JP6223503B1 - Vehicle control device - Google Patents

Abstract

An object of the present invention is to provide a vehicle control device that can effectively use energy at the time of restarting an engine from a coasting running state as drive energy and can suppress vibrations that occur at the time of restart. SOLUTION: A starting method changing means 106e for changing a starting method of an engine 101 according to a vehicle state quantity including an engine speed and a driving wheel side rotational speed of a clutch 105 is provided. When the engine speed is equal to or higher than the idling speed, the motor generator 103 cranks the engine speed to the driving wheel side speed of the clutch 105, and then connects the clutch 105 and restarts the engine 101 until the engine 101 torque is stabilized. During this time, the motor generator 103 is controlled so that the drive wheel side rotation speed of the clutch 105 is suppressed. [Selection] Figure 1

Description

  The present invention relates to a vehicle control device equipped with an engine and a motor generator, and more particularly to a vehicle control device that restarts an engine from coasting.

  As a vehicle fuel efficiency improvement technique, there is a technique called coasting in which a clutch between an engine and a drive wheel is disconnected when an accelerator is off during traveling to stop the engine. The purpose of this is to reduce the fuel consumption by stopping the engine during inertial driving that does not require engine driving. Also, the clutch drag loss between the engine and the drive wheels is disengaged. The purpose is to reduce the weight and to increase the inertial running.

  When the driver makes an acceleration request by operating the accelerator pedal during coasting, the engine must be restarted quickly to transmit power to the drive wheels. Conventionally, for restarting the engine, a starter is used to increase the engine speed to the idling speed, the engine is ignited, and the driving force is transmitted by a transmission including a torque converter.

  However, torque fluctuation occurs when the engine is restarted, and engine speed overshoot occurs. Due to this overshoot, vehicle vibration is generated and the ride comfort is deteriorated.

  Moreover, the oil filled in the torque converter has poor transmission efficiency for transmitting the driving force, and the energy output from the engine cannot be effectively utilized.

  In order to eliminate vibration due to engine speed overshoot, for example, in the technique disclosed in Japanese Patent Laid-Open No. 7-119594 (Patent Document 1), vibration is suppressed by controlling the motor generator after engine ignition. Yes.

Japanese Patent Laid-Open No. 7-119594

  In Patent Document 1, the energy at the time of starting the engine is used for increasing the engine speed and for the regenerative operation of the motor generator. However, due to the regeneration efficiency of the motor generator, the charging efficiency of the battery, etc., much of the energy at the start is lost as a loss, and it cannot be said that it can be effectively utilized.

  An object of the present invention is to provide a vehicle control device that can effectively use energy at the time of restarting an engine from a coasting running state as drive energy and can suppress vibrations that occur when the engine is restarted. It is to provide.

A vehicle control apparatus according to the present invention includes an engine control means for controlling an engine, a motor generator control means for controlling a motor generator for transmitting and receiving power transmission to and from the engine, and a power transmission path between the engine and drive wheels. Clutch control means for controlling the clutch for intermittent connection, acceleration / deceleration request determination means for determining a vehicle acceleration / deceleration request based on signals from an accelerator pedal sensor and a brake pedal sensor, and a vehicle acceleration / deceleration request by the acceleration / deceleration request determination means When it is determined that there is no engine, the clutch is disconnected, the fuel supply to the engine is stopped, coasting traveling means for coasting traveling, and when the engine is restarted from the coasting traveling state, Starting method changing means for changing the starting method, and by the starting method changing means When changing the starting method of the serial engine, said clutch control means to be able to transmit directly to the power to the drive wheel of the engine by connecting the clutch, the motor generator control unit the rotational speed control of the motor generator In a vehicle control device that switches from control to vibration suppression control ,
When it is determined that there is a request for acceleration / deceleration of the vehicle during coasting, and the driving wheel side rotation speed of the clutch is equal to or higher than the idling rotation speed of the engine, the motor generator sets the engine rotation speed by the motor driving wheel. Cranking to the side rotation speed, restarting the engine by connecting the clutch, and rotating the motor generator on the driving wheel side of the clutch until the engine torque stabilizes after the clutch is connected Control is performed so that fluctuations in the number are suppressed .

