JP7424238B2 - Vehicle driving control systems and hybrid vehicles - Google Patents

Description

The present disclosure relates to a vehicle travel control system and a hybrid vehicle.

For example, vehicles such as electric cars and hybrid cars are configured to run by driving a motor using electric power supplied from a battery. As a driving control for such a vehicle, Patent Document 1 discloses a technique for changing the power loss until power is supplied from the battery to the motor based on the input/output allowable power of the battery.

JP2013-013280A

However, a portion of the electric power (hereinafter referred to as "supplied power") supplied to the motor is lost (hereinafter referred to as "loss power") before being converted into torque. Therefore, for example, when the motor outputs torque using only the electric power charged in the battery, such as when the vehicle starts, the difference between the supplied electric power and the lost electric power also becomes small. At this time, if the power loss fluctuates, the power that can be converted into torque may also fluctuate. As a result, the magnitude of the output torque also fluctuates, which may cause vibrations in the vehicle.

The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a vehicle travel control system that can suppress vehicle vibrations caused by power loss in the motor.

(1) A vehicle travel control system according to at least one embodiment of the present disclosure includes a motor and a control device that controls the motor, and the control device controls the motor from power supplied to the motor. If the first power obtained by subtracting the power loss is less than the required power for outputting the torque requested by the motor, the motor is driven with the second power obtained by subtracting a preset theoretical power loss from the supplied power. The motor is controlled as follows.

If the motor converts the first power into torque when the first power is less than or equal to the required power, the magnitude of the output torque may vary, which may cause vibrations in the vehicle. This is because the first power is obtained by subtracting the power loss from the power supply, and the power loss varies. According to the configuration described in (1) above, when the first power is less than or equal to the required power, the control device causes the motor to be driven with the second power obtained by subtracting a preset theoretical loss power from the supplied power. Control. Therefore, by driving the motor with a second power whose fluctuations are suppressed more than the first power instead of the first power which may fluctuate, vibrations of the vehicle due to power loss (power lost in the motor) can be reduced. Can be suppressed.

(2) In some embodiments, in the configuration described in (1) above, the theoretical power loss is set in advance such that the amount of change per unit time is less than a predetermined upper limit.

According to the configuration described in (2) above, it is possible to set the theoretical loss power so that the fluctuation thereof is small compared to the power loss. Therefore, the second power (the power obtained by subtracting the theoretical power loss from the supplied power) can be made more stable than the first power (the power obtained by subtracting the power loss from the power supply), and it is possible to suppress the vibration of the vehicle caused by the power loss. .

(3) In some embodiments, in the configuration described in (2) above, the upper limit value is greater than the amount of change in the power loss per unit time when the first power becomes equal to or less than the required power. It's also small.

The amount of change in power loss per unit time when the first power becomes equal to or less than the required power may be very large. According to the configuration described in (3) above, the upper limit of the amount of change in theoretical power loss per unit time is greater than the amount of change in power loss per unit time when the first power becomes equal to or less than the required power. small. For this reason, it is possible to set the theoretical power loss so that the fluctuation thereof is small compared to the power loss. Therefore, the second power can be made more stable than the first power, and vibrations of the vehicle caused by power loss can be suppressed.

(4) In some embodiments, in the configuration described in any one of (1) to (3) above, the theoretical power loss is set in advance so that the amount of change per unit time is constant. has been done.

According to the configuration described in (4) above, by driving the motor with the second electric power, it is possible to smooth the change in the magnitude of the output torque of the motor and suppress the occurrence of vibration in the vehicle.

(5) In some embodiments, in the configuration described in any one of (1) to (4) above, the theoretical power loss is such that the loss occurs after the first power becomes equal to or less than the required power. It is set in advance so that the power increases monotonically over time until it matches the theoretical power loss.

If the motor is driven with the first power while there is a difference between the power loss and the theoretical power loss, there is a risk that vibrations of the vehicle will occur due to fluctuations in the power loss. According to the configuration described in (5) above, the motor is driven with the second power until the power loss matches the theoretical power loss, so that the motor is driven by the second power until the power loss matches the theoretical power loss. The generation of vibration can be suppressed.

(6) In some embodiments, in the configuration described in any one of (1) to (5) above, when the power loss matches the theoretical power loss, the control device controls the first power The motor is controlled so as to be driven by the motor.

The fluctuation in power loss after the power loss matches the theoretical power loss is smaller than the fluctuation in the power loss before the power loss matches the theoretical power loss. Therefore, after the power loss matches the theoretical power loss, even if the motor is driven with the first power, vibrations of the vehicle due to the power loss are unlikely to occur. Therefore, according to the configuration described in (6) above, the electric power for driving the motor can be switched to the first electric power at an appropriate timing in which vibration of the vehicle due to power loss is unlikely to occur.

