JP2021123217A - Vehicle control device - Google Patents

Abstract

To provide a vehicle control device that can reduce muffled sound that is generated inside a vehicle when a hybrid vehicle decelerates intensely.SOLUTION: A control unit 48 monitors a variable (motor torque command value) which is correlated with any one of vehicle deceleration, a regeneration amount by a second electric motor and a displacement amount of an engine mount 20 and, when detecting that the variable varies from less than a first threshold to the first threshold or more, performs such control of making an operation point 80 of an engine 16 outside the muffled sound generating region 78.SELECTED DRAWING: Figure 3

Description

The present invention relates to a vehicle control device for a hybrid vehicle having an engine, an electric motor for power generation, and an electric motor for driving.

Patent Document 1 discloses a hybrid vehicle that suppresses a driver's discomfort due to an abnormal exhaust noise of the engine when the generator is operated by the power of the engine to charge the battery while the vehicle is stopped. In Patent Document 1, a plurality of operation lines are set in the coordinate system of the engine speed and the torque of the engine, and the operation lines (exhaust abnormal noise) that prioritize the suppression of exhaust abnormal noise over the operating efficiency while the vehicle is stopped. It is disclosed that the engine is controlled by using the suppression operation line).

Japanese Patent No. 5971188

The engine is fixed to the vehicle body via multiple engine mounts. The engine mount suppresses engine vibration propagating from the engine to the vehicle body, and also suppresses noise generated by engine vibration. However, at the time of strong deceleration where the deceleration of the vehicle is large, the amount of displacement of the reference position of the engine mount becomes large, and the amount of vibration and noise that can be reduced by the engine mount decreases. Therefore, during strong deceleration, a muffled sound is generated in the vehicle interior. Patent Document 1 discloses a technique for suppressing an abnormal exhaust noise while the vehicle is stopped, but does not disclose a technique for suppressing a muffled noise generated when the vehicle is strongly decelerated.

The present invention has been made in consideration of such a problem, and an object of the present invention is to provide a vehicle control device capable of reducing muffled noise generated in a hybrid vehicle during strong deceleration.

Aspects of the present invention are
An engine that is fixed to the car body via an engine mount,
A first motor capable of generating electricity with the power of the engine,
A second motor that can drive the drive shaft of the vehicle by power running and generate electricity by regeneration,
A control unit that controls each operation of the engine, the first electric motor, and the second electric motor,
It is a vehicle control device having
The control unit monitors a variable that correlates with any one of the deceleration of the vehicle, the amount of regeneration by the second motor, and the amount of displacement of the engine mount, and the variable is from less than the first threshold value to the first. When it is detected that the change exceeds the threshold value, the operation point of the engine is controlled to be outside the muffled sound generation region.

According to the present invention, it is possible to reduce the muffled sound generated in the vehicle during strong deceleration of the hybrid vehicle.

FIG. 1 is a diagram showing a configuration of a vehicle control device. FIG. 2 is a diagram showing a configuration of a control system of a vehicle control device. FIG. 3 is a diagram showing engine characteristic information. FIG. 4 is a flowchart showing the processing of the vehicle control device. FIG. 5 is a time chart showing changes in vehicle speed, accelerator pedal operation amount, engine speed, traction motor motor torque command value, and battery charge amount.

Hereinafter, the vehicle control device according to the present invention will be described in detail with reference to the accompanying drawings with reference to suitable embodiments.

[1. Configuration of vehicle control device 10]
The configuration of the vehicle control device 10 will be described with reference to FIGS. 1 and 2. The vehicle described in this embodiment is a hybrid vehicle in which the traction motor 30 is driven by the power of the engine 16 and travels by the power of the traction motor 30. The vehicle control device 10 includes an engine 16, an engine drive unit 22, a battery 24, a generator 26, a generator PDU 28, a traction motor 30, a motor PDU 32, a first power transmission mechanism 34a, and a second power transmission mechanism. It has 34b, a sensor group 36, a hybrid ECU 46, an engine ECU 68, and a battery ECU 72.

