JP2017067001A - Control device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of an engine having an EGR device and a fuel injection device, capable of controlling the engine so that vehicle behavior intended by a driver can be accurately realized while securing combustion stability.SOLUTION: A control device of an engine has a basic target torque determination unit (61) for determining basic target torque on the basis of an operating state of a vehicle including an operation of an accelerator pedal, a torque reduction amount determination unit (63) for determining a torque reduction amount on the basis of an operating state of the vehicle excluding the operation of the accelerator pedal, a final target torque determination unit (65) for determining final target torque on the basis of the basic target torque and the torque reduction amount, and an engine control unit (69) for controlling a fuel injection device so that the final target torque is output to the engine, controls an EGR device on the basis of a target state amount in a cylinder when the final target torque is output to the engine, and limits the control of the EGR device according to the change of the final target torque corresponding to the change of a torque reduction amount.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an engine control device, and in particular, an EGR device including an EGR passage that recirculates exhaust gas in an exhaust passage to an intake passage and an EGR valve that adjusts the flow rate of exhaust gas that passes through the EGR passage. The present invention relates to an engine control device that controls an engine having a fuel injection device that injects fuel into a cylinder based on a driving state of a vehicle.

  2. Description of the Related Art Conventionally, devices that control the behavior of a vehicle in a safe direction when the behavior of the vehicle becomes unstable due to slip or the like (such as a skid prevention device) are known. Specifically, it is known to detect that understeer or oversteer behavior has occurred in the vehicle during cornering of the vehicle, and to impart appropriate deceleration to the wheels to suppress them. ing.

  On the other hand, unlike the above-described control for improving safety in a driving state where the behavior of the vehicle becomes unstable, a series of operations (braking, The vehicle motion control device adjusts the load applied to the front wheels, which are the steering wheels, by adjusting the deceleration at the cornering so that the steering incision, acceleration, steering return, etc. are natural and stable. Is known (see, for example, Patent Document 1).

  Furthermore, by reducing the driving force of the vehicle in accordance with the yaw rate related amount corresponding to the steering operation of the driver (for example, yaw acceleration), when the driver starts the steering operation, a deceleration is quickly generated in the vehicle. A vehicle behavior control device has been proposed in which a large load is quickly applied to a front wheel that is a steered wheel (see, for example, Patent Document 2). According to this vehicle behavior control device, the frictional force between the front wheel and the road surface is increased by rapidly applying a load to the front wheel at the start of the steering operation, and the cornering force of the front wheel is increased. The turning performance of the vehicle is improved, and the response to the steering operation is improved. As a result, the vehicle behavior as intended by the driver is realized.

JP 2011-88576 A JP 2014-166014 A

  By the way, in an internal combustion engine such as a gasoline engine or a diesel engine, an EGR device that includes an EGR passage that recirculates exhaust gas in the exhaust passage to the intake passage and an EGR valve that adjusts the flow rate of the exhaust gas that passes through the EGR passage. And a fuel injection device that injects fuel into the cylinder. Such a control device for controlling the engine is in accordance with the driving state of the vehicle (for example, various operations such as accelerator pedal, brake pedal, steering, etc. for the driver, traveling environment such as vehicle speed, temperature, atmospheric pressure, road gradient, road surface μ, etc.). Based on this, the target torque is determined, the fuel injection device is controlled to output the target torque, and the EGR device is controlled so as to realize the target state quantity determined based on the target torque and the engine speed.

In such an engine control device, when the vehicle behavior control device described in Patent Document 2 described above instantaneously changes the target torque to cause the vehicle to decelerate in response to the driver's steering operation. The fuel injection device and the EGR device are controlled so as to realize the change in the target torque. That is, the engine control device controls the fuel injection device so as to change the fuel injection amount in accordance with the change in the target torque, and the flow rate of EGR to be returned to the intake passage in response to the change in the fuel injection amount. The EGR valve is controlled to change.
However, while the fuel injection amount can be controlled with high responsiveness to the change in the target torque, the control is not performed until the control of the EGR valve corresponding to the change in the target torque is reflected in the state quantity in the cylinder. Since a large response delay occurs, there is a mismatch between the fuel injection amount and the in-cylinder state quantity, which may cause abnormal combustion or deteriorate emission performance. For example, when the target torque decreases instantaneously, the EGR valve is controlled in the valve closing direction so as to decrease the flow rate of EGR, but when the target torque increases instantaneously thereafter, the EGR valve opens accordingly. Controlled in direction. At this time, since the EGR valve is temporarily controlled in the valve closing direction, the increase in the EGR flow rate does not catch up with the subsequent increase in the target torque, and the fuel injection amount increases in accordance with the increase in the target torque. On the other hand, when the oxygen concentration in the cylinder becomes excessive or the intake air temperature becomes too high, abnormal combustion occurs.

  The present invention has been made to solve the above-mentioned problems of the prior art, and in an engine having an EGR device and a fuel injection device, the vehicle behavior intended by the driver can be accurately determined while ensuring combustion stability. An object of the present invention is to provide an engine control device that can control the engine so as to be realized.

In order to achieve the above object, an engine control apparatus according to the present invention includes an EGR passage that recirculates exhaust gas in an exhaust passage to an intake passage, an EGR valve that adjusts a flow rate of exhaust gas that passes through the EGR passage, An engine control device that controls an engine having an EGR device and a fuel injection device that injects fuel into a cylinder based on a driving state of the vehicle, based on a driving state of the vehicle including an operation of an accelerator pedal Basic target torque determining means for determining the basic target torque, torque reduction amount determining means for determining a torque reduction amount based on the driving state of the vehicle other than the operation of the accelerator pedal, and a final target based on the basic target torque and the torque reduction amount Final target torque determining means for determining torque, and fuel injection device for controlling the fuel injection device to output the final target torque to the engine Control means, and EGR device control means for controlling the EGR device based on the target state quantity in the cylinder when the final target torque is output to the engine. The EGR device control means responds to a change in torque reduction amount. The control of the EGR device according to the change of the final target torque is limited.
In the present invention configured as described above, the fuel injection device control means causes the fuel to output the final target torque reflecting the torque reduction amount determined based on the driving state of the vehicle other than the operation of the accelerator pedal. Since the injection device is controlled, the engine can be controlled so that a torque reduction amount can be obtained with high responsiveness to the driving state of the vehicle other than the operation of the accelerator pedal, and the load can be quickly applied to the front wheel. The engine can be controlled to accurately realize the intended vehicle behavior.
Further, since the EGR device control means limits the control of the EGR device in accordance with the change in the final target torque corresponding to the change in the torque reduction amount, the EGR device control means responds to the instantaneous change in the final target torque that directly reflects the torque reduction amount. By rapidly controlling the EGR device, it is possible to suppress a large mismatch between the fuel injection amount and the state quantity in the cylinder, and to ensure combustion stability.

