JP2008081118A - Apparatus and method for controlling automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch a control amount for assuring safety of a vehicle or for achieving a state intended by a driver while reducing a shock from a power train so as to achieve both safety and operability. <P>SOLUTION: When a deviation exceeding a predetermined value is produced between a first target value before change as a target control value for at least any one of driving shaft torque, driving force and acceleration/deceleration and a second target value computed according to a travelling mode or a front travelling environment intended by a driver, control is performed so as to suppress variations of at least any one of the driving shaft torque, driving force and acceleration/deceleration. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device and a control method for an automobile, and more particularly to a control device and a control method for controlling an output of a power train including an engine and a transmission according to a recognition result of a forward traveling vehicle or the like and a driving intention of a driver. About.

  There is a technique in which the driving state of the vehicle can be changed according to the driving state of the preceding vehicle or the driving state intended by the driver (see Patent Document 1). In this technology, a method is described in which whether the vehicle is driven according to the driving state of the preceding vehicle or the vehicle is driven according to the driver's intention is selected by an operation by the driver himself, and each driving is switched. Yes. That is, the switching between the two driving states is left to the driver's own judgment so that the driving can be performed with the driving force intended by the driver.

Japanese Unexamined Patent Publication No. 7-47862

  Establishing a technique for ensuring the safety of the host vehicle by detecting the distance and relative speed between the host vehicle and the vehicle ahead (including obstacles) using a radar has become an important issue. In the above-described prior art, it is indispensable to satisfy both the traveling state (linear acceleration feeling corresponding to the accelerator pedal depression amount) intended by the driver and safety (collision prevention).

  However, since the control method of the driving state of the existing vehicle is set so that the driver's intention is always given the highest priority, the driving state of the preceding vehicle and the driving state in consideration of the safety of the own vehicle are determined. Switching automatically is technically difficult, and this switching depends on the operation of the driver. As a result, if there is a large deviation between the two calculated values at the time of switching between the two traveling states described above, a sudden torque change occurs, and an accelerating / decelerating fluctuation unexpected by the driver cannot be avoided.

  For example, in the above prior art, the driver intends when the driver switches from the state where the accelerator pedal depression amount is reduced to the traveling according to the traveling state of the preceding vehicle, that is, the follow-up control to the preceding vehicle. There is a problem that a deviation occurs between the target value and the actual control target value by the follow-up control, resulting in torque fluctuation that the driver feels uncomfortable.

  In the present invention, switching between a control amount for ensuring the safety of a vehicle and a control amount for achieving a state intended by the driver can be performed while reducing a shock from the power train. An object of the present invention is to provide a control device and a control method for an automobile capable of achieving both drivability.

  The present invention is calculated according to the first target value before the change as the target value for at least one of the drive shaft torque, the driving force, and the acceleration / deceleration, and the driving mode or the forward driving environment intended by the driver. An automobile control device that controls to suppress fluctuations in at least one of driving shaft torque, driving force, and acceleration / deceleration when a deviation exceeding a predetermined value occurs between the second target value and provide.

  Preferably, the driver intends in a control apparatus for an automobile that sets a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and controls at least the engine torque in accordance with the target value. Travel mode setting means for setting a travel mode, environment recognition means for recognizing a forward travel environment, target value change means for changing the target value according to a signal obtained by one of the two means, When changing the target value, if a certain deviation exceeds a certain value between the first target value before the change and the second target value calculated by the signal, control is performed so as to suppress fluctuations in the drive shaft torque. Torque fluctuation suppressing means is provided.

  Preferably, the signal used for calculating the target value of the drive shaft torque includes means for detecting the actual acceleration / deceleration of the vehicle and means for detecting the actual vehicle speed in addition to the depression amount of the accelerator pedal.

  Preferably, when the target value is changed by the changing unit, the torque fluctuation suppressing unit changes the first target value before the change as an initial value at a constant rate for a predetermined period. When the deviation from the second target value is reduced to a predetermined value, the second target value is changed.

  Preferably, when the target value is changed by the changing unit, the torque fluctuation suppressing unit switches instantaneously when switching from the second target value to the first target value.

  Preferably, the signal obtained by either the travel mode setting means or the environment recognition means is the inter-vehicle distance and the relative speed with the preceding vehicle.

  Preferably, the vehicle sets a drive shaft torque target value on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls at least the engine torque and the gear ratio according to the target value In this control device, there is provided target rotational speed calculation means for calculating a target value of the transmission input side rotational speed according to the target value, and target rotational speed limit setting means for limiting the transmission input side rotational speed. That is.

