JP2006219066A - Vehicle controller, and method for controlling vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise control response in cruise control with a simple method concerning a vehicle controller for controlling a vehicle by changeover between normal control or cruise control. <P>SOLUTION: When the cruise control is performed in the vehicle controller, the second target driving force itself required for the cruise control, which is calculated by a second target driving force calculating part 4, is inputted to a controlled variable calculating part 2, so as to calculate controlled variable, based on the second target driving force. That is, the controlled variable is calculated not by using the driving force calculated based on a virtual accelerator opening degree but by performing calculation with the driving force required for the cruise control as a physical amount, so as to directly use the driving force for calculation. Consequently, the vehicle is correctly and rapidly approximated to a target control state. Besides, the driving force to be required itself is directly controlled, so that it is applicable regardless of the kinds of the vehicles. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control device and a vehicle control method that can be controlled by switching between normal control for causing a vehicle to travel based on an operation amount such as an accelerator opening degree and cruise control for traveling at a constant speed based on a set vehicle speed.

  Conventionally, from the standpoint of reducing the driver's operation burden, etc., vehicle control has made it possible to drive the vehicle at a constant speed (set vehicle speed) set by the driver regardless of the amount of operation such as the amount of depression of the accelerator pedal. The device is known.

  The control for driving the vehicle at a constant speed is generally called cruise control, and is a normal control state in which the vehicle is accelerated / decelerated based on the accelerator opening by operating a cruise switch provided in the passenger compartment. Transition from. That is, the driver can switch between cruise control and normal control and increase / decrease the set vehicle speed during cruise control by operating this cruise switch. The vehicle-mounted electronic control device calculates a driving force for realizing the set vehicle speed and various control amounts for realizing the driving force, and various control objects including the engine and the transmission are based on the control amounts. To control.

  Specifically, as shown in FIG. 7 as an example of the conventional vehicle control method, a predetermined control map is referred to based on the target vehicle speed and the accelerator opening, and the target drive necessary to realize the target vehicle speed. Calculate the force. Then, the target engine torque and the target engine speed are calculated from the target output obtained by replacing the target driving force with the output so that the optimum fuel consumption condition is satisfied. Then, engine control and shift control are executed so as to realize the target engine torque and the target engine speed. At this time, the accelerator opening is also used for other controls such as engine control and shift control.

  Incidentally, since the accelerator pedal is not normally depressed by the driver during cruise control, the accelerator opening detected by a sensor or the like is naturally 0%. As a result, even when the vehicle is in an accelerating state by cruise control, the electronic control device controls the engine and the transmission with the accelerator opening being 0%.

  In general, a continuously variable transmission capable of continuously changing a gear ratio is employed as a transmission of a vehicle that performs cruise control. However, the gear change control is performed according to the vehicle speed and the accelerator opening. Therefore, when the accelerator opening is set to 0% in spite of the acceleration in this way, the responsiveness of the shift becomes worse than that in the normal control.

  The accelerator opening as the control amount is used as a parameter for determining the driver's intention to accelerate not only in cruise control but also in various other controls for driving the vehicle safely and stably. For this reason, although there is an acceleration instruction during cruise control, it may be determined that the driver does not intend to accelerate in other controls. In this case, there arises a problem that control contradiction and contradiction occur and control responsiveness deteriorates.

  Under such circumstances, during cruise control, the accelerator opening required for the vehicle is virtually calculated from the deviation between the set vehicle speed (target vehicle speed) and the current vehicle speed (actual vehicle speed) (hereinafter, the virtually calculated accelerator opening). Is referred to as “virtual accelerator opening”), and a vehicle control device that controls the vehicle using the virtual accelerator opening has been proposed (see Patent Document 1).

In this vehicle control device, during cruise control, a driving force necessary for the vehicle is calculated from the virtual accelerator opening and the actual vehicle speed using a predetermined control map, and this is used as a target driving force for cooperative control of the engine and the transmission. On the other hand, the virtual accelerator opening is also used for other control that interrupts the engine control or the shift control, for example. As described above, since the virtual accelerator opening is calculated and used as a control amount even during cruise control, the situation where the accelerator opening is 0% does not occur even though the vehicle is in an accelerated state as described above. Responsiveness can be improved.
JP-A-9-177574

  By the way, in such a vehicle control apparatus, the virtual accelerator opening is obtained in the cruise control calculation process as described above, and the target driving force is calculated from the virtual accelerator opening and the actual vehicle speed. However, the accelerator opening itself is essentially a virtual operation amount, and how much driving force can be generated with respect to the depression amount of the accelerator pedal varies depending on the characteristics of the vehicle. For this reason, if the target driving force calculated from the virtual accelerator opening using a specific control map is applied without distinguishing the vehicle, an error from the target driving force that is originally required for the vehicle may occur. . In particular, in a vehicle control device that calculates engine torque and engine speed based on a target driving force and performs cooperative control (torque demand control) on the engine and transmission, an error amount when calculating the driving force is calculated. Has a problem that control responsiveness cannot be sufficiently improved.