(7) In some embodiments, in the configuration described in any one of (1) to (6) above, the control device further includes a generator that generates electric power, and the control device controls the power generated by the generator. When the supplied power includes the supplied power, the motor is controlled to be driven by the first power.

When the power generated by the generator is included in the supplied power, the first power can satisfy the required power. Therefore, even if the motor is driven with the first electric power, vibrations of the vehicle due to power loss will not occur. Therefore, according to the configuration described in (7) above, the electric power for driving the motor can be switched to the first electric power at an appropriate timing when vibrations of the vehicle due to power loss are no longer generated.

(8) In some embodiments, a hybrid vehicle includes the vehicle travel control system described in (7) above, an engine connected to the generator, and a battery charged by the generator.

According to the configuration described in (8) above, the travel control system can be applied to a hybrid vehicle that includes a motor and an engine as a drive source.

According to at least one embodiment of the present disclosure, it is possible to suppress vehicle vibration caused by power loss in the motor.

1 is a schematic diagram showing the configuration of a vehicle to which a travel control system according to an embodiment of the present disclosure is applied. FIG. 1 is a schematic functional block diagram of a control device according to an embodiment of the present disclosure. It is a graph showing generated power according to an embodiment of the present disclosure. 7 is a graph showing theoretical power loss according to an embodiment of the present disclosure. 3 is a graph showing output torque according to an embodiment of the present disclosure.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, and are merely illustrative examples. do not have.

(Composition of travel control system)
FIG. 1 is a schematic diagram showing the configuration of a vehicle 100 to which a travel control system 1 according to an embodiment of the present disclosure is applied. In the exemplary embodiment shown in FIG. 1 , vehicle 100 includes a driving control system 1 including a motor 2 and a control device 4 that controls the motor 2 , a battery 102 , an engine 104 , a generator 106 , and an auxiliary machine 108 . , and a drive wheel 110. Note that in this disclosure, the vehicle 100 will be described as an example of a hybrid vehicle that includes the motor 2 and the engine 104 as drive sources, but is not limited to a hybrid vehicle.

The generator 106 is connected to the engine 104 and generates electric power for driving the motor 2 when the engine 104 is driven. The battery 102 is charged with electric power generated by the generator 106. Each of the motor 2 and the auxiliary machine 108 is driven when the electric power charged in the battery 102 is supplied. The drive wheels 110 are driven to rotate when the torque output by the drive of the motor 2 is transmitted. The vehicle 100 is configured to travel by rotationally driving the drive wheels 110. Note that the auxiliary equipment 108 is not particularly limited as long as it is driven by the electric power charged in the battery 102, and includes, for example, a heater, an air compressor, a converter, and the like. Further, the driving wheels 110 may include either a front wheel or a rear wheel, or may include both a front wheel and a rear wheel (that is, in this case, the vehicle 100 may be a four-wheel drive vehicle). . Further, in the present disclosure, the electric power generated by the generator 106 is supplied to the motor 2 via the battery 102, but in other embodiments, the electric power is directly supplied to the motor 2 without going through the battery 102. It may be configured as follows.

The control device 4 is electrically connected to each of the motor 2, the battery 102, the generator 106, and the auxiliary machine 108, and is configured to be able to exchange electrical information with each other. The control device 4 is a computer such as an electronic control device, and includes a processor such as a CPU or a GPU (not shown), a memory such as a ROM or a RAM, an I/O interface, and the like. The control device 4 realizes each functional unit included in the control device 4 by a processor operating (operating, etc.) according to instructions of a program loaded into the memory. Each functional unit of the control device 4 will be explained with reference to FIG. 2.

FIG. 2 is a schematic functional block diagram of the control device 4 according to an embodiment of the present disclosure. In the exemplary embodiment shown in FIG. 2, the control device 4 includes a first power calculation section 6, a second power calculation section 8, a required power calculation section 10, a drive control section 12, a storage section 14, and a power generation section 14. An instruction section 16 is included.

