JP7134402B2 - vehicle controller - Google Patents

Description

The present invention relates to a vehicle control device, and more particularly to a vehicle control device that controls the torque of an engine that drives rear wheels based on steering of the vehicle.

2. Description of the Related Art Conventionally, there has been known a device (side slip prevention device, etc.) that controls the behavior of a vehicle in a safe direction when the behavior of the vehicle becomes unstable due to a slip or the like. Specifically, there is known a technology that detects the occurrence of understeer or oversteer behavior in the vehicle when the vehicle is cornering, etc., and applies appropriate deceleration to the wheels so as to suppress them. ing.

On the other hand, apart from the control for improving safety in driving conditions where the behavior of the vehicle becomes unstable, by reducing the torque when turning the steering wheel to cause the vehicle to decelerate, it is possible to reduce the driver during cornering. There is known a technique for controlling vehicle behavior so that the operation of the is natural and stable (see, for example, Patent Document 1). Hereinafter, controlling the attitude of the vehicle by changing the torque according to the driver's steering operation will be referred to as "vehicle attitude control" as appropriate.

Japanese Patent No. 5999360

However, the inventor of the present invention has attempted to apply the control (vehicle attitude control) that decelerates the vehicle in response to steering by the driver, as described in Patent Document 1, etc., to a rear-wheel drive vehicle. However, the effects of improving steering stability, improving responsiveness of vehicle behavior, and improving linear feeling obtained in the invention described in Patent Document 1 could not be obtained.

That is, the inventor of the present invention applied control for decelerating the vehicle in accordance with the steering operation, as described in Patent Document 1 and the like, as the vehicle attitude control. However, when such conventionally known vehicle attitude control is applied to a rear-wheel drive vehicle, it is impossible to obtain the effects of improving vehicle responsiveness and linearity that have been obtained in front-wheel drive vehicles. I couldn't. As a result of intensive research by the inventors of the present invention to solve this newly discovered problem, it has surprisingly been found that, in a rear-wheel drive vehicle, it is possible to increase the driving torque of the vehicle in accordance with the steering by the driver. It became clear that the vehicle responsiveness and linear feeling are improved.

In general, when deceleration is applied to a vehicle, the inertial force acting on the center of gravity of the vehicle causes pitching motion in which the front side of the vehicle sinks. thought to improve. However, in a rear-wheel-drive vehicle, when the driving torque of the rear wheels is reduced and deceleration is applied to the vehicle, in addition to the above-mentioned inertial force, the vehicle body is tilted backward from the rear wheels via the suspension (rear side sinking) force is generated instantaneously. Since this instantaneous force acts to reduce the load on the front wheels, in a rear-wheel drive vehicle, even if deceleration is applied to the vehicle in accordance with the steering by the driver, vehicle responsiveness and linear feel are maintained as expected. could not be improved.

On the contrary, in a rear-wheel-drive vehicle, by increasing the drive torque of the rear wheels, a force that causes the vehicle body to lean forward (sink the front side) momentarily acts from the rear wheels via the suspension. As a result, the load on the front wheels increases, which is thought to improve vehicle responsiveness and linear feel. That is, in a rear-wheel drive vehicle, when acceleration is applied by increasing the driving torque of the rear wheels, an inertial force that tilts the vehicle body backward and an instantaneous force that tilts the vehicle body forward are generated. It is considered that the momentary forward tilting force of the vehicle body dominantly contributes to the responsiveness and linear feeling.

The inventors of the present invention set the increased torque so as to increase the basic torque according to the driving state of the vehicle based on the increase in the steering angle of the steering system mounted on the vehicle, thereby achieving the above instantaneous force. As a result, the load on the front wheels is increased, and it was found that the vehicle responsiveness and linear feeling to steering operation can be improved.

By the way, conventionally, in a multi-cylinder engine having a plurality of cylinders, in order to improve fuel efficiency, a full-cylinder operation in which air-fuel mixture is combusted in all cylinders according to the operating state of the vehicle, and a A technology (cylinder deactivation engine) is known that switches the operation mode between reduced-cylinder operation in which combustion of the air-fuel mixture is halted in some of the cylinders. During the reduced-cylinder operation of such a cylinder deactivation engine, combustion is prohibited in cylinders in which the combustion order is not continuous, and combustion is performed sequentially in the remaining cylinders. Therefore, the combustion interval during reduced-cylinder operation is longer than the combustion interval during full-cylinder operation.

Therefore, if the vehicle attitude control is performed by increasing the driving torque of the rear wheels in the cylinder deactivation engine, the combustion of the cylinders is started after the vehicle attitude control execution request is generated during the full cylinder operation and the reduced cylinder operation. A difference occurs in the time from when the timing first arrives until the vehicle attitude control is actually started. As a result, the response of the torque to the vehicle attitude control execution request deteriorates, which may cause the vehicle to behave differently due to the vehicle attitude control or give the driver a sense of discomfort.

In the above example, the responsiveness of the torque to the execution request for vehicle attitude control deteriorates during reduced-cylinder operation in a cylinder-deactivated engine. However, it can also occur under engine operating conditions where the number of combustions per unit time is relatively small (for example, in a low engine speed range).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The purpose is to appropriately suppress sexual aggravation.

To achieve the above object, the present invention provides a control system for a vehicle, comprising an engine for driving rear wheels of the vehicle, a steering system for steering the vehicle, and a steering system related to the steering angle of the steering system. A steering angle-related value sensor for detecting an angle-related value, a driving state sensor for detecting a driving state of the vehicle, and a controller for controlling the engine, wherein the controller detects the driving state detected by the driving state sensor. , and increases the torque of the engine that drives the rear wheels when the steering angle-related value detected by the steering angle-related value sensor exceeds the first threshold value. By producing a force that propels the wheels forward of the vehicle, resulting in a momentary force that lifts the rear of the vehicle upwards when this force is transmitted from the rear wheels through the suspension to the vehicle's chassis. In order to tilt the vehicle forward, the increased torque of the engine is set, and the increased torque is added to the basic torque to control the engine so that the calculated target torque is generated, and the number of engine combustions per unit time is small. Sometimes the first threshold is configured to be smaller than it is otherwise.
According to the present invention configured as described above, with respect to a vehicle in which the rear wheels are driven by the engine, the controller performs vehicle attitude control to add increased torque when the steering angle-related value exceeds the first threshold value. The first threshold value is decreased when the number of engine combustions per unit time is small. As a result, when the number of engine combustions per unit time is small, the timing at which the request to start the vehicle attitude control is issued is advanced, and delays in the start of the vehicle attitude control can be appropriately suppressed. Therefore, when the number of engine combustions per unit time is small, it is possible to appropriately suppress deterioration in responsiveness to torque increase at the start of vehicle attitude control.

In the present invention, the engine preferably has a plurality of cylinders, is capable of reduced cylinder operation in which combustion is suspended in some of the plurality of cylinders, and the controller suspends combustion in the plurality of cylinders. When the number of cylinders to be controlled is large, the first threshold value is set to be smaller than when it is not.
According to the present invention configured as described above, the number of combustions of the engine per unit time is determined based on the number of cylinders to be deactivated in the reduced cylinder operation (the number of cylinders to be deactivated), and the number of cylinders to be deactivated is determined according to the number of cylinders to be deactivated. The first threshold can be set appropriately.

In the present invention, it is preferable to further include an engine speed sensor for detecting the engine speed, and the controller sets the first threshold when the engine speed detected by the engine speed sensor is low than when it is not. is configured to reduce
According to the present invention configured in this way, it is possible to determine the number of combustions of the engine per unit time based on the current engine speed, and appropriately set the first threshold value.

In the present invention, the controller is preferably configured to increase the torque increase so that the rate of change in the torque increasing direction is greater when the number of combustions in the engine per unit time is low than otherwise. ing.
According to the present invention configured as described above, when the number of combustions of the engine per unit time is small, the torque can be rapidly increased at the start of the vehicle attitude control, and the torque at the start of the vehicle attitude control can be increased. deterioration of responsiveness can be suppressed more effectively.

In the present invention, preferably, the controller reduces the increased torque when the steering angle-related value becomes less than the second threshold after becoming equal to or greater than the first threshold, and the number of engine combustions per unit time is small. Sometimes the second threshold is configured to be larger than otherwise.
According to the present invention configured as described above, the vehicle attitude control is terminated when the steering angle-related value becomes less than the second threshold, and the second threshold is reached when the number of engine combustions per unit time is small. increase the As a result, when the number of engine combustions per unit time is small, the timing at which the vehicle attitude control termination request is issued is advanced, and the delay in the termination of the vehicle attitude control can be appropriately suppressed. Therefore, deterioration of responsiveness of torque recovery (torque reduction) at the end of vehicle attitude control can be appropriately suppressed.

In the present invention, preferably, the controller reduces the increased torque when the steering angle-related value becomes less than the second threshold after becoming equal to or greater than the first threshold, and the number of engine combustions per unit time is small. Sometimes the increasing torque is arranged to decrease such that the rate of change in the decreasing direction of the torque is greater than otherwise.
According to the present invention configured as described above, when the steering angle-related value becomes less than the second threshold value, the increased torque is decreased to end the vehicle attitude control, and the number of combustions of the engine per unit time. Since the rate of change in the decreasing direction of the torque is increased when the torque is small, the torque can be quickly decreased at the end of the vehicle attitude control. Therefore, deterioration of responsiveness of torque recovery (torque reduction) at the end of vehicle attitude control can be appropriately suppressed.

In the present invention, preferably, the controller pulls the rear wheels rearward of the vehicle by reducing the torque of the engine when the steering angle-related value becomes equal to or greater than the third threshold after the application of the increased torque is finished. To generate a force that, when this force is transmitted from the rear wheels through the suspension to the vehicle body, causes the vehicle body to lean back by momentarily exerting a force that causes the rear portion of the vehicle body to sink downward. The engine is controlled to generate the target torque obtained by setting the reduced torque of the engine and subtracting the reduced torque from the basic torque. , is configured to reduce the third threshold.
According to the present invention configured as described above, when the steering angle-related value becomes equal to or greater than the third threshold value after the above-described vehicle attitude control, another vehicle attitude control is performed to add a reduced torque, and the engine speed per unit time is increased. When the number of combustion times of is small, the third threshold value is decreased. As a result, when the number of engine combustions per unit time is small, the timing at which the request to start the vehicle attitude control is issued is advanced, and delays in the start of the vehicle attitude control can be appropriately suppressed. Therefore, it is possible to appropriately suppress deterioration in responsiveness of torque reduction at the start of vehicle attitude control.