  Therefore, in order to obtain an accurate target driving force using a control map from such a virtual accelerator opening, it is necessary to individually create a control map corresponding to each vehicle. Has a problem that its design becomes very complicated.

  The present invention has been made in view of such a point, and in a vehicle control device capable of controlling a vehicle by switching to normal control or cruise control, the control responsiveness during cruise control is improved by a simple method. With the goal.

  In the present invention, in order to solve the above problem, as shown in FIG. 1, a target driving force calculation unit 1 that calculates a target driving force of the vehicle based on the vehicle speed and the accelerator opening, and a control amount for driving the vehicle. And a control means 3 for switching the vehicle to constant speed running or normal running based on the control quantity, and a control means 3 for controlling the vehicle during the constant speed running. The second target driving force calculating unit 4 calculates a second target driving force that is a target driving force of the vehicle based on the target vehicle speed and the actual vehicle speed, and the control amount calculating unit 2 A vehicle control apparatus is provided that calculates the control amount based on the second target driving force.

  In such a vehicle control device, when the vehicle is traveling at a constant speed, the second target driving force required for the constant speed traveling calculated by the second target driving force calculating unit 4 is directly input to the control amount calculating unit 2. The The vehicle is controlled using the control amount calculated by the control amount calculation unit 2 based on the second target driving force.

  In this case, it is preferable that the target driving force calculation unit calculates a virtual accelerator opening obtained by reversely calculating the accelerator opening using the second target driving force as the target driving force, and the control means opens the virtual accelerator opening. The vehicle may be controlled using a degree.

In the present invention, the target driving force of the vehicle is calculated based on the vehicle speed and the accelerator opening, the control amount for driving the vehicle is calculated based on the target driving force, and the vehicle is driven at a constant speed or normal driving. A vehicle control method for controlling the vehicle to calculate the second target driving force, which is the target driving force of the vehicle, based on the target vehicle speed and the actual vehicle speed during the constant speed running, The vehicle control method is characterized in that the control amount is calculated based on the vehicle control method.

  According to the vehicle control device and the vehicle control method of the present invention, instead of calculating the control amount using the driving force calculated from the virtual accelerator opening, the driving force necessary for cruise control is calculated as a physical amount, Using this directly, the control amount is calculated. For this reason, it is possible to accurately and quickly approach the control state for which the vehicle is targeted. Further, since the required driving force itself is used as the control amount, it is sufficient to set it once regardless of the type of vehicle. For this reason, while being able to implement | achieve simply, the versatility as a vehicle control apparatus increases.

  In particular, if the vehicle is controlled using a virtual accelerator opening obtained by calculating back the accelerator opening from the second target driving force, it is convenient for so-called torque demand control. That is, since the target driving force is important in torque demand control, it is calculated as described above, but the accelerator opening is not as important as the target driving force. For this reason, the accelerator opening can be easily calculated using, for example, a map used for calculating the target driving force during normal control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an outline of the present embodiment will be described, and then specific contents of the embodiment will be described. FIG. 1 is a conceptual diagram of the embodiment.

  In this vehicle control device, in normal control that has not changed to cruise control, the target driving force calculation unit 1 calculates the target driving force of the vehicle based on the vehicle speed and the accelerator opening. Here, for example, the target driving force is calculated using a control map in which the relationship between the vehicle speed, the accelerator opening, and the driving force is set in advance. In addition, what was detected by vehicle speed detection means, such as a vehicle speed sensor, can be used for a vehicle speed, and what was detected by accelerator opening detection means, such as an accelerator opening sensor, can be used for an accelerator opening. Then, the control amount calculation unit 2 calculates a control amount for driving the vehicle based on the target driving force, and the control means 3 causes the vehicle to travel normally based on the control amount.

  On the other hand, during constant speed traveling by cruise control, the second target driving force calculation unit 4 calculates the second target driving force required for the vehicle based on the target vehicle speed and the actual vehicle speed. The target vehicle speed is set by, for example, a cruise switch provided in the passenger compartment, and the actual vehicle speed is obtained by detecting the current vehicle speed by the vehicle speed detecting means, for example. Then, the control amount calculation unit 2 calculates the control amount based on the second target driving force, and the control means 3 causes the vehicle to travel at a constant speed based on the control amount.

  According to such a vehicle control device, the second target driving force necessary for the cruise control calculated by the second target driving force calculation unit 4 is input to the control amount calculation unit 2 during cruise control. Then, a control amount is calculated based on the second target driving force.

  That is, instead of calculating the control amount using the driving force calculated from the virtual accelerator opening, the driving force necessary for cruise control is calculated as a physical amount, and this is used directly to calculate the control amount. The vehicle can be brought close to the target control state accurately and quickly. In addition, since it is a control that directly targets the required driving force itself, it can be applied regardless of the type of vehicle, and it can be easily realized because it only needs to be set once from the standpoint of the designer. At the same time, versatility as a vehicle control device is enhanced.

