JP6318950B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device that outputs a drive torque command value for a vehicle engine.

  In recent years, automobiles employing auxiliary driving systems such as cruise control and traction control have been seen. In such a system, electronic throttle control is employed, and the amount of depression of the accelerator pedal is converted into an electric signal. Based on this electric signal and the requirements of the cruise control system and the traction control system, the throttle valve that supplies intake air to the engine is opened. The degree is controlled.

  In order to cope with such a system, there is a vehicle that calculates a required torque based on a driver's operation as an input value to an engine control unit that determines the throttle opening of the electronic throttle.

  Japanese Patent Laying-Open No. 2010-144686 (Patent Document 1) discloses a torque control device for an internal combustion engine that calculates such required torque. In the above Japanese Unexamined Patent Publication No. 2010-144686, the basic value of the required torque is calculated according to the engine speed and the accelerator opening, but in order to avoid vehicle vibration due to a sudden change in the required torque, A filtering process is applied to the basic value. This filtering process is called “annealing process”.

JP 2010-144686 A JP 2007-224886 A

  The internal combustion engine of the vehicle generates idle torque at least in order to maintain the independent operation. Therefore, the required torque needs to be determined in consideration of both the idle torque and the required torque based on the driver's accelerator pedal operation.

  Simply, it is conceivable to calculate the required torque for the engine by adding the driver's required torque exceeding the idle torque to the idle torque with reference to the idle torque. However, since the idle torque may change depending on the operating state of the engine, it is necessary to consider the change of the idle torque.

  In order to maintain responsiveness while avoiding sudden changes in required torque, the following control can be considered. In order to prevent the occurrence of a torque step when the accelerator is depressed, when the accelerator opening is zero (accelerator off), the required torque is calculated based on the engine idle torque. On the other hand, in order to suppress fluctuations in the required torque, when the accelerator is on, the required torque is calculated based on the smoothed torque that has been smoothed to the idle torque.

  However, if the accelerator opening is reduced due to the accelerator being turned off and the calculation reference for the required torque is switched from the smoothed torque to the idle torque, the accelerator is returned if the reference torque value after switching is large. In spite of this, the present inventor has realized that there is a possibility that the required torque may be increased and calculated.

  The present invention has been made to solve the above-described problems, and its purpose is to achieve both smoothness and responsiveness of changes in required torque while preventing increase in required torque when the accelerator pedal is returned. It is providing the control apparatus of the made vehicle.

  In summary, the present invention is a control device that outputs a required torque command value for an engine of a vehicle, an idle torque calculation unit that outputs an idle torque command value for putting the engine in an idle state, an idle torque command value Based on a smoothing processing unit that performs a smoothing process that moderates changes, a required torque calculation unit that calculates a driver required torque command value based on an accelerator opening, and an output of an idle torque command value and a smoothing processing unit A reference torque determination unit that outputs a reference torque command value, and an addition unit that adds the reference torque command value to the driver request torque command value in order to calculate the request torque command value. When the idle torque command value is larger than the output of the smoothing processing unit, the reference torque determining unit sets the output of the smoothing processing unit as the reference torque command value until the accelerator opening becomes zero.

  According to the present invention, when the idle torque command value is larger than the output of the smoothing processing unit, the output of the smoothing processing unit is used as the reference torque command value until the accelerator opening becomes zero. Even when the value is switched from the smoothed torque command value to the idle torque command value, the reference torque can be prevented from exceeding the idle torque command value. As a result, it is possible to suppress a phenomenon in which the required torque command value increases momentarily when the accelerator opening is reduced and the reference torque command value is switched.

1 is a block diagram of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. It is a block diagram which shows the structure of the target torque determination part in the examination example. 3 is a flowchart for explaining a process executed by a reference torque determination unit 106A in FIG. FIG. 3 is a diagram showing an example of a map used in a driver request torque calculation unit 108 in FIG. 2. It is a wave form diagram showing an example of change of demand torque command value TE_T in an examination example. It is a block diagram which shows the structure of the target torque determination part in this Embodiment. It is a flowchart for demonstrating the process which the reference torque determination part of FIG. 6 performs. It is a wave form diagram showing an example of change of demand torque command value TE_T in this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a block diagram of a vehicle equipped with a vehicle control apparatus according to an embodiment of the present invention.

  Referring to FIG. 1, vehicle 10 includes an engine 12, a torque converter 14, an automatic transmission 16, and a control device 80. The vehicle 10 is an example of a vehicle to which the present invention is applied. The vehicle 10 is not limited to this, and the torque converter 14 and the automatic transmission 16 are not necessarily provided as long as the vehicle is equipped with an engine such as a hybrid vehicle. It is not necessary.