In the present invention, it is preferable that the EGR device control means controls the EGR device based on a target state quantity in the cylinder when the basic target torque is output to the engine.
In the present invention configured as described above, since the EGR device is controlled based on the target state quantity in the cylinder when the engine outputs the basic target torque that does not reflect the torque reduction amount, the torque reduction amount is reflected. Abrupt control of the EGR device according to the instantaneous change in the final target torque ensures that a large mismatch between the fuel injection amount and the state quantity in the cylinder is prevented, and combustion stability is ensured. can do.

In the present invention, preferably, the fuel injection device control means changes the fuel injection amount of the fuel injection device in accordance with a change in the final target torque corresponding to the torque reduction amount, and the EGR device control means The EGR device is feedback-controlled so that the state quantity approaches the target state quantity.
In the present invention configured as described above, the fuel injection device control means changes the fuel injection amount in accordance with the change in the final target torque for fuel injection control reflecting the torque reduction amount, and the EGR device control means Since the EGR device is feedback-controlled so that the state quantity in the cylinder that changes according to the injection amount approaches the target state quantity, a torque reduction amount can be obtained with high responsiveness to the driving state of the vehicle other than the operation of the accelerator pedal. Inconsistency between the fuel injection amount and the in-cylinder state quantity can be more reliably suppressed while controlling the engine so that the emission performance is prevented from deteriorating and combustion stability is ensured. can do.

In the present invention, it is preferable that the torque reduction amount determining means determines the torque reduction amount according to the steering operation of the vehicle.
In the present invention configured as described above, the time change of the torque reduction amount determined based on the steering operation can be reflected in the time change of the final target torque, whereby the deceleration corresponding to the driver's steering operation is achieved. Can be quickly applied to the vehicle to apply a load to the front wheels, and the cornering force can be increased rapidly to improve the response to the steering operation, ensuring the combustion stability and the driver's intended vehicle behavior. The engine can be controlled to achieve accurately.

In the present invention, it is preferable that the torque reduction amount determining means determines the torque reduction amount so as to increase the torque reduction amount and reduce the increase rate of the increase amount as the vehicle steering speed increases. .
In the present invention configured as described above, when the steering of the vehicle is started and the steering speed of the vehicle starts to increase, the amount of torque reduction can be increased rapidly, thereby reducing the amount at the start of steering of the vehicle. The speed can be quickly applied to the vehicle, and a sufficient load can be quickly applied to the front wheels, which are the steering wheels. As a result, the frictional force between the front wheels, which are the steering wheels, and the road surface increase, and the cornering force of the front wheels increases, so that the turning ability of the vehicle at the beginning of the curve approach can be improved, and combustion stability is ensured. On the other hand, the responsiveness to the steering operation can be improved.

In the present invention, it is preferable that the basic target torque determining means determines the target acceleration of the vehicle based on the driving state of the vehicle including the operation of the accelerator pedal, and determines the basic target torque based on the target acceleration.
In the present invention configured as described above, since the basic target torque is determined based on the target acceleration, the engine can be controlled so as to accurately realize the acceleration intended by the driver while ensuring the combustion stability. .

In the present invention, preferably, the engine control device is a diesel engine control device.
In the present invention configured as described above, the fuel injection amount of the diesel engine is changed in accordance with the final target torque reflecting the torque reduction amount, and is determined based on the driving state of the vehicle other than the operation of the accelerator pedal. The time change of the torque reduction amount can be accurately realized with high responsiveness, and the engine can be controlled to accurately realize the vehicle behavior intended by the driver.

  According to the engine control device of the present invention, in an engine having an EGR device and a fuel injection device, the engine can be controlled to accurately realize the vehicle behavior intended by the driver while ensuring combustion stability. it can.

1 is a schematic configuration diagram of an engine system to which an engine control device according to an embodiment of the present invention is applied. It is a block diagram which shows the electric constitution of the control apparatus of the engine by embodiment of this invention. It is a flowchart of the engine control process which the engine control apparatus by embodiment of this invention controls an engine. It is a flowchart of the torque reduction amount determination process in which the control apparatus of the engine by embodiment of this invention determines torque reduction amount. It is the map which showed the relationship between the target additional deceleration and the steering speed which the control apparatus of the engine by embodiment of this invention determines. FIG. 6A is a diagram showing a time change of parameters related to engine control by the engine control device when a vehicle equipped with the engine control device according to the embodiment of the present invention makes a turn. FIG. FIG. 6B is a plan view schematically showing the vehicle to be performed, FIG. 6B is a diagram showing a change in the steering angle of the vehicle turning right as shown in FIG. 6A, and FIG. 6C is FIG. FIG. 6D is a diagram showing a change in the steering speed of the vehicle that turns right as shown in FIG. 6B. FIG. 6D is a graph showing the additional deceleration determined based on the steering speed shown in FIG. 6 (e) is a diagram showing a change in torque reduction determined based on the additional deceleration shown in FIG. 6 (d), and FIG. 6 (f) is a smoothing by a torque change filter. FIG. 6G is a diagram showing changes in the basic target torque before and after conversion, and FIG. FIG. 6H is a diagram showing a change in the final target torque for fuel injection control determined based on the basic target torque, and FIG. 6H is a diagram showing a change in the final target torque for EGR / turbo determined based on the basic target torque. i) is a diagram showing a change in the required injection amount determined based on the final target torque for fuel injection control, and FIG. 6 (j) is a case where the fuel injection amount is controlled as shown in FIG. 6 (i). FIG. 6 (k) is a diagram showing the change between the target oxygen concentration in the cylinder and the actual oxygen concentration, and FIG. 6 (k) shows the EGR valve opening when the fuel injection amount is controlled as shown in FIG. 6 (i). FIG. 6 (l) shows the change in the yaw rate (actual yaw rate) generated in the vehicle when the fuel injection amount is controlled as shown in FIG. 6 (i), and the torque reduction amount is determined. If the fuel injection amount is not controlled based on the torque reduction amount determined by the Is a diagram showing the change of the yaw rate.

  Hereinafter, an engine control apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<System configuration>
First, an engine system to which an engine control apparatus according to an embodiment of the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an engine system to which an engine control apparatus according to an embodiment of the present invention is applied.

  As shown in FIG. 1, the engine system 200 mainly includes an engine E as a diesel engine, an intake system IN that supplies intake air to the engine E, a fuel supply system FS that supplies fuel to the engine E, It has an exhaust system EX that exhausts exhaust gas from the engine E, sensors 96 to 110 that detect various states related to the engine system 200, and a PCM (Power-train Control Module) 60 that controls the engine system 200.