  In this case, for the accelerator opening as the control amount, the target driving force calculation unit 1 calculates a virtual accelerator opening obtained by reversely calculating the accelerator opening using the second target driving force as the target driving force, and the control means The vehicle may be controlled using the virtual accelerator opening.

  In this way, a situation in which the accelerator opening is 0% does not occur even though the vehicle is in an accelerating state during cruise control, and the control responsiveness can be improved. In this case, the accelerator opening as the control amount is calculated backward from the target driving force using, for example, the control map, contrary to the case of the normal control, and the accuracy may slightly decrease. There is. However, since the accelerator opening itself is originally virtual as described above, it is considered that the influence on the entire vehicle control is small. For this reason, it is not necessary to create the control map for every vehicle, and the versatility as a vehicle control apparatus increases more.

The vehicle control apparatus described above is considered to be particularly effective for a vehicle equipped with a continuously variable transmission capable of continuously changing the gear ratio as a transmission.
As a specific function of the control amount calculation unit, for example, the target output calculation unit calculates the target output of the vehicle from the target driving force and the vehicle speed. Here, the target output is obtained by multiplying the target driving force and the vehicle speed.

  Subsequently, the target control amount calculation unit calculates the target engine torque and the target engine speed so that the optimum fuel consumption condition is satisfied from the target output. Here, for example, a control map representing the relationship between the engine torque, the engine speed, and the output is used, and the engine torque and the engine speed calculated so as to satisfy the point where the optimum fuel consumption line set in the control map and the target output intersect. The numbers are the target engine torque and the target engine speed, respectively.

  Then, the control means 3 controls the engine control actuator so as to realize the target engine torque, calculates the target speed ratio based on the target engine speed, and changes the speed so as to realize the target speed ratio. Control the actuator for control.

  Such a vehicle control device is of a type that performs coordinated control of engine control and shift control based on a single calculated target driving force, and such coordinated control is particularly required as described above. It is considered effective to directly input the target driving force to achieve accurate control.

  By the way, when the virtual accelerator opening is calculated and used as described above, if the difference between the accelerator opening during normal control and the virtual accelerator opening during cruise control is large, the control state of the vehicle suddenly changes at the time of switching. The vehicle behavior may become unstable.

  Therefore, the control means 3 switches from the accelerator opening during normal driving to the virtual accelerator opening during constant speed driving, and the switching from the virtual accelerator opening during constant speed driving to the accelerator opening during normal driving. At least one may be performed by predetermined change control. By doing in this way, switching of control can be made smooth.

  In that case, when switching from cruise control to normal control, the driver's willingness to accelerate the vehicle may be strong, for example, and if the driver does not respond quickly, the driver may feel uncomfortable. There is sex.

  Therefore, the control means 3 switches from the accelerator opening during normal driving to the virtual accelerator opening during constant speed driving by switching from the virtual accelerator opening during constant speed driving to the accelerator opening during normal driving. Is also performed slowly, in other words, it is preferable to quickly switch from the virtual accelerator opening during constant speed travel to the accelerator opening during normal travel.

Further, from the same viewpoint, it is preferable that the change control is changed more rapidly as the deviation between the target control amount after switching and the actual control amount at the time of switching is larger.
During cruise control, the vehicle speed (set vehicle speed) set by the driver's intention may be increased or decreased. In this case as well, it is necessary to maintain the stability of the vehicle behavior. Therefore, when the second target driving force changes in response to the request for changing the vehicle speed during constant speed travel, the control means opens the virtual accelerator that changes with the change in the second target driving force. The degree is preferably used so as to follow the change in the second target driving force with a predetermined time constant.

  However, since it is considered that the driver's intention to accelerate is stronger as the change in the second target driving force is larger, the time constant is preferably set to be smaller as the change in the second target driving force is larger.

  In addition, if the accelerator opening becomes larger than the virtual accelerator opening by depressing the accelerator pedal during constant speed driving, the driver's intention to accelerate is considered to be particularly strong. It is preferable to accelerate the vehicle quickly by using the accelerator opening instead of the opening.

  Alternatively, the driver's intention to accelerate further than the current vehicle speed is respected, the target driving force calculation unit calculates the second virtual accelerator opening obtained by adding the accelerator opening to the virtual accelerator opening, and the control means The vehicle may be controlled using the second virtual accelerator opening.

  Incidentally, in vehicle control, an upper limit speed is usually set for safety. For example, when the vehicle speed exceeds 180 km / h, the driving force is intentionally reduced regardless of the amount of depression of the accelerator pedal, and the vehicle speed is maintained at 180 km / h.

  Therefore, when a request for increasing the vehicle speed is made during constant speed traveling by cruise control, and the target vehicle speed exceeds a predetermined upper limit speed, the second target driving force calculation unit sets the second target driving force equal to or higher than the upper limit speed. It is good to limit and calculate so that the vehicle speed does not come out. For example, the second target driving force may be set to the upper limit speed.