The first power calculation unit 6 calculates the power charged in the battery 102 (hereinafter referred to as charging power e1), the power consumed for driving the auxiliary machine 108 (hereinafter referred to as auxiliary machine power consumption e2), And the power actually lost by driving the motor 2 (hereinafter referred to as power loss e3 of the motor 2) is obtained. Then, the first power calculation unit 6 calculates the first power e5 by subtracting the auxiliary machine power consumption e2 and the power loss e3 of the motor 2 from the charging power e1. In other words, the first power e5 is the power obtained by subtracting the power loss e3 of the motor 2 from the power supply e4 supplied to the motor 2 (=charging power e1 - auxiliary power consumption e2), and is the power that is output by driving the motor 2. This is the actual power that can be converted into torque (hereinafter referred to as output torque Tr). Note that the first power calculation unit 6 may obtain the charging power e1 from the battery 102, or may obtain it from a device other than the battery 102, such as a device that monitors the charging power e1 of the battery 102. good. Similarly, the first power calculation unit 6 may acquire the auxiliary machine power consumption e2 from the auxiliary machine 108, or obtain it from a device other than the auxiliary machine 108, such as a device that monitors the operation of the auxiliary machine. You may.

The second power calculation unit 8 calculates the charging power e1 charged in the battery 102, the auxiliary machine power consumption e2 consumed for driving the auxiliary machine 108, and the preset power stored in the storage unit 14. (hereinafter referred to as theoretical loss power e6) is obtained. Then, the second power calculation unit 8 calculates the second power e7 by subtracting the auxiliary machine power consumption e2 and the theoretical loss power e6 from the charging power e1. In other words, the second electric power e7 is the theoretical electric power obtained by subtracting the theoretical loss electric power e6 from the supplied electric power e4 (=charging electric power e1 - auxiliary power consumption e2) supplied to the motor 2. Although the theoretical power loss e6 will be explained later, in the present disclosure, the case where the second power e7 is larger than the first power e5 will be described as an example.

The required power calculation unit 10 obtains the required torque Tq requested of the motor 2 from the operator based on, for example, the amount of depression of the accelerator pedal. Then, the required power calculation unit 10 calculates the required power e8 for outputting this required torque Tq.

The drive control unit 12 obtains each of the first power e5, the second power e7, and the required power e8. Then, if the first power e5 exceeds the required power e8, the drive control unit 12 transmits a drive signal S1 to the motor 2 to drive with the first power e5. When the motor 2 receives the drive signal S1, it is driven with the first electric power e5. In this case, since the first power e5 exceeds the required power e8, the motor 2 does not convert the entire first power e5 into the output torque Tr, but a portion of the first power e5 (equivalent to the required power e8). power) is converted into output torque Tr.

On the other hand, if the first power e5 is less than or equal to the required power e8, a drive signal S2 is sent to the motor 2 to drive it with the second power e7. When the motor 2 receives the drive signal S2, it is driven by the second electric power e7. In this case, battery 102 releases power exceeding charging power e1. Specifically, the battery 102 is configured so that reserve power other than the charging power e1 continues to remain in the battery 102 in order to maintain the quality of the battery 102. If the first power e5 is less than or equal to the required power e8, the drive control unit 12 causes the battery 102 to discharge this reserve power in addition to the charging power e1. Therefore, even if the second power e7 is greater than the first power e5, the motor 2 can be driven by the second power e7. Note that the output torque Tr output by converting the second electric power e7 may satisfy the required torque Tq or may be smaller than the required torque Tq.

The power generation instruction unit 16 acquires the power loss e3 of the motor 2 and transmits a power generation signal S3 to the generator 106 to generate power for driving the motor 2. Upon receiving the power generation signal S3, the generator 106 generates electric power for driving the motor 2 by driving the engine 104. In this way, the generator 106 generates electric power based on the power loss e3 of the motor 2, thereby suppressing the shortage of generated electric power. Electric power generated by the generator 106 (hereinafter referred to as generated power eg) is charged into the battery 102. In other words, the charging power e1 includes the generated power eg. Then, when the generated power eg is included in the supplied power e4 supplied to the motor 2, the drive control unit 12 transmits a drive signal S1 to the motor 2 and controls the motor 2 to be driven with the first power e5. do.

Next, with reference to FIG. 4, the theoretical loss power e6 will be specifically explained. FIG. 3 is a diagram showing generated power eg converted into output torque Tr by the motor 2 according to an embodiment of the present disclosure. FIG. 4 is a diagram showing the theoretical power loss e6 according to an embodiment of the present disclosure. FIG. 5 is a diagram showing the output torque Tr according to an embodiment of the present disclosure. In each of FIGS. 3 to 5, the horizontal axis represents time, and t1 is the timing at which the operator depresses the accelerator pedal to start the vehicle 100. In other words, this is the timing at which the required torque Tq is requested from the motor 2. t2 is the timing at which the motor 2 starts converting the generated power eg into the output torque Tr. Further, in FIG. 4, the power loss e3 of the motor 2 is illustrated by a dashed line. Further, in FIG. 5, the output torque Tr when the motor 2 is driven with the first electric power e5 is shown by a dashed line. Furthermore, for the purpose of explaining the operation of the travel control system 1, it is assumed that the first electric power e5 becomes equal to or less than the required electric power e8 at t1.