First, the intake system IN has an intake passage 1 through which intake air passes, and an air cleaner 3 that purifies air introduced from the outside in order from the upstream side, and intake air that passes through the intake passage 1. The compressor 5a of the turbocharger 5 that compresses and raises the intake pressure, the intake shutter valve 7 that adjusts the flow rate of the intake air that passes through, and the water-cooled intercooler that cools the intake air using the coolant that has passed through 8 and a surge tank 12 for temporarily storing intake air supplied to the engine E.
In the intake system IN, an air flow sensor 101 for detecting the intake air amount and an intake air temperature sensor 102 for detecting the intake air temperature are provided on the intake passage 1 immediately downstream of the air cleaner 3, and the turbocharger 5. The compressor 5a is provided with a turbo rotational speed sensor 103 for detecting the rotational speed (turbo rotational speed) of the compressor 5a. The intake shutter valve 7 has an intake shutter valve for detecting the opening degree of the intake shutter valve 7. A position sensor 105 is provided, and an intake air temperature sensor 106 for detecting the intake air temperature and an intake air pressure sensor 107 for detecting the intake air pressure are provided on the intake passage 1 immediately downstream of the intercooler 8. The intake manifold temperature sensor 108 is provided. These various sensors 101 to 108 provided in the intake system IN output detection signals S101 to S108 corresponding to the detected parameters to the PCM 60, respectively.

  Next, the engine E includes an intake valve 15 for introducing the intake air supplied from the intake passage 1 (specifically, an intake manifold) into the combustion chamber 17, a fuel injection valve 20 for injecting fuel toward the combustion chamber 17, A piston 23 that reciprocates by combustion of the air-fuel mixture in the combustion chamber 17, a crankshaft 25 that is rotated by reciprocation of the piston 23, and exhaust gas that is generated by combustion of the air-fuel mixture in the combustion chamber 17 And an exhaust valve 27 for discharging to 41.

  Next, the fuel supply system FS includes a fuel tank 30 for storing fuel, and a fuel supply passage 38 for supplying fuel from the fuel tank 30 to the fuel injection valve 20. In the fuel supply passage 38, a low-pressure fuel pump 31, a high-pressure fuel pump 33, and a common rail 35 are provided in order from the upstream side.

Next, the exhaust system EX has an exhaust passage 41 through which the exhaust gas passes. The exhaust passage 41 is rotated by the exhaust gas passing through the exhaust passage 41 in order from the upstream side. A turbine 5b of the turbocharger 5 that drives the compressor 5a, a diesel oxidation catalyst (DOC) 45 having a function of purifying exhaust gas, a diesel particulate filter (DPF) 46, and a passage And an exhaust shutter valve 49 for adjusting the exhaust flow rate. The DOC 45 is a catalyst that oxidizes hydrocarbon (HC), carbon monoxide (CO), and the like using oxygen in the exhaust gas to change it into water and carbon dioxide, and the DPF 46 is a particulate substance ( It is a filter that collects PM (Particulate Matter).
Further, in the exhaust system EX, an exhaust pressure sensor 109 for detecting the exhaust pressure is provided on the exhaust passage 41 upstream of the turbine 5 b of the turbocharger 5, and on the exhaust passage 41 immediately downstream of the DPF 46. Is provided with a linear O ₂ sensor 110 for detecting the oxygen concentration. These various sensors 109 and 110 provided in the exhaust system EX output detection signals S109 and S110 corresponding to the detected parameters to the PCM 60, respectively.

  Further, in the present embodiment, the turbocharger 5 is configured in a small size so as to be able to perform supercharging efficiently even during low-speed rotation with low exhaust energy, and a plurality of movable parts so as to surround the entire circumference of the turbine 5b. Type flaps 5c are provided, and these flaps 5c are configured as a variable geometry turbocharger (VGT) that changes the flow cross-sectional area (nozzle cross-sectional area) of the exhaust gas to the turbine 5b. . For example, the flap 5c is rotated by an actuator with the magnitude of the negative pressure acting on the diaphragm adjusted by an electromagnetic valve. Further, a VGT opening sensor 104 is provided for detecting the opening of the flap 5c (which is the flap opening, hereinafter referred to as “VGT opening” as appropriate) depending on the position of the actuator. The VGT opening sensor 104 outputs a detection signal S104 corresponding to the detected VGT opening to the PCM 60.

  The engine system 200 according to the present embodiment further includes a high pressure EGR device 43 and a low pressure EGR device 48. The high-pressure EGR device 43 connects the exhaust passage 41 upstream of the turbine 5b of the turbocharger 5 and the intake passage 1 downstream of the compressor 5b of the turbocharger 5 (specifically, downstream of the intercooler 8). And a high pressure EGR valve 43b that adjusts the flow rate of exhaust gas that passes through the high pressure EGR passage 43a. The low pressure EGR device 48 includes an exhaust passage 41 on the downstream side of the turbine 5b of the turbocharger 5 (specifically, on the downstream side of the DPF 46 and the upstream side of the exhaust shutter valve 49) and the upstream side of the compressor 5b of the turbocharger 5. A low pressure EGR passage 48a that connects the intake passage 1 of the engine, a low pressure EGR cooler 48b that cools the exhaust gas that passes through the low pressure EGR passage 48a, and a low pressure EGR valve 48c that adjusts the flow rate of the exhaust gas that passes through the low pressure EGR passage 48a. And a low pressure EGR filter 48d.

  The amount of exhaust gas recirculated to the intake system IN by the high pressure EGR device 43 (hereinafter referred to as “high pressure EGR gas amount”) is the exhaust pressure upstream of the turbine 5 b of the turbocharger 5 and the opening of the intake shutter valve 7. It is generally determined by the intake pressure produced by the degree and the opening degree of the high pressure EGR valve 43b. Further, the amount of exhaust gas recirculated to the intake system IN by the low pressure EGR device 48 (hereinafter referred to as “low pressure EGR gas amount”) is the intake pressure on the upstream side of the compressor 5 a of the turbocharger 5 and the exhaust shutter valve 49. Is roughly determined by the exhaust pressure produced by the opening of the valve and the opening of the low pressure EGR valve 48c.

Next, the electrical configuration of the engine control apparatus according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing an electrical configuration of the engine control apparatus according to the embodiment of the present invention.
In addition to the detection signals S101 to S110 of the various sensors 101 to 110 described above, the PCM 60 (engine control device) according to the embodiment of the present invention includes a steering angle sensor 96 that detects the rotation angle of the steering wheel, and the accelerator pedal opening. Detection signals output from an accelerator opening sensor 97 that detects (accelerator opening), a vehicle speed sensor 98 that detects vehicle speed, an outside air temperature sensor 99 that detects outside air temperature, and an atmospheric pressure sensor 100 that detects atmospheric pressure. Based on S96 to S100, control signals S130 to S133 are output in order to control the turbocharger 5, the fuel injection valve 20, the high pressure EGR device 43, and the low pressure EGR device 48.