  Preferably, the vehicle sets a drive shaft torque target value on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls at least the engine torque and the gear ratio according to the target value In this control apparatus, there is provided target speed ratio calculating means for calculating the target value of the speed ratio in accordance with the target value, and target speed ratio limit setting means for limiting the speed ratio.

  Preferably, the vehicle sets at least one of drive shaft torque, driving force, and acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controls at least engine torque in accordance with the target value In the control apparatus, a driving load calculating means for calculating a driving load of the automobile, a deceleration calculating means for calculating an actual deceleration of the automobile, a deceleration calculated by at least the deceleration calculating means, and the accelerator A target deceleration calculating means for calculating a target deceleration based on a pedal depression amount, and according to the traveling load calculated by the traveling load calculating means and the target deceleration calculated by the target deceleration calculating means And providing target value calculating means for calculating the target value.

  Preferably, the traveling load calculation means is a weight rewriting means capable of rewriting the calculated traveling load.

  According to the present invention, switching between the control amount for ensuring the safety of the vehicle and the control amount for achieving the state intended by the driver can be performed while reducing the shock from the power train, Compatibility and drivability can be achieved.

  An embodiment will be described below with reference to the drawings.

  FIG. 1 is a block diagram of control according to an embodiment. First, control logic when a general driver operates an accelerator pedal (not shown) to drive an automobile (not shown) will be described.

  The accelerator pedal depression amount α and the vehicle speed No are input to the first target drive shaft torque calculating means 1, and the first target value Ttar 1 is calculated and input to the target value changing means 2. From the changing means 2, the first target value Ttar1 is directly substituted for the target value Ttar, and the target value Ttar is directly set to the target brake force calculating means 3, the target engine torque calculating means 4, and the target gear ratio calculating means 5. Is input.

  The calculation means 3 searches a brake control area composed of the target value Ttar and the target transmission input shaft side rotation speed shown in FIG. 8 and calculates the target brake force Bt. This target brake force Bt is input to the brake actuator 6 and brake control is executed.

  The target gear ratio calculation means 5 calculates a target gear ratio It using the target value Ttar and the vehicle speed No as parameters during acceleration. Further, at the time of deceleration, an engine brake control area composed of the target value Ttar and the target transmission input shaft side rotation speed shown in FIG. 8 is searched, and the target gear ratio It is calculated. The target speed ratio It is input to the speed change actuator 7, and acceleration control and engine brake control are executed.

  Further, the target engine torque calculation means 4 calculates the target engine torque Tet from the target value Ttar and the target speed ratio It, and inputs it to the target throttle opening calculation means 8. The target throttle opening θt is calculated and output to the throttle actuator 9. At this time, by using the actual speed ratio Ir, which is the ratio of the input shaft speed Nt of the transmission and the vehicle speed No, instead of the target speed ratio It, the followability of the actual drive shaft torque with respect to the target value Ttar is improved. Good torque control becomes possible.

  Similar results can be obtained by using vehicle longitudinal acceleration or driving force instead of the driving shaft torque. Furthermore, although brake control is used in this embodiment, it is possible to execute better acceleration / deceleration control than that of a conventional vehicle only by controlling engine torque and gear ratio, and driving that is intended by the driver is possible. Become.

  In the above description, an automobile equipped with an engine that injects fuel into the intake port is targeted. However, an engine that injects fuel into the combustion cylinder can increase the air-fuel ratio. By adopting air-fuel ratio control that combines throttle control and fuel amount control, more accurate drive shaft torque control is possible.

  Next, the control logic when the driver requests constant vehicle speed control or constant inter-vehicle distance control in place of normal traveling by using the travel mode change switch SW or the like will be described.

  In FIG. 1, when a constant vehicle speed control is requested, the target vehicle speed Vt and the vehicle speed No are input to the second target drive shaft torque calculation means 10 until the deviation between the target vehicle speed Vt and the vehicle speed No and the target vehicle speed Vt are reached. The target acceleration / deceleration is obtained by time, and the second target value Ttar2 is calculated using the vehicle weight, tire radius, gravity acceleration, and flat ground running resistance. Then, the second target value Ttar2 is inputted to the limiter setting means 11, and as shown in FIG. 4, if the second target value Ttar2 exceeds the target limit drive shaft torque Ttar2 ', the limit drive shaft The torque is limited to Ttar 2 '. As a result, sudden acceleration during traveling at a constant vehicle speed can be avoided, and acceleration control without a sense of incongruity for the driver becomes possible. Then, instead of the first target value Ttar1 during normal traveling, the actuators 6, 7, and 9 are driven with the value of the limit drive shaft torque Ttar2 'or the second target value Ttar2 itself as the target value to travel the vehicle.

