JP2018127020A - Vehicle control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an interval between a first gear shift and a second gear shift so as to improve gear shift responsiveness when a continuous gear shift in which the first gear shift and the second gear shift are successive is performed.SOLUTION: A vehicle control unit can perform a continuous gear shift, in which a first gear shift by a first gear shift instruction that instructs a predetermined target gear ratio and target engine rpm is performed continuously before a second gear shift by a second gear shift instruction in which the target gear ratio is larger than the first gear shift instruction. In the case where the continuous gear shift is performed, when the engine rpm reaches in the first gear shift the target engine rpm in the first gear shift instruction, fuel supply is stopped to perform a fuel cut while maintaining an intake amount of air. When the second gear shift is started, the fuel supply is started, the fuel cut is cancelled, and blipping control that increases the engine rpm at the time of downshifting is performed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle control device that executes shift control of a vehicle equipped with an automatic transmission and controls driving force.

  Patent Document 1 describes a vehicle control device that aims to reduce shift shocks by blipping control during downshifting and to improve shift response in multiple shifts (continuous shifts). The control device described in Patent Document 1 performs so-called blipping control. The blipping control is a control for increasing the engine speed toward the synchronous speed after the shift at the time of downshift, thereby reducing the engagement shock of the friction engagement elements such as the clutch and the brake in the shift operation. To do. In the middle of the shift to the target shift stage of the first shift, when performing a continuous shift that requires a shift to the target shift stage of the second shift, it is engaged when the target shift stage of the first shift is established. In addition, until the clutch that is released when the target gear position of the first shift is established is fully released, the rotational speed is set to the highest possible value within a range in which the turbine rotational speed does not reach the synchronous rotational speed of the target gear stage of the first shift. Adjust the intake air amount of the engine so that

  Patent Document 2 describes a control device for an internal combustion engine for the purpose of securing a negative pressure necessary to obtain an operating force of a brake booster during vehicle deceleration. The control device described in Patent Literature 2 selectively switches between vehicle stabilization control and blipping control according to the negative pressure of the brake booster during vehicle deceleration. In the vehicle stabilization control, the engine output is increased by opening one throttle valve. In the blipping control, the engine output is increased by opening one or two throttle valves according to the negative pressure of the brake booster.

  Patent Document 3 discloses a driving force control device for a vehicle that is intended to reaccelerate at an appropriate shift stage that reflects the driver's intention and driving orientation when the vehicle reaccelerates after decelerating. Is described. The control device described in Patent Document 3 stores acceleration characteristics that define the relationship between the acceleration at the time of reacceleration and the vehicle speed as a control index when the vehicle travels at a reduced speed after the vehicle has traveled at a reduced speed. A reacceleration acceleration (target acceleration) corresponding to the current vehicle speed is obtained based on the travel data and acceleration characteristics of the vehicle before traveling. Then, before starting the reacceleration running, a shift stage capable of realizing the obtained acceleration at the time of reacceleration is set, and a downshift is executed.

JP 2011-247227 A JP 2011-26975 A JP 2006-173177 A

  As described above, the control device described in Patent Document 1 reduces the time required for synchronization after the first shift while reducing the engagement shock of the friction engagement element during the downshift of the continuous shift. In addition, it is possible to improve the shift response in the continuous shift. On the other hand, in the control device described in Patent Document 1, blipping control is performed in both the first shift and the second shift in the continuous shift. When the synchronization is once completed at the first shift and the friction engagement element is operated, it is increased in order to increase the engine speed in the first blipping control in order to reduce the engagement shock at that time. The engine torque that has been once reduced. That is, the throttle valve is closed, and both the fuel supply amount and the intake air amount to the engine are reduced. Therefore, when shifting from the first shift to the second shift and performing the second blipping control for the second shift, the throttle valve is opened to increase the fuel supply amount and the intake air amount, and the engine torque I have to wait for you to get up. In particular, it is necessary to wait for the intake air amount to rise with low response. Therefore, in the case of continuous gear shifting, although the gear shifting time of the first gear shifting and the second gear shifting can be shortened by shortening the time required for synchronizing the rotation speed, the response of the intake air amount as described above Due to the delay, the time interval between the first shift and the second shift cannot be shortened. Therefore, the conventional control as described in Patent Document 1 may not be able to effectively improve the shift response in a continuous shift.

  The present invention has been conceived by paying attention to the above technical problem, and during the initial downshift (first shift), the second downshift (second shift) in which the speed ratio of the shift destination is larger. ) Is required, and when the continuous shift in which the first shift and the second shift are continuous is performed, the entire continuous shift is particularly reduced by shortening the time interval between the first shift and the second shift. It is an object of the present invention to provide a vehicle control device that can shorten the shift time and improve the shift response of a continuous shift.