  The engine 12 is an internal combustion engine that uses gasoline or the like as a fuel, and is a driving force source that generates a driving torque by burning the fuel.

  The drive torque generated by the engine 12 is transmitted to the automatic transmission 16 via the torque converter 14 as a fluid transmission device, and is transmitted from the output shaft 18 to the drive wheels via a final reduction gear, an axle (not shown), and the like. The driving torque is transmitted to the driving wheel and generates a driving force on the ground contact surface of the driving wheel.

  The automatic transmission 16 is a stepped automatic transmission in which a plurality of gear stages are selectively switched. For example, any one of six forward speeds, one reverse speed, and neutral is selected, and the gear ratio of each gear stage is set. The corresponding speed conversion is performed.

  The engine 12 is provided with an intake pipe 24 and an exhaust pipe 26. The intake pipe 24 is provided with an electronic throttle valve 30 that is controlled to open and close by a throttle actuator 28 and a throttle position sensor 48. The electronic throttle valve 30 is basically controlled so that the throttle opening degree θTH becomes an opening degree corresponding to the accelerator opening degree Acc indicating the driver's required output amount. A fuel injection valve 52 that injects fuel to the intake air that has passed through the electronic throttle valve 30 is provided in the intake pipe 24.

  The control device 80 includes an engine control unit 82, a shift control unit 84, and a target torque determination unit 88 as control blocks. The control device 80 is an ECU (Electrical Control Unit) having a built-in memory and a microcomputer for storing programs and various maps, and a control block function is realized by the ECU. The engine control unit 82, the shift control unit 84, and the target torque determination unit 88 may be realized by separate ECUs, but the boundary between the engine control unit 82, the shift control unit 84, and the target torque determination unit 88 is the same. It is not limited to. The engine control unit 82, the shift control unit 84, and the target torque determination unit 88 may be realized by one or a plurality of ECUs having boundaries different from those in FIG.

  Vehicle 10 further includes rotation sensors 32, 34, 36, accelerator pedal 44, accelerator position sensor 46, shift lever 40, and shift position sensor 42.

  The rotation sensor 32 detects the rotational speed NE of the output shaft of the engine 12 and outputs it to the engine control unit 82. The rotation sensor 34 detects the turbine rotation speed NT of the torque converter 14 and outputs it to the shift control unit 84. The rotation sensor 36 detects the rotation speed NOUT of the output shaft 18 of the automatic transmission 16 and outputs it to the shift control unit 84.

  The accelerator position sensor 46 detects the accelerator opening Acc corresponding to the depression amount of the accelerator pedal 44 and outputs it to the target torque determination unit 88. The shift position sensor 42 outputs a signal PSH indicating the shift range selected by the shift lever 40 to the target torque determining unit 88.

  Although not shown, if the vehicle 10 has a vehicle speed control function for controlling the vehicle speed regardless of the accelerator operation amount, that is, a function for executing so-called cruise control, the accelerator 10 Instead of the opening degree Acc, a command value from a cruise control device including an inter-vehicle distance changeover switch, a cruise control switch, a laser radar sensor and the like is used.

  The target torque determination unit 88 outputs the target engine speed NE_T and the target engine torque TE_T to the engine control unit according to the accelerator opening Acc, the signal PSH indicating the shift range, and the like.

  The engine control unit 82 and the shift control unit 84 determine the control amounts for the engine 12 and the automatic transmission 16 in cooperation with each other. The engine control unit 82 determines the engine ignition timing TF and the fuel injection timing TI, and transmits a drive signal TA to the throttle actuator 28 while monitoring the throttle opening θTH from the throttle position sensor 48. The shift control unit 84 outputs a control signal SC to a solenoid valve that hydraulically shifts the automatic transmission 16.

  In such a vehicle, depending on the processing of the target torque determining unit 88, it does not hinder the running of the vehicle. You may feel dissatisfied.

  FIG. 2 is a block diagram illustrating a configuration of a target torque determination unit in the examination example. Referring to FIG. 2, target torque determination unit 88A of this examination example includes idle torque calculation unit 102, smoothing processing unit 104, driver request torque calculation unit 108, reference torque determination unit 106A, and addition processing unit. 110 and a maximum value selection unit 112.

  The idle torque calculation unit 102 calculates the idle torque TE_I based on the vehicle state such as the engine rotation speed NE. The annealing processing unit 104 performs temporal filtering processing on the idle torque TE_I, such as taking an average value with the previously calculated idle torque TE_I, and outputs the annealing torque TE_N. The driver request torque calculation unit 108 outputs the driver request torque TE_D based on the accelerator opening Acc and the engine speed NE.