  In that case, there is a possibility that control to increase / decrease the target driving force and make it temporarily zero may be adopted, but according to this, the accelerator opening as a control amount used for control other than cruise control If zero is also zero, there is a possibility that control contradiction or contradiction will occur. For this reason, it is good for a control means to control a vehicle using the 3rd virtual accelerator opening set separately. In this case, for the third virtual accelerator opening, for example, a specific fixed value that does not cause a control problem can be set. However, the accelerator is obtained by calculating back the second target driving force corresponding to the upper limit speed as the target driving force. The opening may be set and held.

  In some cases, a predetermined throttle opening degree may be required during the constant speed traveling by the cruise control to realize another traveling control having a higher priority than the constant speed traveling. For example, due to a request for vehicle stabilization control (VSC) or the like that maintains the running stability of a vehicle during a curve run, a required opening degree for closing the throttle and a required opening degree for opening the throttle may be required. is there.

  As described above, when there is a request by another traveling control having a high priority, the control unit controls the vehicle using the fourth virtual accelerator opening calculated based on the requested throttle opening. Is preferred.

Also in this case, it is preferable that the control means performs switching from the virtual accelerator opening at the time of constant speed traveling to the fourth virtual accelerator opening at the time of another traveling control by predetermined change control. For example, in the case of vehicle stabilization control, the degree of change control may be changed depending on the difference between the requested opening and the requested opening.

  Also, during cooperative control of the engine and transmission, for example, when the accelerator pedal is released during high-speed driving of the vehicle, so-called idle on fuel cut is performed, and retard control is performed to reduce the shock at the time of return. Sometimes done. Also in this case, if the retardation amount is set by the above-described virtual accelerator opening and vehicle speed, consistency with the cooperative control can be improved.

It should be noted that the accelerator pedal fully closed determination at the time of cruise control constant speed traveling described above may also be performed based on the virtual accelerator opening.
In addition, when a predetermined failure diagnosis is made for the vehicle during constant speed traveling, the cruise control may malfunction. For this reason, it is good for a control means to use the accelerator opening based on the amount by stepping on an accelerator pedal instead of a virtual accelerator opening.

Hereinafter, embodiments of the present invention will be specifically described.
In the present embodiment, the vehicle control device of the present invention is applied to a vehicle equipped with a continuously variable transmission. FIG. 2 is a block diagram showing the configuration of the vehicle control device according to the present embodiment.

  As shown in the figure, an oil pump 12, a torque converter 13, a forward / reverse clutch 14, a continuously variable transmission 15, and a reduction gear 16 are sequentially connected to one output shaft of the engine 11. Is transmitted to the left and right drive wheels 18 via the differential 17. Further, the engine 11 is provided with an electronic throttle 19 that electronically controls the intake air amount based on the depression amount of the throttle pedal.

  The torque converter 13 is for smoothly transmitting the power of the engine 11 to the axle. The pump impeller 21 connected to the output shaft of the engine 11, the turbine liner 22 connected to the output shaft of the torque converter 13, and the like And a lockup clutch 24 for fastening the pump impeller 21 and the turbine liner 22 under a predetermined condition.

  The forward / reverse clutch 14 includes a planetary gear, and includes a sun gear 31 connected to the output shaft of the torque converter 13, a carrier 32 connected to the input shaft of the continuously variable transmission 15, and a ring gear 34 connected to the brake 33.

  The continuously variable transmission 15 includes a primary pulley 41 connected to the input shaft, a secondary pulley 42 connected to the output shaft, and a belt 43 stretched between the pulleys, and torque transmitted from the input shaft. Is transmitted to the output shaft. The shift control of the continuously variable transmission 15 is performed by hydraulic control by the hydraulic control device 45. The hydraulic control device 45 performs hydraulic control using hydraulic oil pumped up from a predetermined hydraulic source by the mechanical oil pump 12. Then, the groove width of the primary pulley 41 is changed by hydraulic control, while the clamping pressure of the secondary pulley 42 on the belt 43 is held by hydraulic control, and the engagement diameter of the belt 43 in each pulley is changed, whereby the input shaft The gear ratio, which is the ratio of the rotational speeds of the motor and the output shaft, is continuously changed.

  The reduction gear 16 matches the rotation direction of the axle with the rotation direction of the output shaft of the engine 11. That is, in the continuously variable transmission 15, the rotation direction is reversed between the input shaft and the output shaft, but the reduction gear 16 further reverses the rotation direction of the reversed output shaft to rotate the input shaft. To match.

  The differential 17 transmits the output of the reduction gear 16 to the accelerator shafts connected to the left and right drive wheels 18, respectively, and absorbs the difference in rotation between the left and right drive wheels 18 when the vehicle travels a curve, so that the vehicle travels smoothly. Is realized.

  Each control object is controlled by an electronic control unit (hereinafter referred to as “ECU”) 50 mounted on the vehicle. The ECU 50 is provided with an engine control unit 51 that controls the engine 11, a shift control unit 52 that controls the continuously variable transmission 15, a cruise control unit 53 that executes cruise control, and the like. Although the configuration in which each control unit is provided in one ECU is shown here, each control unit is configured as an independent ECU, that is, an engine control ECU, a shift control ECU, and a cruise control ECU, and has a predetermined communication. They may be connected to each other via a line.