  In order to achieve the above object, the present invention includes an engine, drive wheels, an automatic transmission that transmits torque between the engine and drive wheels, a fuel supply amount and an intake air amount for the engine, and the A controller for controlling a gear ratio of the automatic transmission, wherein the controller changes the gear ratio according to a gear shift instruction that instructs a target gear ratio and a target engine speed for the automatic transmission. A fuel cut that stops fuel supply to the engine while the vehicle is running; a blipping control that increases the engine speed of the engine during a downshift in the automatic transmission; and the predetermined target gear ratio and the target After the first shift according to the first shift instruction for instructing the engine speed, the target gear ratio becomes the first A continuous shift that continuously executes a second shift according to a second shift instruction that is larger than a speed instruction can be executed. When the continuous shift is executed, the engine speed is set to the first shift in the first shift. When the target engine speed in the instruction is reached, the fuel supply is stopped while the intake air amount is maintained, the fuel cut is executed, and the fuel supply is started when the second shift is started. Then, the fuel cut is terminated and the blipping control is executed.

  In the vehicle control device of the present invention, when shifting from the first shift to the second shift in the continuous shift, the engine torque is reduced by the fuel cut in order to reduce the shift shock when the first shift is completed. However, during the fuel cut, the fuel supply to the engine is stopped, but the intake air amount of the engine is maintained without being reduced, for example, by maintaining the opening of the throttle valve. Thereafter, the engine torque is increased by blipping control in order to reduce the engagement shock when the second shift is executed. In this case, since the intake air amount of the engine is maintained, the engine torque can be increased quickly only by starting the fuel supply without waiting for the rise of the intake air amount. Can be raised promptly. Therefore, the second shift can be started immediately after the first shift. Therefore, according to the vehicle control apparatus of the present invention, the time interval between the first shift and the second shift in the continuous shift can be shortened. As a result, the shift time in the continuous shift can be shortened, and the shift response of the vehicle can be improved.

It is a figure which shows an example of the structure of the vehicle used as the object of control by this invention, and a control system. It is a flowchart for demonstrating an example of the control performed by the control apparatus of the vehicle in this invention. FIG. 3 is a time chart for explaining behaviors such as throttle valve opening, engine torque, and engine speed when a single shift downshift is executed in the shift control shown in the flowchart of FIG. 2. FIG. 6 is a time chart for explaining behaviors such as throttle valve opening, engine torque, engine speed, and the like when a downshift of a continuous shift is executed by conventional shift control. FIG. 3 is a time chart for explaining behaviors such as throttle valve opening, engine torque, and engine speed when a downshift of a continuous shift is executed by the shift control shown in the flowchart of FIG. 2. FIG.

  Next, an embodiment of the present invention will be described with reference to the drawings. A vehicle to which the present invention can be applied is a vehicle equipped with an automatic transmission capable of shifting the power output from an engine and transmitting it to drive wheels. The automatic transmission according to the present invention may be a continuously variable transmission capable of continuously changing a gear ratio, such as a belt type continuously variable transmission or a toroidal continuously variable transmission. The present invention can also be applied to a hybrid vehicle provided with a power split mechanism that combines and splits the power output from the engine and the motor. That is, since the power split mechanism in such a hybrid vehicle functions as a so-called electric continuously variable transmission mechanism, such an electric continuously variable transmission mechanism can also be included in the automatic transmission of the present invention.

  As an example of a vehicle to which the present invention can be applied, FIG. 1 shows the configuration and control system of a vehicle in which an automatic transmission is mounted on the output side of an engine. A vehicle Ve shown in FIG. 1 has a front wheel 1 and a rear wheel 2. In the example shown in FIG. 1, a vehicle Ve is a rear wheel that generates driving force by transmitting power output from an engine (ENG) 3 to a rear wheel 2 via an automatic transmission (AT) 4 and a differential gear 5. It is configured as a driving car. The vehicle Ve to which the present invention can be applied may be a front-wheel drive vehicle that generates power by transmitting the power output from the engine 3 to the front wheels 2. Alternatively, it may be a four-wheel drive vehicle that generates driving force by transmitting power output from the engine 3 to the front wheels 1 and the rear wheels 2, respectively.

  The engine 3 includes, for example, an electronically controlled throttle valve or an electronically controlled fuel injection device, and an airflow sensor (or an airflow meter) that detects the flow rate of intake air. In the example shown in FIG. 1, an electronic throttle valve 6, an air flow sensor 7, and a fuel injection device 8 are provided. Therefore, for example, the output of the engine 3 can be automatically controlled by electrically controlling the operation of the electronic throttle valve 6 based on detection data of an accelerator position sensor 10 described later.

