JP5369912B2 - Control device for automatic transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a busy shift in the case of changing speed from a hysteresis region to a speed stage excellent in fuel economy. <P>SOLUTION: This control device constituted to execute a shift to a speed stage excellent in fuel economy in the case that the drive state or the traveling state of a vehicle stays in a region in which hysteresis in a shift diagram is set for a predetermined time or longer includes: a shift predicting means for predicting that the shift based on the shift diagram is generated during a time from a present time point when a vehicle state has stayed in a region in which the hysteresis in the shift diagram is set for a predetermined time or longer to a time point when the predetermined time set to prohibit the busy shift passes (steps S101-S108); and a shift stage selecting means for executing the shift to a speed stage excellent in fuel economy in the case that the shift based on the shift diagram is not predicted (steps S112). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a control device for an automatic transmission in which a shift is controlled based on a shift diagram in which a shift speed region is set by an upshift line and a downshift line, and in particular, between an upshift line and a downshift line. The present invention relates to a control device configured to perform a shift even in a state where the so-called hysteresis region remains.

  An automatic transmission for a vehicle that can set a plurality of shift stages such as four to eight forward speeds depends on two parameters, a required driving amount such as an accelerator opening degree and an engine output, and a traveling state such as a vehicle speed and a turbine rotational speed. Shifting is controlled based on a shift diagram (so-called map) in which a shift speed region is set. More specifically, an upshift line that defines an area that causes an upshift and a downshift line that defines an area that causes a downshift are set according to each shift stage, and the vehicle speed and accelerator opening are set. The driving state or the traveling state of the vehicle changes such as across the upshift line or downshift line, thereby causing an upshift or a downshift.

  Usually, a hysteresis is provided between the upshift line and the downshift line. This is to avoid the so-called busy shift in which a shift occurs whenever the accelerator opening or the vehicle speed slightly changes. Generally, the downshift line is far away from the upshift line on the low speed side. Is set.

  In a stepped automatic transmission, shifting is executed by changing the driving state or running state of the vehicle so that it crosses the upshift line or the downshift line, but the vehicle speed or the required drive amount is not necessarily increased. The state on the shift line or the state close to the upshift line is not maintained, and the state close to the center of the so-called hysteresis region may be maintained. Since the upshift line is usually set so as to achieve both fuel efficiency and power performance of the vehicle, if it is maintained in a driving state far away from the upshift line, the fuel efficiency decreases. there is a possibility. Therefore, the apparatus described in Patent Document 1 detects a state of greatly entering the hysteresis region, and if the state is not temporary, even if a change across the upshift line or the downshift line does not occur. Further, the shift to the shift stage where the fuel efficiency is good is generated.

  Patent Document 2 and Patent Document 3 describe apparatuses that forcibly execute a shift even when the driving state or traveling state of the vehicle remains in the hysteresis region. That is, Patent Document 2 is configured to execute a downshift when the running state of the vehicle is in the hysteresis region and the speed ratio of the torque converter continues for a predetermined time or longer and is equal to or lower than a threshold value. A device is described. In this method, for example, entering an uphill road is estimated from the speed ratio of the torque converter, and a downshift is executed to increase the driving force. Further, Patent Document 3 describes an apparatus configured to perform a downshift when the vehicle traveling state is in a hysteresis region and the signal increase rate with respect to the engine output is equal to or greater than a predetermined value. This is to correct the downshift delay due to the provision of hysteresis, and is configured to execute the downshift before the running state of the vehicle changes across the downshift line. is there.

JP-A-6-193721 JP-A-1-188760 JP-A-1-206144

  In the inventions described in the above Patent Documents 1, 2, and 3, when the vehicle traveling state is in a so-called hysteresis region in the shift diagram (shift map), the traveling state changes so as to cross the shift line. This is an invention that prescribes conditions for forcibly causing a shift even if there is no such thing. Specifically, the invention described in Patent Document 1 is deeply intruding into the hysteresis region, and it is temporary. It is an invention that stipulates that it is not. The invention described in Patent Document 2 is an invention that prescribes that the speed ratio of the torque converter continues for a predetermined time and is equal to or greater than a threshold value. Furthermore, the invention described in Patent Document 3 is an invention that stipulates that the increase rate of the signal with respect to the engine output is a predetermined value or more. Therefore, in the invention described in Patent Document 2 or Patent Document 3, a downshift occurs when the speed ratio of the torque converter and the increase rate of the signal with respect to the engine output satisfy the conditions. If this condition is met, a downshift will occur again, resulting in a so-called busy shift in which shifting is repeated in a short time, giving the driver a sense of incongruity and impairing the ride comfort of the vehicle. there is a possibility.