In the present invention, preferably, the controller pulls the rear wheels rearward of the vehicle by reducing the torque of the engine when the steering angle-related value becomes equal to or greater than the third threshold after the application of the increased torque is finished. To generate a force that, when this force is transmitted from the rear wheels through the suspension to the vehicle body, causes the vehicle body to lean back by momentarily exerting a force that causes the rear portion of the vehicle body to sink downward. The engine is controlled to generate the target torque obtained by setting the reduced torque of the engine and subtracting the reduced torque from the basic torque. , the reduction torque is increased so that the rate of change in the torque decrease direction is increased.
According to the present invention configured as described above, when the steering angle-related value becomes equal to or greater than the third threshold value after the above-described vehicle attitude control, another vehicle attitude control is performed to add a reduced torque, and the engine speed per unit time is increased. Since the rate of change in the decreasing direction of the torque is increased when the number of times of combustion is small, the torque can be quickly decreased at the start of the vehicle attitude control. Therefore, it is possible to more effectively suppress deterioration in responsiveness of torque reduction at the start of vehicle attitude control.

In the present invention, preferably, the controller reduces the reduction torque when the steering angle-related value becomes less than the fourth threshold after becoming equal to or greater than the third threshold, and the number of engine combustions per unit time is small. Sometimes the fourth threshold is configured to be larger than otherwise.
According to the present invention configured as described above, the vehicle attitude control is terminated when the steering angle-related value becomes less than the fourth threshold value during the vehicle attitude control, and the number of engine combustions per unit time is determined. is small, the fourth threshold is increased. As a result, when the number of engine combustions per unit time is small, the timing at which the vehicle attitude control termination request is issued is advanced, and the delay in the termination of the vehicle attitude control can be appropriately suppressed. Therefore, deterioration of responsiveness of torque recovery (torque increase) at the end of vehicle attitude control can be appropriately suppressed.

In the present invention, preferably, the controller reduces the reduction torque when the steering angle-related value becomes less than the fourth threshold after becoming equal to or greater than the third threshold, and the number of engine combustions per unit time is small. Sometimes, the reduced torque is configured to decrease such that the rate of change in the torque increasing direction is greater than otherwise.
According to the present invention configured as described above, when the steering angle-related value becomes less than the fourth threshold value during the vehicle attitude control, the reduction torque is decreased to end the second vehicle attitude control. Since the rate of change in the increasing direction of the torque is increased when the number of engine combustions per unit time is small, the torque can be rapidly increased at the end of the vehicle attitude control. Therefore, deterioration of responsiveness of torque recovery (torque increase) at the end of vehicle attitude control can be appropriately suppressed.

From another aspect, in order to achieve the above object, the present invention provides a control device for a vehicle having an engine for driving rear wheels of the vehicle and a steering device for steering the vehicle, wherein steering of the steering device By increasing the torque of the engine driving the rear wheels when the steering angle-related value associated with the steering angle exceeds a threshold value, a force is generated to propel the rear wheels forward of the vehicle. Vehicle attitude control means for increasing engine torque to tilt the vehicle body forward by instantaneously applying a force that lifts the rear portion of the vehicle body upward when transmitted from the rear wheels to the vehicle body via the suspension. and threshold value setting means for setting the threshold value smaller when the number of times of combustion of the engine per unit time is small than otherwise.
According to the present invention configured as described above, the vehicle control apparatus performs vehicle attitude control for increasing torque when the steering angle-related value exceeds a threshold value for a vehicle in which the rear wheels are driven by the engine. , this threshold value is decreased when the number of engine combustions per unit time is small. As a result, when the number of engine combustions per unit time is small, the timing at which the request to start the vehicle attitude control is issued is advanced, and delays in the start of the vehicle attitude control can be appropriately suppressed. Therefore, it is possible to appropriately suppress deterioration in responsiveness to an increase in torque at the start of vehicle attitude control.

Advantageous Effects of Invention According to the present invention, it is possible to appropriately suppress deterioration of torque responsiveness during vehicle attitude control in a vehicle control apparatus that performs vehicle attitude control for a vehicle having rear wheels driven by an engine.

1 is a block diagram showing the overall configuration of a vehicle to which a vehicle control device according to an embodiment of the invention is applied; FIG. 1 is a schematic configuration diagram of an engine system to which a vehicle control device according to an embodiment of the invention is applied; FIG. 1 is a schematic plan view of an engine according to an embodiment of the invention; FIG. 1 is a block diagram showing an electrical configuration of a vehicle control device according to an embodiment of the present invention; FIG. 4 is a map conceptually showing an operating range of an engine in which operating modes are switched in the embodiment of the present invention. 4 is a flowchart of vehicle attitude control processing according to the embodiment of the present invention; 4 is a flowchart of increased torque setting processing according to the embodiment of the present invention; 4 is a map defining a start threshold value and an end threshold value for the first vehicle attitude control according to the embodiment of the present invention; 4 is a map showing the relationship between additional acceleration and steering speed according to an embodiment of the present invention; 4 is a map for correcting additional acceleration according to an embodiment of the invention; 4 is a flowchart of a reduced torque setting process according to the embodiment of the present invention; 4 is a map defining a start threshold and an end threshold for second vehicle attitude control according to an embodiment of the present invention; 4 is a map showing the relationship between additional deceleration and steering speed according to an embodiment of the present invention; 4 is a map for correcting additional deceleration according to an embodiment of the present invention; 4 is a time chart showing changes over time in parameters relating to vehicle attitude control when the vehicle makes a turn according to the embodiment of the present invention;

A vehicle control device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

<Vehicle configuration>
First, a vehicle to which a vehicle control apparatus according to an embodiment of the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram showing the overall configuration of a vehicle to which a vehicle control device according to an embodiment of the invention is applied.

In FIG. 1, reference numeral 200 denotes a vehicle equipped with the vehicle control device according to this embodiment. Left and right front wheels 202a, which are steered wheels, are provided at the front portion of the vehicle body of the vehicle 200, and left and right rear wheels 202b, which are drive wheels, are provided at the rear portion of the vehicle body. A front wheel 202a and a rear wheel 202b of the vehicle 200 are respectively supported by suspensions 203 with respect to the vehicle body. An engine 10, which is a prime mover for driving the rear wheels 202b, is mounted on the front portion of the vehicle body of the vehicle 200. As shown in FIG. In this embodiment, the engine 10 is a gasoline engine, but an internal combustion engine such as a diesel engine can also be used as the prime mover. In this embodiment, the vehicle 200 is a so-called FR vehicle in which the engine 10 mounted on the front of the vehicle body drives the rear wheels 202b via the transmission 204a, the propeller shaft 204b, and the differential gear 204c. The present invention can be applied to any vehicle in which the rear wheels are driven by the engine 10, such as a so-called RR vehicle in which the rear wheels 202b are driven by the engine 10 mounted in the rear part of the vehicle body.

The vehicle 200 is also equipped with a steering device 207 including a steering wheel 206 (hereinafter also simply referred to as “steering”). It is designed to be steered (steered) by Further, the vehicle 200 has a steering angle sensor 40 that detects the steering angle of the steering device 207, an accelerator opening sensor 30 that detects the depression amount (accelerator opening) of the accelerator pedal, and a vehicle speed sensor 39 that detects the vehicle speed. . The steering angle sensor 40 typically detects the rotation angle of the steering wheel 206, but in addition to or instead of the rotation angle, the steering angle (tire angle) of the front wheels 202a may also be detected. good. Each of these sensors outputs respective detection signals to a PCM (Power-train Control Module) 50, which is a controller.

Next, an engine system to which the vehicle control apparatus according to the embodiment of the present invention is applied will be described with reference to FIGS. 2 to 4. FIG. FIG. 2 is a schematic configuration diagram of an engine system to which a vehicle control device according to an embodiment of the invention is applied. 3 is a schematic plan view of an engine according to an embodiment of the invention; FIG. FIG. 4 is a block diagram showing the electrical configuration of the vehicle control device according to the embodiment of the present invention.

As shown in FIG. 2, the engine system 100 mainly includes an intake passage 1 through which intake air (air) introduced from the outside passes; An engine 10 (specifically, a gasoline engine) that burns the air-fuel mixture with the supplied fuel to generate power for the vehicle, and an exhaust passage 25 that discharges the exhaust gas generated by the combustion in the engine 10. have.

The intake passage 1 has, in order from the upstream side, an air cleaner 3 for purifying intake air introduced from the outside, a throttle valve 5 for adjusting the amount of intake air passing through (intake air amount), and a temporary supply of intake air to the engine 10. A surge tank 7 is provided to store the power. On the other hand, the exhaust passage 25 is provided with exhaust purification catalysts 26a and 26b having an exhaust gas purification function, such as a NOx catalyst, a three-way catalyst, and an oxidation catalyst.

As shown in FIG. 3, the engine 10 of this embodiment is an in-line four-cylinder engine having four cylinders 2 (2A to 2D) arranged in a straight line. This engine 10 mainly includes an intake valve 12 that introduces the intake air supplied from the intake passage 1 into the combustion chamber 11, a fuel injection valve 13 that injects fuel toward the combustion chamber 11, and a A spark plug 14 that ignites the supplied air-fuel mixture, a piston 15 that reciprocates due to combustion of the air-fuel mixture in the combustion chamber 11, a crankshaft 16 that rotates due to the reciprocating motion of the piston 15, and an exhaust valve 17 for discharging the exhaust gas generated by the combustion of the air-fuel mixture in the combustion chamber 11 to the exhaust passage 25 . Each piston 15 provided in cylinders 2A to 2D reciprocates with a phase difference of 180° (180°CA) in the crank angle. Correspondingly, the ignition timings of the cylinders 2A to 2D are set to timings that are phase-shifted by 180° CA.