  An automatic transmission 4 for shifting the output torque of the engine 3 and transmitting it to the drive wheel side is provided on the output side of the engine 3. In the example shown in FIG. 1, the automatic transmission 4 is a conventional general stepped automatic transmission that includes, for example, a planetary gear mechanism (not shown) and a clutch / brake mechanism (not shown). In other words, by controlling the operation of the clutch mechanism and the brake mechanism, the gear position (or gear ratio) set by the automatic transmission 4 can be automatically controlled.

  A controller (ECU) 9 for controlling the output of the engine 3 and the shift operation of the automatic transmission 4 is provided. The controller 9 is an electronic control device mainly composed of a microcomputer, for example. The engine 3 is connected to the controller 9 so that communication for control is possible. The automatic transmission 4 is connected to the controller 9 via a hydraulic control device (not shown) so that communication for control is possible. Although FIG. 1 shows an example in which one controller 9 is provided, a plurality of controllers 9 may be provided for each device or device to be controlled, or for each control content.

  The controller 9 is configured to receive detection signals from various sensors in each part of the vehicle Ve, information signals from various in-vehicle devices, and the like. For example, the air flow sensor 7 described above, an accelerator position sensor 10 that detects an accelerator opening (specifically, an operation amount and an operation speed of an accelerator device such as an accelerator pedal), a brake sensor that detects a depression amount of a brake pedal (or Brake switch) 11, an engine speed sensor 12 for detecting the speed of the output shaft 3a of the engine 3, an output speed sensor 13 for detecting the speed of the output shaft 4a of the automatic transmission 4, and each wheel 1, A detection signal from a vehicle speed sensor 14 or the like that obtains the vehicle speed by detecting each of the rotational speeds 2 is input to the controller 9. And it is comprised so that it may calculate using the input data, the data memorize | stored previously, etc., and a control command signal may be output based on the calculation result. For example, the controller 9 controls the fuel supply amount and the intake air amount to the engine by outputting a control command signal. Further, the gear ratio of the automatic transmission 4 is controlled.

  In the vehicle Ve configured as described above, as described above, when the vehicle Ve re-accelerates after traveling at a reduced speed, a downshift may be performed when the driver depresses the accelerator pedal. If the downshift performed at the time of deceleration traveling is not appropriate, the driving force is insufficient at the time of reacceleration traveling, and when the reacceleration traveling is started, the gearshift is further lowered (the gear ratio is increased). Become. As a result, the driver may feel uncomfortable or feel that the acceleration feeling is not good. In addition, the driver's intention and driving intention also vary depending on the individual difference of the driver and the driving environment. On the other hand, if the downshift at the time of deceleration traveling as described above is performed uniformly, there is a possibility that the driving force and acceleration intended by the driver cannot be obtained when reacceleration traveling is started.

  Therefore, the controller 9 is configured to appropriately re-accelerate the vehicle Ve by executing the driving force control of the vehicle Ve while reflecting the driver's intention and driving intention in the control. Specifically, the controller 9 obtains “acceleration at the time of reacceleration” as a control index when the vehicle Ve decelerates and travels again after decelerating. The speed ratio of the automatic transmission 4 capable of realizing “acceleration” is set. The “acceleration at the time of reacceleration” serves as a control index at the time of reacceleration running after decelerating, and is an estimate of the acceleration desired by the driver or the acceleration expected by the driver during the reacceleration running. This “acceleration during re-acceleration” is obtained based on acceleration characteristics and travel data of the vehicle Ve. The acceleration characteristic defines the relationship between the “acceleration during reacceleration” and the vehicle speed, and is stored in advance in the form of, for example, an arithmetic expression or a map. The traveling data of the vehicle Ve is a physical quantity representing the traveling state of the vehicle Ve, such as the vehicle speed, acceleration, the gear ratio of the automatic transmission 4, or the engine speed, and is extracted from the traveling history before the current deceleration traveling. The For example, if the controller 9 clears the travel data when the ignition switch (not shown) or the main switch (not shown) is turned off, the travel history before the current deceleration travel is, for example, This is a history of travel data acquired from the time when the ignition switch of the vehicle Ve is finally turned ON for the current travel and the control described below in FIG. 2 is first started to the present. .

  More specific control contents executed by the controller 9 are shown in the flowchart of FIG. In the flowchart of FIG. 2, first, it is determined whether or not the acceleration traveling of the vehicle Ve has ended (step S1). For example, it is possible to determine whether or not the acceleration traveling has ended based on the detection value of the vehicle speed sensor 14 or the longitudinal acceleration sensor (not shown). In step S1, it is determined that “the acceleration of the vehicle Ve has ended” when the acceleration of the vehicle Ve becomes zero after it has been determined that the vehicle Ve has been accelerated. Or it is a case where it shifts to the deceleration driving | running | working from which the acceleration of the vehicle Ve becomes 0 or less. Alternatively, this is the case when the brake switch 11 is turned on. Accordingly, in all other cases, a negative determination is made in this step S1. For example, after the start of this control, the vehicle Ve has not been accelerated yet, the vehicle Ve is decelerating, the vehicle Ve is accelerated, or the vehicle Ve is steady. If there is, a negative determination is made in step S1.

