JP7539302B2 - Vehicle control method and vehicle control device - Google Patents

Description

The present invention relates to a vehicle control method and a vehicle control device for controlling a vehicle.

Patent document 1 discloses an electric vehicle equipped with a generator, an engine configured to drive the generator, a catalytic converter configured to purify exhaust gas discharged from the engine, and a control unit (PCU) configured to control the operation of the engine.

In the electric vehicle described in Patent Document 1, when the engine is started and the generator starts generating electricity, a warm-up mode is executed in which the engine is operated so that the driving force is lower than the generating driving force after the catalyst device reaches the activated state until the catalyst device reaches the activated state.

JP 2017-52500 A

However, in the electric vehicle described in Patent Document 1, after the vehicle starts to run, the engine is operated in warm-up mode before the engine starts to generate electricity. This lengthens the engine operating time, which means the driver is exposed to engine vibrations and noise for longer periods of time, and the sound and vibration performance cannot be said to be good.

The present invention was made in consideration of these technical issues, and aims to improve noise and vibration performance when starting the engine.

According to one aspect of the present invention, a vehicle includes an engine and a first catalyst provided in an exhaust passage of the engine for purifying exhaust gas discharged into the atmosphere and having a heating device heated by electric power from a battery. A method for controlling this vehicle includes estimating a catalyst warm-up time required for the heating device to raise the first catalyst to a first predetermined temperature, supplying electric power to the heating device for the catalyst warm-up time before a scheduled time for the vehicle to start running to warm up the first catalyst, and if the vehicle does not start running at the scheduled time for the vehicle to start running, supplying a smaller electric power to the heating device than that used for warm-up to maintain the first catalyst at or above the first predetermined temperature .

According to the present invention, the temperature of the first catalyst can be raised at the scheduled start time of driving. This eliminates the need to drive the engine just to warm up the first catalyst when the vehicle starts driving and the engine starts. This improves noise and vibration performance.

FIG. 1 is a schematic diagram of a vehicle according to an embodiment of the present invention. FIG. 2 is a flowchart showing the warm-up control according to the embodiment of the present invention. FIG. 3 is a flowchart of control in the standby mode according to the embodiment of the present invention. FIG. 4 is an example of a time chart of the warm-up control according to the embodiment of the present invention. FIG. 5 is a flowchart of the warm-up control according to the modified example. FIG. 6 is a flowchart of control in the standby mode according to a modified example. FIG. 7 is an example of a time chart of the warm-up control according to the modified example.

The following describes an embodiment of the present invention with reference to the drawings.

With reference to FIG. 1, a control method for a vehicle 100 according to an embodiment of the present invention will be described.

The vehicle 100 includes an engine 1, a generator motor 2 as a first motor, a battery 3, a traction motor 4 as a second motor, an intake passage 11 through which outside air is drawn into the engine 1, an exhaust passage 12 through which exhaust gas from the engine 1 passes, and a controller 20 as a control device that controls the operation of the vehicle 100. The vehicle 100 of this embodiment is a series-type hybrid vehicle in which the engine 1 is used only for generating electricity and the traction motor 4 is used for driving the wheels 5 and for regenerating electricity.

Engine 1 is a gasoline-fueled internal combustion engine and has multiple cylinders 10 (three in FIG. 1).

A throttle valve 14 is disposed in the intake passage 11. The throttle valve 14 is driven and controlled by a controller 20. The throttle valve 14 adjusts the flow rate of the intake air supplied to the engine 1.

Each cylinder 10 of the engine 1 is provided with a fuel injection device (not shown), an intake valve (not shown), an exhaust valve (not shown), a valve mechanism (not shown) that adjusts the valve timing of the intake valve and exhaust valve, and an ignition plug (not shown). By controlling the fuel injection device at a predetermined timing, fuel is injected into the cylinder 10 of the engine 1, and a mixture of fuel and air is formed in the cylinder 10 as the piston (not shown) moves. This mixture is combusted based on a spark generated by the spark plug.

The engine 1 is mechanically connected to the generator motor 2 via the reduction gear 13. The power of the engine 1 is transmitted to the generator motor 2 via the reduction gear 13, and the generator motor 2 rotates by the power of the engine 1 to generate electricity. The generator motor 2 is electrically connected to the battery 3, and the generated power of the generator motor 2 is charged to the battery 3.

The exhaust passage 12 is provided with a first catalyst 30 that purifies exhaust gas from the engine 1, and a second catalyst 40 that purifies exhaust gas that has passed through the first catalyst 30. In this embodiment, for example, a three-way catalyst is used as the first catalyst 30. The first catalyst 30 oxidizes and reduces NOx, CO, HC, etc. in the exhaust gas to convert them into harmless nitrogen, water, carbon dioxide, etc. In addition, in this embodiment, for example, a GPF (gasoline particulate filter) is used as the second catalyst 40. The GPF is, for example, an elliptical cylindrical ceramic filter that removes fine particulate matter. The first catalyst 30 and the second catalyst 40 are warmed up by the heat of the exhaust gas, and when the temperature reaches or exceeds a predetermined activation temperature, they can purify the exhaust gas with high efficiency.