The PCM 60 includes a basic target torque determination unit 61 that determines a basic target torque based on the driving state of the vehicle including the operation of the accelerator pedal, and a torque reduction that determines a torque reduction amount based on the driving state of the vehicle that does not include the operation of the accelerator pedal. An amount determination unit 63, a final target torque determination unit 65 that determines a final target torque based on the basic target torque and the torque reduction amount, a torque change filter 67 that smoothes the temporal change of the final target torque, and a final target torque. And an engine control unit 69 that controls the engine E to output.
Each component of the PCM 60 includes a CPU, various programs that are interpreted and executed on the CPU (including a basic control program such as an OS and an application program that is activated on the OS to realize a specific function), a program, It is configured by a computer having an internal memory such as a ROM or RAM for storing various data.

Next, processing performed by the engine control device will be described with reference to FIGS.
FIG. 3 is a flowchart of an engine control process in which the engine control apparatus according to the embodiment of the present invention controls the engine E, and FIG. FIG. 5 is a map showing the relationship between the additional deceleration determined by the engine control apparatus according to the embodiment of the present invention and the steering speed.

The engine control process of FIG. 3 is started and executed repeatedly when the ignition of the vehicle 1 is turned on and power is turned on to the engine control device.
When the engine control process is started, as shown in FIG. 3, in step S1, the PCM 60 acquires the driving state of the vehicle. Specifically, the PCM 60 detects the steering angle detected by the steering angle sensor 96, the accelerator opening detected by the accelerator opening sensor 97, the vehicle speed detected by the vehicle speed sensor 98, and the gear stage currently set for the transmission of the vehicle. The detection signals S96 to S110 output by the various sensors 96 to 110 described above are acquired as the operation state.

  Next, in step S2, the basic target torque setting unit of the PCM 60 sets a target acceleration based on the driving state of the vehicle including the operation of the accelerator pedal acquired in step S1. Specifically, the basic target torque setting unit reads the current vehicle speed and gear stage from acceleration characteristic maps (created in advance and stored in a memory or the like) defined for various vehicle speeds and various gear stages. The acceleration characteristic map corresponding to is selected, and the target acceleration corresponding to the current accelerator opening is determined with reference to the selected acceleration characteristic map.

  Next, in step S3, the basic target torque determining unit 61 determines the basic target torque of the engine E for realizing the target acceleration determined in step S2. In this case, the basic target torque determining unit 61 determines the basic target torque within the range of torque that can be output by the engine E based on the current vehicle speed, gear stage, road surface gradient, road surface μ, and the like.

  Next, in step S4, the torque change filter 67 smoothes the time change of the basic target torque determined in step S3. As a specific method of this smoothing, various known methods (for example, limiting the rate of change of the basic target torque to a threshold value or less, calculating a moving average of the time change of the basic target torque, etc.) are used. be able to.

  In parallel with the processing in steps S2 to S4, in step S5, the torque reduction amount determination unit 63 determines the torque reduction amount based on the driving state of the vehicle other than the operation of the accelerator pedal. Execute. The torque reduction amount determination process will be described with reference to FIG.

  As shown in FIG. 4, when the torque reduction amount determination process is started, in step S21, the torque reduction amount determination unit 63 determines whether or not the absolute value of the steering angle acquired in step S1 is increasing. As a result, when the absolute value of the steering angle is increasing, the process proceeds to step S22, and the torque reduction amount determination unit 63 calculates the steering speed based on the steering angle acquired in step S1.

Next, in step S23, the torque reduction amount determination unit 63 determines whether or not the absolute value of the steering speed is decreasing.
As a result, when the absolute value of the steering speed has not decreased, that is, when the absolute value of the steering speed has increased or the absolute value of the steering speed has not changed, the process proceeds to step S24 and the torque reduction amount determination unit 63 Acquires the target additional deceleration based on the steering speed. This target additional deceleration is a deceleration to be applied to the vehicle in accordance with the steering operation in order to accurately realize the vehicle behavior intended by the driver.

Specifically, the torque reduction amount determination unit 63 acquires the target additional deceleration corresponding to the steering speed calculated in step S22 based on the relationship between the target additional deceleration and the steering speed shown in the map of FIG. .
The horizontal axis in FIG. 5 indicates the steering speed, and the vertical axis indicates the target additional deceleration. As shown in FIG. 5, when the steering speed is less than a threshold value T _S (for example, 10 deg / s), the corresponding target additional deceleration is zero. That is, when the steering speed is less than the threshold value T _S , the control for adding the deceleration to the vehicle according to the steering operation is not performed.
On the other hand, when the steering speed is equal to or higher than the threshold value T _S , the target additional deceleration corresponding to the steering speed gradually approaches a predetermined upper limit value D _max (for example, 1 m / s ² ) as the steering speed increases. That is, as the steering speed increases, the target additional deceleration increases, and the increase rate of the increase amount decreases.

Next, in step S25, the torque reduction amount determination unit 63 determines the additional deceleration in the current process within a range where the increase rate of the additional deceleration is equal to or less than a threshold value Rmax (for example, 0.5 m / s ³ ).
Specifically, when the increase rate from the additional deceleration determined in the previous process to the target additional deceleration determined in step S24 of the current process is equal to or less than Rmax, the torque reduction amount determining unit 63 determines in step S24. The determined target additional deceleration is determined as the additional deceleration in the current process.
On the other hand, when the rate of change from the additional deceleration determined in the previous process to the target additional deceleration determined in step S24 of the current process is larger than Rmax, the torque reduction amount determination unit 63 adds the value determined in the previous process. The value increased by the increase rate Rmax from the acceleration / deceleration until the current processing is determined as the additional deceleration in the current processing.

  If the absolute value of the steering speed is decreasing in step S23, the process proceeds to step S26, where the torque reduction amount determination unit 63 determines the additional deceleration determined in the previous process as the additional deceleration in the current process. To do. That is, when the absolute value of the steering speed is decreasing, the additional deceleration at the maximum steering speed (that is, the maximum value of the additional deceleration) is held.

In step S21, if the absolute value of the steering angle is not increasing (constant or decreasing), the process proceeds to step S27, where the torque reduction amount determination unit 63 sets the additional deceleration determined in the previous process this time. The amount to be reduced (deceleration reduction amount) is acquired in the process. The deceleration reduction amount is calculated based on, for example, a constant reduction rate (for example, 0.3 m / s ³ ) stored in advance in a memory or the like. Alternatively, it is calculated based on the reduction rate determined according to the driving state of the vehicle acquired in step S1 and the steering speed calculated in step S22.

  In step S28, the torque reduction amount determination unit 63 determines the additional deceleration in the current process by subtracting the deceleration decrease acquired in step S27 from the additional deceleration determined in the previous process.