  In addition, when the acceleration traveling of the vehicle Ve is finished as described above, the fuel cut is executed by satisfying a predetermined execution condition. The fuel cut is a control for forcibly stopping the fuel supply to the engine 3 and improving the fuel consumption, and is a control generally performed conventionally. For example, when the accelerator is returned during traveling, that is, when the amount of operation of the accelerator becomes zero, the fuel cut is performed under predetermined conditions such as an engine speed equal to or higher than an idling speed and a predetermined vehicle speed or higher. Executed. In the embodiment of the present invention, the fuel cut is executed in parallel with the control after step S2 or step S4 when, for example, affirmative determination is made in step S1 and a predetermined execution condition is satisfied. The Alternatively, it is executed when a predetermined execution condition is satisfied based on another flowchart (not shown) for determining whether or not fuel cut is necessary. Specifically, the fuel cut is executed by stopping the fuel supply to the engine 3 by the fuel injection device 8 and closing the electronic throttle valve 6. Further, for example, as will be described later, fuel cut can be executed by stopping the fuel supply by the fuel injection device 8 with the electronic throttle valve 6 opened.

  If an affirmative determination is made in step S1 because the acceleration traveling of the vehicle Ve has ended, the process proceeds to step S2. In step S2, the expected vehicle speed Vexp and the gradient coefficient K are calculated and updated. Specifically, travel data of the vehicle Ve (for example, vehicle speed at the start of acceleration, maximum acceleration during acceleration travel, etc.) stored during acceleration travel determined to be finished in step S1 is read, and the travel data is stored in the travel data. Based on this, the expected vehicle speed Vexp and the gradient coefficient K are updated. When the driver operates the vehicle Ve, it can be assumed that the driver is always driving aiming at a predetermined vehicle speed. In the control by the controller 9, the vehicle speed targeted by the driver as described above or the vehicle speed estimated to be desired by the driver is defined as "expected vehicle speed". For example, under the same driving environment, the “expected vehicle speed” increases if the driving orientation of the driver becomes a driving orientation (sport driving orientation) that emphasizes power performance and exercise performance than usual. On the other hand, if the driver's driving orientation is a driving orientation that emphasizes fuel efficiency and efficiency more than usual (fuel consumption driving orientation), the “expected vehicle speed” decreases. The expected vehicle speed Vexp can be obtained based on the travel history of the vehicle Ve in which data such as the vehicle speed, longitudinal acceleration, lateral acceleration, steering angle, road surface gradient, and vehicle attitude are recorded. The slope coefficient K represents the slope of the correlation line used when obtaining the “expected vehicle speed”. Note that the applicant of the present application in Japanese Patent Application No. 2015-190815 (the above-mentioned Patent Document 3) uses the expected vehicle speed Vexp and the gradient coefficient K described above, and can perform reacceleration running with an appropriate driving force. A force control device is proposed. Therefore, the details of the driving force control using the expected vehicle speed Vexp and the gradient coefficient K are detailed in the above-mentioned Patent Document 3, and therefore, detailed description thereof will be omitted here and an outline of the control will be described.

  On the other hand, if a negative determination is made in step S1, the process proceeds to step S3. In step S3, the previous values of the expected vehicle speed Vexp and the gradient coefficient K are held. That is, the expected vehicle speed Vexp and the gradient coefficient K that are calculated and stored when the previous acceleration travel ends are held until the current acceleration travel ends. Note that if acceleration traveling has not yet been performed since the start of this control, for example, the expected vehicle speed Vexp and the gradient coefficient K stored when the ignition switch is turned on and this control is first started are stored. Will continue to be retained. In the configuration in which the expected vehicle speed Vexp and the gradient coefficient K are cleared when the ignition switch is turned off, the preset initial values are read when the ignition switch is turned on, and the expected vehicle speed Vexp and the gradient are read. Stored as coefficient K. Therefore, when acceleration traveling has not yet been performed since the start of this control as described above, the initial values of the expected vehicle speed Vexp and the gradient coefficient K are held. In the configuration in which the expected vehicle speed Vexp and the gradient coefficient K at that time are stored when the ignition switch is turned OFF, as described above, when acceleration traveling has not yet been performed, The expected vehicle speed Vexp and the gradient coefficient K stored when the ignition switch is turned off are read and held continuously.