The first catalyst 30 has a heating device 31 near the inlet. The heating device 31 is, for example, an electric heater. The heating device 31 generates heat when power is supplied from the battery 3, and directly heats the first catalyst 30. This allows the catalytic performance of the first catalyst 30 to be exerted more quickly. However, this is not limited to this, and the heating device 31 can also be configured to heat the exhaust gas flowing near the inlet of the first catalyst 30, and the first catalyst 30 can be heated by this heated exhaust gas.

The battery 3 is, for example, a lithium-ion battery. The battery 3 is charged with the power regenerated by the driving motor 4 and the power generated by the power generation motor 2, and supplies the charged power to the driving motor 4.

The SOC (charging rate) of the battery 3 is detected by the SOC sensor 3a and transmitted to the controller 20. The controller 20 controls the charging of the battery 3 based on the SOC (charging rate).

The traction motor 4 is driven by power supplied from the battery 3 via an inverter 6. The rotational power of the traction motor 4 is transmitted to the wheels 5 via a gear mechanism 7, causing the vehicle 100 to move.

When the vehicle 100 requires a large driving force, for example, during high load, and the required driving force cannot be met by the power from the battery 3 alone, in addition to the power from the battery 3, the power from the generator motor 2 connected to the engine 1 (power generated by the engine 1) is also supplied to the travel motor 4. In contrast, when a large driving force is not required, such as during medium or low load, power is supplied to the travel motor 4 only from the battery 3, and all of the power generated by the engine 1 is charged to the battery 3.

The controller 20 is composed of general-purpose electronic circuits and peripheral devices, including a microcomputer, a microprocessor, and a CPU. The controller 20 executes various controls of the vehicle 100 by executing a pre-stored program based on the running state of the vehicle 100 (vehicle speed, SOC, etc.).

Next, we will explain the charging control of battery 3.

The charging of the battery 3 is controlled by the controller 20. When the SOC of the battery 3 falls to the lower limit of the charging control, the controller 20 drives the engine 1. This drives the generator motor 2, and the power generated by the generator motor 2 is supplied to the battery 3, thereby charging the battery 3.

When the SOC of the battery 3 rises to the upper limit of the charging control, the controller 20 stops the engine 1. This stops the generator motor 2, and power generation by the generator motor 2 stops.

In addition, when the vehicle 100 is decelerating or coasting, the driving force of the wheels 5 rotates the traction motor 4 to regenerate power. The power regenerated by the traction motor 4 is charged into the battery 3.

However, immediately after the vehicle 100 starts to move, the temperature of the first catalyst 30 is almost equal to the outside air temperature. Therefore, if the engine 1 is started in this state, exhaust performance will deteriorate. Therefore, it is possible to heat the first catalyst 30 using the heating device 31. However, in this case, the power that can be supplied from the battery 3 to the driving motor 4 will decrease, which may cause the driving performance to deteriorate.

Therefore, in the vehicle 100 of this embodiment, warm-up control is performed to warm up the first catalyst 30 and the engine 1 before the vehicle 100 starts traveling. The warm-up control of this embodiment will be described below with reference to Figures 2 and 3.

Figure 2 is a flowchart showing the flow of control related to the warm-up control of this embodiment. The warm-up control shown in the flowchart in Figure 2 is executed based on a program pre-stored in the controller 20.

In step S1, the scheduled start time ts of the vehicle 100 is acquired. Specifically, the scheduled start time ts set in advance by the driver is stored in the memory of the controller 20, and the controller 20 reads out this set scheduled start time ts from the memory.

In step S2, the outside air temperature Ta at the scheduled start time ts of driving is acquired. The controller 20 estimates the outside air temperature Ta at the scheduled start time ts of driving, for example, based on the current outside air temperature Tr detected by the outside air temperature sensor 8 and the change in outside air temperature up to the present. Note that this is not limited to the above, and for example, if the vehicle 100 is equipped with equipment capable of communicating with the outside, the expected outside air temperature at the scheduled start time ts of driving may be acquired from a weather forecast or the like, and this expected outside air temperature may be used as the outside air temperature Ta.

In step S3, the warm-up times tw1 to tw3 are calculated. Here, we will explain the warm-up times tw1 to tw3.

The warm-up time tw1 is the time required for the heating device 31 to warm up the first catalyst 30 to the first predetermined temperature T1 (hereinafter, also referred to as the "first catalyst warm-up time"). The controller 20 calculates the first catalyst warm-up time (warm-up time tw1) based on the difference between the first predetermined temperature T1, which is the target value, and the current outside air temperature Tr, or the difference between the first predetermined temperature T1 and the outside air temperature Ta estimated in step S2, the amount of heat generated per unit time by the heating device 31, and the heat capacity of the first catalyst 30. Note that since the temperature of the first catalyst 30 when calculating the warm-up time tw1 can be considered to be equivalent to the outside air temperature Tr, the warm-up time tw1 is calculated using the outside air temperature Tr, but the warm-up time tw1 may be calculated using the temperature of the first catalyst 30 detected by the temperature sensor 30a (first catalyst temperature Tcat).

The warm-up time tw2 is the time required to warm up the second catalyst 40 by the heating device 31 and the exhaust gas of the engine 1 (hereinafter, also referred to as the "second catalyst warm-up time"). The controller 20 calculates the second catalyst warm-up time (warm-up time tw2) based on the current outside air temperature Tr or the outside air temperature Ta estimated in step S2, the amount of heat generated per unit time by the heating device 31 Qh, and the flow rate and heat amount Qe of the exhaust gas of the engine 1. As described below, when the second catalyst 40 is warmed up, the engine 1 is driven at a predetermined rotation speed N3 (second rotation speed). Therefore, the flow rate and heat amount Qe of the exhaust gas of the engine 1 can be easily calculated.