  After step S25, S26, or S28, in step S29, the torque reduction amount determination unit 63 determines the torque reduction amount based on the current additional deceleration determined in step S25, S26, or S28. Specifically, the torque reduction amount determination unit 63 determines the torque reduction amount necessary for realizing the current additional deceleration based on the current vehicle speed, gear stage, road surface gradient, etc. acquired in step S1. To do. After this step S29, the torque reduction amount determination unit 63 ends the torque reduction amount determination processing and returns to the main routine.

  Returning to FIG. 3, after performing the processing of steps S2 to S4 and the torque reduction amount determination processing of step S5, in step S6, the final target torque determination unit 65 performs the basic target torque after smoothing in step S4. From this, the final target torque for fuel injection control for controlling the fuel injection valve 20 is determined by subtracting the torque reduction amount determined in the torque reduction amount determination process in step S5.

Next, in step S7, the engine control unit 69 sets a required injection amount to be injected from the fuel injection valve 20 based on the final target torque for fuel injection control set in step S6 and the engine speed.
Subsequently, in step S8, the engine control unit 69 sets a fuel injection pattern and a fuel pressure based on the required injection amount set in step S7 and the engine speed.
Next, in step S9, the engine control unit 69 controls the fuel injection valve 20 based on the injection pattern and fuel pressure set in step S8.

  In parallel with the processing of steps S6 to S9, in step S10, the final target torque determination unit 65 converts the basic target torque after smoothing in step S4 to the turbocharger 5, the high pressure EGR device 43. And the final target torque for EGR / turbo control for controlling the low pressure EGR device 48.

  Next, in step S11, the engine control unit 69 causes the engine E to output the EGR / turbo control final target torque based on the EGR / turbo control final target torque set in step S10 and the engine speed. In this case, the required injection amount to be injected from the fuel injection valve 20 is set.

  Subsequently, in step S12, the engine control unit 69 determines the target oxygen concentration in the cylinder, the target intake air temperature, the EGR control mode (high pressure EGR) based on the requested injection amount set in step S11 and the engine speed. A mode in which both or one of the device 43 and the low pressure EGR device 48 is operated, or a mode in which neither the high pressure EGR device 43 nor the low pressure EGR device 48 is operated) is set.

  Next, in step S13, the engine control unit 69 sets various state quantities that realize the target oxygen concentration and target intake air temperature set in step S12. For example, the various state quantities include the amount of exhaust gas recirculated to the intake system IN by the high pressure EGR device 43 (high pressure EGR gas amount), and the amount of exhaust gas recirculated to the intake system IN by the low pressure EGR device 48 (low pressure EGR gas amount). ) And the supercharging pressure by the turbocharger 5 are included.

Next, in step S14, the engine control unit 69 controls each actuator that drives each component of the engine system 200 based on the various state quantities set in step S13.
In this case, the engine control unit 69 performs feedforward control of the high-pressure EGR device 43 and the low-pressure EGR device 48 so as to realize the various state quantities set in step S13, and the actual state quantity (oxygen concentration and intake air) in the cylinder. The high pressure EGR device 43 and the low pressure EGR device 48 are feedback-controlled so that the temperature is close to the state quantity set in step S12 (that is, the target oxygen concentration or the target intake air temperature).
Note that the engine control unit 69 determines the oxygen concentration in the cylinder by, for example, the intake charge amount, the intake air amount, the flow rate and oxygen concentration of the high pressure EGR gas, and the flow rate and oxygen concentration of the low pressure EGR gas as parameters. The oxygen concentration is estimated by an intake / exhaust model. Here, the intake charge amount is calculated based on detection signals S107 and S108 from the intake pressure sensor 107 and the intake manifold temperature sensor 108. The intake air amount is specified by the detection signal S101 of the air flow sensor 101. The oxygen concentration of the high-pressure EGR gas and the low-pressure EGR gas, the detection signal S110 of the linear O ₂ sensor 110, is calculated based on the time delay until the linear O ₂ sensor 110 detects the actual exhaust oxygen concentration .
In addition, the engine control unit 69 sets a limit value and a limit range according to various state quantities, and sets a control amount for each actuator such that the state value complies with the limit value and the limit range, and executes control. To do.
After steps S9 and S14, the PCM 60 ends the engine control process.

  Next, the operation of the engine control apparatus according to the embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing time changes in parameters related to engine control by the engine control device when a vehicle equipped with the engine control device according to the embodiment of the present invention turns.

  FIG. 6A is a plan view schematically showing a vehicle that makes a right turn. As shown in FIG. 6A, the vehicle 1 starts turning right from position A and continues turning right from position B to position C with a constant steering angle.

FIG. 6B is a diagram showing changes in the steering angle of the vehicle that turns right as shown in FIG. In FIG. 6B, the horizontal axis indicates time, and the vertical axis indicates the steering angle.
As shown in FIG. 6B, rightward steering is started at the position A, and the rightward steering angle is gradually increased by performing the steering addition operation, and the rightward steering angle is maximized at the position B. It becomes. Thereafter, the steering angle is kept constant up to position C (steering holding).

FIG. 6C is a diagram showing a change in the steering speed of the vehicle that turns right as shown in FIG. In FIG. 6B, the horizontal axis indicates time, and the vertical axis indicates the steering speed.
The steering speed of the vehicle is expressed by time differentiation of the steering angle of the vehicle. That is, as shown in FIG. 6C, when the rightward steering is started at the position A, a rightward steering speed is generated, and the steering speed is kept substantially constant between the position A and the position B. Thereafter, the rightward steering speed decreases, and when the rightward steering angle becomes maximum at the position B, the steering speed becomes zero. Further, the steering speed remains zero while the rightward steering angle is maintained from position B to position C.

  FIG. 6D is a diagram showing a change in the additional deceleration determined based on the steering speed shown in FIG. In FIG. 6D, the horizontal axis indicates time, and the vertical axis indicates additional deceleration. Also, the solid line in FIG. 6D indicates the change in the additional deceleration determined in the torque reduction amount determination process in FIG. 4, and the alternate long and short dash line indicates the change in the target additional deceleration based on the steering speed. Similar to the change in the steering speed shown in FIG. 6C, the target additional deceleration indicated by the alternate long and short dash line starts to increase from the position A and is kept substantially constant between the position A and the position B, and thereafter Decrease to zero at position B.