  The target value is changed by a signal from the change switch SW. Alternatively, when it is determined that the inter-vehicle distance St is considerably small and dangerous, a logic for automatically changing the target value is included. That is, the driving environment in front is recognized by a radar, a camera, etc., and the recognition result is input to the target value changing means 2, and the target value of the drive shaft torque is changed from the first target value Ttar1 to the second target value Ttar2. Is automatically changed.

  Next, when the constant inter-vehicle distance control is requested, the relative speed Vs, the inter-vehicle distance St, the target inter-vehicle distance Stt and the vehicle speed No with the preceding vehicle are input to the second target drive shaft torque calculating means 10 and The target acceleration / deceleration is obtained from the deviation between the target vehicle speed Vtt and the vehicle speed No obtained from the relative speed Vs, the inter-vehicle distance St and the target inter-vehicle distance Stt, and the time to the target vehicle speed, and further the vehicle weight, tire radius, gravitational acceleration, and flat ground A second target value Ttar2 is calculated using the running resistance. Thereafter, the same control as the constant vehicle speed control is executed.

  A method for changing the first target value Ttar1 and the second target value Ttar2 will be described with reference to FIGS.

  3 is a time chart when the target value change from the first to the second is executed, and FIG. 4 is a time chart when the target value change from the second to the first is executed. In FIG. 3, for example, let us consider a case where the target value of the drive shaft torque is changed from the first to the second at time a in a state where α is larger than 0, that is, in an accelerating state. At time a, the second target value Ttar2 is calculated and the target value is changed from the first target value Ttar1 to the second target value Ttar2, but if the target vehicle speed Vt or the target vehicle speed Vtt is higher than the current vehicle speed No. If it is considerably large, the deviation Δk between the first target value Ttar1 and the second target value Ttar2 becomes large. Therefore, if the target value is changed immediately at time a, the actual wheel torque fluctuates (conventional) and the riding comfort deteriorates.

  On the other hand, in the present invention, when the target value is changed from the first target value Ttar1 to the second target value Ttar2 at time a, the target value is reached until time b after a predetermined period Ts in the target value changing means 2. The value Ttar is gradually increased so that the second target value Ttar2 and the second target value Ttar2 are not used until the second target value Ttar2 and the target value Ttar reach a predetermined value k1 at which torque fluctuation does not occur. Thereby, the fluctuation | variation of the actual wheel torque which generate | occur | produced after the (a) time can be suppressed, and the transition without a sense of incongruity to a smooth target value change, ie, constant vehicle speed control, constant vehicle distance control is attained.

  Next, in FIG. 4, for example, in a state where the accelerator pedal depression amount α is larger than 0, that is, in an accelerating state, the drive shaft torque target value is changed from the second target value Ttar2 to the first target value Ttar1 at time c. Consider a change. At time c, the first target value Ttar1 is calculated from the accelerator pedal depression amount α and the vehicle speed No, and the target value is changed from the second target value Ttar2 to the first target value Ttar1, but in this case, the driver In order to emphasize the acceleration intention, the target value is changed instantaneously. Further, a time constant that does not deteriorate the acceleration feeling, that is, about 200 milliseconds or less may be provided.

  FIG. 2 is a system configuration diagram of the present invention. An engine 16 and a transmission 17 are mounted on the vehicle body 15, and the driving horsepower transmitted to the power train from the engine 16 to the wheel 18 is controlled by the engine power train control unit 19. The engine powertrain control unit 19 calculates a first target value Ttar1 (or driving force, acceleration / deceleration) of the drive shaft torque, and a target throttle opening θt (or air) according to the calculated target value. Flow rate), fuel amount, ignition timing, brake pressure Bt, gear ratio It, and transmission control oil pressure PL are calculated. For the fuel control, a currently mainstream intake port injection method or a cylinder control method with good controllability is used.

  In addition, the vehicle body 15 is equipped with a television camera 20 for detecting the external environment and an antenna 21 for detecting infrastructure information. The image of the television camera 20 is input to the image processing unit 22, and image processing is performed to recognize road gradient, corner radius of curvature, traffic signal information, road signs, traffic regulations, other vehicles, pedestrians, obstacles, and the like. The recognized traveling environment signal is input to the environment-friendly powertrain control unit 23.