  When the expected vehicle speed Vexp and the gradient coefficient K are updated in the above step S2, or when the previous values of the expected vehicle speed Vexp and the gradient coefficient K are held in the above step S3, the process proceeds to step S4. In step S4, a reacceleration acceleration Gexp is obtained. When the vehicle Ve decelerates without stopping, the vehicle Ve shifts to a state in which the vehicle Ve re-accelerates after finishing the decelerating travel. For example, when the vehicle Ve turns in a corner, the vehicle Ve generally enters the corner while decelerating from the front of the corner. In corners, decelerate or turn at a constant speed. And, when escaping from the corner, it re-accelerates. Thus, when the vehicle Ve travels again after decelerating, it can be assumed that the driver accelerates the vehicle Ve toward the expected vehicle speed Vexp. Therefore, if the vehicle speed difference ΔV (ΔV = Vexp−Vcur) between the expected vehicle speed Vexp and the current vehicle speed Vcur is large, the driver requests a large acceleration to reduce the vehicle speed difference ΔV and re-accelerates the vehicle Ve. I can guess it.

  Based on the above assumption, in this step S4, the acceleration Gexp at the time of reacceleration is obtained as the acceleration expected by the driver during the reacceleration running from the vehicle speed difference ΔV between the expected vehicle speed Vexp and the current vehicle speed Vcur. For example, it is known from the results of running experiments and simulations that there is a negative correlation between the “acceleration during reacceleration” and the vehicle speed as described above. In the embodiment of the present invention, the correlation between the “acceleration during reacceleration” and the vehicle speed as described above can be expressed by a “correlation line (approximate line)” of a linear function. Also, such a correlation line can be obtained for each driving orientation of the driver. The “correlation line (approximate line)” representing the correlation between the “acceleration during reacceleration” and the vehicle speed may be a curve. For example, the “correlation line (approximate line)” can be obtained as an approximate curve of past travel data.

  As described above, the “expected vehicle speed” is defined as the vehicle speed targeted by the driver during acceleration traveling. Therefore, when the vehicle speed reaches this “expected vehicle speed”, it is unnecessary to further accelerate the vehicle Ve, and as a result, it can be estimated that the acceleration becomes zero. Therefore, the “expected vehicle speed” can be obtained by calculating the vehicle speed at which the acceleration is zero in the correlation line of the linear function as described above.

  Using the correlation between the “acceleration at the time of reacceleration” and the vehicle speed as described above, the relationship between the “acceleration at the time of reacceleration” and the vehicle speed is determined in advance as the acceleration characteristic of the vehicle Ve and stored in the controller 9. I can leave. By determining such acceleration characteristics as a function of vehicle speed, it is possible to calculate “acceleration during reacceleration” corresponding to the “expected vehicle speed” and “current vehicle speed” as described above.

  As described above, when the reacceleration acceleration Gexp is obtained in step S4, the gear position of the automatic transmission 4 capable of realizing the reacceleration acceleration Gexp is obtained (step S5). In other words, an optimum gear stage set by the automatic transmission 4 is required in order for the vehicle Ve to accelerate with the acceleration Gexp during reacceleration.

  When the gear position (speed ratio) of the automatic transmission 4 capable of realizing the reacceleration acceleration Gexp is calculated in step S5, it is determined whether or not the vehicle Ve is traveling at a reduced speed (step S6). For example, it can be determined whether or not the vehicle Ve is traveling at a reduced speed based on the detection value of the vehicle speed sensor 14 or the longitudinal acceleration sensor (not shown), the operation signal of the brake switch 11, and the like. If the vehicle Ve is not traveling at a reduced speed, and if a negative determination is made in step S6, the routine is temporarily terminated without executing the subsequent control. On the other hand, when the vehicle Ve is traveling at a reduced speed, if the determination in step S6 is affirmative, the process proceeds to step S7.

  In step S7, whether or not the gear stage currently set in the automatic transmission 4 is higher than the gear stage calculated in step S5, that is, the gear ratio of the current gear stage is calculated. It is determined whether or not the transmission gear ratio is smaller than the transmission gear ratio. If the current shift speed is lower than the calculated shift speed, and if a negative determination is made in step S7, this routine is temporarily terminated without executing the subsequent control. On the other hand, if the current shift speed is higher than the calculated shift speed, and if a positive determination is made in step S7, the process proceeds to step S8.

  In step S8, it is determined whether or not a fuel cut (F / C) is being executed. As described above, the fuel cut is executed when a predetermined condition is satisfied when the accelerator is returned while the vehicle Ve is traveling. If a positive determination is made in step S8 because the fuel cut is being executed, the process proceeds to step S9.