  The ECU 50 is an independent electronic control unit mainly composed of a calculation unit composed of a microcomputer. A CPU (Central Processing Unit) that executes various calculation processes, and a ROM (Read Only) that stores various control calculation programs and data. Memory), RAM (Random Access Memory) in which numerical values and flags of arithmetic processes are stored in a predetermined area, EEPROM (Electronically Erasable and Programmable Read Only Memory) that is a nonvolatile storage device in which the results of arithmetic processing are stored, An A / D (Analog / Digital) converter that converts an input analog signal into a digital signal, an input / output interface for inputting / outputting various digital signals, a timer for timekeeping used in the calculation process, and each of these devices A bus line to be connected is provided.

  The ECU 50 incorporates a signal input / output unit that takes in output signals from various sensors that detect the state of each control target and outputs drive signals to various actuators that control each control target.

  That is, the signal input / output unit of the ECU 50 includes an accelerator opening sensor that detects the amount of depression of the accelerator pedal, an air flow meter that detects the amount of intake air, an intake air temperature sensor that detects the temperature of intake air, and the opening of the throttle valve. Throttle opening sensor to detect, water temperature sensor to detect cooling water temperature, engine speed sensor to detect engine speed, vehicle speed sensor to detect vehicle speed from rotation of vehicle drive shaft, rotation speed of input shaft of continuously variable transmission 15 Primary pulley rotation sensor that detects the output, secondary pulley rotation sensor that detects the rotation speed of the output shaft of the continuously variable transmission 15, oil temperature sensor that detects the temperature of the hydraulic oil, and oil pressure (belt clamping pressure) in the secondary pulley. Belt clamping pressure sensor, shift position sensor to detect current shift position, ignition switch, cruise control Sensors and switches such as cruise switch setting is operated is connected. Various detection signals including an accelerator opening signal, a primary pulley rotation sensor signal, a secondary pulley rotation sensor signal, a vehicle speed sensor signal, a cruise set signal, and the like are input to the ECU 50. The cruise switch includes a cruise main switch for starting cruise control, a cruise cancel switch for ending cruise control, a cruise vehicle speed set switch for setting a target vehicle speed, and increasing the target vehicle speed by a predetermined amount. For example, a cruise acceleration request switch for decelerating the target vehicle speed by a predetermined amount, and the like, and a driver can be set in the passenger compartment.

The signal input / output unit of the ECU 50 includes an injector provided for each cylinder of the engine 11 for injecting fuel, an igniter for generating high voltage for ignition, a fuel pump for pumping fuel from a fuel tank and supplying the fuel to the injector, Various actuators for engine control, such as the electronic throttle 19 for controlling opening / closing of a throttle valve provided in the intake pipe of the engine 11, are connected. The ECU 50 outputs various control command signals including a fuel injection signal, an ignition signal, an electronic throttle drive signal, a lockup control signal, a forward / reverse clutch control signal, a shift control signal, a belt clamping pressure control signal, and the like. It has become.

  The ECU 50 performs a predetermined engine control process for generating a driving torque necessary for driving the vehicle in accordance with a control program stored in the ROM, and a predetermined shift control process for causing the vehicle to travel at a target gear ratio. Do.

  Specifically, in the latter speed change control process, feedback control is performed using a deviation between a target speed ratio that is a target speed ratio and an actual speed ratio that is the current speed ratio. Specifically, by setting the control amount to be proportional to the difference between the target gear ratio and the actual gear ratio, proportional control that gradually brings the actual gear ratio closer to the target gear ratio, or a steady deviation that cannot be eliminated only by proportional control is reduced. PID control including integral control for the purpose and differential control for reducing the time constant to quickly bring the actual gear ratio closer to the target gear ratio, and calculating control instruction values to be output to each hydraulic actuator for gear shifting control To do. In the hydraulic control device 45, each hydraulic actuator is driven based on this control instruction value to control the operation of each valve, and the amount of hydraulic oil supplied to and discharged from the primary pulley 41 and the secondary pulley so as to obtain the target gear ratio. The pressure (belt clamping pressure) of hydraulic oil supplied to and discharged from 42 is adjusted.

  In addition, the ECU 50 performs traveling control processing such as predetermined cruise control by setting a cruise switch, vehicle stabilization control for maintaining vehicle traveling stability during curve traveling, and traction control for preventing acceleration slip of a drive wheel. Also execute.

  Next, an outline of engine control and shift control will be described. FIG. 3 is a functional block diagram illustrating an example of a vehicle control process executed mainly by the cruise control unit of the ECU. In the figure, the solid line arrow represents the flow of normal control, the alternate long and short dash line arrow represents the flow of cruise control, and the thick solid line represents the flow of control common to both controls. FIG. 4 is an explanatory diagram showing a method for calculating a target driving force calculated at the time of cruise control. FIG. 4A is a functional block diagram showing a cruise calculation process for calculating the driving force required for the vehicle at the time of cruise control. (B) represents a computation model used for the computation processing, and (C) represents a computation map showing the relationship between the vehicle speed and the running resistance.