  On the other hand, the invention described in Patent Document 1 determines that the state of deeply entering the hysteresis region is not temporary in order to avoid such a busy shift, and the determination is established. Since the shift is performed, the shift does not occur again immediately after the preceding shift. However, since the factors related to gear shifting, such as the required amount of driving such as the accelerator opening and the vehicle speed, vary depending on the traveling environment of the vehicle, the so-called forced gear shifting in the state of the hysteresis region described above does not become a busy shift. However, if the driving environment at the time when the forced shift occurs requires a shift from the shift stage after the forced shift, the traveling state or drive state of the vehicle crosses the shift line. Since it will change, a shift will occur. That is, even if the forcible shift itself is not a busy shift, there is a possibility that a shift occurs immediately after that, resulting in a busy shift.

  The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a device capable of performing shift control so that a so-called forced shift in the hysteresis region does not cause a busy shift. It is what.

In order to achieve the above-mentioned object, the invention of claim 1 executes a shift based on a shift diagram in which a predetermined hysteresis is set between an upshift line and a downshift line, and the vehicle drive state or If the running state has remained the first place constant time or more in a region where the hysteresis in the shift diagram is set, configured automatic transmission for a vehicle to perform a shift to a good shift speed fuel economy in the control device of the machine, the drive state or traveling state of the vehicle is set so as to prohibit busy shift from the current time when the hysteresis has remained first place constant time or more in a region that is set in the shift map wherein a speed change predicting means for predicting that the shifting based on the shift diagram is generated, the shift diagram is the shifting predicting means until the constant time second place has elapsed And it is characterized in that it comprises a gear stage selecting means for executing the shift of the good gear position of the fuel consumption when not predict the possible shift occurs based.

  According to a second aspect of the present invention, in the first aspect of the present invention, the gear stage having the best fuel consumption has the best fuel efficiency among the gear stages that generate a driving force equivalent to that when performing a shift based on the shift diagram. A control device for an automatic transmission for a vehicle, characterized in that it includes various gears.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the shift prediction means predicts that the vehicle load or the vehicle speed changes according to a road condition of a planned traveling road ahead of the vehicle, and the prediction A control device for an automatic transmission for a vehicle, comprising means for predicting whether or not a shift based on the vehicle speed occurs.

  According to a fourth aspect of the present invention, in the invention of the third aspect, the road condition includes any one of a slope, presence / absence of traffic congestion, a corner entrance or exit, a stop signal, or a stop instruction. This is a transmission control device.

A fifth aspect of the present invention, in any one of the claims 1 to 4, wherein the speed change predicting means, before Symbol upshift in the shift diagram driving state or the running state of the vehicle after the second place constant time A control device for an automatic transmission for a vehicle, comprising means for establishing a prediction that the shift will occur when the state changes across a line or a downshift line.

  According to the first aspect of the present invention, when the driving state or traveling state of the vehicle stays in the hysteresis region set between the upshift line and the downshift line for a predetermined time or more, the driving state or traveling state of the vehicle Even if the state does not change across the shift line, the so-called forced shift to the shift stage where the fuel efficiency is good is executed, but the shift is performed until the predetermined time elapses from the current point in the hysteresis region. When a shift based on the diagram is predicted to occur, so-called forced shift is not executed. The predetermined time is a time set so as not to cause a continuous shift that is perceived as a busy shift, so that a so-called forced shift is prevented from being a busy shift.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1 described above, even if so-called forced shift is executed, the change of the driving force becomes gentle, or the change of the driving force is hardly changed. Since it does not occur, it is possible to prevent or suppress the driver from feeling uncomfortable.

  According to the third to fifth aspects of the present invention, it is possible to reliably predict the shift.