In particular, the engine 10 of the present embodiment is a cylinder deactivation engine capable of deactivating two of the four cylinders 2A to 2D and activating the remaining two cylinders, that is, reducing the number of cylinders. Specifically, if cylinder 2A is the first cylinder, cylinder 2B is the second cylinder, cylinder 2C is the third cylinder, and cylinder 2D is the fourth cylinder in order from the left side of FIG. , ignition is performed in the order of the first cylinder 2A, the third cylinder 2C, the fourth cylinder 2D, and the second cylinder 2B. Further, during reduced-cylinder operation, the ignition operation of the spark plugs 14 is prohibited in two cylinders (in this embodiment, the first cylinder 2A and the fourth cylinder 2D) whose ignition order is not continuous, and the remaining two cylinders (that is, the third cylinder) are prohibited. Ignition is alternately performed in the cylinder 2C and the second cylinder 2B).

In addition, the engine 10 sets the operating timings (corresponding to valve phases) of the intake valves 12 and the exhaust valves 17 to a variable intake valve mechanism 18 and a variable exhaust valve mechanism as variable valve timing mechanisms. 19 are variably configured. As the variable intake valve mechanism 18 and the variable exhaust valve mechanism 19, various known types can be applied. You can change the timing.

The engine 10 also has a valve stop mechanism 20 that stops opening and closing operations of the intake valves 12 and the exhaust valves 17 of the first cylinder 2A and the fourth cylinder 2D during reduced-cylinder operation. The valve stop mechanism 20 includes, for example, a so-called lost motion mechanism that is interposed between the cam and the valve to enable or disable transmission of the drive force of the cam to the valve. Alternatively, the valve stop mechanism 20 includes two types of cams having different cam profiles: a first cam having cam ridges for opening and closing the valve, and a second cam for stopping the opening and closing of the valve. It may include a so-called cam shifting mechanism that selectively transmits the operating state of one of the second cams to the valve.

Furthermore, the engine system 100 is provided with sensors 30 to 40 that detect various states of the engine system 100 (see FIGS. 2 and 4). The accelerator opening sensor 30, vehicle speed sensor 39 and steering angle sensor 40 are as described above. The airflow sensor 31 detects the amount of intake air corresponding to the flow rate of intake air passing through the intake passage 1 . A throttle opening sensor 32 detects the throttle opening, which is the opening of the throttle valve 5 . The pressure sensor 33 detects an intake manifold pressure (intake manifold pressure) corresponding to the pressure of intake air supplied to the engine 10 . A crank angle sensor 34 detects the crank angle of the crankshaft 16 (corresponding to the engine speed). This crank angle sensor 34 corresponds to an engine speed sensor. A water temperature sensor 35 detects the water temperature, which is the temperature of cooling water for cooling the engine 10 . The temperature sensor 36 detects the in-cylinder temperature, which is the temperature inside the cylinder 2 of the engine 10 . The cam angle sensors 37 and 38 detect operation timings including closing timings of the intake valve 12 and the exhaust valve 17, respectively. These various sensors 30-40 output detection signals S30-S40 corresponding to the detected parameters to the PCM 50, respectively.

The PCM 50 controls components within the engine system 100 based on the detection signals S30-S40 input from the various sensors 30-40 described above. Specifically, as shown in FIG. 4, the PCM 50 supplies a control signal S105 to the throttle valve 5 to control the opening/closing timing and throttle opening of the throttle valve 5, and sends a control signal S113 to the fuel injection valve 13. A control signal S114 is supplied to the ignition plug 14 to control the ignition timing, and a control signal S118 is supplied to each of the variable intake valve mechanism 18 and the variable exhaust valve mechanism 19. , S119 to control the operation timing of the intake valve 12 and the exhaust valve 17, and a control signal S120 to the valve stop mechanism 20 to control the intake valve 12 and the exhaust valve of the first cylinder 2A and the fourth cylinder 2D. It controls the stop/activation of the opening/closing operation of 17.

Each component of these PCM 50 includes one or more processors, various programs interpreted and executed on the processor (basic control programs such as OS, and application programs activated on the OS to realize specific functions). , and a computer equipped with internal memory such as ROM and RAM for storing programs and various data.

Incidentally, in one example, the vehicle control device in the present invention is mainly composed of the engine 10, the steering device 207, the steering angle sensor 40, the accelerator opening sensor 30, the vehicle speed sensor 39, and the PCM 50. In another example, the vehicle control device in the present invention is configured by the PCM 50, and in this example, the PCM 50 functions as vehicle attitude control means and threshold value setting means in the present invention.
Furthermore, the accelerator opening sensor 30 and the vehicle speed sensor 39 correspond to driving state sensors that detect the driving state of the vehicle 200 . Further, the steering angle sensor 40 corresponds to a steering angle related value sensor that detects a steering angle related value related to the steering angle of the steering device 207 . In the following, an embodiment using steering speed as the steering angle related value is exemplified. This steering speed is obtained by the PCM 50 from the steering angle detected by the steering angle sensor 40 . In this case, the steering angle related value sensor is composed of the steering angle sensor 40 and the PCM 50 .

<Driving mode>

Next, with reference to FIG. 5, the operating regions in which the reduced-cylinder operation and full-cylinder operation are respectively performed in the embodiment of the present invention will be described. FIG. 5 is a map conceptually showing the operating range of the engine 10 in which the operating mode is switched in the embodiment of the present invention. In FIG. 5, the horizontal axis indicates the engine speed, and the vertical axis indicates the engine load. As shown in FIG. 5, a reduced-cylinder operation region A in which the reduced-cylinder operation is performed is set in a range where the engine speed is relatively low and the engine load is low. , an all-cylinder operation region B in which all-cylinder operation is performed is set. The PCM 50 refers to such a map to determine in which of the reduced-cylinder operation region A and the full-cylinder operation region B the engine speed and the engine load are included in, and performs reduced-cylinder operation according to the determination result. and full-cylinder operation are controlled to stop/activate the opening/closing operations of the intake valves 12 and the exhaust valves 17 of the first cylinder 2A and the fourth cylinder 2D.

<Vehicle attitude control>
Next, in this embodiment, the content of control performed by the PCM 50 to control the attitude of the vehicle 200 (vehicle attitude control) will be described. First, referring to FIG. 6, the overall flow of vehicle attitude control processing performed by the PCM 50 in this embodiment will be described. FIG. 6 is a flowchart of vehicle attitude control processing according to the embodiment of the present invention.

The vehicle attitude control process of FIG. 6 is started when the ignition of the vehicle 200 is turned on and the power of the PCM 50 is turned on, and is repeatedly executed at a predetermined cycle (for example, 50 ms).
When the vehicle attitude control process is started, as shown in FIG. 6, the PCM 50 acquires various sensor information regarding the driving state of the vehicle 200 in step S1. Specifically, the PCM 50 corresponds to the steering angle detected by the steering angle sensor 40, the accelerator opening detected by the accelerator opening sensor 30, the vehicle speed detected by the vehicle speed sensor 39, and the crank angle detected by the crank angle sensor 34. Detection signals output from the various sensors described above, including the engine speed, the gear position currently set in the transmission 204a of the vehicle 200, and the like, are acquired as information on the driving state.

Next, in step S2, PCM 50 sets a target acceleration based on the driving state of vehicle 200 acquired in step S1. Specifically, the PCM 50 selects an acceleration characteristic map (created in advance and stored in a memory or the like) defined for various vehicle speeds and various gear stages, and selects an acceleration map corresponding to the current vehicle speed and gear stage. A characteristic map is selected, and a target acceleration corresponding to the current accelerator opening is set by referring to the selected acceleration characteristic map.

Next, in step S3, the PCM 50 determines the basic torque that should be generated by the engine 10 in order to achieve the target acceleration set in step S2. In this case, the PCM 50 determines the basic torque within the range of torque that the engine 10 can output based on the current vehicle speed, gear stage, road surface gradient, road surface μ, and the like.

Also, in parallel with the processing of steps S2 and S3, in step S4, the PCM 50 executes an increase torque setting process of setting torque (increase torque) for adding acceleration to the vehicle 200 based on the steering operation. In this step S4, the PCM 50 sets an increase torque for increasing the basic torque in response to an increase in the steering angle of the steering device 207, that is, in response to the turning operation of the steering wheel. In this embodiment, the PCM 50 controls the vehicle attitude by temporarily increasing the torque to add acceleration to the vehicle 200 when the steering wheel is turned. Hereinafter, the vehicle attitude control that is performed using the increased torque when the steering is turned is appropriately referred to as "first vehicle attitude control". The increased torque setting process in step S4 will be described later with reference to FIG. 7 and the like.

Next, in step S5, the PCM 50 executes reduction torque setting processing for setting torque (reduction torque) for applying deceleration to the vehicle 200 based on the steering operation. In this step S5, the PCM 50 sets a reduction torque for reducing the basic torque according to the decrease in the steering angle of the steering device 207, that is, according to the steering return. In this embodiment, the PCM 50 controls the vehicle attitude by temporarily reducing the torque and adding deceleration to the vehicle 200 when the steering is turned back. Hereinafter, the vehicle attitude control that is performed using the reduced torque at the time of steering return is appropriately referred to as "second vehicle attitude control". Typically, this second vehicle attitude control tends to be implemented after the first vehicle attitude control described above. The reduced torque setting process in step S5 will be described later with reference to FIG. 11 and the like.

After executing the processing of steps S2 and S3, the increased torque setting processing of step S4, and the reduced torque setting processing of step S5, in step S6, the PCM 50 sets the basic torque set in step S3, the increased torque set in step S4, and A final target torque is set based on the reduced torque set in step S5. Specifically, the PCM 50 calculates the final target torque by adding the increased torque to the basic torque and subtracting the decreased torque. Basically, only one of the increase torque and the decrease torque is set, and both the increase torque and the decrease torque are not set. (in this case, the first vehicle attitude control is executed), or by subtracting the reduction torque from the basic torque, the final target torque is calculated (in this case, the second vehicle attitude control is executed). ).