  Further, a radar system 24 such as an FM-CW system is installed in front of the vehicle body 15 to detect a distance St and a relative speed Vs with respect to the preceding vehicle or object. The antenna 21 is connected to the infrastructure information terminal 25, and according to the infrastructure information, the road surface condition ahead (wet, dry, puddle depth, snow condition, freezing, gravel, sand, etc.), weather, etc. Information (rainfall amount, snowfall amount, etc.), traffic jam information, and the like are detected, and the friction coefficient μ between the tire and the road surface is calculated according to the road surface condition and input to the control unit 23.

  Further, the driving environment can be determined from the map information stored in the CD-ROM 26 or the like, and the road conditions ahead (gradient, corner radius of curvature, traffic regulation, etc.) can be detected.

  In the control unit 23, based on signals such as the road gradient, the corner curvature radius, the inter-vehicle distance St, the relative speed Vs, and the friction coefficient μ, the second drive shaft torque of the power train corresponding to the driving environment that will be encountered in the future. A target value Ttar2 (or driving force, acceleration / deceleration) is calculated and input to the control unit 19.

  In the control unit 19, either the first target value Ttar1 or the second target value Ttar2 is selected by the signal of the change switch SW operated by the driver. If the second target value Ttar2 is selected, based on this value, that is, the target drive shaft torque corresponding to the traveling environment, the throttle opening θt, the fuel amount, the ignition timing, the transmission control hydraulic pressure PL, the transmission ratio. It and brake force Bt are calculated. The control unit 19 is input with an accelerator pedal depression amount α, a vehicle speed No, an engine speed Ne, a switch signal Msw (described later), an acceleration sensor signal Gd, a steering angle Sa, and the like.

  FIG. 5 is a control block diagram of another embodiment. However, the base powertrain control unit is the same as that shown in FIG. The difference is engine brake control. In FIG. 1, engine brake control is executed by gear ratio control, but in FIG. 5, engine brake control means 30 and an emblem (engine brake) actuator 31 are newly provided. That is, whether or not the reverse driving force from the tire generated on the downhill is transmitted to the engine side is controlled by the one-way clutch of the stepped transmission and the clutch that turns on and off the function of the one-way clutch. By adopting such a system, smooth deceleration control can be realized.

  The time chart at the time of performing the target deceleration control of FIG. 6, FIG. 5 is shown. First, the target drive shaft torque Ttar having a negative value is determined by a combination of the accelerator pedal depression amount α and the vehicle speed No, or the accelerator pedal depression amount α, the vehicle speed No, and the actual deceleration Gd of the vehicle (described in detail in FIG. 10). Is calculated. Alternatively, the target value Ttar of the drive shaft torque is set by the second target value Ttar2 of the drive shaft torque from the environment-friendly powertrain control unit 23. In the case of a large deceleration control that requires brake control according to this target value Ttar (during the period ef), the target engine torque Tet is almost 0, that is, near the minimum value so that the drive shaft torque becomes the target value Ttar. Further, the target speed ratio It is set according to the value of the target engine torque Tet. However, during the period ef, it is necessary to turn off the engine brake control signal Eb in order to prevent deterioration in deceleration feeling due to interference between the brake control and the engine brake control of the gear ratio control. Thereby, since the deceleration control is only the brake control, the controllability and drivability during deceleration are improved.

  Furthermore, since the gear ratio shifts to the Low side (the side with the larger gear ratio) during deceleration, the feeling of acceleration when the accelerator pedal is depressed again is improved.

  Next, a method of switching control from deceleration to acceleration will be described using cornering control as an example with reference to FIGS. FIG. 7 is a time chart of deceleration-acceleration switching control.

  In the acceleration / deceleration change determining means 32 in FIG. 5, the accelerator pedal depression amount α, that is, the target value Ttar of the drive shaft torque, from the state where the accelerator pedal depression amount α is 0, the drive shaft torque target value Ttar and the target engine torque Tet are negative. Determine whether or not is positive. When the target value Ttar of the drive shaft torque is positive and it is determined that the vehicle is accelerating, the gear ratio change limiting means 33 holds the current gear ratio or limits the change width. Therefore, since the gear ratio is shifted to the Low side (the side where the gear ratio value is large) during deceleration, the increase in engine speed during acceleration is accelerated (not shown), and the acceleration feeling is improved.