  According to the vehicle control apparatus of the present invention, during coasting traveling, the reduction in engine speed is suppressed, so that the time required for the motor generator to start up to the rotational speed on the drive wheel side of the clutch is shortened and the rotational speed is increased. Electric power can be reduced. In addition, when the engine is restarted, the clutch is engaged and the torque converter lockup mechanism transmits power directly, so that the energy used for engine restart can also be used as the driving force. Can do. Further, since power transmission by oil of the torque converter is not performed, the time corresponding to the hydraulic response can be shortened, and re-acceleration from the coasting can be performed more quickly. A smooth start can be realized by compensating the fluctuation of the engine torque generated at that time by the motor generator.

1 is a schematic configuration diagram of an entire vehicle including a vehicle control device according to Embodiment 1 of the present invention. It is a flowchart which shows the process at the time of the engine restart of the vehicle control apparatus by Embodiment 1 of this invention. It is a flowchart which shows the process of the vibration suppression control output with the motor generator of the control apparatus of the vehicle by Embodiment 1 of this invention. 1 is a schematic configuration diagram of an entire vehicle in which a motor generator including a vehicle control device according to the present invention is disposed between an engine and a torque converter.

  Hereinafter, preferred embodiments of a vehicle control apparatus according to the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are simplified or modified as appropriate.

Embodiment 1 FIG.
FIG. 1 shows a schematic configuration of an entire vehicle including a control device according to Embodiment 1 of the present invention. In FIG. 1, a vehicle 100 includes an engine 101, a motor generator 103 connected to the engine 101 by a belt 102, a clutch 105 that interrupts a power transmission path between the engine 101 and driving wheels 104, an engine 101, and a motor. A control device 106 that controls the generator 103 and the clutch 105 is provided. Each cylinder of the engine 101 includes an intake valve 101a and an exhaust valve 101b that can be freely opened and closed, and a crank angle sensor and a cam angle sensor (not shown).

  The motor generator 103 transmits and receives power transmission to and from the engine 101 via the belt 102 via the crankshaft pulley of the engine 101. The motor generator 103 supplies power by performing a regenerative operation when the vehicle is decelerating or when the electrical load of auxiliary equipment increases, while transmitting power to the wheels by performing a power running operation when starting or running at a low torque. . It can also be used as a starter when the engine 101 is restarted.

  The clutch 105 is provided in the transmission and can cut off power transmission between the engine 101 and the drive wheels 104. A torque converter 107 is provided in the transmission, and the torque converter 107 has a power amplification function and a lockup function for directly connecting the engine side and the clutch of the drive wheel shaft. A rotation sensor (not shown) is attached to the drive wheel shaft side and the engine shaft side.

  The control device 106 includes a microprocessor and the like, and includes an engine control means 106a for controlling the engine 101, an MG control means 106b for controlling the motor generator 103, an input means 106c, a clutch control means 106d for controlling the clutch 105, and an engine. 101 includes a starting method changing means 106e for changing the starting method 101, and an acceleration / deceleration request determining means 106f for determining whether or not the driver requests a vehicle acceleration / deceleration. The input means 106c includes a crank angle sensor that measures the engine speed, a cam angle sensor that measures the cam angle of the intake / exhaust valve, an accelerator pedal sensor that acquires the driver's acceleration request, and a brake that acquires the driver's deceleration request. Signals from various sensors such as pedal sensors are input.

  The control device 106 determines vehicle operating conditions based on various sensor signals, and comprehensively controls the engine speed, the engine torque, the control command for the motor generator 103, and the connection command for the clutch 105.

  The vehicle 100 according to the first embodiment is configured as described above. Next, a specific operation of the control device 106 will be described based on the flowchart of FIG.

  In FIG. 2, in step S201, the accelerator pedal sensor signal and the brake pedal sensor signal are input to the input means 106c, and the acceleration / deceleration request determination means 106f determines whether or not there is a driver's vehicle acceleration / deceleration request. . If there is a vehicle acceleration / deceleration request, the system waits until there is no acceleration / deceleration request.

  If it is determined in step S201 that there is no vehicle acceleration / deceleration request, the process proceeds to step S202, and the vehicle is coasted. At the time of coasting control, the drive source and the drive wheel 104 are completely disconnected by disconnecting the clutch 105 inside the transmission between the engine 101 and the drive wheel 104 that are the vehicle drive source. Therefore, during the coasting control, the vehicle becomes a simple inertia body except for mechanical loss included between the clutch 105 and the driving wheel 104, and is decelerated only by a traveling resistance component necessary for traveling. Further, the engine side stops the fuel supply to the engine 101 to reduce wasteful fuel consumption. Further, by closing the intake / exhaust valve of the engine 101, the reduction in engine rotation is delayed by reducing the resistance caused by pumping of the piston in the cylinder. As a result, when the engine 101 is restarted by the motor generator 103, the engine speed can be quickly raised. This step S202 corresponds to a coasting traveling means.

