JP7426250B2 - Vehicle control device - Google Patents

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 caused by engine exhaust noise when the vehicle is stopped and a generator is operated using engine power to charge a battery. In Patent Document 1, a plurality of operating lines are set in the coordinate system of engine rotation speed and engine torque, and when the vehicle is stopped, an operating line that prioritizes suppression of exhaust noise over driving efficiency (exhaust noise A method of controlling an engine using a restraint operating line) is disclosed.

Patent No. 5971188

The engine is fixed to the vehicle body via multiple engine mounts. The engine mount suppresses engine vibrations propagating from the engine to the vehicle body, and also suppresses noise generated due to engine vibrations. However, when the vehicle decelerates strongly, the amount of displacement of the reference position of the engine mount increases, 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. While Patent Document 1 discloses a technique for suppressing abnormal exhaust noise while the vehicle is stopped, it does not disclose a technique for suppressing muffled noise that occurs when the vehicle is strongly decelerated.

The present invention has been made in consideration of such problems, and an object of the present invention is to provide a vehicle control device that can reduce muffled noise generated inside a hybrid vehicle during strong deceleration.

Aspects of the invention include:
An engine that is fixed to the vehicle body via an engine mount,
a first electric motor capable of generating electricity using the power of the engine;
a second electric motor capable of driving the drive shaft of the vehicle through power running and generating electricity through regeneration;
a control unit that controls each operation of the engine, the first electric motor, and the second electric motor;
A vehicle control device having:
The control unit monitors a variable that is correlated with any one of the deceleration of the vehicle, the amount of regeneration by the second electric motor, and the amount of displacement of the engine mount, and the control unit monitors a variable that is correlated with any one of the deceleration of the vehicle, the amount of regeneration by the second electric motor, and the amount of displacement of the engine mount, and changes the variable from less than a first threshold value to a first When it is detected that the change has exceeded the threshold value, control is performed to move the operating point of the engine out of the muffled sound generation area.

According to the present invention, it is possible to reduce the muffled noise generated inside the hybrid vehicle during strong deceleration.

FIG. 1 is a diagram showing the configuration of a vehicle control device. FIG. 2 is a diagram showing the configuration of the control system of the 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, motor torque command value of the traction motor, and battery charge amount.

EMBODIMENT OF THE INVENTION Hereinafter, a preferred embodiment of a vehicle control device according to the present invention will be described in detail with reference to the accompanying drawings.

[1. Configuration of vehicle control device 10]
The configuration of the vehicle control device 10 will be explained using FIGS. 1 and 2. The vehicle described in this embodiment is a hybrid vehicle that drives a traction motor 30 with the power of the engine 16 and travels with 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. 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 includes various devices (fuel injection valves, throttle valves, ignition coils, etc.) that control the operation of the engine 16.

Battery 24 is electrically connected to generator PDU 28 and motor PDU 32. The battery 24 is charged by the power generated by the generator PDU 28 and motor PDU 32. The battery ECU 72 includes a processor, various memories, an A/D conversion circuit, and a communication interface. Battery ECU 72 manages 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.

Generator 26 corresponds to a first electric motor. The rotating shaft of the generator 26 is connected to the rotating shaft of the engine 16 via a first power transmission mechanism 34a. Generator PDU 28 includes a converter that converts AC power output by generator 26 during power generation into DC power and outputs it to battery 24, and a switching element that adjusts the power. Furthermore, the generator PDU 28 includes a generator ECU 70 (FIG. 2) that controls the switching elements.

Traction motor 30 corresponds to a second electric motor. The rotating shaft of the traction motor 30 is connected to the drive shaft 14 via a 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 a switching element that adjusts the power output to the battery 24. It includes an inverter that converts 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 includes a motor ECU 66 (FIG. 2) that controls switching elements.

The first power transmission mechanism 34a and the second power transmission mechanism 34b have gears, clutches, and power distribution mechanisms.