  The reference torque determination unit 106A calculates the reference torque TE_B by weighted averaging the idle torque TE_I and the torque torque TE_N at a ratio according to the accelerator opening Acc. The addition processing unit 110 adds the driver request torque TE_D to the reference torque TE_B. The maximum value selection unit 112 selects the larger one of the idle torque TE_I and the output of the addition processing unit 110 and outputs the requested torque command value TE_T.

  The maximum value selection unit 112 is provided in order to avoid setting a required torque command value (target torque) smaller than the idle torque TE_I necessary for operation so that the engine continues to operate. is there.

  FIG. 3 is a flowchart for explaining processing executed by the reference torque determination unit 106A of FIG. The processing of this flowchart is called from the main routine and executed every certain time or every time a predetermined condition is satisfied. Referring to FIG. 3, reference torque determining unit 106A calculates reference torque TE_B at a ratio K (Acc) corresponding to accelerator opening Acc in step S100.

The ratio K (Acc) is defined as a function of the accelerator opening Acc taking a value between 0 and 1. In this case, the reference torque TE_B is expressed by the following formula.
TE_B = TE_I * K (Acc) + TE_N * (1-K (Acc))
FIG. 4 is a diagram showing an example of a map used in the driver request torque calculation unit 108 of FIG. In FIG. 4, the horizontal axis represents the engine rotation speed Ne, and the vertical axis represents the driver request torque TE_D. And it turns out that driver demand torque TE_D increases as accelerator opening Acc increases with 10%, 30%, 50%, and 100%.

  In the target torque determination unit 88A of the examination example described above, the inventor of the present application has the possibility that the moment when the required torque command value TE_T increases despite the case where the accelerator opening Acc is returned. I came to notice.

  FIG. 5 is a waveform diagram showing an example of a change in the required torque command value TE_T in the study example. Referring to FIGS. 2 and 5, idle torque TE_I increases at time t1. However, due to the annealing process, the annealing torque TE_N increases slowly thereafter.

  For example, a variable valve timing mechanism (VVT mechanism) of the engine can be considered as a factor of fluctuation of the idle torque TE_I. Immediately after the start of engine operation, the pressure of the oil pump driven by the engine cannot be obtained, so the VVT mechanism cannot provide optimal valve timing. However, when the hydraulic pressure increases and the VVT mechanism becomes operable, the idle torque TE_I changes. . Other factors include load fluctuations such as the start of operation of the air conditioner. When the air conditioner switch is changed from the off state to the on state, the engine idle torque TE_I also increases.

  Subsequently, in response to the driver returning the accelerator at time t2, the accelerator opening Acc decreases from time t2 to t4.

  Then, the driver request torque TE_D decreases during the period as the accelerator opening Acc decreases, but the reference torque TE_B starts increasing at time t3. Then, the torque TE_D2, which is the sum of the driver request torque TE_D and the reference torque TE_B, becomes momentarily larger than the idle torque TE_I. For this reason, between times t3 and t4, there is a moment when the required torque command value TE_T increases although the accelerator opening is decreasing. It is preferable that such a moment does not occur as much as possible.

  Therefore, in the vehicle control apparatus according to the present embodiment, the target torque determination unit 88 uses a modified process of the reference torque determination unit in the configuration of FIG.

  FIG. 6 is a block diagram showing the configuration of the target torque determination unit in the present embodiment. Referring to FIG. 2, target torque determination unit 88 of the present embodiment includes idle torque calculation unit 102, smoothing processing unit 104, driver request torque calculation unit 108, reference torque determination unit 106, and addition processing. Part 110 and maximum value selection part 112.

  The idle torque calculation unit 102 outputs an idle torque command value TE_I for setting the engine to an idle state based on the vehicle state such as the engine rotation speed NE. The annealing processing unit 104 performs an annealing process that moderates the change in the idle torque command value TE_I. The annealing process is, for example, a process of applying a temporal filter to the idle torque TE_I by taking an average value with the previously calculated idle torque TE_I. The requested torque calculation unit 108 calculates a driver requested torque command value TE_D based on the accelerator opening Acc.

  The reference torque determination unit 106 outputs the reference torque command value TE_B based on the idle torque command value TE_I and the output of the annealing processing unit 104 (annealing torque TE_N). The addition processing unit 110 adds the reference torque command value TE_B to the driver request torque command value TE_D in order to calculate the request torque command value TE_T.

  When the idle torque command value TE_I is larger than the output of the smoothing processing unit 104 (smoothing torque TE_N), the reference torque determination unit 106 outputs the smoothing processing unit 104 until the accelerator opening Acc becomes zero ( The annealing torque TE_N) is set as a reference torque command value TE_B.