The warm-up time tw3 is the time required for warming up the engine 1 cooling water temperature Twat to the second predetermined temperature T2 (hereinafter also referred to as "engine warm-up time"). The controller 20 calculates the engine warm-up time (warm-up time tw1) based on the difference between the target value, the second predetermined temperature T2, and the current outside air temperature Tr, or the difference between the second predetermined temperature T2 and the outside air temperature Ta estimated in step S2, and the amount of heat generated by the engine 1 per unit time. Note that the cooling water temperature Twat at the time of calculating the warm-up time tw3 can be considered to be equivalent to the outside air temperature Tr, so the warm-up time tw3 is calculated using the outside air temperature Tr, but the warm-up time tw3 may be calculated using the cooling water temperature Twat of the engine 1 detected by the temperature sensor 1a.

In step S4, the warm-up start time tws is calculated. Specifically, the controller 20 adds up the warm-up times tw1, tw2, and tw3 calculated in step S3 to calculate a total time ta1 as the second total time. The controller 20 then calculates time t1, which is the total time ta1 before the scheduled driving start time ts, as the warm-up start time tws. Note that the warm-up start time tws may be set slightly earlier than time t1 to allow for some leeway in the warm-up time.

In step S5, it is determined whether the time has reached the warm-up start time tws. If the time has reached the warm-up start time tws, the process proceeds to step S6. If the time has not reached the warm-up start time tws, the process repeats the determination in step S5, i.e., waits.

In step S6, the heating device 31 is turned on in high warm-up mode. Specifically, the controller 20 supplies power E1 to the heating device 31 using the battery 3 as a power source. The power E1 is set to, for example, the rated power of the heating device 31 in order to warm up the first catalyst 30 more quickly.

In step S6, when the supply of electric power E1 to the heating device 31 begins, the first catalyst 30 is heated by the heat generated by the heating device 31, and the first catalyst temperature Tcat rises.

In step S7, it is determined whether the first catalyst temperature Tcat has reached or exceeded the first predetermined temperature T1. Specifically, the controller 20 determines whether the temperature of the first catalyst 30 detected by the temperature sensor 30a (first catalyst temperature Tcat) has risen to the first predetermined temperature T1. The first predetermined temperature T1 is set to, for example, the lower limit of the activation temperature of the first catalyst 30. If it is determined in step S7 that the first catalyst temperature Tcat has reached or exceeded the first predetermined temperature T1, it is determined that the warm-up of the first catalyst 30 has been completed and the process proceeds to step S8. If the first catalyst temperature Tcat has not risen to the first predetermined temperature T1, the determination in step S7 is repeated.

In step S8, the heating device 31 is turned on in low warm-up mode. Specifically, the controller 20 supplies power E2 to the heating device 31. In the low warm-up mode, power E2, which is smaller than the power E1 supplied in the high warm-up mode, is supplied to the heating device 31.

In step S9, the engine 1 is driven in catalyst warm-up mode. Specifically, the controller 20 drives the engine 1 at a rotation speed N3 (second rotation speed). The rotation speed N3 of the engine 1 is set to, for example, a value close to the minimum value at which the engine 1 can rotate independently without generating electricity using the generator motor 2.

By driving the engine 1 in catalyst warm-up mode, exhaust gas from the engine 1 passes through the exhaust passage 12 and is released to the outside. At this time, the heating device 31 is ON in low warm-up mode. Therefore, the exhaust gas passing through the heating device 31 is warmed, and this warmed exhaust gas flows into the second catalyst 40, heating the second catalyst 40. Note that immediately after starting the engine 1, the temperature of the first catalyst 30 temporarily drops because cold exhaust gas inside the engine 1 is discharged into the exhaust passage 12. However, as the engine 1 burns (over time), the first catalyst temperature Tcat also rises again.

In step S10, it is determined whether the first catalyst temperature Tcat has become equal to or higher than the first predetermined temperature T1. The specific method of determination is the same as in step S7, and therefore will not be described. If it is determined in step S10 that the first catalyst temperature Tcat has again become equal to or higher than the first predetermined temperature T1, the process proceeds to step S11, and if the first catalyst temperature Tcat has not risen to the first predetermined temperature T1, the determination in step S10 is repeated.

In step S11, the heating device 31 is turned off. Specifically, the controller 20 stops the supply of power to the heating device 31.

In step S12, the engine 1 is driven in the coolant warm-up mode. Specifically, the controller 20 drives the engine 1 at a rotation speed N1 (first rotation speed) that is faster than the rotation speed N3 (second rotation speed) in the catalyst warm-up mode. This causes the coolant temperature Twat of the engine 1 to increase.

In step S13, it is determined whether the cooling water temperature Twat has reached or exceeded the second predetermined temperature T2. Specifically, the controller 20 determines whether the cooling water temperature Twat detected by the temperature sensor 1a that detects the cooling water temperature Twat has risen to the second predetermined temperature T2. If it is determined in step S13 that the cooling water temperature Twat has reached or exceeded the second predetermined temperature T2, it is determined that the warm-up of the engine 1 has been completed and the process proceeds to step S14. If the cooling water temperature Twat has not risen to the second predetermined temperature T2, the determination in step S13 is repeated.