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 near the accelerator pedal (also referred to as AP), detects the amount of operation 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. Motor rotation sensor 42 is a resolver or encoder provided in traction motor 30, detects the rotational position of the rotation shaft of traction motor 30, and outputs a detected value to hybrid ECU 46. Engine rotation sensor 44 is a resolver or encoder provided in engine 16 and detects the rotational position of a rotating shaft (crankshaft, etc.) of engine 16, and outputs a detected value to hybrid ECU 46.

In addition to the control section 48 and the storage section 50, the hybrid ECU 46 includes an A/D conversion circuit and a communication interface (not shown). The control unit 48 is configured by a processor including, for example, a CPU. The control unit 48 implements various functions by executing programs 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 section 62 and a generator torque command value calculation section 64.

The target driving force calculation unit 52 calculates the target driving force of the vehicle using the detected value of the AP sensor 38 and the detected value of the vehicle speed sensor 40. The motor torque command value calculation unit 54 converts the target driving force into a target torque of the traction motor 30, and outputs the motor torque command value to the motor ECU 66. The vehicle power requirement calculation unit 56 calculates the power to be generated, that is, the vehicle power requirement, using the target torque of the traction motor 30, the detected value of the motor rotation sensor 42, the power consumption of 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. Engine torque command value calculation section 62 calculates an engine target torque using the engine target output and the detected value of engine rotation sensor 44, and outputs the engine torque command value to engine ECU 68. Generator torque command value calculation section 64 calculates a target torque of generator 26 using the engine target rotation speed and the detected value of engine rotation sensor 44, and outputs the generator torque command value to 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 types of information used in the processing performed by the control unit 48 in addition to various programs. Here, the storage unit 50 stores the first threshold value and the second threshold value. The first threshold value is the value of the motor torque for determining whether or not muffled noise occurs. The second threshold value is the 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 determined 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. Motor ECU 66 controls each switching element of motor PDU 32 according to the motor torque command value. Engine ECU 68 controls engine drive section 22 according to the engine torque command value. Generator ECU 70 controls each switching element of 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 disposed on the front side is compressed. When the engine 16 generates high torque in this state, the vibrations of the engine 16 are not reduced by the engine mount 20 and propagate to the vehicle body 18. As a result, a muffled sound is generated.

In this embodiment, the control unit 48 performs processing to suppress muffled sounds. 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 is correlated with any one 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 power requirement 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 muffled noise occurs.

Here, the operation of the engine 16 will be explained using FIG. 3. 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 power generated by the generator 26 increases. At this time, as shown in FIG. 3, the output (engine speed x engine torque) of the engine 16 increases along the operating line 76 (arrow 82a). Note that in FIG. 3, the equal output line 74 corresponds to the power generated by the generator 26.

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

In step S1, the vehicle power requirement calculation unit 56 uses the detected value of the AP sensor 38 to determine whether the AP is being operated. For example, when the AP is not operated (step S1: YES) as at time t1 to t4 in FIG. 5, the process moves to step S2. In this case, the traction motor 30 functions as a regenerative brake, so the vehicle decelerates. On the other hand, if the AP is being operated, for example, from time t0 to t1 in FIG. processing is executed.

In step S2, the vehicle power requirement calculation unit 56 compares the latest motor torque command value calculated by the motor torque command value calculation unit 54 with a first threshold value stored in advance in the storage unit 50. The motor torque command value takes a positive value during power running and a negative value during regeneration. Further, the first threshold value is a negative threshold value indicating regenerative torque. Here, for convenience of explanation, absolute values of the motor torque command value and various threshold values are used. For example, as at time t2 in FIG. 5, when the state changes from |motor torque command value|<|first threshold| to |motor torque command value|≧|first threshold| (step S2: YES), the process The process moves 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, if |motor torque command value|<|first threshold| (step S2: NO), for example, as at time t1 to t2 in FIG. When this occurs, the process of step S1 is executed again.