As shown in FIG. 3, the motor 2 does not start converting the generated power eg into the output torque Tr at the same time as the required torque Tq is requested, but converts the generated power eg into the output torque Tr after the required torque Tq is requested. Start converting to . The time difference between t1 and t2 is the time difference from when the power generation signal S3 is transmitted from the power generation instruction unit 16 of the control device 4 until the generated power eg is supplied to the motor 2.

In the exemplary embodiment shown in FIG. 4, the theoretical loss power e6 is set in advance so that the amount of change per unit time is constant between t1 and t2. This theoretical power loss e6 monotonically increases starting from t1. This monotonous increase continues until the power loss e3 and the theoretical power loss e6 match. Note that the present disclosure is not limited to the amount of change in the theoretical power loss e6 per unit time being constant. For example, the amount of increase in theoretical power loss e6 per unit time may gradually decrease from t1 to t2.

Moreover, the theoretical loss power e6 is set in advance so that the amount of change per unit time is less than a predetermined upper limit value. This upper limit value is smaller than the amount of change in power loss e3 per unit time at t1 (when the first power e5 becomes equal to or less than the required power e8). In the exemplary embodiment shown in FIG. 4, the upper limit is 50 kw/s (0.5 kw/10 ms), and the amount of change in theoretical power loss e6 per unit time is 10 kw/s (0.1 kw/10 ms). ) to 40kw/s (0.4kw/10ms).

(action/effect)
The functions and effects of the travel control system 1 for the vehicle 100 according to an embodiment of the present disclosure will be described. According to the findings of the present inventors, when the motor 2 converts the first power e5 into torque when the first power e5 is less than or equal to the required power e8, the magnitude of the output torque Tr also changes, and the vibration of the vehicle 100 is reduced. We have found that there is a possibility that this may occur. This is because the first power e5 is obtained by subtracting the power loss e3 of the motor 2 from the power supply e4, and the power loss e3 of the motor 2 varies (see FIG. 4).

To explain more specifically, for example, when the vehicle 100 starts, the supplied power e4 is the power obtained by subtracting the auxiliary machine power consumption e2 from the charging power e1 charged in the battery 102 before the vehicle 100 starts. In this case, the supply power e4 supplied to the motor 2 is small, and the difference between the supply power e4 and the loss power e3 of the motor 2 is often small. At this time, as shown by the dashed line in FIG. 4, when the power loss e3 of the motor 2 changes, the first power e5 obtained by subtracting the power loss e3 of the motor 2 from the supplied power e4 becomes less than or equal to the required power e8. There is. As a result, as shown by the dashed line in FIG. 5, when the motor 2 is driven with the first electric power e5, the magnitude of the output torque Tr output from the motor 2 also changes, causing vibrations in the vehicle 100. There is a risk that you may let it happen.

According to the present embodiment, when the first power e5 is less than or equal to the required power e8, the control device 4 causes the motor to be driven with the second power e7 obtained by subtracting a preset theoretical loss power e6 from the supplied power e4. Control 2. As illustrated and explained in FIG. 4, the theoretical power loss e6 is set to have smaller fluctuations than the power loss e3. Therefore, by driving the motor 2 with the second electric power e7 instead of the first electric power e5, a stable output torque Tr can be output as shown in FIG. Therefore, vibration of vehicle 100 caused by power loss e3 can be suppressed. Note that the power loss e3 of the motor 2 varies greatly, especially in the low rotation range of the motor 2. Therefore, the travel control system 1 for the vehicle 100 according to the present disclosure is advantageous in suppressing vibrations when the vehicle 100 starts, but is not limited thereto. For example, while the vehicle 100 is running, the control device 4 may control the motor 2 to be driven with the second power e7 if the first power e5 is less than or equal to the required power e8.

Further, according to the present embodiment, the theoretical loss power e6 is set in advance so that the amount of change per unit time is constant between t1 and t2. Therefore, as shown in FIG. 5, between t1 and t2, compared to the case where the output torque Tr is output with the first power e5, the change in the magnitude of the output torque Tr is smoothed, and the loss of the motor 2 is It is possible to suppress the occurrence of vibrations in the vehicle 100 caused by the electric power e3.

Further, according to the present embodiment, the theoretical loss power e6 is set in advance so that the amount of change per unit time is less than a predetermined upper limit value. Therefore, the amount of change in the theoretical power loss e6 can be made smaller than the amount of change in the power loss e3 of the motor 2. Therefore, the second electric power e7 can be made more stable than the first electric power e5, and the vibration of the vehicle 100 caused by the power loss e3 of the motor 2 can be suppressed.