In step S14, it is determined whether the vehicle 100 has started to run. Specifically, for example, the controller 20 determines whether the vehicle speed has reached a certain value or more. If the vehicle speed has reached a certain value or more, the controller 20 determines that the vehicle 100 has started to run and ends the warm-up control. In contrast, if the controller 20 determines that the vehicle 100 has not started to run, the process proceeds to step S15 and executes the standby mode. Note that it may also be possible to determine whether the vehicle 100 has started to run based on the operation of an ignition switch.

Next, we will explain the control in standby mode in this embodiment with reference to the flowchart shown in Figure 3.

In step S150, the heating device 31 is turned off and the engine 1 is stopped. Specifically, the controller 20 stops the supply of power to the heating device 31 and stops the engine 1.

In step S151, it is determined whether the first catalyst temperature Tcat has become lower than the first predetermined temperature T1. Specifically, the controller 20 determines whether the temperature of the first catalyst 30 detected by the temperature sensor 30a (first catalyst temperature Tcat) has fallen below the first predetermined temperature T1. If it is determined in step S151 that the first catalyst temperature Tcat has fallen below the first predetermined temperature T1, the process proceeds to step S152, and if the first catalyst temperature Tcat has not fallen below the first predetermined temperature T1, the process proceeds to step S158.

In step S152, the heating device 31 is turned on in the heat retention mode. Specifically, the controller 20 supplies the heating device 31 with power E3 that is smaller than the power E2 supplied in the low warm-up mode. The power E3 may be sufficient as long as it is sufficient for the heating device 31 to maintain the first catalyst temperature Tcat at the first predetermined temperature T1.

In step S153, it is determined whether the cooling water temperature Twat has become lower than the third predetermined temperature T3. Specifically, the controller 20 determines whether the cooling water temperature Twat detected by the temperature sensor 1a that detects the cooling water temperature Twat has decreased to the third predetermined temperature T3. The third predetermined temperature T3 is a value smaller than the second predetermined temperature T2, and is set to a value near the lower limit at which it can be determined that the engine 1 is warmed up.

If it is determined in step S153 that the cooling water temperature Twat is lower than the third predetermined temperature T3, it is determined that the engine 1 needs to be warmed up, and the process proceeds to step S154. On the other hand, if the cooling water temperature Twat is equal to or higher than the third predetermined temperature T3, the determination in step S153 is repeated.

In step S154, the engine 1 is driven in the heat retention mode. Specifically, the controller 20 drives the engine 1 at a rotation speed N2 that is slower than the rotation speed N1 (first rotation speed) in the coolant warm-up mode and faster than the rotation speed N3 (second rotation speed) in the catalyst warm-up mode. This causes the coolant temperature Twat of the engine 1 to increase.

In step S155, the heating device 31 is turned OFF. Specifically, the controller 20 stops the supply of power to the heating device 31. In step S154, the engine 1 is running, so it is possible to maintain the first catalyst 30 at or above the first predetermined temperature T1 by the exhaust gas. For this reason, the heating device 31 is turned OFF.

In step S156, it is determined whether the cooling water temperature Twat has reached or exceeded the second predetermined temperature T2. The specific method of determination is the same as in step S13, and therefore will not be described. If it is determined in step S156 that the cooling water temperature Twat has reached or exceeded the second predetermined temperature T2, it is determined that the warm-up of the engine 1 has been completed, and the process proceeds to step S157. If the cooling water temperature Twat has not risen to the second predetermined temperature T2, the determination in step S156 is repeated.

In step S157, engine 1 is stopped and the process returns to step S151.

Next, we will explain the case where it is determined in step S151 that the first catalyst temperature Tcat is equal to or higher than the first predetermined temperature T1 and the process proceeds to step S158.

In step S158, it is determined whether the cooling water temperature Twat has become lower than the third predetermined temperature T3. The specific method of determination is the same as in step S153, so a description thereof will be omitted. If it is determined in step S158 that the cooling water temperature Twat has become lower than the third predetermined temperature T3, it is determined that warming up of the engine 1 is necessary, and the process proceeds to step S159. On the other hand, if the cooling water temperature Twat is equal to or higher than the third predetermined temperature T3, the process returns to step S151 again.

In step S159, engine 1 is driven in heat-retention mode. The specific method is the same as in step S154, so a detailed explanation is omitted. After engine 1 is driven in heat-retention mode, the process proceeds to step S156.

The controller 20 ends the standby mode when the vehicle 100 starts traveling. Note that the standby mode ends when a predetermined time has passed since the scheduled travel start time ts without the vehicle 100 starting traveling. Even if the predetermined time has not passed since the scheduled travel start time ts, the controller 20 ends the standby mode when the remaining capacity of the battery 3 falls below a predetermined value.

Next, a specific example of the warm-up control of this embodiment will be described with reference to the time chart of FIG. 4. In the example shown in FIG. 4, the high warm-up mode of the heating device 31 and the catalyst warm-up mode of the engine 1 are slightly overlapped, and the high warm-up mode of the heating device 31 and the coolant warm-up mode of the engine 1 are slightly overlapped.