As described with reference to FIG. 4, the torque reduction amount determining unit 63 determines that the absolute value of the steering speed has not decreased in step S23, that is, the absolute value of the steering speed has increased or the absolute value of the steering speed has not increased. If the value has not changed, the target additional deceleration is acquired based on the steering speed in step S24. Subsequently, in step S25, the torque reduction amount determination unit 63 determines the additional deceleration in each processing cycle in a range where the increase rate of the additional deceleration is equal to or less than the threshold value Rmax.
FIG. 6D shows a case where the increase rate of the target additional deceleration that has started increasing from the position A exceeds the threshold value Rmax. In this case, the torque reduction amount determination unit 63 increases the additional deceleration so that the increase rate = Rmax (that is, at a slower increase rate than the target additional deceleration indicated by the one-dot chain line). When the target additional deceleration is kept substantially constant between the position A and the position B, the torque reduction amount determination unit 63 determines that the additional deceleration is equal to the target additional deceleration.

  Further, as described above, when the absolute value of the steering speed is decreased in step S23 of FIG. 4, the torque reduction amount determination unit 63 holds the additional deceleration at the maximum steering speed. In FIG. 6 (d), when the steering speed decreases toward the position B, the target additional deceleration indicated by the alternate long and short dash line decreases accordingly, but the maximum value of the additional deceleration indicated by the solid line reaches the position B. maintain.

  Furthermore, as described above, when the absolute value of the steering angle is constant or decreasing in step S21 of FIG. 4, the torque reduction amount determination unit 63 acquires the deceleration reduction amount in step S27, and the deceleration is obtained. Addition deceleration is decreased by the amount of decrease. In FIG. 6 (d), the torque reduction amount determination unit 63 adds an additional deceleration so that the rate of decrease of the additional deceleration gradually decreases, that is, the slope of the solid line indicating the change of the additional deceleration gradually decreases. Decrease acceleration / deceleration.

FIG. 6E is a diagram showing a change in the torque reduction amount determined based on the additional deceleration shown in FIG. In FIG. 6E, the horizontal axis indicates time, and the vertical axis indicates the torque reduction amount.
As described above, the torque reduction amount determination unit 63 determines the torque reduction amount necessary for realizing the additional deceleration based on parameters such as the current vehicle speed, gear stage, and road surface gradient. Therefore, when these parameters are constant, the torque reduction amount is determined so as to change in the same manner as the change in the additional deceleration shown in FIG.

FIG. 6F is a diagram showing changes in the basic target torque before and after smoothing by the torque change filter 67. In FIG. 6F, the horizontal axis indicates time, and the vertical axis indicates torque. Further, the dotted line in FIG. 6F indicates the basic target torque before smoothing by the torque change filter 67, and the solid line indicates the basic target torque after smoothing by the torque change filter 67.
The basic target torque determined so as to achieve the target acceleration set based on the accelerator opening, the vehicle speed, the gear stage, etc. is steep due to various disturbances, noise, etc., as indicated by the dotted line in FIG. May include changes. By smoothing the basic target torque by the torque change filter 67, a steep change is suppressed as shown by a solid line in FIG. 8F, and a rapid acceleration / deceleration of the vehicle is suppressed.

FIG. 6G is a diagram showing changes in the final target torque for fuel injection control determined based on the basic target torque and the torque reduction amount. In FIG. 6G, the horizontal axis represents time, and the vertical axis represents torque. Further, the dotted line in FIG. 6 (g) indicates the basic target torque after smoothing shown in FIG. 6 (f), and the solid line indicates the final target torque for fuel injection control.
As described with reference to FIG. 3, the final target torque determination unit 65 subtracts the torque reduction amount determined in the torque reduction amount determination process in step S5 from the basic target torque after smoothing in step S4. By doing so, the final target torque for fuel injection control is determined. Of the basic target torque and torque reduction amount used to determine the final target torque, the smoothing by the torque change filter 67 is performed based on the basic state determined based on the driving state of the vehicle including the operation of the accelerator pedal. Only target torque. In other words, in the time change of the final target torque, the time change corresponding to the torque reduction amount determined based on the steering operation that is a driving state other than the operation of the accelerator pedal is not smoothed by the torque change filter 67. . Therefore, as shown by a solid line in FIG. 6G, the torque reduction amount is reflected on the final target torque as it is without being smoothed by the torque change filter 67.

  FIG. 6H is a diagram showing a change in the final target torque for EGR / turbo control determined based on the basic target torque. In FIG. 6H, the horizontal axis indicates time, and the vertical axis indicates torque. As described with reference to FIG. 3, the final target torque determination unit 65 supplies the turbo target turbocharger 5, the high pressure EGR device 43, and the low pressure EGR device 48 to the basic target torque after smoothing in step S <b> 4. It is determined as the final target torque for EGR / turbo control for control. Accordingly, as shown in FIG. 6H, the final target torque for EGR / turbo control changes in the same manner as the time change of the basic target torque after smoothing.

FIG. 6I is a diagram showing a change in the required injection amount determined based on the final target torque for fuel injection control. In FIG. 6 (i), the horizontal axis indicates time, and the vertical axis indicates the required injection amount. Also, the dotted line in FIG. 6 (i) indicates the required injection amount corresponding to the smoothed basic target torque shown in FIG. 6 (f), and the solid line indicates the final target for fuel injection control shown in FIG. 6 (g). The required injection amount corresponding to the torque is shown.
In the example of FIG. 6 (i), the engine control unit 69 causes the fuel injection valve 20 to inject the time change corresponding to the torque reduction amount in the time change of the final target torque for fuel injection control set in step S6. Control is performed according to the injection amount. Accordingly, the required injection amount changes in the same manner as the time change of the final target torque for fuel injection control shown in FIG. 6 (g), as shown by the solid line in FIG. 6 (i).

FIG. 6 (j) is a diagram showing a change between the target oxygen concentration in the cylinder and the actual oxygen concentration when the fuel injection amount is controlled as shown in FIG. 6 (i). In FIG. 6J, the horizontal axis indicates time, and the vertical axis indicates the oxygen concentration in the cylinder. 6 (j) shows the target oxygen concentration determined based on the final target torque for EGR / turbo control shown in FIG. 6 (h), and the solid line shows the actual oxygen concentration in the cylinder (that is, engine control). Oxygen concentration estimated by the unit 69).
As shown by the solid line in FIG. 6 (i), when the fuel injection amount is controlled so as to realize the final target torque for fuel injection control, the oxygen concentration in the cylinder changes according to the fuel injection amount. . That is, when the fuel injection amount starts to decrease due to a decrease in the final target torque for fuel injection control corresponding to the torque reduction amount, the amount of oxygen consumed by combustion decreases, so as shown by the solid line in FIG. The oxygen concentration in the cylinder begins to rise at timing T1 delayed from the start of the decrease in the fuel injection amount. Thereafter, when the fuel injection amount increases corresponding to the increase in the final target torque for fuel injection control, the amount of oxygen consumed by combustion increases. Therefore, the oxygen in the cylinder is delayed at a timing T2 delayed from the start of the increase in the fuel injection amount. The concentration begins to decrease.
On the other hand, as shown in FIG. 6 (h), the final target torque for EGR / turbo control does not reflect the change in the torque reduction amount, and changes in the same manner as the time change of the basic target torque after smoothing. The target oxygen concentration set based on the final target torque for EGR / turbo control does not change according to the torque reduction amount as shown by the solid line in FIG. It changes in the same way as time changes.