Next, at step S7, the PCM 50 sets the actuator control amount for realizing the final target torque set at step S6. Specifically, the PCM 50 determines various state quantities necessary to achieve the final target torque based on the final target torque set in step S6, and based on these state quantities, each component of the engine 10 Set the control amount for each actuator that drives the . In this case, the PCM 50 sets a limit value and a limit range according to the state quantity, and sets the control amount of each actuator so that the state value complies with the limit set by the limit value and the limit range. Subsequently, at step S8, the PCM 50 outputs a control command to each actuator based on the control amount set at step S7.

Specifically, when the final target torque is set by adding the increased torque to the basic torque in step S6, the PCM 50 sets the ignition timing of the spark plug 14 to be higher than the ignition timing for generating the basic torque. Advance. Further, instead of advancing the ignition timing, or together with it, the PCM 50 increases the throttle opening of the throttle valve 5 and advances the closing timing of the intake valve 12 which is set after the bottom dead center. By doing so, the amount of intake air is increased. In this case, the PCM 50 increases the amount of fuel injected by the fuel injection valve 13 in response to the increase in intake air amount so as to maintain a predetermined air-fuel ratio.

On the other hand, when the final target torque is set by subtracting the reduced torque from the basic torque in step S6, the PCM 50 retards the ignition timing of the spark plug 14 from the ignition timing for generating the basic torque. let (retard). Further, instead of retarding the ignition timing or together with it, the PCM 50 reduces the throttle opening of the throttle valve 5 or retards the closing timing of the intake valve 12 set after the bottom dead center. This reduces the amount of intake air. In this case, the PCM 50 reduces the amount of fuel injected by the fuel injection valve 13 in accordance with the increase in intake air amount so that a predetermined air-fuel ratio is maintained.

When the engine 10 is a diesel engine, when the final target torque is set by adding the increased torque to the basic torque in step S6, the PCM 50 causes the fuel injection amount by the fuel injection valve 13 to generate the basic torque. Increase the fuel injection amount for On the other hand, when the PCM 50 sets the final target torque by subtracting the reduction torque from the basic torque in step S6, the fuel injection amount by the fuel injection valve 13 is reduced below the fuel injection amount for generating the basic torque. Let

After such step S8, the PCM 50 terminates the vehicle attitude control process.

<Increase torque setting process>
Next, the increased torque setting process (see step S4 in FIG. 6) in the embodiment of the present invention will be described with reference to FIGS. 7 to 10. FIG. This increased torque setting process is performed to set the increased torque used in the first vehicle attitude control when the steering is turned.

FIG. 7 is a flowchart of increased torque setting processing according to the embodiment of the present invention. FIG. 8 is a map defining a start threshold and an end threshold for the first vehicle attitude control according to the embodiment of the present invention. FIG. 9 is a map showing the relationship between additional acceleration and steering speed according to an embodiment of the present invention. FIG. 10 is a map for correcting additional acceleration according to an embodiment of the invention.

As shown in FIG. 7, when the increased torque setting process is started, the PCM 50 sets the start condition for the first vehicle attitude control in step S101 based on the engine speed and the operation mode (reduced cylinder operation or full cylinder operation). Then, in step S102, a termination threshold (corresponding to a second threshold) that defines the termination condition of the first vehicle attitude control is set. These start threshold and end threshold are used to determine the steering speed (an absolute value is used in the increased torque setting process; the same shall apply hereinafter) when starting and ending the first vehicle attitude control, respectively. is the threshold. Here, with reference to FIG. 8, the start threshold value and the end threshold value will be specifically described.

FIG. 8(a) shows a map defining the relationship between the engine speed (horizontal axis) and the start threshold value (vertical axis) as the first threshold, and FIG. 8(b) shows the engine speed (horizontal axis). axis) and the end threshold (vertical axis) as the second threshold. In FIGS. 8(a) and 8(b), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation.

As shown in FIG. 8A, in this embodiment, the lower the engine speed, the smaller the start threshold value is set. In addition, in reduced-cylinder operation, the start threshold is set to a smaller value than in full-cylinder operation. The condition for starting the first vehicle attitude control is established when the steering speed is equal to or higher than the start threshold. The conditions for starting the first vehicle attitude control are relaxed. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the torque increase responsiveness deteriorates at the start of the first vehicle attitude control. In order to suppress this, the start threshold is set to a small value to relax the start condition of the first vehicle attitude control.

Further, as shown in FIG. 8B, in the present embodiment, the lower the engine speed, the larger the end threshold is set. In addition, in reduced-cylinder operation, the termination threshold is set to a larger value than in full-cylinder operation. The end condition of the first vehicle attitude control is established when the steering speed is less than the end threshold. The conditions for ending the first vehicle attitude control are relaxed. In this embodiment, when the engine speed is low and when the reduced cylinder operation is performed, that is, when the number of combustions of the engine 10 per unit time is small, the torque recovery at the end of the first vehicle attitude control (specifically, In order to suppress deterioration of responsiveness due to torque reduction), the termination threshold is set to a large value to relax the termination condition of the first vehicle attitude control.

In addition, in FIGS. 8A and 8B, a rotation speed at least higher than the idle rotation speed is applied to the engine rotation speed N1. In addition, basically, the first vehicle attitude control is not executed in a region where the engine speed is less than N1 (because there is not much meaning in executing the first vehicle attitude control). Further, the engine speed N3 is set to a speed such that above this speed, even if the start threshold value and the end threshold value are changed according to the engine speed, the effect is not so great. In one example, the engine speed N1 is about 700 to 1200 rpm, the engine speed N3 is about 2800 to 3200 rpm, and the engine speed N2 between these N1 and N3 is about 1800 to 2200 rpm. is. The engine speeds N1 to N3 described here are similarly applied to FIGS. 10, 12 and 14, which will be described later.
In addition, in FIGS. 8A and 8B, the start threshold and the end threshold are continuously changed according to the engine speed. It may be changed in a target (stepwise) manner. In one example, the start threshold and the end threshold may be changed stepwise depending on whether the engine speed is less than or equal to or greater than a predetermined speed.

Returning to FIG. 7, in step S103, the PCM 50 determines whether or not the first vehicle attitude control is currently being executed. As a result, when it is determined that the first vehicle attitude control is not executed (step S103: Yes), the process proceeds to step S104, and the PCM 50 checks whether the steering speed is equal to or higher than the start threshold set in step S101. judge. Note that the PCM 50 calculates the steering speed based on the steering angle acquired in step S1. In such step S104, when it is determined that the steering speed is equal to or higher than the start threshold (step S104: Yes), that is, when the condition for starting the first vehicle attitude control is satisfied, the process proceeds to step S105. On the other hand, if it is determined that the steering speed is less than the start threshold (step S104: No), that is, if the condition for starting the first vehicle attitude control is not satisfied, the process ends.

Next, in step S105, the PCM 50 determines whether or not the steering speed is increasing. As a result, when it is determined that the steering speed is increasing (step S105: Yes), the process proceeds to step S106, and the PCM 50 sets additional acceleration based on the steering speed. This additional acceleration is the acceleration that should be applied to the vehicle 200 in accordance with the steering operation in order to control the vehicle posture as intended by the driver.

Specifically, the PCM 50 sets the additional acceleration corresponding to the current steering speed based on the relationship between the additional acceleration and the steering speed shown in the map of FIG. In FIG. 9, the horizontal axis indicates the steering speed, and the vertical axis indicates the additional acceleration. As shown in FIG. 9, as the steering speed increases, the additional acceleration corresponding to this steering speed asymptotically approaches a predetermined upper limit value _Amax . That is, as the steering speed increases, the additional acceleration increases, and the rate of increase in the amount of increase decreases. This upper limit value A _max is set to an acceleration that does not make the driver feel that there has been control intervention even if acceleration is added to the vehicle 200 in response to the steering operation (for example, 0.5 m/s ² ≈0.05 G). ). Note that when the steering speed exceeds a predetermined threshold value, the additional acceleration is maintained at the upper limit value _Amax .

Next, in step S107, the PCM 50 sets an additional acceleration correction value for correcting the additional acceleration set in step S106 based on the engine speed and the operating mode (reduced cylinder operation or full cylinder operation). Then, in step S108, the PCM 50 corrects the additional acceleration set in step S106 using the additional acceleration correction value set in step S107. Specifically, the PCM 50 corrects the additional acceleration by multiplying the additional acceleration by the additional acceleration correction value. In this case, the larger the additional acceleration correction value is, the larger the additional acceleration is corrected. Correcting the additional acceleration to a large extent means causing the vehicle to quickly generate the additional acceleration. Next, at step S109, the PCM 50 sets an increased torque based on the additional acceleration corrected at step S108. Specifically, the PCM 50 sets the additional torque required to achieve additional acceleration by increasing the basic torque based on the current vehicle speed, gear stage, road surface gradient, etc. obtained in step S1. After that, the PCM 50 ends the increased torque setting process and returns to the main routine.

Here, a method for setting the additional acceleration correction value in the embodiment of the present invention will be described with reference to FIG. 10(a). In FIG. 10(a), the horizontal axis indicates the engine speed, and the vertical axis indicates the additional acceleration correction value. In FIG. 10(a), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation. As shown in FIG. 10(a), in this embodiment, the lower the engine speed, the larger the additional acceleration correction value is set. In addition, in reduced-cylinder operation, the additional acceleration correction value is set to a larger value than in full-cylinder operation. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the additional acceleration correction value is increased to increase the rate of change of the additional acceleration. By doing so, the speed of change in the increasing direction of the engine torque is increased, thereby suppressing deterioration in responsiveness to torque increase at the start of the first vehicle attitude control.

Returning to FIG. 7, when it is determined in step S105 that the steering speed has not increased (step S105: No), typically when the steering speed has not changed, the process proceeds to step S110. In step S110, the PCM 50 sets the additional acceleration set in the previous process as the additional acceleration in the current process. Then, in step S109, the PCM 50 sets the increased torque based on the additional acceleration set in step S110. After that, the PCM 50 ends the increased torque setting process and returns to the main routine.