It is a flowchart for demonstrating an example of the control performed by the control apparatus which concerns on this invention, Comprising: The example of control for determining whether what is called a forced shift turns into a busy shift is shown. It is a diagram which shows an example of the threshold value of the accelerator opening used in the example of control of FIG. It is a diagram which shows an example of the threshold value of the gradient used in the example of control of FIG. It is a diagram which shows an example of the threshold value of the accelerator opening variation | change_quantity used by the example of control of FIG. It is a diagram which shows an example of the threshold value of the acceleration / deceleration used in the control example of FIG. It is a diagram which shows an example of the threshold value of the elapsed time which does not become a busy shift used by the example of control of FIG. FIG. 6 is a flowchart for explaining another example of the control example executed by the control device according to the present invention, and is a flowchart obtained by adding a step of determining whether or not the auto cruise switch is ON to the flowchart shown in FIG. 1. It is a flowchart explaining the example of control for judging the presence or absence of the future gear shift of predetermined time from the present time, and selecting the minimum fuel consumption gear position based on the result of the judgment. It is a flowchart explaining an example of the control for estimating the near future load fluctuation. It is a figure which shows typically the drive system of the vehicle which can be made into object by this invention. FIG. 6 is a diagram schematically showing an upshift line, a downshift line, and a hysteresis region in a shift diagram.

  First, the vehicle targeted by the present invention will be described. The example shown in FIG. 10 is a vehicle using the internal combustion engine 1 as a driving force source, and the driving force output from the internal combustion engine 1 is transmitted via the automatic transmission 2. It is comprised so that it may transmit to a driving wheel. An automatic transmission 2 is connected to the output side of the internal combustion engine 1, and its output shaft 3 is connected to drive wheels 5 via a differential 4. The internal combustion engine 1 is a heat engine that generates power by burning fuel such as gasoline, light oil, or LPG (liquefied natural gas). Examples of this type of internal combustion engine include a gasoline engine, a diesel engine, and a gas engine. The internal combustion engine 1 is configured to be able to electrically control the supply and stop of fuel. For example, an electrically controlled fuel injection device is provided. In the following description, the internal combustion engine 1 is referred to as the engine 1. In the figure, the internal combustion engine 1 is denoted as E / G.

  The automatic transmission 2 connected to the output side of the engine 1 is a transmission mechanism that changes the gear ratio by a command signal from the outside or manually operated, and is mounted on a conventional general vehicle. It is a stepped automatic transmission. The automatic transmission 2 may include a transmission mechanism 6 such as a torque converter with a lock-up clutch. The most common example of this type of automatic transmission 2 includes a plurality of planetary gear mechanisms, and selectively connects or disengages the rotating elements such as sun gear, carrier, or ring gear by a clutch. The automatic transmission is configured to change a transmission ratio of a torque by changing selectively a torque transmission path by selectively fixing with a brake. The shift control is executed so that the power performance and the fuel efficiency are as good as possible. More specifically, the driving state such as the accelerator opening, the engine output or the throttle opening, the vehicle speed and the turbine speed It is configured to perform based on a map (shift diagram) in which the gear ratio or gear position is determined based on the traveling state.

  In the shift diagram, an upshift line that causes an upshift and a downshift line that causes a downshift are set, and the upshift line changes when the driving state or the running state changes across the upshift line. Upshift control is executed when the shift determination is established, and downshift control is executed when the drive state or the running state changes so as to cross the upshift line and downshift control is executed. FIG. 11 schematically shows the upshift line and the downshift line, and the upshift line from the nth stage to the (n + 1) th stage is set to be (n + 1) th stage at a predetermined vehicle speed V or higher. In addition, the vehicle speed at the boundary is set so that the higher the accelerator opening θ is, the higher the vehicle speed is when the accelerator opening θ is equal to or greater than a predetermined value. On the other hand, the downshift line from the (n + 1) stage to the n stage is set on the lower vehicle speed side than the upshift line. Such a difference between the upshift line and the downshift line is hysteresis, and a shift is not caused by a slight change in the driving state such as the vehicle speed and the accelerator opening degree. Therefore, even if the driving state or the traveling state changes within a so-called hysteresis region between the upshift line and the downshift line, no shift occurs. On the other hand, the upshift line is set to a vehicle speed or an accelerator opening at which fuel efficiency becomes good. Therefore, when the driving state or running state of the vehicle is within the hysteresis region, particularly when the vehicle is in the central portion of the hysteresis region, the fuel consumption is lower than when the vehicle is near the upshift line.