In step S3, the vehicle power requirement calculation unit 56 executes power generation amount reduction control. For example, the storage unit 50 stores a map showing the relationship between the deceleration, the rotational speed of the engine 16, etc., and the vehicle power requirement that can suppress muffled noise. The vehicle power requirement calculation unit 56 uses this map to determine the target power 74a (FIG. 3) as the vehicle power requirement that can suppress muffled noise. The engine target output calculation unit 58 calculates the engine target output according to the target electric power 74a. 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 in response to a decrease in the vehicle required power (target power 74a) and the engine target output. On the other hand, since the engine speed is affected by inertia, it takes longer to decrease than the engine torque. Therefore, in the output of the engine 16 (operating point 80), 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 area 78. Therefore, muffled sounds are suppressed.

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

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

In step S5, the vehicle required power calculation unit 56 cancels the power generation reduction control. At this time, the vehicle power requirement calculation unit 56 calculates the vehicle power requirement 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, etc., as usual. When step S5 ends, the series of processes ends.

[3. Modified example]
In the embodiment described above, the vehicle required power calculation unit 56 determines the target power 74a that can suppress muffled noise. Alternatively, 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 embodiment described above, the vehicle power requirement calculation unit 56 sets the vehicle power requirement to the target power 74a, which is suppressed more than usual, as a control to move 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 section 56 sets the vehicle required power to the normal target power 74b, and the engine target rotation speed calculation section 60 and the engine torque command value calculation section 62 set the vehicle required power to the normal target power 74b. 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 area 78.

[4. Technical ideas obtained from the embodiment]
The technical idea that can be understood from the above embodiment will be described below.

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

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

In an aspect of the invention,
The control unit 48 controls the operating point 80 of the engine 16 to be outside the muffled sound generation region 78 by reducing the amount of power generated by the first electric motor (generator 26) compared to when the amount is less than a first threshold. Performs power generation reduction control.

According to the above configuration, since the power generation amount reduction control is performed, it is possible to reduce the muffled noise generated inside the hybrid vehicle when the hybrid vehicle is strongly decelerated. In particular, a variable that is correlated with any one of the deceleration of the vehicle, the amount of regeneration by the second electric motor (traction motor 30), and the amount of displacement of the engine mount 20, such as a motor torque command value, is compared with the first threshold value. By doing so, it is possible to predict the occurrence of muffled sounds. Therefore, power generation amount reduction control to suppress muffled noise can be started quickly.

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

In an aspect of the invention,
When the control unit 48 is performing the power generation amount reduction control and detects that the variable has changed to the second threshold value or less, which is smaller than the first threshold value, the control unit 48 performs the power generation amount reduction control. may be canceled, and power generation amount recovery control may be performed to return the power generation amount of the first electric motor (generator 26) to normal.

According to the above configuration, the battery 24 can be charged by power generation by 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 can of course take various configurations without departing from the gist of the present invention.

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

Claims (4)

An engine that is fixed to the vehicle body via an engine mount,
a first electric motor capable of generating electricity using the power of the engine;
a second electric motor capable of driving the drive shaft of the vehicle through power running and generating electricity through regeneration;
a control unit that controls each operation of the engine, the first electric motor, and the second electric motor;
A vehicle control device having:
The control unit monitors a variable that is correlated with any one of the deceleration of the vehicle, the amount of regeneration by the second electric motor, and the amount of displacement of the engine mount, and changes the variable from less than a first threshold value to the first one. reducing the target output of the engine to a predetermined output when it is detected that the engine has changed to a predetermined output;
In the vehicle control device , the predetermined output is an output of the engine that is outside a muffled sound generation region regardless of the rotation speed of the engine . The vehicle control device according to claim 1,
The control unit performs power generation reduction control to reduce the power generation amount of the first electric motor compared to when the power generation amount is less than the first threshold value, as control to bring the target output of the engine out of a muffled sound generation region. , vehicle control equipment. 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,
The control unit cancels the power generation amount reduction control when performing the power generation amount reduction control and detects that the variable has changed to a second threshold value or less that is smaller than the first threshold value. and a vehicle control device that performs power generation recovery control to return the power generation amount of the first electric motor to normal.

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