On the other hand, when it is determined in step S103 that the first vehicle attitude control is being executed (step S103: No), the process proceeds to step S111. In step S111, the PCM 50 determines whether or not the steering speed is less than the end threshold set in step S102. As a result, if it is determined that the steering speed is equal to or higher than the end threshold (step S111: No), that is, if the conditions for ending the first vehicle attitude control are not satisfied, the process proceeds to step S105. In this case, the PCM 50 performs the processes after step S105 described above to continue the first vehicle attitude control.

On the other hand, if it is determined that the steering speed is less than the end threshold (step S111: Yes), that is, if the condition for ending the first vehicle attitude control is satisfied, the process proceeds to step S112. In step S112, the PCM 50 acquires the amount by which the additional acceleration set in the previous process is decreased in the current process (additional acceleration decrease amount). In one example, the PCM 50 calculates the additional acceleration reduction amount based on the reduction rate corresponding to the steering speed using a map such as that shown in FIG. 9 in the same manner as for the additional acceleration. In another example, the PCM 50 calculates the additional acceleration decrease amount based on a constant decrease rate pre-stored in memory or the like.

Next, in step S113, the PCM 50 sets an additional acceleration reduction amount correction value for correcting the additional acceleration reduction amount set in step S112 based on the engine speed and the operating mode (reduced cylinder operation or full cylinder operation). do. Then, in step S114, the PCM 50 corrects the additional acceleration decrease amount set in step S112 using the additional acceleration decrease amount correction value set in step S113. Specifically, the PCM 50 corrects the additional acceleration decrease amount by multiplying the additional acceleration decrease amount by the additional acceleration decrease amount correction value. In this case, the greater the additional acceleration decrease amount correction value, the greater the correction of the additional acceleration decrease amount. Correcting the additional acceleration reduction amount to a large value means to quickly reduce the acceleration generated in the vehicle, in other words, to quickly return the vehicle to the state before the acceleration was applied. do. Next, in step S115, the PCM 50 subtracts the additional acceleration decrease amount corrected in step S114 from the additional acceleration set in the previous process, thereby setting the additional acceleration in the current process. Then, in step S109, the PCM 50 sets the increased torque based on the additional acceleration set in step S115. After that, the PCM 50 ends the increased torque setting process and returns to the main routine.

Here, with reference to FIG. 10(b), a method of setting the additional acceleration decrease amount correction value in the embodiment of the present invention will be described. In FIG. 10(b), the horizontal axis indicates the engine speed, and the vertical axis indicates the additional acceleration reduction amount correction value. In FIG. 10(b), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation. As shown in FIG. 10(b), in the present embodiment, the lower the engine speed, the larger the additional acceleration reduction amount correction value is set. In addition, in reduced-cylinder operation, the additional acceleration reduction amount correction value is set to a larger value than in full-cylinder operation. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the additional acceleration decrease amount correction value is increased to reduce the additional acceleration decrease amount. By increasing the rate of change, the rate of change in the restoration direction (decrease direction) of the engine torque is increased, thereby suppressing deterioration in torque restoration responsiveness at the end of the first vehicle attitude control.

In FIGS. 10A and 10B, the additional acceleration correction value and the additional acceleration reduction amount correction value are continuously changed according to the engine speed. The additional acceleration decrease amount correction value may be changed in a stepwise manner according to the engine speed. In one example, the additional acceleration correction value and the additional acceleration reduction amount correction value may be changed stepwise depending on whether the engine speed is less than or equal to or greater than a predetermined speed.

Further, in the above-described embodiment, the threshold applied in the first vehicle attitude control is changed and the additional acceleration applied in the first vehicle attitude control is corrected based on the combustion state (engine speed and driving mode) of the engine 10. However, in another example, only one of changing the threshold value and correcting the additional acceleration may be performed. For example, only the threshold may be changed according to the combustion state of the engine 10 .

<Reduction torque setting process>
Next, the reduction torque setting process (see step S5 in FIG. 6) in the embodiment of the present invention will be described with reference to FIGS. 11 to 14. FIG. This reduction torque setting process is performed to set the reduction torque used in the second vehicle attitude control when the steering is returned.

FIG. 11 is a flow chart of the reduced torque setting process according to the embodiment of the present invention. FIG. 12 is a map defining a start threshold and an end threshold for the second vehicle attitude control according to the embodiment of the present invention. FIG. 13 is a map showing the relationship between additional deceleration and steering speed according to an embodiment of the present invention. FIG. 14 is a map for correcting additional deceleration according to an embodiment of the invention.

As shown in FIG. 11, when the reduction torque setting process is started, the PCM 50 sets the start condition for the second vehicle attitude control in step S201 based on the engine speed and the operation mode (reduced cylinder operation or full cylinder operation). Then, in step S202, a termination threshold (corresponding to a fourth threshold) that defines the termination condition of the second vehicle attitude control is set. These start threshold and end threshold are used to determine the steering speed (absolute value is used in the reduction torque setting process; the same shall apply hereinafter) when starting and ending the second vehicle attitude control, respectively. is the threshold. Here, with reference to FIG. 12, the start threshold value and the end threshold value will be specifically described.

FIG. 12(a) shows a map defining the relationship between the engine speed (horizontal axis) and the start threshold value (vertical axis) as the third threshold, and FIG. axis) and the termination threshold (vertical axis) as the fourth threshold. In FIGS. 12(a) and 12(b), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation.

As shown in FIG. 12(a), in this embodiment, the lower the engine speed, the smaller the start threshold is set. In addition, in reduced-cylinder operation, the start threshold is set to a smaller value than in full-cylinder operation. The condition for starting the second vehicle attitude control is established when the steering speed is greater than or equal to the start threshold. The conditions for starting the second vehicle attitude control are relaxed. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the responsiveness of the torque reduction at the start of the second vehicle attitude control is deteriorated. In order to suppress this, the start threshold is set to a small value to relax the conditions for starting the second vehicle attitude control.

Further, as shown in FIG. 12(b), in the present embodiment, the lower the engine speed, the larger the end threshold is set. In addition, in reduced-cylinder operation, the termination threshold is set to a larger value than in full-cylinder operation. The end condition of the second vehicle attitude control is established when the steering speed is less than the end threshold. The conditions for ending the second vehicle attitude control are relaxed. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the torque recovery at the end of the second vehicle attitude control (specifically, In order to suppress deterioration of responsiveness due to torque increase), the termination threshold value is set to a large value to relax the termination condition of the second vehicle attitude control.

In addition, in FIGS. 12A and 12B, the start threshold and the end threshold are continuously changed according to the engine speed. It may be changed in a target (stepwise) manner. In one example, the start threshold and the end threshold may be changed stepwise depending on whether the engine speed is less than or equal to or greater than a predetermined speed.

Returning to FIG. 11, in step S203, the PCM 50 determines whether or not the second vehicle attitude control is currently being executed. As a result, when it is determined that the second vehicle attitude control is not executed (step S203: Yes), the process proceeds to step S204, and the PCM 50 checks whether the steering speed is equal to or higher than the start threshold set in step S201. judge. As a result, if it is determined that the steering speed is equal to or higher than the start threshold (step S204: Yes), that is, if the conditions for starting the second vehicle attitude control are satisfied, the process proceeds to step S205. On the other hand, if it is determined that the steering speed is less than the start threshold (step S204: No), that is, if the conditions for starting the second vehicle attitude control are not satisfied, the process ends.

Next, in step S205, the PCM 50 determines whether the steering speed is decreasing. As a result, when it is determined that the steering speed is decreasing (step S205: Yes), the process proceeds to step S206, and the PCM 50 sets additional deceleration based on the steering speed. This additional deceleration is deceleration that should be applied to the vehicle 200 according to the steering operation in order to control the vehicle posture in accordance with the driver's intention.

Specifically, the PCM 50 sets the additional deceleration corresponding to the current steering speed based on the relationship between the additional deceleration and the steering speed shown in the map of FIG. In FIG. 13, the horizontal axis indicates the steering speed, and the vertical axis indicates the additional deceleration. As shown in FIG. 13, as the steering speed increases, the additional deceleration corresponding to this steering speed asymptotically approaches a predetermined upper limit value _Dmax . That is, as the steering speed increases, the additional deceleration increases, and the rate of increase in the amount of increase decreases. This upper limit value D _max is set to a deceleration level at which the driver does not feel that there has been control intervention even if deceleration is added to the vehicle 200 according to the steering operation (for example, 0.5 m/s ² ≈0 .05G). Note that when the steering speed reaches or exceeds a predetermined threshold, the additional deceleration is maintained at the upper limit value _Dmax .

Next, in step S207, the PCM 50 sets an additional deceleration correction value for correcting the additional deceleration set in step S206 based on the engine speed and the operating mode (reduced cylinder operation or full cylinder operation). Then, in step S208, the PCM 50 corrects the additional deceleration set in step S206 using the additional deceleration correction value set in step S207. Specifically, the PCM 50 corrects the additional deceleration by multiplying the additional deceleration by the additional deceleration correction value. In this case, the larger the additional deceleration correction value is, the larger the additional deceleration is corrected. Correcting the additional deceleration to a large extent means causing the vehicle to quickly generate the additional deceleration. Next, in step S209, the PCM 50 sets the reduction torque based on the additional deceleration corrected in step S208. Specifically, the PCM 50 sets the reduction torque required to realize the additional deceleration by suppressing the basic torque based on the current vehicle speed, gear stage, road surface gradient, etc. acquired in step S1. After that, the PCM 50 ends the reduced torque setting process and returns to the main routine.

Here, a method of setting the additional deceleration correction value in the embodiment of the present invention will be described with reference to FIG. 14(a). In FIG. 14(a), the horizontal axis indicates the engine speed, and the vertical axis indicates the additional deceleration correction value. In FIG. 14(a), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation. As shown in FIG. 14(a), in this embodiment, the lower the engine speed, the larger the additional deceleration correction value is set. In addition, in reduced-cylinder operation, the additional deceleration correction value is set to a larger value than in full-cylinder operation. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the additional deceleration correction value is increased to increase the rate of change of the additional deceleration. is increased to increase the speed of change in the decreasing direction of the engine torque, thereby suppressing deterioration in responsiveness of torque decrease at the start of the second vehicle attitude control.