  In FIG. 7, the transmission ratio holding period or the change width restriction period Tl1 is determined by the magnitude of the target value Ttar of the drive shaft torque or the like. When the target value Ttar of the drive shaft torque is large, it means that a large acceleration is required, so that the holding or limiting period needs to be increased. Further, when the steering angle Sa is changed during the period Tl1, that is, when it is determined that cornering is being performed, until the steering angle Sa returns to 0 (that is, the vehicle travels straight), until the period Tl2 has elapsed. The holding or control period is extended. Further, when cornering continues, an extension to the period T13 can be considered. In addition to the steering angle Sa, the determination of whether or not the corner is a road curvature radius R (calculated by the road curvature radius estimation means 34) obtained from the steering angle Sa, a lateral acceleration sensor, a yaw rate sensor, infrastructure information, and navigation information. It is possible to detect and judge from the above. Here, in the present embodiment, the limit value of the speed ratio width is set within ± 0.5 as a range that does not affect the feeling of acceleration.

  Next, a method for setting the gear ratio during the target deceleration control will be described. In the case of acceleration, a conventional gear ratio map or a gear ratio in consideration of fuel consumption can be applied. However, in the case of deceleration, engine braking is required, so setting of the gear ratio is difficult. Conventionally, the driving range where the automatic transmission does not operate as intended by the driver is the deceleration side. The present invention solves this problem by using the contents of the description of FIG. 5 and the following FIG.

  FIG. 8 is a characteristic diagram showing an outline of speed ratio control during deceleration. In FIG. 8, the horizontal axis represents the target transmission input shaft side rotational speed (this is the target gear ratio It when the vehicle speed No is constant), and the vertical axis represents the drive shaft torque target value Ttar (ie, a negative value). Indicates the target deceleration).

  The horizontal line area is a brake control area, and the hatched area is a gear ratio control area including engine brake control. In the case of a continuously variable transmission, the control can be arbitrarily set in the entire shaded area. However, in the case of a stepped transmission (for example, a transmission having a gear ratio of four forward speeds), a solid line also in the shaded area. Only the upper part of can be set.

  First, the continuously variable transmission will be described. For example, when the target value Ttar of the drive shaft torque is set to the value of the point A in the figure, it is possible to select all the gear ratios on the solid line from the point B to the point C in the shaded part. . Therefore, it is necessary to use some condition in order to determine the target gear ratio from among the infinite number of the gear ratios. For example, the driver's intention to slow down, safety, fuel economy, and the like. Here, the target limit engine speed was applied as a parameter for satisfying these conditions. For example, by setting the target limit engine speed Nlmt to the value of point D, the target transmission input shaft side speed at point D, that is, the target gear ratio is determined.

  Next, the stepped transmission will be described. In this case, when the target value Ttar of the drive shaft torque is set to the value of the point A, the first speed that intersects the value of the point A among the gear ratios represented by the four thin solid lines in the hatched portion or Only the gear ratio of the second gear is selected. However, if the target limit engine speed Nlmt is set to the value of the point D as described above, it is impossible to select the second speed that is larger than the value of the point D, and the first speed is necessarily selected. If this is the case, the deceleration will be at point E, and the target deceleration cannot be obtained, so the engine torque is increased and set to point D of the target value. The engine torque is increased by increasing the throttle opening or increasing the fuel amount.

  As described above, by setting the negative gear ratio based on the target value Ttar of the drive shaft torque and the limit engine speed Nlmt, the conventional automatic transmission does not operate as intended by the driver. Can solve problems in the region. The target limit engine speed Nlmt is set in the speed ratio limiting means 35 based on the signal of the manual limit speed setting switch Msw shown in FIG. The target gear ratio calculating means 5 calculates and outputs the target gear ratio It based on the target value Ttar of the drive shaft torque, the target limit engine speed Nlmt, and the characteristics of FIG. 8 stored in a memory (not shown). The

  FIG. 9 is a perspective view of the shift lever 40 for explaining the outline of the manual limit rotational speed setting method set by the manual limit rotational speed setting switch Msw of FIG.

  By operating the shift lever 40, an economy mode (EM: Economy Mode), a normal drive mode (NDM: Normal Drive Mode), and a sports mode (SM: Sport Mode) can be selected. In NDM, the limit engine speed for engine braking is set to a constant value of a low value of about 1500 rpm, so that a large deceleration cannot be obtained. In ED, since the fuel efficiency is more important than the feeling of acceleration, a gear ratio considering the fuel efficiency is set. In the case of deceleration, the engine brake area is expanded as much as possible while satisfying the target deceleration, and fuel supply is interrupted to reduce fuel consumption. On the other hand, in SM, the target limit engine speed Nlmt shown in FIG. 8 can be set by a driver's operation. That is, by operating the shift lever 40 several times to the position of High in FIG. 9, the target limit engine speed Nlmt increases and decreases at the Low position, and this magnitude is detected by the manual limit speed setting switch Msw. To do. The signal of the manual limit speed setting switch Msw is input to the engine power train control unit 19 and the target limit engine speed Nlmt is set by the gear ratio limiting means 35. Further, the target limit engine speed Nlmt is output from the engine powertrain control unit 19 to the display means 41, and displayed as, for example, Sport Mode, Limiter Rev4000rpm, to inform the driver of the current operation mode. In addition, when the second target value Ttar2 is used as the target value of the drive shaft torque, acceleration / deceleration control that emphasizes safety is executed in any mode.