  In step S9, it is determined whether or not the previous shift control is being executed. Specifically, it is determined whether or not a downshift instructed to shift before the currently executing routine is still being executed. If a downshift due to the previous shift instruction has not been executed and if a negative determination is made in step S9, the process proceeds to step S10. If it is determined negative in step S8 because the fuel cut is not being executed, the process similarly proceeds to step S10.

  In step S10, the automatic transmission 4 performs a downshift. That is, a shift instruction for downshifting toward the shift stage calculated in step S5 is output, and the automatic transmission 4 performs a so-called “single shift” downshift.

  In this case, the shift is a normal shift in which the current shift operation and a new shift instruction do not overlap, and two shifts with different shift speeds do not continue. Such a shift is defined as “single shift” in the embodiment of the present invention. Such a normal single shift state is shown in the time chart of FIG. In the time chart of FIG. 3, when the fuel cut is executed before the gear shift and the gear shift instruction is output at the time t11 and the gear shift is started, the electronic throttle valve 6 is opened at a predetermined opening degree. Is done. At this time, the fuel cut is still continued, and the fuel supply to the engine 3 is stopped. Therefore, at time t11, the opening of the electronic throttle valve 6 increases while the fuel injection device 8 stops supplying fuel to the engine 3, and as a result, only the intake air amount of the engine 3 increases. . This is a preliminary control that is executed in a preliminary manner in order to implement so-called blipping control. The blipping control is a control for shortening the time required for synchronization by increasing the engine speed at the time of downshift, that is, for shortening the time required for shifting.

  By executing the preliminary control for the blipping control as described above, the engine 3 does not yet output the engine torque, but is in a state where the engine torque can be output as shown by a one-dot chain line in FIG. Thereafter, when the fuel cut is released and fuel supply to the engine 3 is resumed at time t12, the engine torque increases rapidly due to the effect of the preliminary control for the blipping control as described above. Accordingly, the engine speed starts to increase toward the target engine speed after the shift. That is, blipping control is performed.

  When the engine speed reaches the target engine speed after the shift at time t13 and synchronizes, the engagement / release operation of the clutch mechanism and the brake mechanism in the automatic transmission 4 is completed, and the shift is completed. At the same time t13, fuel cut is instructed at the same time, fuel supply is stopped by the fuel injection device 8, and the electronic throttle valve 6 is closed to a state where the opening degree is 0 (that is, fully closed). The As a result, the engine torque decreases. In this case, the engine 3 is in a state of generating running resistance (that is, outputting braking torque), and so-called engine braking is applied to the vehicle Ve.

  By the blipping control as described above, the engine speed can be quickly increased to the target engine speed after the shift, and the time required for the shift can be shortened. Further, by instructing fuel cut at the synchronous timing of the rotation speed and stopping the fuel supply to the engine 3, the engine torque can be reduced and the engagement shock at the time of shifting can be suppressed.

  As described above, when a single shift downshift is performed in step S10, this routine is once ended.

  On the other hand, if the previous shift control is being executed, that is, if the downshift instructed to be shifted before the currently executed routine is still being executed, the determination in the above step S9 is affirmative. In step S11, the process proceeds to step S11.

  In step S11, when the previous shift is completed, the next shift control (instructed to shift this time) is started without closing the electronic throttle valve 6. In step S10, the automatic transmission 4 performs a so-called “continuous shift” downshift.

  In this case, the current shift operation and a new shift instruction overlap, and two shifts with different shift speeds are consecutive. That is, after the first shift by the first shift instruction for instructing the predetermined target gear ratio and the target engine speed, the second shift by the second shift instruction having a target gear ratio larger than the first shift instruction is continuously executed. To shift. Such a shift is defined as “continuous shift” in the embodiment of the present invention. Such a state of continuous shift is shown in the time charts of FIGS. The time chart of FIG. 4 shows an example in which a continuous shift is performed by conventional shift control to which the shift control according to the embodiment of the present invention is not applied. Further, the time chart of FIG. 5 shows an example in the case where a continuous shift is performed by the shift control in the embodiment of the present invention.

  In the conventional shift control, when the above-described continuous shift is performed, the single shift as shown in the time chart of FIG. 3 is repeated twice. That is, as shown in the time chart of FIG. 4, the first downshift from the fifth speed (5th) to the fourth speed (4th) at time t21 in a state where the fuel cut is executed before the shift ( That is, a shift instruction for the first shift (that is, the first shift instruction) is output and the shift is started. In this case as well, the electronic throttle valve 6 is opened at a predetermined opening while fuel supply to the engine 3 is stopped by the fuel injection device 8 as in the case of single shift. That is, preliminary control for blipping control is executed. As a result, the engine 3 is in a state capable of outputting engine torque as indicated by a one-dot chain line in FIG. Thereafter, at time t22, when the fuel cut is released and the fuel supply to the engine 3 is resumed, the engine torque is quickly increased by the effect of the preliminary control for the blipping control, and the engine speed is the fourth speed. Starts rising toward the target engine speed. That is, actual blipping control is performed.