  In step S203, the acceleration / deceleration request determination unit 106f determines whether to continue coasting or to restart the engine 101 to perform acceleration / deceleration based on the driver's acceleration / deceleration request. If there is no request for acceleration / deceleration of the vehicle, it is determined that coasting is to be maintained, and the system waits until there is an acceleration / deceleration request.

  If it is determined in step S203 that there is a request for acceleration / deceleration of the vehicle, it is determined that the engine 101 needs to be restarted, and the process proceeds to step S204 to prepare for restarting the engine 101.

  In step S205, when the rotational speed of the drive wheel side clutch is equal to or higher than the idling rotational speed of the engine 101, it is determined that the engine 101 can be restarted after the clutch 105 is connected, and the process proceeds to step S206.

In step S206, in order to connect the clutch 105 in the transmission, the MG control means 106b controls the rotational speed of the motor generator 103 and synchronizes the engine rotational speed with the driving wheel side clutch rotational speed.

  In step S207, the engine control means 106a returns the control to open and close the intake / exhaust valves in synchronization with the normal cam angle in order to restart the engine. Further, the clutch control means 106 d connects the clutch 105 so that the engine-side power can be transmitted to the drive wheels 104. At this time, the torque converter 107 is in a lock-up state with the best transmission efficiency.

  In step S208, in order to suppress the acceleration / deceleration response of the vehicle and the torque pulsation during engine start, the start method changing means 106e changes the control of the motor generator 103 by the MG control means 106b from vibration speed control to vibration suppression control. Start. That is, the starting method changing means 106e changes the starting method of the engine according to the vehicle state quantity when the engine 101 is restarted from the coasting running state. Thus, drivability is improved because the motor generator 103 suppresses a rapid change in the vehicle speed while using the energy at the start of the engine 101 as drive energy.

  In step S209, in order to determine whether vibration suppression control of the motor generator 103 is necessary, the engine control unit 106a determines whether the engine torque is stable. When it is not stable, it performs vibration suppression control until it is stabilized and waits.

  If it is determined in step S209 that the operation is stable, the process proceeds to step S210, and the vibration suppression control is stopped. This is because when vibration suppression control is introduced, if there is a sudden acceleration / deceleration request such as sudden braking, the vibration may be recognized and obstructed. Note that the vibration suppression control may be stopped by determining that the engine torque has stabilized after a predetermined time has elapsed since the engine was started.

  In step S205, when the rotational speed of the drive wheel side clutch is less than the idling rotational speed of the engine 101, the clutch control means 106d determines that the clutch 105 is to be engaged after restarting the engine 101, and proceeds to step S211.

  In step S211, in preparation for engine restart, the engine control means 106a returns the control to open and close the intake valve 101a and the exhaust valve 101b in synchronization with the normal cam angle. Thereafter, the motor generator 103 synchronizes the engine speed with the idling speed.

  In step S212, the engine 101 is restarted and the vehicle is ready for acceleration / deceleration.

  In step S213, the clutch control means 106d connects the clutch 105 inside the transmission so that the engine torque can be transmitted to the drive wheels 104. Further, the torque converter 107 performs power transmission using a fluid.

  In step S214, the starting method changing means 106e changes the control of the motor generator 103 by the MG control means 106b from the rotational speed control to the torque control mode, and outputs the torques of the engine 101 and the motor generator 103 that respond to the driver's acceleration request.

  FIG. 3 shows a flowchart of vibration suppression control of the motor generator 103. This control suppresses steep rotation speed fluctuations due to torque at the time of engine start, improves drivability, and compensates when engine torque is insufficient.

  In FIG. 3, in step S301, an accelerator pedal sensor signal or a brake pedal signal when a reacceleration request or a redeceleration request is received from the coasting is read to estimate how much acceleration / deceleration the driver needs. Set the cutoff frequency of the high-pass filter for vibration suppression. Here, the greater the depression amount of the accelerator pedal and the brake pedal, the higher the allowable range of the change amount of the vehicle speed can be set by setting the cutoff frequency of the high pass filter higher.