Returning to FIG. 11, when it is determined in step S205 that the steering speed has not decreased (step S205: No), typically when the steering speed has not changed, the process proceeds to step S210. In step S210, the PCM 50 sets the additional deceleration set in the previous process as the additional deceleration in the current process. Then, in step S209, the PCM 50 sets the reduction torque based on the additional deceleration set in step S210. After that, the PCM 50 ends the reduced torque setting process and returns to the main routine.

On the other hand, if it is determined in step S203 that the second vehicle attitude control is being executed (step S203: No), the process proceeds to step S211. In step S211, the PCM 50 determines whether or not the steering speed is less than the end threshold set in step S202. As a result, if it is determined that the steering speed is equal to or higher than the end threshold (step S211: No), that is, if the conditions for ending the second vehicle attitude control are not satisfied, the process proceeds to step S205. In this case, the PCM 50 performs the processes after step S205 described above in order to continue the second vehicle attitude control.

On the other hand, if it is determined that the steering speed is less than the end threshold (step S211: Yes), that is, if the conditions for ending the second vehicle attitude control are satisfied, the process proceeds to step S212. In step S212, the PCM 50 acquires the amount by which the additional deceleration set in the previous process is decreased in the current process (additional deceleration reduction amount). In one example, the PCM 50 calculates the additional deceleration reduction amount based on the reduction rate according to the steering speed using a map such as that shown in FIG. 13 in the same manner as for the additional deceleration. In another example, the PCM 50 calculates the additional deceleration reduction amount based on a constant reduction rate pre-stored in memory or the like.

Next, in step S213, the PCM 50 sets an additional deceleration reduction amount correction value for correcting the additional deceleration reduction amount set in step S212 based on the engine speed and the operation mode (reduced cylinder operation or full cylinder operation). set. Then, in step S214, the PCM 50 corrects the additional deceleration reduction amount set in step S212 using the additional deceleration reduction amount correction value set in step S213. Specifically, the PCM 50 corrects the additional deceleration reduction amount by multiplying the additional deceleration reduction amount by the additional deceleration reduction amount correction value. In this case, the larger the additional deceleration reduction amount correction value, the larger the correction of the additional deceleration reduction amount. Correcting the additional deceleration reduction amount to a large amount means to quickly reduce the deceleration occurring in the vehicle, in other words, to quickly return the vehicle to the state before the deceleration was applied. means that Next, in step S215, the PCM 50 subtracts the additional deceleration reduction amount corrected in step S214 from the additional deceleration set in the previous process, thereby setting the additional deceleration in the current process. Then, in step S209, the PCM 50 sets the reduction torque based on the additional deceleration set in step S215. After that, the PCM 50 ends the reduced torque setting process and returns to the main routine.

Here, a method of setting the additional deceleration reduction amount correction value in the embodiment of the present invention will be described with reference to FIG. 14(b). In FIG. 14(b), the horizontal axis indicates the engine speed, and the vertical axis indicates the additional deceleration reduction amount correction value. In FIG. 14(b), the solid line indicates the map applied in full-cylinder operation, and the dashed line indicates the map applied in reduced-cylinder operation. As shown in FIG. 14(b), in this embodiment, the lower the engine speed, the larger the additional deceleration reduction amount correction value is set. In addition, in reduced-cylinder operation, the additional deceleration reduction amount correction value is set to a larger value than in full-cylinder operation. In this embodiment, when the engine speed is low and when the cylinder operation is reduced, that is, when the number of combustions of the engine 10 per unit time is small, the additional deceleration reduction amount correction value is increased to decrease the additional deceleration. By increasing the change speed of the engine torque in the restoring direction (increasing direction) of the engine torque, deterioration of responsiveness of torque restoration at the end of the second vehicle attitude control is suppressed. .

In FIGS. 14A and 14B, the additional deceleration correction value and the additional deceleration reduction amount correction value are continuously changed according to the engine speed. The correction value and the additional deceleration reduction amount correction value may be changed step by step according to the engine speed. In one example, the additional deceleration correction value and the additional deceleration reduction amount correction value may be changed stepwise depending on whether the engine speed is less than a predetermined speed or higher than a predetermined speed. .

Further, in the above-described embodiment, the threshold applied in the second vehicle attitude control is changed based on the combustion state (engine speed and driving mode) of the engine 10, and the additional deceleration applied in the second vehicle attitude control is changed. Although correction has been made, in another example, only either one of changing the threshold value and correcting the additional deceleration may be executed. For example, only the threshold may be changed according to the combustion state of the engine 10 .

<Action and effect>
Next, with reference to FIG. 15, the operation of the vehicle control device according to the embodiment of the present invention will be described. FIG. 15 is a time chart showing changes over time in parameters related to vehicle attitude control when the vehicle 200 makes a turn according to the embodiment of the present invention.

The time chart of FIG. 15 shows, from the top, the steering angle [deg] of the steering device 207, the steering speed [deg/s] of the steering device 207, the additional acceleration and the additional deceleration [m/s ² ] to be applied to the vehicle 200. ], the final target torque of the engine 10 [Nm], the command value of the ignition timing of the spark plug 14 [deg/CA], and the actual torque of the engine 10 [Nm]. The actual torque is the torque actually generated from the engine 10 when the final target torque is applied (in other words, the driving torque actually applied to the vehicle 200), and the actual torque is naturally the final target torque command. It tends to lag behind. In addition, in the example shown in FIG. 15, the basic torque is assumed to be constant.

Moreover, FIG. 15 shows the results of the control according to the present embodiment and the results of the control according to the comparative example. In this embodiment, as described above, the threshold value for determining the steering speed is changed according to the operation mode (full cylinder operation/reduced cylinder operation) (steps S101 and S102 in FIG. 7, FIG. 8, FIG. 11, steps S201 and S202, see FIG. 12), in the comparative example, the threshold for determining the steering speed is not changed according to the driving mode, that is, a constant threshold is used regardless of the driving mode.

Specifically, in this embodiment, during all-cylinder operation, the start threshold value Th1a and the end threshold value Th2a are used when performing the first vehicle attitude control, and when performing the second vehicle attitude control, A start threshold Th3a and an end threshold Th4a are used. In this embodiment, when the first vehicle attitude control is performed during reduced-cylinder operation, the start threshold Th1b and the end threshold Th2b are used, which are obtained by changing the start threshold Th1a and the end threshold Th2a used during all-cylinder operation. . The absolute value of the start threshold Th1b used during reduced-cylinder operation is smaller than the start threshold Th1a used during all-cylinder operation. It is larger than the termination threshold Th2a used during operation. In addition, in the present embodiment, when the second vehicle attitude control is performed during reduced-cylinder operation, a start threshold Th3b and an end threshold Th4b that are obtained by changing the start threshold Th3a and end threshold Th4a used during all-cylinder operation are used. be done. The absolute value of the start threshold Th3b used during reduced-cylinder operation is smaller than the start threshold Th3a used during all-cylinder operation. It is larger than the termination threshold Th4a used during operation. On the other hand, in the comparative example, regardless of the driving mode, the start threshold Th1a and the end threshold Th2a are used when performing the first vehicle attitude control, and the start threshold Th3a and Th2a are used when performing the second vehicle attitude control. A termination threshold Th4a is used. That is, in the comparative example, the threshold values Th1a to Th4a for all-cylinder operation are used as they are even during reduced-cylinder operation. In FIG. 15, in this embodiment, only the threshold values applied in the first and second vehicle attitude controls are changed based on the combustion state (especially the driving mode) of the engine 10, and the first and second vehicle attitude controls are changed. The results are illustrated when the additional acceleration and additional deceleration applied in 1 are not corrected.

In FIG. 15, in graphs of additional acceleration, additional deceleration, final target torque, ignition timing, and actual torque, thick solid lines, broken lines, and thin solid lines illustrate three results. The thick solid line indicates the results of this embodiment when the first and second vehicle attitude controls are performed during reduced-cylinder operation. In particular, when the first and second vehicle attitude controls are performed during reduced-cylinder operation, the thresholds Th1b through Th4b obtained by changing the thresholds Th1a through Th4a used during full-cylinder operation as described above are applied. (this result is hereinafter referred to as "first example"). The dashed lines show the results when the first and second vehicle attitude controls are performed during full-cylinder operation (these results are hereinafter referred to as "second example"). In this case, the thresholds Th1a to Th4a that have not been changed are used as they are because the engine is in all-cylinder operation. A thin solid line indicates the result of comparison when the first and second vehicle attitude controls are performed during reduced-cylinder operation. In particular, the results are shown when the first and second vehicle attitude controls are performed during reduced-cylinder operation and the thresholds Th1a to Th4a used during full-cylinder operation are not changed (the results are shown below. (referred to as the "third example").

As shown in FIG. 15, first, the steering angle and the steering speed (absolute values) increase when the steering operation is performed. In the first example (thick solid line) according to the present embodiment, at time t1, the steering speed becomes equal to or greater than the start threshold value Th1b for the first vehicle attitude control (step S104 in FIG. 7: Yes), and the first vehicle attitude control is started. be done. Specifically, after time t1, the additional acceleration is set, the increased torque corresponding to this added acceleration is set (steps S106 to S109 in FIG. 7), and the final target torque corresponding to this increased torque is Then, the actuator of the engine 10 is controlled so that the final target torque is achieved (steps S6 to S8 in FIG. 6). In this case, the ignition timing of the spark plug 14 is advanced from the ignition timing for generating the basic torque so that the increased torque generates a torque that is an increased basic torque. On the other hand, in the second and third examples (broken line and thin solid line), at time t2 after time t1, the steering speed becomes equal to or greater than the start threshold Th1a, and the first vehicle attitude control is started. Specifically, after time t2, the additional acceleration is set, the increased torque is set according to the added acceleration, and the final target torque is set according to the increased torque. Actuators of engine 10 are controlled to achieve.