When the warm-up start time tws calculated as described above arrives (time t1), the controller 20 turns on the heating device 31 in high warm-up mode. Specifically, the controller 20 supplies power E1 to the heating device 31. When power is supplied to the heating device 31, the heating device 31 generates heat, the first catalyst 30 is heated, and the temperature of the first catalyst 30 (first catalyst temperature Tcat) rises.

Just before the temperature of the first catalyst 30 (first catalyst temperature Tcat) rises to the first predetermined temperature T1 (time t2), the controller 20 drives the engine 1 in the catalyst warm-up mode. Specifically, the controller 20 drives the engine 1 at a rotation speed N3.

Then, at time t3, when the first catalyst temperature Tcat rises to the first predetermined temperature T1, the controller 20 reduces the power supplied to the heating device 31 to power E2.

As described above, immediately after starting the engine 1, the cold exhaust gas in the engine 1 flows through the exhaust passage 12 to the first catalyst 30, causing the first catalyst temperature Tcat to temporarily drop. However, as time passes, the exhaust gas from the engine 1 also becomes hotter, causing the first catalyst temperature Tcat to rise again. In addition, as described above, when the engine 1 is driven, the second catalyst 40 is heated by the exhaust gas from the engine 1.

When the first catalyst temperature Tcat rises to near the first predetermined temperature T1 (time t4), the controller 20 drives the engine 1 in the coolant warm-up mode. Specifically, the controller 20 drives the engine 1 at a rotation speed N1.

Then, at time t5, when the first catalyst temperature Tcat rises to the first predetermined temperature T1, the controller 20 stops supplying power to the heating device 31.

When the engine 1 is driven at the rotation speed N1, the coolant is warmed and the coolant temperature Twat rises. At this time, the first catalyst temperature Tcat also rises due to the exhaust gas from the engine 1. Then, at time t6, when the coolant temperature Twat rises to the second predetermined temperature T2, the controller 20 stops the engine 1. Note that time t6 is the scheduled start time ts of the vehicle 100, but in the example shown in FIG. 4, the vehicle 100 does not start running and goes into standby mode.

After the scheduled driving start time ts, the heating device 31 is turned off and the engine 1 is stopped, so the first catalyst temperature Tcat and the cooling water temperature Twat gradually decrease.

At time t7, when the first catalyst temperature Tcat becomes lower than the first predetermined temperature T1, the controller 20 turns on the heating device 31 in the heat retention mode. Specifically, the controller 20 supplies power E3 to the heating device 31. This maintains the first catalyst temperature Tcat at or above the first predetermined temperature. During this time, the engine 1 is stopped, so the cooling water temperature Twat further decreases.

At time t8, when the cooling water temperature Twat falls to the third predetermined temperature T3, the controller 20 drives the engine 1 in the heat retention mode. Specifically, the controller 20 drives the engine 1 at the rotation speed N2. This causes the cooling water temperature Twat to rise.

At time t9, when the cooling water temperature Twat rises to the second predetermined temperature T2, the controller 20 stops the engine 1. After that, the controller 20 continues to control the first catalyst temperature Tcat and the cooling water temperature Twat to maintain their respective predetermined temperatures.

As described above, in the warm-up control of this embodiment, the controller 20 estimates the scheduled start time ts and starts warming up the first catalyst 30, the second catalyst 40, and the engine 1 a total time ta1 before the scheduled start time ts of the vehicle 100. This makes it possible to prevent the engine 1 from being started in a state in which the first catalyst temperature Tcat and the cooling water temperature Twat are low when the vehicle 100 starts to run, thereby preventing the exhaust performance from deteriorating. In addition, since the first catalyst temperature Tcat and the cooling water temperature Twat can be raised at the scheduled start time ts, it is not necessary to drive the engine 1 just to warm up the first catalyst 30 when the vehicle 100 starts to run and the engine 1 starts. This makes it possible to improve the sound and vibration performance.

In addition, in the warm-up control of this embodiment, the controller 20 executes a standby mode (heat retention control) in which the first catalyst temperature Tcat is maintained at or above the first predetermined temperature T1, and the cooling water temperature Twat is maintained at or above the third predetermined temperature T3. As a result, even if the vehicle 100 starts traveling after the scheduled travel start time ts, the first catalyst 30 has already been warmed up, so there is no need to drive the engine 1 to warm up the first catalyst 30. This makes it possible to prevent deterioration of exhaust performance and improve sound and vibration performance.

In addition, in the embodiment shown in FIG. 4, an overlap is provided in the switching of the warm-up mode as described above, so that time lag due to switching of control can be prevented.

After the vehicle 100 starts traveling, the controller 20 estimates the outside air temperature Ta at the next scheduled start time ts of traveling, and based on the estimated outside air temperature Ta, estimates the amount of energy Qr required for the next warm-up by the heating device 31, and controls the charging rate of the battery 3 so that the amount of energy Qr is secured when the vehicle 100 stops traveling.

Specifically, for example, when it is detected from information such as navigation that the vehicle is approaching home, the charging rate of the battery 3 is controlled based on the outside air temperature Ta at the estimated next scheduled start time ts of driving so that the amount of energy Qr required for the next warm-up control is secured. This makes it possible to prevent a situation in which the next warm-up control (warm-up before the scheduled start time ts of driving) cannot be performed due to an insufficient charging rate of the battery 3.

Note that in the warm-up control, it is not necessary to warm up the engine 1 and the second catalyst 40 before the scheduled driving start time ts.