FIG. 6 (k) shows changes in the EGR valve opening (opening of the high pressure EGR valve 43b and / or the low pressure EGR valve 48c) when the fuel injection amount is controlled as shown in FIG. 6 (i). FIG.
As shown in FIG. 6J, the target oxygen concentration in the cylinder does not change according to the torque reduction amount, but changes in the same manner as the time change of the basic target torque after smoothing. In other words, even when the required injection amount starts to decrease corresponding to the torque reduction amount, the EGR valve opening is not feedforward controlled so as to realize the state amount corresponding to the required injection amount.
Thereafter, when the actual oxygen concentration rises at timing T1 delayed from the start of reduction of the fuel injection amount corresponding to the torque reduction amount, and the actual oxygen concentration becomes higher than the target oxygen concentration, the actual oxygen concentration is changed to the target oxygen. Feedback control is performed to increase the EGR valve opening in order to approach the concentration, that is, to decrease the oxygen concentration in the cylinder by increasing the EGR gas amount. Further, when the actual oxygen concentration decreases at the timing T2 delayed from the start of the increase in the fuel injection amount corresponding to the torque reduction amount, and the actual oxygen concentration approaches the target oxygen concentration, the EGR valve opening is decreased accordingly. Thus, feedback control is performed.
In this way, the high pressure EGR device 43 and the low pressure EGR device 48 are not suddenly controlled according to the instantaneous change in the final target torque for fuel injection control reflecting the torque reduction amount. It is possible to suppress a large mismatch between the oxygen concentration and the oxygen concentration. In addition, a difference between the target oxygen concentration and the actual oxygen concentration is caused by a change in the fuel injection amount according to the final target torque for fuel injection control, but the high pressure EGR is set so that the actual oxygen concentration approaches the target oxygen concentration. By performing feedback control of the device 43 and the low-pressure EGR device 48, mismatch between the fuel injection amount and the oxygen concentration in the cylinder is more reliably suppressed.

FIG. 6 (l) shows a case where the fuel injection amount is controlled based on the final target torque for fuel injection control shown in FIG. 6 (i) in the vehicle that is steered as shown in FIG. 6 (b). When the control corresponding to the change in the yaw rate (actual yaw rate) generated in the vehicle and the torque reduction amount shown in FIG. 6E is not performed (that is, after the smoothing shown by the dotted line in FIG. 6G) It is a diagram which shows the change of the actual yaw rate when the fuel injection amount is controlled based on the basic target torque. In FIG. 6 (l), the horizontal axis indicates time, and the vertical axis indicates the yaw rate. Further, the solid line in FIG. 6 (l) shows the change in the actual yaw rate when the fuel injection amount is controlled based on the final target torque for fuel injection control, and the dotted line does not perform the control corresponding to the torque reduction amount. Shows the change in the actual yaw rate.
When the rightward steering is started at the position A and the torque reduction amount is increased as shown in FIG. 6E as the rightward steering speed increases, the load on the front wheels, which are the steering wheels of the vehicle, increases. As a result, the frictional force between the front wheels and the road surface increases, and the cornering force of the front wheels increases, so that the turning performance of the vehicle is improved. That is, as shown in FIG. 6 (l), the fuel injection control for reflecting the torque reduction amount is performed more than when the control corresponding to the torque reduction amount is not performed between the position A and the position B (dotted line). When the fuel injection amount is controlled based on the final target torque (solid line), the clockwise (CW) yaw rate generated in the vehicle increases.
Further, as shown in FIGS. 6D and 6E, when the steering speed decreases toward the position B, the target additional deceleration also decreases, but the torque reduction amount is maintained at the maximum value. While the steering cut is continued, the load applied to the front wheels is maintained, and the turning ability of the vehicle is maintained.
Further, when the absolute value of the steering angle is constant from the position B to the position C, the torque reduction amount is smoothly reduced. Therefore, the load applied to the front wheels is gradually reduced according to the end of the steering incision. By reducing the cornering force, the output torque of the engine E is recovered while stabilizing the vehicle body.

Next, further modifications of the embodiment of the present invention will be described.
In the above-described embodiment, it has been described that the torque reduction amount determination unit 63 acquires the target additional deceleration based on the steering speed and determines the torque reduction amount based on the target additional deceleration, but other than the operation of the accelerator pedal. The torque reduction amount may be determined based on the driving state of the vehicle (steering angle, yaw rate, slip ratio, etc.).
For example, the torque reduction amount determination unit 63 calculates a target yaw acceleration to be generated in the vehicle based on the target yaw rate calculated from the steering angle and the vehicle speed or the yaw rate input from the yaw rate sensor, and the target yaw acceleration is calculated based on the target yaw acceleration. The additional deceleration may be acquired to determine the torque reduction amount. Alternatively, a lateral acceleration generated as the vehicle turns may be detected by an acceleration sensor, and the torque reduction amount may be determined based on the lateral acceleration.

In the above-described embodiment, the engine control unit 69 outputs the EGR / turbo control final target torque that does not reflect the torque reduction amount (that is, the basic target torque after smoothing) to the engine E. Although it has been described that the high pressure EGR device 43 and the low pressure EGR device 48 are controlled based on the target state quantity in the cylinder, the target in the cylinder when the engine E outputs the final target torque for EGR / turbo control reflecting the torque reduction amount. The high pressure EGR device 43 and the low pressure EGR device 48 may be controlled based on the state quantity.
In this case, the engine control unit 69 restricts the control of the high pressure EGR device 43 and the low pressure EGR device 48 according to the change in the final target torque corresponding to the change in the torque reduction amount. For example, in step S10 of the engine control process shown in FIG. 3, the final target torque determination unit 65 determines the torque determined in the torque reduction amount determination process in step S5 from the basic target torque after smoothing in step S4. By subtracting the correction torque reduction amount obtained by multiplying the reduction amount by a correction coefficient less than 1, the final target torque for EGR / turbo control for controlling the turbocharger 5, the high pressure EGR device 43, and the low pressure EGR device 48 is obtained. decide. In the final target torque for EGR / turbo control determined in this way, the final target torque corresponding to the change in the torque reduction amount is compared with the final target torque for fuel injection control obtained by subtracting the torque reduction amount as it is from the basic target torque. Since the change becomes smaller, the control of the high pressure EGR device 43 and the low pressure EGR device 48 according to the change of the final target torque corresponding to the change of the torque reduction amount is limited.