  FIG. 10 is a time chart of the target deceleration control when the actual deceleration Gd is used. It is determined that the accelerator pedal depression amount α has become 0 or less, a signal of actual deceleration Gd is detected for an arbitrary time (period g−h), and a target deceleration is calculated. That is, since the change in the deceleration Gd is delayed from the change in the accelerator pedal depression amount α, it is necessary to provide a period of an arbitrary length for determining the target deceleration. For example, if the brake depression force β increases during this determination period, the deceleration Gd at that time is set as the target deceleration. As a result, the actual powertrain control start timing is the time point h.

  However, if the determination period is too long, a problem occurs in the driver's intention and safety, and if it is too short, it is difficult to determine the deceleration intended by the driver. It is reasonable to set between 800 milliseconds.

  In the case of a stepped transmission, after the start of control, from the 4th speed to the 3rd speed when there is no brake depression, from the 4th speed to the 2nd speed when there is no brake depression, A target gear ratio It is set. Further, the opening control of the target throttle opening degree θt at the time of shifting is a control for improving the shift response, and will be described in detail below with reference to FIG.

  FIG. 11 is a time chart of the throttle control during shifting. In particular, in the case of a stepped transmission, it is necessary to change the gear ratio in a stepwise manner, and auxiliary control by engine torque control is effective. That is, it is determined whether the current gear ratio Ir is applied by using the actual gear ratio Ir and whether the gear ratio Ir has reached the throttle control start timing k2. When the time k2 is reached, the engine speed that is expected to change after the shift is predicted, and the throttle opening corresponding to the engine speed is calculated and output. At this time, the hydraulic pressure PL supplied to the clutch of the transmission is lowered in advance when the shift start command signal is generated. Thereby, a high-speed downshift is possible. Then, at time k3, the throttle control for increasing the engine speed is terminated, and the process proceeds to the target deceleration control described with reference to FIG. At the same time, the hydraulic pressure PL is set according to the target engine torque Tet, that is, the target throttle opening θt, and the hydraulic pressure PL is increased. As described above, in the target deceleration control, it is difficult to shift down as the engine speed decreases, and the cooperative control of the throttle and the hydraulic pressure shown in FIG. 11 is indispensable.

  FIG. 12 is a time chart showing the deceleration characteristics when the road gradient is changed, and FIG. 13 is a calculation block diagram of a target value corresponding to the traveling load.

  In FIG. 12, the solid line indicates the deceleration characteristics when the accelerator pedal depression amount α is zero on a flat ground, the dotted line indicates the deceleration characteristics when the accelerator pedal depression amount α is zero on the downhill, and the wavy line indicates the acceleration pedal depression amount on the uphill. This is the deceleration characteristic when α is zero. The deviation between the solid line, the dotted line, and the wavy line is the traveling load TL. As described above, the target deceleration required by the driver is grasped at an arbitrary time after the accelerator pedal depression amount α becomes zero. For example, when the driver sets the accelerator pedal depression amount α to zero, it is considered that the power train is controlled so as to achieve a solid line deceleration. This deceleration is the target value requested by the driver.

  On the other hand, on the downhill, since the traveling load is small, the deceleration is small, that is, shifts in the acceleration direction. Therefore, the driver feels uncomfortable and executes the brake operation because it is different from the deceleration requested by the driver. On the uphill, the traveling load increases, so the deceleration is large, that is, the vehicle moves in the deceleration direction. Therefore, the driver feels uncomfortable and executes the accelerator operation because it is different from the deceleration requested by the driver.

  Thus, by obtaining the travel load and obtaining and correcting the target deceleration according to the travel load, it is possible to realize acceleration control corresponding to a change in road gradient. Furthermore, here, the driving performance can be further improved by correcting the traveling load according to the age and sex of the driver.

  Next, the control logic shown in FIG. 12 will be described with reference to FIG. First, the vehicle speed No is input to the deceleration calculation means 45, and the actual deceleration Gd of the vehicle is calculated. The deceleration Gd, the accelerator pedal depression amount α, and the brake depression force β are input to the target deceleration calculation means 46, and the target deceleration Gdt is calculated.