The engine 16 is fixed to the vehicle body 18 via a plurality of engine mounts 20. The engine drive unit 22 has various devices (fuel injection valve, throttle valve, ignition coil, etc.) that control the operation of the engine 16.

The battery 24 is electrically connected to the generator PDU 28 and the motor PDU 32. The battery 24 is charged by the electric power generated by the generator PDU 28 and the motor PDU 32. The battery ECU 72 has a processor, various memories, an A / D conversion circuit, and a communication interface. The battery ECU 72 manages the battery 24. For example, the battery ECU 72 calculates the SOC and outputs the target charging power of the battery 24 to the hybrid ECU 46.

The generator 26 corresponds to the first electric motor. The rotation shaft of the generator 26 is connected to the rotation shaft of the engine 16 via the first power transmission mechanism 34a. The generator PDU 28 includes a converter that converts alternating current power output by the generator 26 during power generation into direct current power and outputs the power to the battery 24, and a switching element that adjusts the power. Further, the generator PDU 28 has a generator ECU 70 (FIG. 2) that controls a switching element.

The traction motor 30 corresponds to the second electric motor. The rotating shaft of the traction motor 30 is connected to the drive shaft 14 via the second power transmission mechanism 34b. The motor PDU 32 includes a converter that converts AC power output by the traction motor 30 during regeneration into DC power and outputs it to the battery 24, a switching element that adjusts the power output to the battery 24, and the battery 24 during power running. It has an inverter that converts the output DC power into AC power and outputs it to the traction motor 30, and a switching element that adjusts the power output to the traction motor 30. Further, the motor PDU 32 has a motor ECU 66 (FIG. 2) that controls a switching element.

The first power transmission mechanism 34a and the second power transmission mechanism 34b have a gear, a clutch, and a power distribution mechanism.

As shown in FIG. 2, the sensor group 36 includes an AP sensor 38, a vehicle speed sensor 40, a motor rotation sensor 42, and an engine rotation sensor 44. The AP sensor 38 is a displacement meter provided in the vicinity of the accelerator pedal (also referred to as AP), detects the operation amount of the AP, and outputs the detected value to the hybrid ECU 46. The vehicle speed sensor 40 is a resolver or encoder provided on the drive shaft 14 or the like of the vehicle, detects the rotational position of the drive shaft 14, and outputs the detected value to the hybrid ECU 46. The motor rotation sensor 42 is a resolver or an encoder provided in the traction motor 30, detects the rotation position of the rotation shaft of the traction motor 30, and outputs the detected value to the hybrid ECU 46. The engine rotation sensor 44 is a resolver or an encoder provided in the engine 16, detects the rotation position of the rotation shaft (crankshaft, etc.) of the engine 16 and outputs the detected value to the hybrid ECU 46.

The hybrid ECU 46 has an A / D conversion circuit (not shown) and a communication interface in addition to the control unit 48 and the storage unit 50. The control unit 48 is composed of a processor including, for example, a CPU. The control unit 48 realizes various functions by executing a program stored in the storage unit 50. In the present embodiment, the control unit 48 includes a target driving force calculation unit 52, a motor torque command value calculation unit 54, a vehicle required power calculation unit 56, an engine target output calculation unit 58, and an engine target rotation speed calculation unit 60. It functions as an engine torque command value calculation unit 62 and a generator torque command value calculation unit 64.

The target driving force calculation unit 52 calculates the target driving force of the vehicle by using the detection value of the AP sensor 38 and the detection value of the vehicle speed sensor 40. The motor torque command value calculation unit 54 converts the target driving force into the target torque of the traction motor 30 and outputs the motor torque command value to the motor ECU 66. The vehicle required power calculation unit 56 calculates the power to be generated, that is, the vehicle required power, using the target torque of the traction motor 30, the detected value of the motor rotation sensor 42, the power consumption of the electrical components, and the like. The engine target output calculation unit 58 calculates the engine target output using the vehicle required power and the target charging power of the battery 24. The engine target rotation speed calculation unit 60 calculates the engine target rotation speed using the engine target output. The engine torque command value calculation unit 62 calculates the engine target torque using the engine target output and the detection value of the engine rotation sensor 44, and outputs the engine torque command value to the engine ECU 68. The generator torque command value calculation unit 64 calculates the target torque of the generator 26 using the engine target rotation speed and the detection value of the engine rotation sensor 44, and outputs the generator torque command value to the generator ECU 70.