  In step S302, the electrical angle is acquired from the resolver attached to the motor, and the motor rotation speed is calculated. Since a pulsation component due to torque fluctuation generated at the time of starting the engine is generated in the motor rotation speed, the pulsation component is acquired, multiplied by a negative gain, and output by the motor generator 108 to suppress vibration.

  In step S303, only the vibration component due to torque fluctuation is extracted by multiplying the acquired motor rotation speed by the cutoff frequency of the high-pass filter.

  In step S304, the vibration suppression torque is determined by multiplying the extracted vibration component by a negative gain.

  In step S <b> 305, the calculated vibration suppression torque is output by the motor generator 108. This compensates for torque fluctuations when starting the engine and suppresses vibration.

As described above, according to the control apparatus for a vehicle according to the first embodiment, when performing the restart of the engine 101 from coasting performs cranking while reducing the load of the motor generator 103, generating at the start of the engine By using the torque as the driving torque, the fuel can be effectively used. Further, since the torque converter 107 is locked up, the time required for the hydraulic response can be shortened. Further, the drivability can be improved by suppressing the torque fluctuation at the time of engine start by the motor generator 103.

  The motor generator 103 is not limited in its mounting location and connection method as long as the driving force can be exchanged between the engine 101 and the motor generator 103, for example, between the engine 101 and the torque converter 107 as shown in FIG. It may be provided. Reference numeral 200 in FIG. 4 denotes a vehicle, and the other parts are the same as those in FIG.

  Further, although the resolver attached to the motor is used as the electrical angle used in the vibration suppression control, a crank angle sensor attached to the engine 101 or a rotation sensor in the transmission may be used.

  The vehicle control apparatus according to the first embodiment of the present invention has been described above. However, the present invention can be appropriately modified and omitted within the scope of the present invention.

100, 200 Vehicle, 101 Engine, 101a Intake valve, 101b Exhaust valve, 102 Belt, 103 Motor generator, 104 Drive wheel, 105 Clutch, 106 Control device, 106a Engine control means, 106b MG control means, 106c Input means, 106d Clutch Control means, 106e Start method change means, 106f Acceleration / deceleration request determination means, 107 Torque converter

Claims (5)

Engine control means for controlling the engine;
Motor generator control means for controlling a motor generator for transferring power to and from the engine;
Clutch control means for controlling a clutch for intermittently connecting a power transmission path between the engine and the drive wheel;
Acceleration / deceleration request determination means for determining a vehicle acceleration / deceleration request based on signals from an accelerator pedal sensor and a brake pedal sensor;
Coasting traveling means for disengaging the clutch and stopping the fuel supply to the engine for coasting traveling when the acceleration / deceleration request determining means determines that there is no vehicle acceleration / deceleration request;
Starting method changing means for changing a starting method of the engine when the engine is restarted from a coasting running state,
When changing the method of starting the engine by the starting-method changing portion, said clutch control means to be able to transmit directly to the power to the drive wheel of the engine by connecting the clutch, the motor generator control unit is a motor In a vehicle control device that changes the generator control from vibration speed control to vibration suppression control ,
When it is determined that there is a request for acceleration / deceleration of the vehicle during coasting, and the driving wheel side rotation speed of the clutch is equal to or higher than the idling rotation speed of the engine, the motor generator sets the engine rotation speed to the driving wheel of the clutch. Cranking to the side rotation speed, restarting the engine by connecting the clutch, and rotating the motor generator on the driving wheel side of the clutch until the engine torque stabilizes after the clutch is connected A control apparatus for a vehicle, characterized in that control is performed such that fluctuations in the number are suppressed .   The starting method changing means changes the starting method of the engine by at least the signal of the accelerator pedal sensor, the signal of the brake pedal sensor, the engine speed, and the driving wheel side speed of the clutch. The vehicle control device according to claim 1. It means for suppressing the fluctuation in driving wheel-side rotation speed of the clutch, according to claim 1 or 2 is multiplied by the negative gain values through the engine rotational speed to a high-pass filter and outputting from said motor generator The vehicle control device described in 1. The vehicle control device according to claim 3 , wherein the cut-off frequency of the high-pass filter is set higher as the accelerator pedal depression amount or the brake pedal depression amount is larger. The engine includes an intake valve and an exhaust valve that can be freely opened and closed, and when the clutch is disconnected and no fuel is supplied to the engine, the intake valve and the exhaust valve are fully closed. The vehicle control device according to any one of 1 to 4 .

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