  The calculation of the target deceleration Gdt is executed when the accelerator pedal depression amount α is zero and the brake depression force β is changed as described above in the target deceleration grasping period of FIG.

  Next, the vehicle speed No, the turbine speed Nt, and the engine speed Ne are input to the drive shaft torque calculation means 47, and the actual drive shaft torque To is calculated. In the drive shaft torque calculation means 47, the drive shaft torque To is obtained from the torque converter characteristics and the gear ratio that changes suddenly at the start of actual shift. The details of the calculation of the drive shaft torque are the same as the method described in detail in JP-A-6-207660.

  The drive shaft torque To, the deceleration Gd, and the vehicle speed No are input to the travel load calculating means 48, and the travel load TL is calculated. In FIG. 13, the traveling load TL is represented by a functional expression, but in practice, it can be obtained by the following driving equation (1) of the vehicle.

TL = To-Iv · Gd (1)
Iv: Vehicle inertia weight Finally, the travel load TL and the target deceleration Gdt are input to the first target drive shaft torque calculation means 1, and the first target value Ttar is calculated. This conversion formula is based on formula (1). Moreover, you may obtain | require by experiment from an actual vehicle characteristic. Subsequent calculations from the target engine torque calculation means 4 are the same as those in FIG.

  Further, the weight b of the function formula of the traveling load calculation means 48 in FIG. 13 will be described.

  In general, since the preference of the deceleration at the time of climbing is different depending on the driver, this can be freely changed in the present invention. A rewrite switch signal manually operated by the driver is input to the weight rewriting means 49, and the deceleration at the time of climbing up and down can be freely changed. That is, the weight b calculated by the weight rewriting means 49 is input to the traveling load calculating means 48, and the magnitude of the traveling load TL can be changed.

  By applying the control logic as described above, the torque fluctuation from the power train at the time of switching between the control amount for ensuring the safety of the vehicle and the control amount for achieving the state intended by the driver is suppressed, It prevents the driver from unintentionally accelerating / decelerating, and the driver's required deceleration can be obtained in all driving areas from flat to uphill, enabling comfortable driving and improving safety and driving performance. Both can be achieved.

The block diagram of control of one Example. System Configuration. The time chart at the time of performing the target value change from 1st to 2nd. The time chart at the time of performing the target value change from the 2nd to the 1st. The block diagram of control of other examples. Time chart of target deceleration control. Time chart of deceleration-acceleration switching control. The characteristic view which shows the outline of the gear ratio control at the time of deceleration. The perspective view of the shift lever 40 explaining the outline of the manual limit rotation speed setting method. The time chart of the target deceleration control at the time of using actual deceleration Gd. Time chart of throttle control during shifting. The time chart which shows the deceleration characteristic when changing the road gradient. The block diagram of the calculation of the target value corresponding to traveling load.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... First target drive shaft torque calculating means, 2 ... Target value changing means, 3 ... Target brake force calculating means, 4 ... Target engine torque calculating means, 5 ... Target speed ratio calculating means, 10 ... Second target drive Shaft torque calculation means, 11... Limiter setting means.

Claims (15)