  Next, effects of the engine control apparatus according to the above-described embodiment of the present invention and the modification of the embodiment of the present invention will be described.

First, the engine control unit 69 controls the fuel injection valve 20 so as to cause the engine E to output the final target torque for fuel injection control that reflects the torque reduction amount determined based on the driving state of the vehicle other than the operation of the accelerator pedal. Therefore, the engine E can be controlled so that a torque reduction amount can be obtained with high responsiveness to the driving state of the vehicle other than the operation of the accelerator pedal, and the load can be quickly applied to the front wheels. The engine E can be controlled so as to accurately realize the vehicle behavior.
Further, since the engine control unit 69 restricts the control of the high pressure EGR device 43 and the low pressure EGR device 48 according to the change in the final target torque corresponding to the change in the torque reduction amount, the fuel injection control that directly reflects the torque reduction amount. By rapidly controlling the high pressure EGR device 43 and the low pressure EGR device 48 according to the instantaneous change in the final target torque for use, it is possible to suppress a large mismatch between the fuel injection amount and the state quantity in the cylinder. , Combustion stability can be ensured.

  In particular, the engine control unit 69 sets the target state quantity in the cylinder when the engine E outputs the final target torque for EGR / turbo control (that is, the basic target torque after smoothing) that does not reflect the torque reduction amount. Since the high-pressure EGR device 43 and the low-pressure EGR device 48 are controlled based on this, the high-pressure EGR device 43 and the low-pressure EGR device 48 are rapidly controlled according to the instantaneous change in the final target torque for fuel injection control reflecting the torque reduction amount. As a result, it is possible to suppress a large mismatch between the fuel injection amount and the state quantity in the cylinder, and to ensure combustion stability.

  In particular, the engine control unit 69 changes the fuel injection amount in accordance with the change in the final target torque for fuel injection control reflecting the torque reduction amount, and sets the state quantity in the cylinder that changes in accordance with the fuel injection amount to the target state. Since the high pressure EGR device 43 and the low pressure EGR device 48 are feedback controlled so as to approach the amount, the engine E is controlled so as to obtain a torque reduction amount with high responsiveness to the driving state of the vehicle other than the operation of the accelerator pedal. On the other hand, the mismatch between the fuel injection amount and the state quantity in the cylinder can be more reliably suppressed, thereby preventing the deterioration of the emission performance and ensuring the combustion stability.

  Further, since the torque reduction amount determination unit 63 determines the torque reduction amount according to the steering operation of the vehicle, the time change of the torque reduction amount determined based on the steering operation can be reflected in the time change of the final target torque. It is possible to improve the responsiveness to the steering operation by quickly adding a deceleration to the vehicle according to the driver's steering operation and applying a load to the front wheels, and increasing the cornering force quickly, and combustion The engine E can be controlled so as to accurately realize the vehicle behavior intended by the driver while ensuring the stability.

  In particular, the torque reduction amount determination unit 63 determines the torque reduction amount so as to increase the torque reduction amount and reduce the increase rate of the increase amount as the steering speed of the vehicle increases. Once the vehicle's steering speed begins to increase, the amount of torque reduction can be increased quickly, thereby quickly adding deceleration to the vehicle at the start of vehicle steering and providing sufficient load to the steering wheel. Can be quickly added to the front wheels. As a result, the frictional force between the front wheels, which are the steering wheels, and the road surface increase, and the cornering force of the front wheels increases, so that the turning ability of the vehicle at the beginning of the curve approach can be improved, and combustion stability is ensured. On the other hand, the responsiveness to the steering operation can be improved.

  In addition, the basic target torque determination unit 61 determines the target acceleration of the vehicle based on the driving state of the vehicle including the operation of the accelerator pedal, and determines the basic target torque based on the target acceleration, thus ensuring combustion stability. The engine E can be controlled to accurately realize the acceleration intended by the driver.

  Further, since the engine control device is a diesel engine control device, by changing the fuel injection amount of the diesel engine in accordance with the final target torque for fuel injection control reflecting the torque reduction amount, the control device other than the operation of the accelerator pedal The time change of the torque reduction amount determined based on the driving state of the vehicle can be accurately realized with high responsiveness, and the engine E can be controlled to accurately realize the vehicle behavior intended by the driver. .

DESCRIPTION OF SYMBOLS 1 Intake passage 5 Turbocharger 5a Compressor 5b Turbine 5c Flap 20 Fuel injection valve 41 Exhaust passage 43 High pressure EGR device 48 Low pressure EGR device 60 PCM
61 Basic target torque determination unit 63 Torque reduction amount determination unit 65 Final target torque determination unit 67 Torque change filter 69 Engine control unit 200 Engine system E Engine

Claims (7)

An EGR device that includes an EGR passage that recirculates exhaust gas in the exhaust passage to the intake passage, an EGR valve that adjusts the flow rate of the exhaust gas that passes through the EGR passage, and a fuel injection device that injects fuel into the cylinder. An engine control device that controls an engine having an engine based on a driving state of the vehicle,
Basic target torque determining means for determining a basic target torque based on the driving state of the vehicle including the operation of an accelerator pedal;
Torque reduction amount determining means for determining a torque reduction amount based on the driving state of the vehicle other than the operation of the accelerator pedal;
Final target torque determining means for determining a final target torque based on the basic target torque and the torque reduction amount;
Fuel injection device control means for controlling the fuel injection device to output the final target torque to the engine;
EGR device control means for controlling the EGR device based on a target state quantity in a cylinder when the final target torque is output to the engine,
The engine control device, wherein the EGR device control means limits the control of the EGR device in accordance with a change in the final target torque corresponding to a change in the torque reduction amount.   The engine control device according to claim 1, wherein the EGR device control means controls the EGR device based on a target state quantity in a cylinder when the basic target torque is output to the engine. The fuel injection device control means changes the fuel injection amount of the fuel injection device in accordance with a change in the final target torque corresponding to the torque reduction amount,
The engine control device according to claim 1 or 2, wherein the EGR device control means feedback-controls the EGR device so that a state quantity in the cylinder approaches the target state quantity.   The engine control device according to any one of claims 1 to 3, wherein the torque reduction amount determination means determines the torque reduction amount in accordance with a steering operation of the vehicle.   5. The torque reduction amount determination unit according to claim 4, wherein the torque reduction amount determination means determines the torque reduction amount so as to increase the torque reduction amount and reduce an increase rate of the increase amount as the steering speed of the vehicle increases. Engine control device.   6. The basic target torque determining means determines a target acceleration of the vehicle based on a driving state of the vehicle including an operation of the accelerator pedal, and determines the basic target torque based on the target acceleration. The engine control device according to claim 1.   The engine control device according to any one of claims 1 to 6, wherein the engine control device is a diesel engine control device.

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