Looking at the actual torque at this time, it can be seen that in the third example (thin solid line), the start of increase in the actual torque in the first vehicle attitude control is delayed compared to the second example (broken line). . That is, when the first vehicle attitude control is performed without changing the start threshold value Th1a during reduced-cylinder operation, compared with the case where the first vehicle attitude control is performed during full-cylinder operation, the first vehicle attitude It can be said that the torque increase responsiveness deteriorates at the start of control. This is due to the difference in the number of combustions per unit time in the engine 10, as described in "Problems to be Solved by the Invention". On the other hand, in the first example (thick solid line), the actual torque increase start timing in the first vehicle attitude control is almost the same as in the second example (broken line). In other words, by using the start threshold Th1b obtained by changing the start threshold Th1a during reduced-cylinder operation, the deterioration of responsiveness to torque increase at the start of the first vehicle attitude control is improved.

Next, when the steering speed decreases during the first vehicle attitude control, in the first example (thick solid line) according to the present embodiment, the steering speed becomes less than the first vehicle attitude control end threshold Th2b at time t3 (Fig. 7 step S111: Yes), the first vehicle attitude control begins to end. Specifically, after time t3, an additional acceleration reduction amount for reducing the additional acceleration is set, an increase torque is set by applying this additional acceleration reduction amount (steps S112 to S115 in FIG. 7), and , the final target torque is set according to this increased torque, and the actuator of the engine 10 is controlled so as to achieve this final target torque (steps S6 to S8 in FIG. 6). In this case, the ignition timing of the spark plug 14 is retarded toward the ignition timing for generating the basic torque in order to decrease the increased torque toward 0 (that is, to decrease the final target torque toward the basic torque). be cornered. On the other hand, in the second and third examples (broken line and thin solid line), at time t4 after time t3, the steering speed becomes less than the end threshold Th2a, and the first vehicle attitude control begins to end. Specifically, after time t4, an additional acceleration decrease amount for decreasing the additional acceleration is set, an increase torque is set by applying this additional acceleration decrease amount, and a final target corresponding to this increase torque is set. A torque is set and the actuators of the engine 10 are controlled to achieve this final target torque.

Looking at the actual torque at this time, in the third example (thin solid line), compared to the second example (broken line), the start of reduction in the actual torque in the first vehicle attitude control is delayed. I understand. That is, when the first vehicle attitude control is performed without changing the end threshold value Th2a during reduced cylinder operation, the first vehicle attitude control is compared to when the first vehicle attitude control is performed during full cylinder operation. It can be said that the responsiveness of torque recovery deteriorates at the end of control. This is due to the difference in the number of combustions per unit time in the engine 10, as described above. On the other hand, in the first example (thick solid line), the actual torque reduction start timing in the first vehicle attitude control is substantially the same as in the second example (broken line). In other words, by using the end threshold Th2b obtained by changing the end threshold Th2a during reduced-cylinder operation, deterioration in responsiveness of torque restoration (torque reduction) at the end of the first vehicle attitude control is improved.

Note that when a torque obtained by increasing the basic torque is generated by the increased torque in the first vehicle attitude control, the increased torque is transmitted to the rear wheels 202b, which are driving wheels, and acts as a force to propel the rear wheels 202b forward of the vehicle. When this force is transmitted from the front wheels 202a to the vehicle body of the vehicle 200 via the suspension 203, a force momentarily acts to lift the rear portion of the vehicle body upward, and a moment acts to tilt the vehicle body forward. A force that causes the front part to sink downward acts, and the front part of the vehicle body sinks, increasing the load on the front wheels. As a result, it is possible to improve the responsiveness or linearity of the vehicle 200 to the turning operation of the steering wheel. That is, in a rear-wheel drive vehicle, when acceleration is applied by increasing the drive torque of the rear wheels 202b, an inertial force that tilts the vehicle body backward and an instantaneous force that tilts the vehicle body forward are generated. It is considered that the momentary forward tilting force of the vehicle due to the increased torque predominantly contributes to the vehicle responsiveness and linear feeling.

Next, when a steering return operation is performed after the steering is held, the steering angle decreases and the steering speed (absolute value) increases. In the first example (thick solid line) according to the present embodiment, at time t5, the steering speed becomes equal to or greater than the second vehicle attitude control start threshold Th3b (step S204 in FIG. 11: Yes), and the second vehicle attitude control is started. be done. Specifically, after time t5, the additional deceleration is set, the reduced torque is set according to this additional deceleration (steps S206 to S209 in FIG. 11), and the final target is set according to this reduced torque. A torque is set, and the actuator of the engine 10 is controlled so as to achieve the final target torque (steps S6 to S8 in FIG. 6). In this case, the ignition timing of the ignition plug 14 is retarded from the ignition timing for generating the basic torque so that the reduced torque generates a torque that suppresses the basic torque. On the other hand, in the second and third examples (broken line and thin solid line), at time t6 after time t5, the steering speed becomes equal to or greater than the start threshold Th3a, and the second vehicle attitude control is started. Specifically, after time t6, the additional deceleration is set, the reduction torque is set according to the additional deceleration, and the final target torque is set according to the reduction torque. The actuators of engine 10 are controlled such that torque is realized.

Looking at the actual torque at this time, in the third example (thin solid line), compared to the second example (dashed line), it can be seen that the start of reduction in the actual torque is delayed in the second vehicle attitude control. . That is, when the second vehicle attitude control is performed without changing the start threshold value Th3a during reduced-cylinder operation, the second vehicle attitude control is compared to when the second vehicle attitude control is performed during full-cylinder operation. It can be said that the deterioration of the responsiveness of torque reduction occurs at the start of control. This is due to the difference in the number of combustions per unit time in the engine 10, as described above. On the other hand, in the first example (thick solid line), the actual torque reduction start timing in the second vehicle attitude control is substantially the same as in the second example (broken line). In other words, by using the start threshold value Th3b obtained by changing the start threshold value Th3a during reduced-cylinder operation, the deterioration of responsiveness of torque reduction at the start of the second vehicle attitude control is improved.

Next, when the steering speed decreases during the second vehicle attitude control, in the first example (thick solid line) according to the present embodiment, the steering speed becomes less than the second vehicle attitude control end threshold Th4b at time t7 (Fig. 11 step S211: Yes), the second vehicle attitude control begins to end. Specifically, after time t7, an additional deceleration reduction amount for reducing the additional deceleration is set, and the reduction torque is set by applying this additional deceleration reduction amount (steps S212 to S215 in FIG. 11). ), and the final target torque is set according to this reduced torque, and the actuator of the engine 10 is controlled so as to achieve this final target torque (steps S6 to S8 in FIG. 6). In this case, in order to reduce the reduction torque itself toward 0 (that is, to increase the final target torque toward the basic torque), the ignition timing of the spark plug 14 is adjusted toward the ignition timing for generating the basic torque. be advanced. On the other hand, in the second and third examples (broken line and thin solid line), at time t8 after time t7, the steering speed becomes less than the end threshold Th4a, and the second vehicle attitude control begins to end. Specifically, after time t8, an additional deceleration reduction amount for reducing the additional deceleration is set, a reduction torque is set by applying this additional deceleration reduction amount, and the reduction torque is set. A final target torque is set, and the actuator of the engine 10 is controlled so as to achieve the final target torque.

Looking at the actual torque at this time, in the third example (thin solid line), compared to the second example (dashed line), the start of the actual torque increase in the second vehicle attitude control is delayed. I understand. That is, when the second vehicle attitude control is performed without changing the end threshold value Th4a during reduced cylinder operation, the second vehicle attitude control is performed in comparison with the case where the second vehicle attitude control is performed during full cylinder operation. It can be said that the responsiveness of torque recovery deteriorates at the end of control. This is due to the difference in the number of combustions per unit time in the engine 10, as described above. On the other hand, in the first example (thick solid line), the actual torque increase start timing in the second vehicle attitude control is almost the same as in the second example (broken line). In other words, by using the end threshold Th4b obtained by changing the end threshold Th4a during reduced-cylinder operation, the deterioration of the responsiveness of torque restoration (torque increase) at the end of the second vehicle attitude control is improved.

Note that when a torque obtained by reducing the basic torque is generated in the second vehicle attitude control, the reduced torque is transmitted to the rear wheels 202b, which are driving wheels, and acts as a force to pull the rear wheels 202b rearward of the vehicle. When this force is transmitted from the rear wheels 202b to the vehicle body of the vehicle 200 via the suspension 203, a force that causes the rear portion of the vehicle body to sink downward momentarily acts, and a moment acts in the direction of tilting the vehicle body backward. As a result, a force acts to lift the front portion of the vehicle body upward, lifting the front portion of the vehicle body and reducing the load on the front wheels. As a result, it is possible to improve the vehicle responsiveness and the linear feeling with respect to the steering return operation. That is, in a rear wheel drive vehicle, when the driving torque of the rear wheels 202b is reduced to decelerate, an inertial force that causes the vehicle body to tilt forward and an instantaneous force that causes the vehicle body to tilt backward are generated. It is considered that the momentary rearward tilting force of the vehicle body due to the reduced torque predominantly contributes to the vehicle responsiveness to the return operation and the linear feeling.

Next, effects of the vehicle control device according to the embodiment of the present invention will be described.

According to the present embodiment, the PCM 50 performs the first vehicle attitude control to add increased torque when the steering speed becomes equal to or greater than a predetermined threshold (first threshold), and the number of combustions of the engine 10 per unit time is When less, the first threshold is made smaller. As a result, when the number of combustions of the engine 10 per unit time is small, the timing at which the request to start the first vehicle attitude control is issued is advanced, and the delay in starting the first vehicle attitude control can be appropriately suppressed. can. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to appropriately suppress deterioration in responsiveness to torque increase at the start of the first vehicle attitude control.

Further, according to the present embodiment, the PCM 50 determines the number of combustions of the engine 10 per unit time based on the number of cylinders that are deactivated in the reduced cylinder operation (the number of deactivated cylinders), and according to the number of deactivated cylinders, 1 The first threshold for vehicle attitude control can be set appropriately.

Further, according to the present embodiment, the PCM 50 can determine the number of combustions of the engine 10 per unit time based on the current engine speed, and appropriately set the first threshold value for the first vehicle attitude control. can.