In a control device that sets at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controls at least an engine torque according to the target value,
There is a deviation exceeding a predetermined value between the first target value before the change as the target value and the second target value calculated according to the driving mode or the forward driving environment intended by the driver. A control device that controls to suppress at least any variation of the drive shaft torque, drive force, and acceleration / deceleration when it occurs. In a control device that sets at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controls at least an engine torque according to the target value,
Driving mode setting means for setting the driving mode intended by the driver, or environment recognition means for recognizing the forward driving environment;
Target value changing means for changing the target value in accordance with a signal obtained by at least one of the two means;
When changing the target value, if the deviation between the first target value before the change and the second target value calculated by the signal is a certain value or more, fluctuation of the drive shaft torque is suppressed. A control device comprising torque fluctuation suppressing means for performing control.   When the target value is changed by the target value changing means, the target value changing means changes the first target value before the change at a constant rate for a predetermined period, and changes the first target value and the first target value. The control device according to claim 2, wherein the first target value is changed to a second target value when the deviation from the second target value is reduced to a predetermined value. The first target value is at least one of the drive shaft torque, the driving force, and the acceleration / deceleration calculated based on the operation amount of the driver,
The second target value is at least one of the driving shaft torque, driving force, and acceleration / deceleration calculated according to a signal obtained by the mode setting means or the environment recognition means, and at least an upper limiter is provided. The control device according to claim 2.   The control device according to claim 2, wherein the signal obtained by the travel mode setting unit or the environment recognition unit is at least an inter-vehicle distance and a relative speed with respect to a preceding vehicle. In a control device that sets a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls the gear ratio according to the target value.
Engine brake control means for controlling engine brakes for transmitting reverse driving force from the wheels to the engine;
Brake force control means for controlling the brake force of the wheel so as to follow or follow the target value;
When at least the engine torque and the gear ratio are controlled according to the target value, and the target value represents a deceleration request, the engine torque is controlled to be near the minimum value, and during the period in which the braking force is controlled, A control device comprising: a gear ratio changing unit that prohibits engine brake control by the engine brake control unit and changes the gear ratio according to the target value. In a control device that sets a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls at least the engine torque and the gear ratio according to the target value,
Acceleration / deceleration change determining means for determining whether or not the target value has changed from a deceleration request to an acceleration request;
A control apparatus, comprising: a gear ratio change width limiting means for limiting a change width from a current gear ratio for a certain period when it is determined by the acceleration / deceleration change determining means that the speed change request is changed to an acceleration request. In a control device that sets a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls at least the engine torque and the gear ratio according to the target value,
Target rotational speed calculation means for calculating a target value of the transmission input side rotational speed according to the target value;
A control device comprising: target rotation speed limit setting means for limiting the transmission input side rotation speed. In a control device that sets a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controls at least the engine torque and the gear ratio according to the target value,
Target gear ratio calculating means for calculating a target value of the gear ratio according to the target value;
A control device comprising target gear ratio limit setting means for limiting the gear ratio. In a control method for setting at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controlling at least an engine torque according to the target value,
There is a deviation exceeding a predetermined value between the first target value before the change as the target value and the second target value calculated according to the driving mode or the forward driving environment intended by the driver. A control method for performing control so as to suppress fluctuations in at least one of the drive shaft torque, drive force, and acceleration / deceleration when it occurs. In a control method for setting at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controlling at least an engine torque according to the target value,
When changing the target value according to the signal obtained in at least one of the driving mode intended by the driver or the forward driving environment, the second target value calculated by the first target value before the change and the signal is used. A control method for performing control so as to suppress fluctuations in the drive shaft torque when a deviation from a target value becomes a certain value or more. In a control method of setting a target value of the drive shaft torque on the transmission output shaft side based on at least the accelerator pedal depression amount and the actual deceleration of the vehicle, and controlling the gear ratio according to the target value,
Controls the engine brake that transmits the reverse driving force from the wheels to the engine,
Control the braking force of the wheel to follow or follow the target value,
Control at least the engine torque and the gear ratio according to the target value,
If the target value represents a deceleration request, the engine torque is controlled near the minimum value,
During the period when the brake force is controlled, the engine brake control is prohibited,
A control method for changing the gear ratio according to the target value. In a control device that sets at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controls at least an engine torque according to the target value,
Drive shaft torque calculating means for calculating drive shaft torque from the vehicle speed of the automobile, the engine speed, and the turbine speed of the transmission;
Deceleration calculation means for calculating an actual deceleration of the vehicle based on a change in the vehicle speed of the vehicle;
A driving load calculating means for calculating a driving load of the vehicle from the vehicle speed, the deceleration calculated by the deceleration calculating means, and the drive shaft torque calculated by the drive shaft torque calculating means;
A target deceleration calculation means for calculating a target deceleration based on at least the deceleration calculated by the deceleration calculation means and the accelerator pedal depression amount;
A control apparatus comprising target value calculation means for calculating the target value in accordance with the travel load calculated by the travel load calculation means and the target deceleration calculated by the target deceleration calculation means.   The control device according to claim 13, wherein the traveling load calculation means includes weight rewriting means capable of rewriting the calculated magnitude of the traveling load. In a control method for setting at least one of a drive shaft torque, a driving force, and an acceleration / deceleration on the transmission output shaft side as a target value based on at least an accelerator pedal depression amount, and controlling at least an engine torque according to the target value,
The drive shaft torque is calculated from the vehicle speed of the automobile, the engine speed, and the turbine speed of the transmission,
Calculate the actual deceleration of the vehicle based on the change in vehicle speed of the vehicle,
Calculate the driving load of the automobile from the calculated deceleration, the vehicle speed, and the drive shaft torque,
Based on at least the deceleration and the accelerator pedal depression amount, the target deceleration is calculated,
A control method for calculating the target value according to the travel load and the target deceleration.

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