The storage unit 50 is composed of a RAM, a ROM, and a memory such as a hard disk. The storage unit 50 stores various information used in the processing performed by the control unit 48 in addition to the various programs. Here, the storage unit 50 stores the first threshold value and the second threshold value. The first threshold value is a value of motor torque for determining whether or not a muffled sound is generated. The second threshold value is a value of the motor torque for determining whether or not the muffled sound has disappeared. The first threshold value and the second threshold value are obtained in advance by simulation or the like.

The motor ECU 66, the engine ECU 68, and the generator ECU 70 have a processor, various memories, an A / D conversion circuit, a communication interface, and a driver. The motor ECU 66 controls each switching element of the motor PDU 32 according to the motor torque command value. The engine ECU 68 controls the engine drive unit 22 according to the engine torque command value. The generator ECU 70 controls each switching element of the generator PDU 28 according to the generator torque command value.

[2. Operation of vehicle control device 10]
When a strong deceleration occurs in the vehicle, the engine mount 20 arranged on the front side is compressed. When the engine 16 generates a high torque in this state, the vibration of the engine 16 propagates to the vehicle body 18 without being reduced by the engine mount 20. As a result, a muffled sound is generated.

In the present embodiment, the control unit 48 performs a process for suppressing a muffled sound. Each calculation unit of the control unit 48 calculates each value at predetermined time intervals. At this time, the control unit 48 monitors a variable that correlates with any of the deceleration of the vehicle, the amount of regeneration by the traction motor 30, and the amount of displacement of the engine mount 20. For example, the vehicle required power calculation unit 56 of the control unit 48 monitors the motor torque command value output by the motor torque command value calculation unit 54. The motor torque command value is an index for determining whether or not a muffled sound is generated.

Here, the operation of the engine 16 will be described with reference to FIG. When the AP is operated, the vehicle required power output by the vehicle required power calculation unit 56 increases, and the engine target output output by the engine target output calculation unit 58 also increases. Then, the output of the engine 16 (engine speed x engine torque) increases, and the generated power of the generator 26 increases. At this time, as shown in FIG. 3, the output of the engine 16 (engine speed x engine torque) rises along the operation line 76 (arrow 82a). In FIG. 3, the equal output line 74 corresponds to the generated power of the generator 26.

The control unit 48 performs the process shown in FIG. 4, that is, the process of suppressing the muffled sound. The process shown in FIG. 4 is repeatedly executed during the operation of the vehicle.

In step S1, the vehicle required power calculation unit 56 determines whether or not the AP is being operated by using the detection value of the AP sensor 38. For example, when the AP is not operated (step S1: YES) as in the time points t1 to t4 in FIG. 5, the process proceeds to step S2. In this case, the traction motor 30 functions as a regenerative brake, so that the vehicle decelerates. On the other hand, for example, when the AP is operated (step S1: NO) as in the time points t0 to t1 in FIG. 5, the process is completed, and when the timing for performing the next series of processes arrives, step S1 is performed again. Processing is executed.

In step S2, the vehicle required power calculation unit 56 compares the latest motor torque command value calculated by the motor torque command value calculation unit 54 with the first threshold value stored in advance in the storage unit 50. The motor torque command value becomes a positive value during power running and a negative value during regeneration. The first threshold value is a negative threshold value indicating the regenerative torque. Here, for convenience of explanation, the motor torque command value and the absolute value of various threshold values are used. For example, when the state of | motor torque command value | << | first threshold value | changes to | motor torque command value | ≧ | first threshold value | as in time point t2 of FIG. 5 (step S2: YES), processing Goes to step S3. In FIG. 3, the output of the engine 16 at this time is shown as an operating point 80a. On the other hand, for example, when | motor torque command value | << | first threshold value | (step S2: NO) as in the time points t1 to t2 in FIG. 5, the processing is completed, and then the timing for performing a series of processing is performed. Is reached, the process of step S1 is executed again.

