorbed by the catalyst 3 due to a sudden rise in the catalyst temperature, and can suppress the discharge of ammonia desorbed from the catalyst 3. Furthermore, when the SOC of the battery 6 is high, the vehicle S can increase the motor output more than the engine output, thereby suppressing the discharge of ammonia desorbed from the catalyst 3.

[0074] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0075] S Hybrid vehicle 1 Accelerator 2 engines 3. Catalyst 4 Exhaust duct 5 motors 6 Battery 11 Temperature Sensor 12 Flow sensor 13 Rotational speed sensor 14 Driving control device 20 Power determining device 21 Memory section 22 Control Unit 221 Acquisition Department 222 Estimation Department 223 First Decision Section 224 Second Decision Section 225 Third Decision Section 226 Calculation Unit

Claims

1. a first determination unit that determines a fuel injection amount of the engine and a motor torque generated by the motor based on an accelerator opening; a second determination unit that determines a correction coefficient for correcting the fuel injection amount and the motor torque based on a temperature of a catalyst that purifies NOx contained in exhaust gas from the engine by causing the NOx to react with ammonia contained in the urea water injected into the exhaust gas and a charging rate of a battery that supplies electricity to the motor; a calculation unit that calculates a correction fuel injection amount that is smaller than the fuel injection amount and a correction motor torque that is larger than the motor torque based on the correction coefficient, Hybrid vehicle.

2. the second determination unit increases the correction coefficient as the temperature of the catalyst decreases, the calculation unit reduces the correction fuel injection amount and increases the correction motor torque as the correction coefficient increases; The hybrid vehicle according to claim 1 .

3. the second determination unit increases the correction coefficient as the charging rate of the battery increases; The hybrid vehicle according to claim 2 .

4. the second determination unit determines, as the correction coefficients, a first correction coefficient for correcting the fuel injection amount and a second correction coefficient for correcting the motor torque; the calculation unit calculates the corrected fuel injection amount based on the first correction coefficient, and calculates the corrected motor torque based on the second correction coefficient. The hybrid vehicle according to claim 1 .

5. the calculation unit calculates the corrected fuel injection amount by subtracting a first correction amount, which is obtained by multiplying the fuel injection amount by the correction coefficient, from the fuel injection amount, and calculates the corrected motor torque by adding a second correction amount, which is obtained by multiplying the motor torque by the correction coefficient, to the motor torque. A hybrid vehicle according to any one of claims 1 to 4.

6. a third determination unit that determines a fuel injection amount correction term for correcting the fuel injection amount and a motor torque correction term for correcting the motor torque based on the accelerator opening and the engine speed, the calculation unit calculates the corrected fuel injection amount by subtracting a first correction amount, which is obtained by multiplying the fuel injection amount correction term by the correction coefficient, from the fuel injection amount, and calculates the corrected motor torque by adding a second correction amount, which is obtained by multiplying the motor torque correction term by the correction coefficient, to the motor torque. A hybrid vehicle according to any one of claims 1 to 4.

7. The exhaust gas control system further includes an estimation unit that estimates the temperature of the catalyst based on a temperature of an inlet through which the exhaust gas flows into the catalyst and a flow rate of the exhaust gas. The hybrid vehicle according to claim 1 .

8. a first determination step of determining a fuel injection amount of the engine and a motor torque generated by the motor based on an accelerator opening; a second determination step of determining a correction coefficient for correcting the fuel injection amount and the motor torque based on a temperature of a catalyst that purifies NOx contained in the exhaust gas of the engine by reacting it with ammonia contained in the urea water injected into the exhaust gas, and a charging rate of a battery that supplies electricity to the motor; a calculation step of calculating a correction fuel injection amount that is smaller than the fuel injection amount and a correction motor torque that is larger than the motor torque based on the correction coefficient, Power determination method.

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