  At time t23, a second downshift from the fourth speed (4th) to the third speed (3rd) (that is, the second shift) is output, so that the second shift instruction is output continuously. A shift state is entered. In that case, the electronic throttle valve 6 is kept open at a predetermined opening. Further, since the fuel cut is cancelled, the fuel supply to the engine 3 is continued. Therefore, the engine speed continues to increase toward the target engine speed of the fourth speed. At time t24, the engine speed reaches the fourth target engine speed and synchronizes. Further, in order to reduce the engagement shock when the fourth speed is formed, the fuel cut is instructed at the synchronous timing of the rotational speed, and the fuel supply to the engine 3 is stopped. Further, the electronic throttle valve 6 is operated to be closed in a state where the opening degree is 0 (that is, fully closed). As a result, the engine torque decreases, and the vehicle Ve enters a state where the engine brake is applied.

  At time t23, since the shift instruction for continuous shift to the third speed (3rd) is output, at time t25, the downshift (fourth speed) from the fourth speed (4th) to the third speed (3rd) is performed. When the second shift) is started, the electronic throttle valve 6 is opened at a predetermined opening while fuel supply to the engine 3 is stopped by the fuel injection device 8. That is, the preliminary control for blipping control is resumed. Thereafter, at time t26, when the fuel cut is canceled and the fuel supply to the engine 3 is resumed, the engine torque increases rapidly due to the effect of the preliminary control for the blipping control. Along with this, the engine speed starts to increase toward the target engine speed of the third speed. That is, actual blipping control is performed.

  At time t27, the engine speed reaches the third target engine speed and synchronizes. Further, in order to reduce the engagement shock when the third speed is formed, the fuel cut is instructed at the synchronous timing of the rotational speed, the fuel injection to the engine 3 is stopped by the fuel injection device 8, and the electronic The throttle valve 6 is closed so that the opening degree is 0 (that is, fully closed). As a result, the engine torque decreases, and the vehicle Ve enters a state where the engine brake is applied. In this state, the continuous shift from the fifth speed to the fourth speed and the third speed is completed.

  As described above, when the continuous shift is performed by the conventional shift control, the single shift is simply repeated twice. Therefore, in the conventional shift control, it takes about twice as long as the shift time in the single shift from the start of the shift in the continuous shift to the completion of the shift.

  On the other hand, in the shift control according to the embodiment of the present invention, when performing the above-described continuous shift, in order to shorten the shift time in the continuous shift, the interval between the first shift and the second shift in the continuous shift is set. During this period, the electronic throttle valve 6 is kept open. Accordingly, it is not necessary to wait for the intake air amount to rise at the start of the second shift in the continuous shift, and the start timing of the second shift in the continuous shift can be advanced compared to the conventional shift control.

  Specifically, in the shift control according to the embodiment of the present invention, as shown in the time chart of FIG. 5, the fuel cut is executed before the shift, and the fifth speed (5th) is changed from the fifth speed (5th) at time t31. A shift instruction (that is, a first shift instruction) for the first downshift (that is, a first shift instruction) to the fourth speed (4th) is output and a shift is started. In this case as well, the electronic throttle valve 6 is opened at a predetermined opening while fuel supply to the engine 3 is stopped by the fuel injection device 8 as in the case of single shift. That is, preliminary control for blipping control is executed. As a result, the engine 3 is in a state capable of outputting engine torque as indicated by a one-dot chain line in FIG. Thereafter, at time t32, when the fuel cut is released and the fuel supply to the engine 3 is resumed, the engine torque rapidly increases due to the effect of the preliminary control for the blipping control, and the engine speed is the fourth speed. Starts rising toward the target engine speed. That is, actual blipping control is performed.

  At time t33, the second downshift from the fourth speed (4th) to the third speed (3rd) (that is, the second shift) is output as a shift instruction (that is, the second shift instruction). A shift state is entered. In that case, the electronic throttle valve 6 is kept open at a predetermined opening. Further, since the fuel cut is cancelled, the fuel supply to the engine 3 is continued. Therefore, the engine speed continues to increase toward the target engine speed of the fourth speed. As described above, the control executed between time t31 and time t33 in the time chart of FIG. 5 corresponds to time t21 to time t23 in the time chart of FIG. 4, and the time chart of FIG. The control content is the same as that of the conventional shift control shown in FIG.