In step S3, the vehicle required power calculation unit 56 executes the power generation amount reduction control. For example, the storage unit 50 stores a map showing the relationship between the deceleration, the number of revolutions of the engine 16, and the required electric power of the vehicle capable of suppressing muffled noise. The vehicle required power calculation unit 56 uses this map to obtain a target power 74a (FIG. 3) as a vehicle required power capable of suppressing muffled noise. The engine target output calculation unit 58 calculates the engine target output according to the target power 74a. Then, the engine torque command value calculation unit 62 outputs the engine torque command value to the engine ECU 68, and the generator torque command value calculation unit 64 outputs the generator torque command value to the generator ECU 70.

At this time, since the engine torque has high responsiveness, it decreases relatively quickly according to the decrease in the vehicle required electric power (target electric power 74a) and the engine target output. On the other hand, since the engine speed is affected by inertia, it takes time to decrease compared with the engine torque. Therefore, the output of the engine 16 (operating point 80) is such that the engine torque first decreases from the operating point 80a (arrow 82b), and then the engine speed decreases (arrow 82c). The equal output line 74 corresponding to the target power 74a is set so as not to intersect with the muffled sound generation region 78. Therefore, the muffled sound is suppressed.

When the output of the engine 16 decreases, the charge amount of the battery 24 decreases as immediately after t2 in FIG. In FIG. 5, the charge amount when the power generation amount reduction control is executed is shown by a solid line, and the charge amount when the power generation amount reduction control is not executed is shown by a broken line. FIG. 5 shows the charge amount as a negative value, indicating that the charge amount is higher toward the lower part of the drawing and lower at the upper part of the drawing. The determination in step S4 is performed in parallel with the process in step S3.

In step S4, the vehicle demand power calculation unit 56 compares the latest motor torque command value calculated by the motor torque command value calculation unit 54 with the second threshold value stored in advance in the storage unit 50. The second threshold value, like the first threshold value, is a negative threshold value indicating the regenerative torque, and its absolute value is smaller than the absolute value of the first threshold value. For example, when the state of | motor torque command value |> | second threshold value | changes to | motor torque command value | ≤ | second threshold value | as in time point t3 of FIG. 5 (step S4: YES), processing Goes to step S5. On the other hand, for example, when the | motor torque command value |> | second threshold value | (step S4: NO) as in the time points t2 to t3 of FIG. 5, the process of step S4 is repeatedly executed.

In step S5, the vehicle required power calculation unit 56 releases the power generation amount reduction control. At this time, the vehicle required power calculation unit 56 calculates the vehicle required power using the target torque of the traction motor 30, the detected value of the motor rotation sensor 42, the power consumption of the electrical components, and the like as usual. When step S5 ends, a series of processes ends.

[3. Modification example]
In the above-described embodiment, the vehicle required power calculation unit 56 obtains a target power 74a capable of suppressing muffled noise. Instead, the engine target output calculation unit 58 may calculate the engine target output by reducing the output of the engine 16 by a predetermined amount.

For example, in the above-described embodiment, the vehicle required power calculation unit 56 sets the vehicle required power to the target power 74a, which is suppressed more than usual, as a control for keeping the operating point 80 of the engine 16 outside the muffled sound generation region 78. .. However, as shown in FIG. 3, the vehicle required power calculation unit 56 sets the vehicle required power as the normal target power 74b, and the engine target rotation speed calculation unit 60 and the engine torque command value calculation unit 62 are in the muffled sound generation region 78. Control may be performed to operate the engine 16 near the boundary 74c. In this case, the operating point 80 is maintained near the boundary 74c of the muffled sound generation region 78.

[4. Technical idea obtained from the embodiment]
The technical ideas that can be grasped from the above embodiments are described below.