  As shown in FIG. 3, first, at the time of normal control that has not shifted to cruise control, a predetermined control map is referred to by the target driving force calculation unit 61, the actual vehicle speed spd detected by the vehicle speed sensor, and the accelerator Based on the accelerator opening accp detected by the opening sensor, the driving force force required for the vehicle is calculated. This driving force force is set as a target driving force force-cnt in normal control (a cruise control execution flag xcrs set in advance in RAM is 0) and is input to the target output calculation unit 62.

  Subsequently, the target output calculation unit 62 calculates the target output power of the vehicle from the target driving force force-cnt and the actual vehicle speed spd. Here, the target output power is obtained by multiplying the target driving force force-cnt by the actual vehicle speed spd.

  Subsequently, the target control amount calculation unit 63 refers to a predetermined control map, and the target engine torque trqtgt and the target engine speed nintgt are calculated from the target output power so that the optimum fuel consumption condition is satisfied. Here, a control map representing the relationship between the engine torque TE, the engine speed NIN, and the output power is used, and the engine torque calculated so as to satisfy the point where the optimum fuel consumption line set in the control map and the target output power intersect. And the engine speed are a target engine torque trqtgt and a target engine speed nintgt, respectively. The target engine torque trqtgt and the target engine speed nintgt are output to the engine control unit 51 and the shift control unit 52, respectively.

  Further, the accelerator opening accp detected by the accelerator opening sensor is an accelerator opening accp-cnt as a control amount in normal control (a cruise control execution flag xcrs set in advance in RAM is 0). And output to the engine control unit 51 and the shift control unit 52.

  Then, the engine control unit 51 controls the engine control actuator so as to realize the target engine torque trqtgt. Further, the speed change control unit 52 calculates a target speed ratio for controlling the continuously variable transmission 15 from the target engine speed nintgt, and controls the speed control actuator so as to realize the target speed ratio. The engine control unit 51 and the shift control unit 52 use the accelerator opening accp-cnt as necessary.

  Thereby, good engine control and shift control in the normal control are executed, and acceleration / deceleration traveling of the vehicle based on the operation amount including the accelerator opening based on the depression amount of the accelerator pedal by the driver is realized.

On the other hand, at the time of cruise control, first, a cruise calculation process for calculating a driving force required for the vehicle using a separately set calculation formula is executed.
That is, as shown in FIG. 4, in this cruise calculation process, the set vehicle speed set by the cruise switch is set as the target vehicle speed Vtgt, and the deviation (Vtgt−Vreal) from the actual vehicle speed Vreal detected by the vehicle speed sensor is used. By performing the feedback calculation process, the driving force Ftgt required to bring the vehicle speed close to the target vehicle speed Vtgt is calculated.

  For this calculation, for example, a model as shown in FIG. As shown in the figure, the force F received by the vehicle in the traveling direction is obtained by subtracting the traveling resistance Frl including the road surface resistance and air resistance received when the vehicle travels from the target driving force Ftgt. For this reason, constant speed running can be realized by controlling the force F to be zero.

As shown in the graph of FIG. 10C, the running resistance Frl and the vehicle speed spd are in a substantially proportional relationship, so the running resistance Frl can be calculated from the actual vehicle speed Vreal.
Specifically, in this cruise calculation process, the target driving force Ftgt is calculated using the equation shown in FIG. Here, the first term on the right side is a feed-forward term based on FIG. 2B, and the second term on the right side is to maintain its stability when the vehicle is in an unstable traveling state such as traveling on a slope. The feedback term.

  The target driving force Ftgt calculated as described above is used as the driving force force-crs necessary for the vehicle during cruise control. In the present embodiment, the calculation unit that performs this cruise calculation process corresponds to the second target driving force calculation unit.

  Returning to FIG. 3, in this cruise control (the cruise control execution flag xcrs set in advance in the RAM is 1), the driving force force-crs is set as the target driving force force-cnt, and the target output calculation unit 62. Since the subsequent processing is the same as in the case of the normal control described above, the description thereof is omitted. That is, in cruise control, the driving force force-crs as a physical quantity calculated in the cruise calculation process is used as it is, and cooperative control of engine control and shift control is performed.

Further, during cruise control, since the driver does not normally depress the accelerator pedal, the accelerator opening accp detected by the accelerator opening sensor is zero. Therefore, here, the target driving force calculation unit 61 refers to the control map using the driving force force-crs calculated as described above, and calculates the virtual accelerator opening in reverse. In the figure, two control maps of the target driving force calculation unit 61 are shown, but these are the same. The virtual accelerator opening accp-crs calculated at this time is the accelerator opening accp-cnt as a control amount during cruise control (the cruise control execution flag xcrs set in advance in the RAM is 1). The output is output to the engine control unit 51 and the shift control unit 52. The engine control unit 51 and the shift control unit 52 control each control target using the accelerator opening degree accp-cnt as necessary.

  Thereby, good engine control and shift control in cruise control are executed, and the vehicle can be driven at a constant speed so as to maintain the set vehicle speed set by the cruise switch.