Below, as a modified example, warm-up control that only warms up the first catalyst 30 will be described with reference to Figures 5 to 7.

Figure 5 is a flowchart showing the flow of warm-up control in the modified example. Also, Figure 6 is a flowchart showing the flow of standby mode control in the modified example. Note that in the flowcharts shown in Figures 5 and 6, steps showing the same processing as in Figures 2 and 3 are given the same numbers and explanations are omitted as appropriate, and the explanation will focus on steps showing different processing.

In step S3A in FIG. 5, the warm-up time t1 is calculated. The specific method for calculating the warm-up time t1 is the same as in step S3 in FIG. 2, so the explanation is omitted.

In step S4A, the warm-up start time tws is calculated. Specifically, the controller 20 calculates the warm-up start time tws as the time that is before the scheduled driving start time ts by the warm-up time tw1 calculated in step S3.

Next, we will explain the standby mode in the modified example shown in Figure 6.

In this modified example, if the vehicle 100 has not started traveling even though the first catalyst 30 has completed warming up, the vehicle transitions to standby mode. In this modified example, the heating device 31 is turned OFF when the vehicle transitions to standby mode (processing of step S11 in FIG. 5), so the first catalyst temperature Tcat gradually decreases.

In step S151, it is determined whether the first catalyst temperature Tcat has become smaller than the first predetermined temperature T1. If it is determined in step S151 that the first catalyst temperature Tcat has fallen below the first predetermined temperature T1, the process proceeds to step S152. In contrast, if the first catalyst temperature Tcat has not fallen below the first predetermined temperature T1, the determination in step S151A is repeated.

In step S152, the heating device 31 is turned on in the keep warm mode. Specifically, the controller 20 supplies power E3 to the heating device 31.

After that, the controller 20 continues in standby mode until a predetermined time has elapsed from the scheduled start time ts, the vehicle 100 has started to travel, or the remaining capacity of the battery 3 falls below a predetermined value.

Next, a specific example of warm-up control in the modified example will be described with reference to the time chart in Figure 7.

When the warm-up start time tws calculated as described above arrives (time t1), the controller 20 turns on the heating device 31 in high warm-up mode. Specifically, the controller 20 supplies electric power E1 to the heating device 31. When the supply of electric power E1 to the heating device 31 begins, the first catalyst 30 is heated by the heat generated by the heating device 31, and the first catalyst temperature Tcat rises.

Then, at time t11, when the first catalyst temperature Tcat rises to the first predetermined temperature T1, the controller 20 stops the supply of power to the heating device 31. Note that time t11 is the scheduled start time ts of the vehicle 100, but in the modified example shown in FIG. 7, the vehicle 100 does not start running and goes directly into the standby mode.

At time t12, when the first catalyst temperature Tcat becomes lower than the first predetermined temperature T1, the controller 20 turns on the heating device 31 in the heat retention mode. Specifically, the controller 20 supplies power E3 to the heating device 31. This maintains the first catalyst temperature Tcat at or above the first predetermined temperature.

In this manner, even in this modified example, the supply of power to the heating device 31 is started one warm-up time ta before the scheduled driving start time ts of the vehicle 100 to warm up the first catalyst 30, so that it is possible to prevent the engine 1 from being started when the first catalyst temperature Tcat is low. This makes it possible to prevent the exhaust performance from deteriorating. In addition, since the first catalyst temperature Tcat can be raised at the scheduled driving start time ts, when the vehicle 100 starts driving and the engine 1 starts, it is not necessary to drive the engine 1 just to warm up the first catalyst 30. This makes it possible to improve the sound and vibration performance.

Furthermore, in this modified example, a standby mode (heat retention control) is executed to maintain the first catalyst temperature Tcat at or above the first predetermined temperature T1. As a result, even if the vehicle 100 starts traveling after the scheduled travel start time ts, the first catalyst 30 has already been warmed up, so there is no need to drive the engine 1 to warm up the first catalyst 30. This makes it possible to prevent deterioration of exhaust performance and improve sound and vibration performance.

When only the first catalyst 30 and the engine 1 are warmed up, the controller 20 calculates the total time ta2 as the first total time by adding up the warm-up time tw1 and the warm-up time tw3. The controller 20 then calculates the time t1, which is the total time ta2 before the scheduled driving start time ts, as the warm-up start time tws. Note that, even in this case, the warm-up start time tws may be set slightly earlier than time t1 to allow for some leeway in the warm-up time.

The configuration, operation, and effects of the embodiment of the present invention configured as described above are now explained.

The vehicle 100 includes an engine 1, a first catalyst 30 that is provided in the exhaust passage 12 of the engine 1 and purifies exhaust gas discharged into the atmosphere, and has a heating device 31 that is heated by power from the battery 3, and a controller 20 (control device) that controls the operation of the engine 1 and the heating device 31.

The controller 20 estimates the first catalyst warm-up time tw1 required for the heating device 31 to warm up the first catalyst 30 to the first predetermined temperature T1, and starts supplying electric power E1 to the heating device 31 at least the first catalyst warm-up time tw1 before the scheduled start time ts of the vehicle 100 to warm up the first catalyst 30.