Further, according to the present embodiment, when the first vehicle attitude control is started, the PCM 50 increases the rate of change in the torque increasing direction when the number of combustions of the engine 10 per unit time is small. Torque can be increased quickly at the start of attitude control. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to more effectively suppress the deterioration of the torque increase responsiveness at the start of the first vehicle attitude control.

Further, according to the present embodiment, the PCM 50 terminates the first vehicle attitude control when the steering speed becomes less than a predetermined threshold value (second threshold value) during the first vehicle attitude control. The second threshold value is increased when the number of times of combustion of the engine 10 is small. As a result, when the number of combustions of the engine 10 per unit time is small, the timing at which the end request for the first vehicle attitude control is issued is advanced, and the delay in the end of the first vehicle attitude control can be appropriately suppressed. can. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, deterioration of responsiveness of torque recovery (torque reduction) at the end of the first vehicle attitude control can be appropriately suppressed.

Further, according to the present embodiment, when the steering speed becomes less than a predetermined threshold value (second threshold value) during the first vehicle attitude control, the PCM 50 reduces the increased torque and ends the first vehicle attitude control. When the number of combustions of the engine 10 per unit time is small, the rate of change in the decreasing direction of the torque is increased, so that the torque can be quickly decreased when the first vehicle attitude control ends. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to appropriately suppress deterioration in responsiveness of torque recovery (torque reduction) at the end of the first vehicle attitude control.

Further, according to the present embodiment, the PCM 50 performs the second vehicle attitude control for adding the reduced torque when the steering speed becomes equal to or greater than a predetermined threshold value (third threshold value) after the first vehicle attitude control. The third threshold value is decreased when the number of times of combustion of the engine 10 per hit is small. As a result, when the number of combustions of the engine 10 per unit time is small, the timing at which the request to start the second vehicle attitude control is issued is advanced, and the delay in starting the second vehicle attitude control can be appropriately suppressed. can. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to appropriately suppress deterioration in responsiveness due to torque reduction at the start of the second vehicle attitude control.

Further, according to the present embodiment, the PCM 50 performs the second vehicle attitude control for adding the reduced torque when the steering speed becomes equal to or greater than a predetermined threshold value (third threshold value) after the first vehicle attitude control. Since the rate of change in the decreasing direction of the torque is increased when the number of times of combustion of the engine 10 per hit is small, the torque can be quickly decreased at the start of the second vehicle attitude control. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to more effectively suppress deterioration in responsiveness due to torque reduction at the start of the second vehicle attitude control.

Further, according to the present embodiment, the PCM 50 terminates the second vehicle attitude control when the steering speed becomes less than a predetermined threshold value (fourth threshold value) during the second vehicle attitude control. The fourth threshold is increased when the number of combustions of the engine 10 is small. As a result, when the number of combustions of the engine 10 per unit time is small, the timing at which the end request for the second vehicle attitude control is issued is advanced, and the delay in the end of the second vehicle attitude control can be appropriately suppressed. can. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to appropriately suppress deterioration in responsiveness of torque recovery (torque increase) at the end of the second vehicle attitude control.

Further, according to the present embodiment, when the steering speed becomes less than a predetermined threshold (fourth threshold) during the second vehicle attitude control, the PCM 50 reduces the reduction torque and ends the second vehicle attitude control. When the number of combustions of the engine 10 per unit time is small, the rate of change in the increasing direction of the torque is increased, so that the torque can be quickly increased at the end of the second vehicle attitude control. Therefore, in an operating state in which the number of combustions of the engine 10 per unit time is small, it is possible to appropriately suppress deterioration in responsiveness of torque recovery (torque increase) at the end of the second vehicle attitude control.

<Modification>
In the embodiment described above, the present invention is applied to the engine 10 (four-cylinder engine) that has only two operation modes, reduced-cylinder operation and full-cylinder operation. In this engine 10, the reduced-cylinder operation mode consists only of a mode in which two of the cylinders 2A to 2D are deactivated and the remaining two are activated. In another example, the invention is also applicable to engines having two or more modes of operation for reduced cylinder operation. For example, in a 6-cylinder engine, in addition to the all-cylinder operation mode in which all six cylinders are operated, there is a mode in which two cylinders are deactivated and the remaining four cylinders are activated, and three cylinders are deactivated. Two reduced-cylinder operation modes, one in which the remaining three cylinders are operated, can be realized as operation modes.
When the present invention is applied to an engine having two or more operation modes as reduced-cylinder operation, the threshold values applied in the first and second vehicle attitude controls are changed according to the number of cylinders to be deactivated, and The additional acceleration and additional deceleration applied in the first and second vehicle attitude controls may be corrected.

In the above-described embodiment, the vehicle attitude control was executed based on the steering angle and steering speed. Attitude control may be performed. These steering angle, steering speed, yaw rate, lateral acceleration, yaw acceleration and lateral jerk correspond to steering angle related values in the present invention.

2 (2A to 2D) cylinder 5 throttle valve 10 engine 13 fuel injection valve 14 spark plug 18 variable intake valve mechanism 20 valve stop mechanism 30 accelerator opening sensor 39 vehicle speed sensor 49 steering angle sensor 50 PCM
100 engine system 200 vehicle 202a front wheel (steering wheel)
202b rear wheel (drive wheel)
207 steering gear

Claims (11)

A control device for a vehicle,
an engine that drives the rear wheels of the vehicle;
a steering device for steering the vehicle;
a steering angle-related value sensor for detecting a steering angle-related value related to the steering angle of the steering device;
a driving state sensor that detects the driving state of the vehicle;
a controller that controls the engine;
The controller is
setting a basic torque of the engine based on the operating state detected by the operating state sensor;
When the steering angle-related value detected by the steering angle-related value sensor exceeds a first threshold value , the torque of the engine that drives the rear wheels is increased to propel the rear wheels forward of the vehicle. produces a force which, when this force is transmitted from the rear wheels through the suspension to the vehicle bodywork, causes the vehicle body to lean forward by momentarily exerting a force that lifts the rear bodywork upwards. setting the increased torque of the engine so as to
controlling the engine to generate the target torque obtained by adding the increased torque to the basic torque;
When the number of combustions of the engine per unit time is small, the first threshold is made smaller than otherwise.
A vehicle control device characterized by: The engine has a plurality of cylinders, and is capable of reduced-cylinder operation in which combustion is suspended in some of the plurality of cylinders,
2. The control device for a vehicle according to claim 1, wherein said controller is configured to make said first threshold smaller when the number of cylinders in which combustion is suspended among said plurality of cylinders is greater than when not. . It further has an engine speed sensor that detects the engine speed,
3. The vehicle according to claim 1, wherein the controller is configured to make the first threshold smaller when the engine speed detected by the engine speed sensor is low than when it is not. Control device. The controller is configured to increase the increased torque so that when the number of combustions of the engine per unit time is small, the rate of change in the increasing direction of the torque is greater than otherwise. Item 4. The vehicle control device according to any one of Items 1 to 3. The controller is
reducing the increased torque when the steering angle-related value becomes less than a second threshold after becoming equal to or greater than the first threshold;
When the number of combustions of the engine per unit time is small, the second threshold is set larger than otherwise.
The vehicle control device according to any one of claims 1 to 4. The controller is
reducing the increased torque when the steering angle-related value becomes less than a second threshold after becoming equal to or greater than the first threshold;
When the number of combustions of the engine per unit time is small, the increased torque is reduced so that the rate of change in the torque decreasing direction is greater than otherwise.
The vehicle control device according to any one of claims 1 to 5. The controller is
When the steering angle-related value becomes equal to or greater than a third threshold after the application of the increased torque is finished, the torque of the engine is reduced to generate a force that pulls the rear wheels rearward of the vehicle, resulting in , when this force is transmitted from the rear wheels to the vehicle body through the suspension, the engine is operated to tilt the vehicle body backward by instantaneously applying a force that causes the rear portion of the vehicle body to sink downward. set the reduced torque,
controlling the engine to generate the target torque obtained by subtracting the reduced torque from the basic torque;
When the number of combustions of the engine per unit time is small, the third threshold is made smaller than otherwise.
The vehicle control device according to any one of claims 1 to 6. The controller is
When the steering angle-related value becomes equal to or greater than a third threshold after the application of the increased torque is finished, the torque of the engine is reduced to generate a force that pulls the rear wheels rearward of the vehicle, resulting in , when this force is transmitted from the rear wheels to the vehicle body through the suspension, the engine is operated to tilt the vehicle body backward by instantaneously applying a force that causes the rear portion of the vehicle body to sink downward. set the reduced torque,
controlling the engine to generate the target torque obtained by subtracting the reduced torque from the basic torque;
When the number of combustions of the engine per unit time is small, the reduction torque is increased so that the rate of change in the torque decreasing direction is greater than otherwise.
The vehicle control device according to any one of claims 1 to 7. The controller is
reducing the reduction torque when the steering angle-related value becomes less than a fourth threshold after becoming equal to or greater than the third threshold;
When the number of combustions of the engine per unit time is small, the fourth threshold is set to be larger than otherwise.
The vehicle control device according to claim 7 or 8. The controller is
reducing the reduction torque when the steering angle-related value becomes less than a fourth threshold after becoming equal to or greater than the third threshold;
When the number of combustions of the engine per unit time is small, the reduction torque is reduced so that the rate of change in the torque increasing direction is greater than otherwise.
The vehicle control device according to any one of claims 7 to 9. A control device for a vehicle having an engine for driving rear wheels of the vehicle and a steering device for steering the vehicle,
When the steering angle-related value related to the steering angle of the steering device exceeds a threshold value , the torque of the engine that drives the rear wheels is increased to generate a force that propels the rear wheels forward of the vehicle. As a result, when this force is transmitted from the rear wheels to the vehicle body through the suspension, the vehicle body is tilted forward by instantaneously applying a force that lifts the rear part of the vehicle body upward. , vehicle attitude control means for increasing the torque of the engine;
threshold setting means for setting the threshold smaller when the number of times of combustion of the engine per unit time is smaller than otherwise;
A control device for a vehicle, comprising:

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