  Next, a specific process flow of the vehicle control process of the present embodiment will be described. FIG. 5 is a timing chart showing the control state of the vehicle by the vehicle control device. In the figure, the horizontal axis represents the passage of time, and the vertical axis represents the presence / absence of cruise control execution from the top, presence / absence of acceleration request in cruise control, presence / absence of deceleration request, accelerator opening, and vehicle speed, respectively. . Regarding the accelerator opening, the solid line represents the actual accelerator opening that is the actual accelerator opening based on the depression of the accelerator pedal, the alternate long and short dash line represents the virtual accelerator opening calculated by back calculation, and the dotted line represents the control amount. It represents the accelerator opening for control to be used. Further, regarding the vehicle speed, the solid line represents the target vehicle speed, and the dotted line represents the actual vehicle speed.

  As shown in the figure, in the normal control state, the vehicle is travel-controlled based on the accelerator opening corresponding to the depression amount of the accelerator pedal of the driver. That is, the vehicle is controlled such that the target driving force calculated based on the actual vehicle speed and the actual accelerator opening is realized.

  When the accelerator pedal is released by the driver and the cruise main switch is turned on at time t1, the cruise control state is entered. At this time, the vehicle is controlled so that the target driving force calculated based on the target vehicle speed and the actual vehicle speed is realized, and the actual vehicle speed follows the target vehicle speed.

  At time t2, when the acceleration request is made by the driver operating the cruise acceleration request switch and the target vehicle speed is changed, the vehicle achieves the target driving force calculated based on the changed target vehicle speed and the actual vehicle speed. The actual vehicle speed follows the target vehicle speed.

  Further, at time t3, when the deceleration request is made by the driver operating the cruise deceleration request switch and the target vehicle speed is changed, the vehicle realizes the target driving force calculated based on the changed target vehicle speed and actual vehicle speed. The actual vehicle speed follows the target vehicle speed.

  When the accelerator pedal is depressed in spite of cruise control, priority is given to the driver's intention to temporarily shift to normal control. That is, the vehicle is controlled such that the target driving force calculated based on the actual vehicle speed and the actual accelerator opening is realized. Therefore, during that period, the actual vehicle speed changes regardless of the target vehicle speed. This temporary normal control is canceled when the accelerator pedal is released.

  At time t4, when the cruise cancel switch is operated and the cruise control is released, the control shifts to the normal control, and the vehicle achieves the target driving force calculated based on the actual vehicle speed and the actual accelerator opening. To be controlled.

As described above, in the vehicle control device of the present embodiment, during cruise control, the driving force necessary for cruise control calculated by the cruise calculation unit is used as control as the target driving force. Further, during cruise control, the virtual accelerator opening obtained by back-calculating the accelerator opening with reference to the control map using the driving force calculated by the cruise calculation unit is used as the control accelerator opening. It is done.

  For this reason, the vehicle can be brought close to the control state targeted in the cruise control accurately and quickly, and the accelerator opening for control can be set appropriately even during the cruise control, and the response of the control can be improved. . Further, since the required driving force itself is used as the control amount, it is sufficient to set it once regardless of the type of vehicle. For this reason, while being able to implement | achieve simply, the versatility as a vehicle control apparatus increases.

  Although not mentioned in the specific example of the above-described embodiment, an upper limit speed is set in advance for safety in the vehicle, so that it is necessary not to exceed this even in the cruise control. FIG. 6 is an explanatory diagram showing a cruise control method provided with such an upper limit speed. In the figure, the horizontal axis represents the passage of time, and the vertical axis represents the actual vehicle speed and the target driving force from the top.

  As shown in the figure, when a vehicle speed increase request is made during constant speed driving by cruise control and the target vehicle speed exceeds a predetermined upper limit speed Vlimit, the target driving force force-cnt is set to a value equal to or higher than the upper limit speed. You may make it calculate by restrict | limiting so that a vehicle speed may not come out. Specifically, as indicated by a solid line in the figure, the target driving force force-cnt can be controlled so as to intermittently repeat the driving force flimit for satisfying the upper limit speed and zero. At that time, in order to keep the behavior of the vehicle stable, the accelerator opening may be held at a value corresponding to the driving force flimit as shown by a two-dot difference line in the figure.

  In the above embodiment, “accelerator opening rate (%)” is used as “accelerator opening”, but “accelerator opening value (raw value)” may be used.