In this configuration, the supply of power to the heating device 31 is started at least one warm-up time ta before the scheduled start time ts of the vehicle 100 to warm up the first catalyst 30, so that the engine 1 can be prevented from being started when the first catalyst temperature Tcat is low. This can prevent the exhaust performance from deteriorating. In addition, since the first catalyst temperature Tcat can be raised at the scheduled start time ts, when the vehicle 100 starts to run and the engine 1 starts, it is not necessary to drive the engine 1 just to warm up the first catalyst 30. This can improve the sound and vibration performance. Furthermore, since the temperature of the first catalyst 30 is at the activation temperature, the exhaust performance can be prevented from deteriorating.

If the vehicle 100 does not start traveling at the scheduled travel start time ts, the controller 20 (control device) supplies a smaller amount of power E3 to the heating device 31 than during warm-up to maintain the first catalyst 30 at or above the first predetermined temperature T1.

In this configuration, even after the scheduled start time ts has passed, the temperature of the first catalyst 30 (first catalyst temperature Tcat) is maintained at or above the first predetermined temperature T1, so that exhaust performance can be prevented from deteriorating even if the vehicle 100 starts traveling after the scheduled start time ts.

The controller 20 (control device) estimates the engine warm-up time tw3 required to warm up the engine 1 to raise the coolant temperature Twat to the second predetermined temperature T2 before the scheduled start time ts of the vehicle 100, calculates the total time ta2 (first total time) by adding up the first catalyst warm-up time tw1 and the engine warm-up time tw3, and starts supplying electric power E1 to the heating device 31 at least the total time ta2 (first total time) before the scheduled start time ts of the vehicle 100, raises the first catalyst 30 to the first predetermined temperature T1, and then drives the engine 1 at the first rotation speed (rotation speed N1) to warm up the engine 1.

This configuration prevents the engine 1 from being started when the cooling water temperature Twat is low, thereby preventing the exhaust performance from deteriorating.

If the vehicle 100 does not start traveling at the scheduled travel start time ts, and the cooling water temperature Twat falls to the third predetermined temperature T3, the controller 20 (control device) drives the engine 1 to raise the cooling water temperature Twat to the second predetermined temperature T2.

In this configuration, the cooling water temperature Twat does not fall below the third predetermined temperature T3 even after the scheduled driving start time ts has passed. As a result, even if the vehicle 100 starts driving after the scheduled driving start time ts, the engine 1 is in a warm-up state, so exhaust performance can be prevented from deteriorating.

When the coolant temperature Twat drops to the third predetermined temperature T3 and the engine 1 is driven, the controller 20 (control device) stops supplying power to the heating device 31.

When the engine 1 is driven during standby mode, even if the supply of power to the heating device 31 is stopped, the first catalyst temperature Tcat can be maintained at or above the first predetermined temperature T1 by the exhaust gas from the engine 1. This makes it possible to reduce power consumption.

The vehicle 100 further includes a second catalyst 40 that purifies exhaust gas released into the atmosphere downstream of the first catalyst 30 in the exhaust passage 12. The controller 20 (control device) estimates the second catalyst warm-up time tw2 required to warm up the second catalyst 40 using the heating device 31 and the exhaust gas of the engine 1, calculates the total time ta1 (second total time) by adding the second catalyst warm-up time tw2 to the total time ta2 (first total time), starts supplying power to the heating device 31 at least the total time ta1 (second total time) before the scheduled start time ts of the vehicle 100 to raise the first catalyst 30 to the first predetermined temperature T1, drives the engine 1 at a second rotation speed (rotation speed N3) slower than the first rotation speed (rotation speed N1) to warm up the second catalyst 40, and then drives the engine 1 at the first rotation speed (rotation speed N1) to raise the coolant temperature Twat of the engine 1 to the second predetermined temperature T2.

In this configuration, the supply of power to the heating device 31 is started a total time ta1 before the scheduled start time ts of the vehicle 100 to warm up the first catalyst 30, and the engine 1 is driven to warm up the engine 1 and the second catalyst 40. This makes it possible to prevent the engine 1 from being started when the first catalyst temperature Tcat and the cooling water temperature Twat are low, so that deterioration of exhaust performance can be more reliably prevented.

The controller 20 (control device) estimates the outside air temperature at the next scheduled start time ts of driving, estimates the amount of energy Qr required for the next warm-up by the heating device 31 based on the estimated outside air temperature, and controls the charging rate of the battery 3 so that the amount of energy Qr is secured when the vehicle 100 finishes driving.

This configuration can prevent a situation in which the next pre-warm-up (warm-up before the scheduled start time ts of driving) cannot be performed due to an insufficient charge rate of battery 3.

Although the embodiments of the present invention have been described above, the above embodiments merely show some 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.

In the above embodiment, a series hybrid vehicle is described as an example of the vehicle 100, but the vehicle is not limited to this, and the above warm-up control can also be applied to parallel hybrid vehicles, etc. Furthermore, if the battery capacity is sufficient, the vehicle can also be applied to a vehicle that is driven only by the engine 1.

The first catalyst 30 and the heating device 31 may be configured separately or integrally.

In the above embodiment, the case where the scheduled start time ts is set in advance by the driver has been described as an example, but this is not limiting. For example, the controller 20 may learn the time when driving starts and set the scheduled start time ts based on the learned time. In addition, the scheduled start time ts may be changed taking into account traffic congestion information, etc. Furthermore, the scheduled start time ts may be estimated based on the driver's schedule and daily actions in conjunction with a mobile terminal (tablet terminal, smartphone) owned by the driver.