Aspects of the present invention are
The engine 16 fixed to the vehicle body 18 via the engine mount 20 and
A first electric motor (generator 26) capable of generating electricity with the power of the engine 16 and
A second electric motor (traction motor 30) capable of driving the drive shaft 14 of the vehicle by power running and generating electricity by regeneration, and
A control unit 48 that controls each operation of the engine 16, the first electric motor, and the second electric motor, and
The vehicle control device 10 having the
The control unit 48 monitors a variable (motor torque command value) that correlates with any of the deceleration of the vehicle, the amount of regeneration by the second electric motor, and the displacement amount of the engine mount 20, and the variable. When it is detected that the engine 16 has changed from less than the first threshold value to more than the first threshold value, the operation point 80 of the engine 16 is controlled to be outside the muffled sound generation region 78.

According to the above configuration, since the operation point 80 of the engine 16 is controlled to be outside the muffled sound generation region 78, the muffled sound generated in the vehicle during strong deceleration of the hybrid vehicle can be reduced.

In aspects of the invention
The control unit 48 reduces the amount of power generated by the first electric motor (generator 26) as compared with the case where the operating point 80 of the engine 16 is less than the first threshold value, as a control to move the operating point 80 of the engine 16 out of the muffled sound generation region 78. Control the amount of power generation to be reduced.

According to the above configuration, since the power generation amount reduction control is performed, it is possible to reduce the muffled sound generated in the vehicle during strong deceleration of the hybrid vehicle. In particular, a variable that correlates with any of the deceleration of the vehicle, the amount of regeneration by the second motor (traction motor 30), and the amount of displacement of the engine mount 20, for example, the motor torque command value is compared with the first threshold value. Therefore, it is possible to predict the occurrence of muffled sound. Therefore, the power generation amount reduction control for suppressing the muffled sound can be started quickly.

In aspects of the invention
The control unit 48 may reduce the output of the engine 16 by a predetermined amount in the power generation reduction control.

In aspects of the invention
When the control unit 48 detects that the variable is smaller than the first threshold value and is equal to or less than the second threshold value in the case where the power generation amount reduction control is performed, the power generation amount reduction control is performed. Is released, and the power generation amount return control for returning the power generation amount of the first electric motor (generator 26) to the normal value may be performed.

According to the above configuration, the battery 24 can be charged by the power generation of the first electric motor (generator 26).

It should be noted that the vehicle control device according to the present invention is not limited to the above-described embodiments and modifications, and of course, various configurations can be adopted without deviating from the gist of the present invention.

10 ... Vehicle control device 16 ... Engine 18 ... Body 20 ... Engine mount 26 ... Generator (first motor)
30 ... Traction motor (second motor)
48 ... Control unit 78 ... Muffled sound generation area

Claims (4)

An engine that is fixed to the car body via an engine mount,
A first motor capable of generating electricity with the power of the engine,
A second motor that can drive the drive shaft of the vehicle by power running and generate electricity by regeneration,
A control unit that controls each operation of the engine, the first electric motor, and the second electric motor,
It is a vehicle control device having
The control unit monitors a variable that correlates with any one of the deceleration of the vehicle, the amount of regeneration by the second electric motor, and the displacement amount of the engine mount, and the variable is from less than the first threshold value to the first. A vehicle control device that controls the operating point of the engine to be outside the muffled sound generation region when it detects that the change has exceeded a threshold value. The vehicle control device according to claim 1.
The control unit controls the operation point of the engine to be outside the muffled sound generation region, and performs power generation reduction control for reducing the power generation amount of the first electric motor as compared with the case where the power generation amount is less than the first threshold value. Vehicle control device. The vehicle control device according to claim 2.
The control unit is a vehicle control device that reduces the output of the engine by a predetermined amount in the power generation reduction control. The vehicle control device according to claim 2.
When the control unit detects that the variable has changed to a second threshold value smaller than the first threshold value in the case where the power generation amount reduction control is performed, the power generation amount reduction control is released. A vehicle control device that controls the power generation amount return to return the power generation amount of the first electric motor to the normal value.

Images