It is a conceptual diagram of embodiment. It is a block diagram showing the structure of a vehicle control apparatus. It is a functional block diagram showing an example of the vehicle control process performed centering on the cruise control part of ECU. It is explanatory drawing showing the calculation method of the target driving force calculated at the time of cruise control. It is a timing chart showing the control state of the vehicle by a vehicle control device. It is explanatory drawing showing the method of the cruise control which provided the upper limit speed. It is explanatory drawing showing the example of the conventional vehicle control method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Target driving force calculation part 2 Control amount calculation part 3 Control means 4 2nd target driving force calculation part 11 Engine 15 Continuously variable transmission 18 Drive wheel 19 Electronic throttle 45 Hydraulic control apparatus 51 Engine control part 52 Shift control part 53 Cruise control Unit 61 Target driving force calculation unit 62 Target output calculation unit 63 Target control amount calculation unit

Claims (18)

A target driving force calculation unit that calculates a target driving force of the vehicle based on the vehicle speed and the accelerator opening, a control amount calculation unit that calculates a control amount for driving the vehicle based on the target driving force, and a vehicle A vehicle control device provided with a control means for switching to high speed driving or normal driving,
A second target driving force calculation unit that calculates a second target driving force that is a target driving force of the vehicle based on the target vehicle speed and the actual vehicle speed during the constant speed traveling;
The control amount calculation unit calculates the control amount based on the second target driving force during the constant speed traveling. The target driving force calculation unit calculates a virtual accelerator opening obtained by reversely calculating the accelerator opening using the second target driving force as the target driving force,
The vehicle control apparatus according to claim 1, wherein the control unit controls the vehicle using the virtual accelerator opening.   3. The vehicle control device according to claim 1, further comprising a continuously variable transmission as the transmission. The control amount calculation unit
A target output calculator for calculating a target output of the vehicle from the target driving force and the vehicle speed;
A target control amount calculation unit that calculates a target engine torque and a target engine speed so that an optimal fuel consumption condition is satisfied from the target output;
With
The control means includes
Perform engine control to achieve the target engine torque,
Calculating a target speed ratio based on the target engine speed and performing speed change control so as to realize the target speed ratio;
The vehicle control device according to claim 3.   The control means switches from the accelerator opening during the normal travel to the virtual accelerator opening during the constant speed travel, and the accelerator during the normal travel from the virtual accelerator opening during the constant speed travel. 4. The vehicle control device according to claim 3, wherein at least one of the switching to the opening is performed by predetermined change control.   The control means switches from the accelerator opening during the normal travel to the virtual accelerator opening during the constant speed travel, and switches the virtual accelerator opening during the constant speed travel to the accelerator during the normal travel. 6. The vehicle control device according to claim 5, wherein the control is performed more slowly than switching to the opening degree.   7. The vehicle control device according to claim 6, wherein the change-over control is changed more rapidly as a deviation between a target control amount after switching and an actual control amount at the time of switching is larger.   When the vehicle speed change request during the constant speed traveling is made, the control means changes the virtual accelerator opening that changes with the change in the second target driving force to the change in the second target driving force. 3. The vehicle control device according to claim 2, wherein the vehicle control device is used so as to follow the vehicle with a predetermined time constant.   9. The vehicle control device according to claim 8, wherein the time constant is set so as to decrease as the change in the second target driving force increases. When the accelerator opening is larger than the virtual accelerator opening by depressing the accelerator pedal during the constant speed running,
The vehicle control apparatus according to claim 2, wherein the control means uses the accelerator opening instead of the virtual accelerator opening. When the accelerator opening is larger than the virtual accelerator opening by depressing the accelerator pedal during the constant speed running,
The target driving force calculation unit calculates a second virtual accelerator opening obtained by adding the accelerator opening to the virtual accelerator opening;
The vehicle control apparatus according to claim 2, wherein the control unit controls the vehicle using a second virtual accelerator opening. When a request for increasing the vehicle speed is made during the constant speed travel and the target vehicle speed is equal to or higher than a predetermined upper limit speed,
The second target driving force calculation unit calculates the second target driving force by limiting the vehicle speed so as not to exceed the upper limit speed,
The vehicle control device according to claim 2, wherein the control means controls the vehicle using a third virtual accelerator opening that is set separately.   The third virtual accelerator opening is held at the accelerator opening calculated by the target driving force calculation unit back calculating the second target driving force corresponding to the upper limit speed as the target driving force. Item 13. The vehicle control device according to Item 12. When a predetermined throttle opening is required during the constant speed travel in order to realize another travel control having a higher priority than the constant speed travel,
The vehicle control apparatus according to claim 2, wherein the control means controls the vehicle using a fourth virtual accelerator opening calculated based on the requested throttle opening.   The control means performs switching from the virtual accelerator opening during the constant speed traveling to the fourth virtual accelerator opening during the other traveling control by predetermined change control. The vehicle control device described.   The vehicle control device according to claim 2, wherein the fully closed determination of the accelerator pedal during the constant speed traveling is performed based on the virtual accelerator opening. When a predetermined failure diagnosis is made for the vehicle during the constant speed running,
The vehicle control apparatus according to claim 2, wherein the control means uses the accelerator opening instead of the virtual accelerator opening. A vehicle that calculates a target driving force of a vehicle based on a vehicle speed and an accelerator opening, calculates a control amount for driving the vehicle based on the target driving force, and controls the vehicle by switching to constant speed driving or normal driving A control method,
During the constant speed running, a second target driving force that is a target driving force of the vehicle is calculated based on a target vehicle speed and an actual vehicle speed, and the control amount is calculated based on the second target driving force. A vehicle control method.

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