In the above embodiment, the controller 20 mounted on the vehicle 100 performs all the steps shown in Figures 2 and 3, but this is not limited to the above. For example, the processes in steps S1-S4 may be performed by a computer such as a personal computer, tablet terminal, or smartphone owned by the driver. Specifically, these devices calculate the warm-up times t1-t3 and the warm-up start time tws based on the set or estimated scheduled start time ts and the acquired outside air temperature Ta at the scheduled start time ts. The calculated warm-up start time tws is transmitted to the controller 20, and the controller 20 performs the processes in steps S5 and after based on the received warm-up start time tws. In this case, these devices and the controller 20 correspond to a control device.

Reference Signs List 100 Vehicle 1 Engine 1a Temperature sensor 2 Generator motor 3 Battery 3a SOC sensor 4 Travel motor 10 Cylinder 11 Intake passage 12 Exhaust passage 20 Controller (control device)
30 First catalyst 31 Heating device 31a Temperature sensor 40 Second catalyst

Claims (8)

The engine,
a first catalyst provided in an exhaust passage of the engine, for purifying exhaust gas discharged into the atmosphere, and having a heating device heated by electric power from a battery, comprising:
estimating a first catalyst warm-up time required for warming up the first catalyst by the heating device to a first predetermined temperature;
supplying electric power to the heating device at least a first catalyst warm-up time before a scheduled time for starting running of the vehicle to warm up the first catalyst ;
A vehicle control method characterized in that, if the vehicle does not start traveling at the scheduled start time, less power is supplied to the heating device than during the warm-up, thereby maintaining the first catalyst at or above the first predetermined temperature . The engine,
a first catalyst provided in an exhaust passage of the engine, for purifying exhaust gas discharged into the atmosphere, and having a heating device heated by electric power from a battery, comprising:
estimating a first catalyst warm-up time required for warming up the first catalyst by the heating device to a first predetermined temperature;
supplying electric power to the heating device at least a first catalyst warm-up time before a scheduled time for starting running of the vehicle to warm up the first catalyst;
Estimating an engine warm-up time required to warm up the engine so as to increase the engine coolant temperature to a second predetermined temperature;
calculating a first total time by adding up the first catalyst warm-up time and the engine warm-up time;
a first engine rotation speed of the engine start signal, the first engine rotation speed being set to a first predetermined speed, and a second engine rotation speed being set to a first predetermined speed. A method for controlling a vehicle according to claim 2 , comprising:
A vehicle control method characterized in that, when the vehicle does not start traveling at the scheduled travel start time and the cooling water temperature drops to a third predetermined temperature, the engine is driven to raise the cooling water temperature to the second predetermined temperature. A vehicle control method according to claim 3 , comprising:
a control method for a vehicle, comprising: stopping supply of electric power to the heating device when the cooling water temperature falls to the third predetermined temperature and the engine is driven. A method for controlling a vehicle according to any one of claims 2 to 4 , comprising:
The vehicle further includes a second catalyst downstream of the first catalyst in the exhaust passage for purifying exhaust gas discharged into the atmosphere,
estimating a second catalyst warm-up time required for warming up the second catalyst by the heating device and the exhaust gas of the engine;
calculating a second total time by adding the second catalyst warm-up time to the first total time;
a first predetermined temperature of the first catalyst by starting to supply electric power to the heating device at least the second total time before a scheduled time for the vehicle to start traveling, and then driving the engine at a second rotational speed slower than the first rotational speed to warm up the second catalyst, and then driving the engine at the first rotational speed to raise a cooling water temperature of the engine to the second predetermined temperature. A method for controlling a vehicle according to any one of claims 1 to 5 , comprising:
Estimate the outside temperature at the scheduled start time of the next trip,
estimating an amount of energy required for the next warm-up by the heating device based on the estimated outside air temperature;
A vehicle control method comprising: controlling a charging rate of the battery so as to secure the amount of energy when the vehicle finishes traveling. The engine,
a first catalyst provided in an exhaust passage of the engine for purifying exhaust gas discharged into the atmosphere and having a heating device that is heated by electric power from a battery;
A vehicle control device comprising:
estimating a first catalyst warm-up time required for warming up the first catalyst by the heating device to a first predetermined temperature;
supplying electric power to the heating device at least a first catalyst warm-up time before a scheduled time for starting running of the vehicle to warm up the first catalyst ;
A vehicle control device characterized in that, if the vehicle does not start traveling at the scheduled start time, less power is supplied to the heating device than during the warm-up, thereby maintaining the first catalyst at or above the first predetermined temperature . The engine,
a first catalyst provided in an exhaust passage of the engine for purifying exhaust gas discharged into the atmosphere and having a heating device that is heated by electric power from a battery;
A vehicle control device comprising:
estimating a first catalyst warm-up time required for warming up the first catalyst by the heating device to a first predetermined temperature;
supplying electric power to the heating device at least a first catalyst warm-up time before a scheduled time for starting running of the vehicle to warm up the first catalyst;
Estimating an engine warm-up time required to warm up the engine so as to increase the engine coolant temperature to a second predetermined temperature;
calculating a first total time by adding up the first catalyst warm-up time and the engine warm-up time;
a first engine rotation speed of the engine start time and a second engine rotation speed of the engine start time, the first engine rotation speed being set to a first rotation speed and a second ...