As shown in FIG. 4, the amount of change per unit time in the power loss e3 of the motor 2 may become extremely large when the first power e5 becomes equal to or less than the required power e8. According to the present embodiment, the upper limit of the amount of change per unit time in the theoretical power loss e6 is the amount of change per unit time in the power loss e3 of the motor 2 when the first power e5 becomes equal to or less than the required power e8. smaller than Therefore, it is possible to set the theoretical power loss e6 to have a smaller variation compared to the power loss e3 of the motor 2. Therefore, the second electric power e7 can be made more stable than the first electric power e5, and the vibration of the vehicle 100 caused by the power loss e3 of the motor 2 can be suppressed.

When the generated power eg is included in the supplied power e4, the first power e5 satisfies the required power e8. Therefore, even if the motor 2 is driven with the first electric power e5, vibrations of the vehicle 100 due to the power loss e3 of the motor 2 will not occur. According to this embodiment, the electric power for driving the motor 2 can be switched to the first electric power e5 at an early timing when the vibration of the vehicle 100 due to the power loss e3 of the motor 2 stops occurring. Note that the battery 102 can quickly secure the above-mentioned reserve power.

If the motor 2 is driven with the first power e5 while there is a difference between the power loss e3 of the motor 2 and the theoretical power loss e6, vibrations of the vehicle 100 may occur due to fluctuations in the power loss e3 of the motor 2. There is. According to this embodiment, since the motor 2 is driven with the second power e7 until the power loss e3 of the motor 2 matches the theoretical power loss e6, there is a gap between the power loss e3 of the motor 2 and the theoretical power loss e6. It is possible to suppress the occurrence of vibrations in the vehicle 100 while there is a difference.

In some embodiments, the drive control unit 12 of the control device 4 controls the motor 2 to drive with the first power e5 when the power loss e3 matches the theoretical power loss e6. The fluctuation in the power loss e3 of the motor 2 after the power loss e3 of the motor 2 matches the theoretical power loss e6 is the fluctuation of the power loss e3 of the motor 2 before the power loss e3 of the motor 2 matches the theoretical power loss e6. small compared to Therefore, after the power loss e3 of the motor 2 matches the theoretical power loss e6, even if the motor 2 is driven with the first power e5, vibrations of the vehicle 100 due to the power loss e3 of the motor 2 will not occur. Hateful. Therefore, the electric power for driving the motor 2 can be switched to the first electric power e5 at an early timing when vibrations of the vehicle 100 due to the power loss e3 of the motor 2 are less likely to occur.

Although the vehicle travel control system of the present disclosure has been described above, the present disclosure is not limited to the above-mentioned form, and various changes can be made without departing from the purpose of the present disclosure.

1 Travel control system 2 Motor 4 Control device 100 Vehicle 102 Battery 104 Engine 106 Generator Tq Required torque Tr Output torque e1 Charging power e2 Auxiliary power consumption e3 Power loss e4 Supply power e5 First power e6 Theoretical power loss e7 Second power e8 Required power eg Generated power

Claims (8)

motor and
A control device that controls the motor,
The control device controls the power supply from the supplied power when the first power obtained by subtracting the power loss of the motor from the supplied power supplied to the motor is less than or equal to the required power for outputting the requested torque to the motor. controlling the motor to be driven with a second power after subtracting a preset theoretical loss power;
Vehicle driving control system. The theoretical power loss is set in advance so that the amount of change per unit time is less than a predetermined upper limit.
The vehicle travel control system according to claim 1. The upper limit value is smaller than the amount of change in the power loss per unit time when the first power becomes equal to or less than the required power.
The vehicle travel control system according to claim 2. The theoretical power loss is set in advance so that the amount of change per unit time is constant.
The vehicle travel control system according to any one of claims 1 to 3. The theoretical power loss is set in advance so as to monotonically increase over time from when the first power becomes less than or equal to the required power until the power loss matches the theoretical power loss.
The vehicle travel control system according to any one of claims 1 to 4. The control device controls the motor to be driven with the first power when the power loss matches the theoretical power loss.
The vehicle travel control system according to any one of claims 1 to 5. It is further equipped with a generator that generates electricity.
The control device controls the motor to be driven by the first electric power when the electric power generated by the generator is included in the supplied electric power.
The vehicle travel control system according to any one of claims 1 to 6. A vehicle travel control system according to claim 7;
an engine connected to the generator;
a battery charged by the generator;
hybrid vehicle.

Images