  At time t34, when the engine speed reaches the fourth target engine speed and synchronizes, in order to reduce the engagement shock when the fourth speed is formed, Fuel cut is instructed. As a result, the engine torque decreases, and the vehicle Ve enters a state where the engine brake is applied. In addition, in the shift control according to the embodiment of the present invention, at this time t34, the electronic throttle valve 6 is opened at a predetermined opening by being opened at time t31 without being closed. Is maintained. Therefore, in this case, the fuel supply to the engine 3 is stopped by instructing the fuel cut. At the same time, the state in which the electronic throttle valve 6 is kept open is maintained, so that only a predetermined amount of air is supplied to the engine 3. As a result, the engine 3 can output an engine torque as indicated by a one-dot chain line in a period from time t34 to time t36 described later in FIG. In other words, the engine 3 resumes the fuel supply, and thus can quickly output the engine torque without waiting for the intake air to rise, that is, with good responsiveness.

  At the time t33, a shift instruction for continuous shift to the third speed (3rd) is output, so that at time t35, a downshift (fourth speed) from the fourth speed (4th) to the third speed (3rd) is performed. 2 shift) is started. The start timing of the second shift (time t35) is set to a time sufficient for the engine torque to be reduced and the fourth speed to be stably formed at time t34 in order to reduce the engagement shock. . For example, the standby time after time t34 is set based on the results of a running experiment or simulation. Then, at time t36, when the fuel cut is released and the fuel supply to the engine 3 is started, the electronic throttle valve 6 is maintained open as described above, so that the intake air rises. Without increasing, the engine torque increases rapidly. Along with this, the engine speed starts to rise rapidly toward the target engine speed of the third speed. That is, actual blipping control is performed.

  Thereafter, at time t37, the engine speed reaches the third target engine speed and synchronizes. Further, in order to reduce the engagement shock when the third speed is formed, the fuel cut is instructed at the synchronous timing of the rotational speed, the fuel injection to the engine 3 is stopped by the fuel injection device 8, and the electronic The throttle valve 6 is closed so that the opening degree is 0 (that is, fully closed). As a result, the engine torque decreases, and the vehicle Ve enters a state where the engine brake is applied. In this state, the continuous shift from the fifth speed to the fourth speed and the third speed is completed.

  As described above, when continuous downshifting is performed in step S11 and step S10, this routine is once ended.

  As described above, when the continuous shift is performed by the shift control according to the embodiment of the present invention, the continuous shift is performed in comparison with the conventional shift control performed by the conventional shift control shown in the time chart of FIG. The time interval between the first shift and the second shift is shortened. As a result, the shift time in the downshift of the continuous shift can be shortened and the shift response of the vehicle Ve can be improved.

  Further, in the flowchart of FIG. 2 described above, even when the above-described continuous shift is performed in the driving force control using the expected vehicle speed Vexp and the gradient coefficient K as shown in steps S1 to S7, the shift is performed. Since the shift response is improved by shortening the time, the automatic transmission 4 reliably sets an appropriate gear ratio (speed) for obtaining the driving force intended by the driver or expected by the driver. can do. Therefore, for example, when the vehicle Ve is turning at a corner, the vehicle Ve can be downshifted sufficiently and appropriately before the corner, and smooth turning and reacceleration can be performed.

  DESCRIPTION OF SYMBOLS 1 ... Front wheel, 2 ... Rear wheel (drive wheel), 3 ... Engine, 4 ... Automatic transmission, 6 ... Electronic throttle valve, 7 ... Air flow sensor (air flow meter), 8 ... Fuel injection device, 9 ... Controller (ECU) ), 10 Accelerator position sensor, 11 Brake sensor (brake switch), 12 Engine speed sensor, 13 Output speed sensor, 14 Vehicle speed sensor, Ve Vehicle.

Claims (1)

An engine, a drive wheel, an automatic transmission that transmits torque between the engine and the drive wheel, and a controller that controls a fuel supply amount and intake air amount to the engine and a gear ratio of the automatic transmission. A control device for a vehicle that changes the speed ratio by a speed change instruction that specifies a target speed ratio and a target engine speed for the automatic transmission;
The controller is
A fuel cut that stops fuel supply to the engine while the vehicle is running; a blipping control that increases the engine speed of the engine during a downshift in the automatic transmission; and the predetermined target gear ratio and the After the first shift according to the first shift instruction for instructing the target engine speed, a continuous shift for continuously executing the second shift according to the second shift instruction in which the target gear ratio is larger than the first shift instruction is executed. Is possible,
When the continuous shift is executed, the fuel supply is stopped while maintaining the intake air amount when the engine speed reaches the target engine speed in the first shift instruction in the first shift. When the fuel cut is executed and the second shift is started, the fuel supply is started to end the fuel cut and the blipping control is executed.

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