  The maximum value selection unit 112 selects the larger one of the idle torque TE_I and the output of the addition processing unit 110 and outputs the requested torque command value TE_T.

  Since the configuration other than the reference torque determination unit 106 is the same as that in FIG. 2, refer to the description of FIG. 2 for each process.

  FIG. 7 is a flowchart for explaining processing executed by the reference torque determination unit 106 of FIG. The processing of this flowchart is called from the main routine and executed every certain time or every time a predetermined condition is satisfied. Referring to FIG. 7, when the process is started, first, in step S1, a magnitude relationship between idle torque TE_I and tempering torque TE_N is determined.

  If the idle torque TE_I is greater than the annealing torque TE_N in step S1 (YES in S1), the process proceeds to step S2, and if not (NO in S1), the process proceeds to step S100.

  In step S2, it is determined whether or not the accelerator opening Acc is 0 (fully closed). If the accelerator opening degree Acc is 0 in step S2 (YES in S2), the process proceeds to step S100. If not (NO in S2), the process proceeds to step S3.

  The process of step S100 is a process of adding the idle torque TE_I and the torque torque TE_N at a ratio according to the accelerator opening, but since it has already been described with reference to FIG. 3, the description thereof will not be repeated here.

  In step S3, the reference torque TE_B is set to the annealing torque TE_N that is smaller than the idle torque TE_I at this time. Therefore, even if the idle torque TE_I suddenly increases, the sudden increase in the reference torque TE_B can be avoided.

  In step S4, the reference torque TE_B obtained in step S3 or step S100 is output to the addition processing unit 110, and in step S5, control is transferred to the main routine.

  FIG. 8 is a waveform diagram showing an example of a change in required torque command value TE_T in the present embodiment. Referring to FIGS. 6 and 8, idle torque TE_I increases at time t1. For example, some engines are provided with a variable valve timing mechanism (VVT mechanism), and one of the fluctuation factors of the idle torque TE_I is the operation of the VVT mechanism. Immediately after the start of engine operation, the pressure of the oil pump driven by the engine cannot be obtained, so the VVT mechanism cannot provide optimal valve timing. However, when the hydraulic pressure increases and the VVT mechanism becomes operable, the idle torque TE_I changes. . Other factors include load fluctuations such as the start of operation of the air conditioner. When the air conditioner switch is changed from the off state to the on state, the engine idle torque TE_I also increases.

  Subsequently, in response to the driver returning the accelerator at time t2, the accelerator opening Acc decreases from time t2 to t4.

  Then, the driver request torque TE_D decreases during that time, and the reference torque TE_B is the smaller TE_N until the accelerator opening Acc becomes zero at time t4, and the process of switching the reference torque TE_B to the idle torque TE_I is performed. It is not performed until time t4. Therefore, the torque TE_D2, which is the sum of the driver request torque TE_D and the reference torque TE_B, also decreases as the accelerator opening Acc decreases. The required torque command value TE_T is suppressed from increasing momentarily as in the waveform shown in FIG.

  As described above, in the present embodiment, the reference torque TE_B does not increase until the accelerator opening Acc is fully closed. For this reason, there is no increase in the target torque when the accelerator opening decreases across the threshold value while the accelerator is off, and it is possible to avoid the driver feeling a moment of acceleration when the accelerator is returned.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 Vehicle, 12 Engine, 14 Torque converter, 16 Automatic transmission, 18 Output shaft, 24 Intake pipe, 26 Exhaust pipe, 28 Throttle actuator, 30 Electronic throttle valve, 32, 34, 36 Rotation sensor, 40 Shift lever, 42 Shift Position sensor, 44 accelerator pedal, 46 accelerator position sensor, 48 throttle position sensor, 52 fuel injection valve, 80 control device, 82 engine control unit, 84 shift control unit, 88 target torque determination unit, 102 idle torque calculation unit, 104 Further processing unit, 106 reference torque determining unit, 108 driver required torque calculating unit, 108 required torque calculating unit, 110 addition processing unit, 112 maximum value selecting unit.

Claims (1)

A control device that outputs a required torque command value for a vehicle engine,
An idle torque calculator for outputting an idle torque command value for setting the engine in an idle state;
An annealing processing unit that performs an annealing process to moderate the change in the idle torque command value;
A required torque calculation unit that calculates a driver required torque command value based on the accelerator opening;
A reference torque determining unit that outputs a reference torque command value based on the idle torque command value and the output of the annealing processing unit;
An adder for adding the reference torque command value to the driver request torque command value in order to calculate the request torque command value;
When the idle torque command value is larger than the output of the smoothing processing unit, the reference torque determining unit determines the output of the smoothing processing unit as the reference torque command value until the accelerator opening becomes zero. A vehicle control device.

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