  The engine 1 and the automatic transmission 2 are configured to be electrically controllable, and an engine electronic control unit (E-ECU) 7 and an automatic transmission electronic control unit (T-ECU) for the control are provided. ) 8 is provided. These electronic control units 7 and 8 are mainly composed of a microcomputer, and perform calculations based on data inputted from various sensors, data stored in advance and calculation programs, and the results of the calculations are used as command signals. It outputs to the engine 1 and the automatic transmission 2, and is comprised so that predetermined | prescribed control may be performed. As an example of such data, data such as engine speed, accelerator opening, engine oil temperature, exhaust purification catalyst temperature, and on / off of auxiliary machinery are input to the engine electronic control unit 7. Further, data such as the vehicle speed, the rotation speed of the output shaft 3, the oil temperature of the automatic transmission 2, the accelerator opening, and the shift range are input to the automatic transmission electronic control unit 8. Note that these electronic control units 7 and 8 are connected so as to be able to perform data communication with each other.

  As described above, the shift control of the automatic transmission 2 targeted by the present invention basically changes the driving state or the traveling state of the vehicle so as to cross the shift line such as the upshift line or the downshift line. However, in order to improve fuel efficiency, it is configured to perform so-called forced shifting even when there is no change across the shift line. It is configured so that forced shifting is not a factor of so-called busy shift. An example of the control will be described next.

  FIG. 1 is a flowchart for explaining the control example. First, information is acquired (step S1). Here, the acquired information (that is, information to be read) includes, for example, vehicle speed, acceleration, the amount of depression of the brake pedal or accelerator pedal, and the important points are the amount of acceleration / deceleration operation by the driver, the driving state of the vehicle, or traveling It is a state quantity indicating a state. Further, when a shift is executed by the automatic transmission 2, the elapsed time from the time when the shift is executed is counted (step S2). Further, it is determined whether or not the accelerator opening is lower than the threshold value θ0 (step S3). This threshold value θ0 is a value equal to or less than the partial opening in the region where the fuel consumption is determined by the shift line, for example, an opening of about 40%, an example of which is schematically shown in FIG. In other words, if the accelerator opening is equal to or greater than the threshold value θ0, a large driving force is required and there is little need to execute a forced shift giving priority to fuel efficiency, and a forced shift is performed. If there is a high possibility that the shock will increase, and therefore the accelerator opening is greater than or equal to the threshold value, the so-called forced shift based on the shift line is not executed. That is, if a negative determination is made in step S3, the process returns without performing any particular control.

  In FIG. 2, in a so-called hysteresis region between the upshift line and the downshift line, a region in which the forced shift is executed when the vehicle driving state or the traveling state remains for a predetermined time or more is hatched. It is shown. This region is set as a region separated by a predetermined amount from the upshift line and the downshift line. This is because if the driving state or the traveling state is close to the upshift line or the downshift line, even in the hysteresis region, even if the gear is forcibly shifted from that state, the effect of improving the fuel efficiency is small.

  If the accelerator opening is smaller than the threshold value θ0 and a positive determination is made in step S3, a threshold value for the road surface gradient, which is one of the driving environments in which the vehicle is traveling, is obtained ( Step S4). This is to determine the magnitude of the road gradient, and the road gradient is determined because the road gradient may be a large factor that induces shifting. The threshold values a and b are upper limit values of a gentle gradient that does not require a rapid acceleration / deceleration operation (for example, pedal operation) by the driver, and an example thereof is shown in FIG. For example, the threshold value a for the downhill is larger than the threshold value for the uphill (uphill). This is because in the case of climbing slope, it is highly likely that a downshift will occur when the accelerator pedal is depressed greatly.

  The threshold values a and b thus calculated are compared with the current gradient of the road surface on which the vehicle is currently traveling (step S5). That is, it is determined whether or not the current gradient is between the threshold values a and b. Here, the current gradient may be obtained from road information obtained by the navigation system, or may be obtained by calculation based on the accelerator opening or throttle opening and acceleration (rate of change in vehicle speed). When the current gradient thus determined is equal to or lower than the downward gradient threshold value a, that is, when the current slope is equal to or higher than the upward gradient threshold value b, that is, when the current gradient is equal to or higher than the downward gradient threshold value a. In the case of an uphill road that is steeper than the gradient threshold value b, priority is given to securing the engine braking force and the uphill force, and so-called forced shift based on the shift line is not executed. That is, if a negative determination is made in step S5, the process returns without performing any particular control.

  On the contrary, if the current gradient is within the range of the threshold values a and b for the gradient and the determination is affirmative in step S5, the amount of change in the accelerator opening is calculated (step S6). ). This calculation can be performed by obtaining a change in a detected value by an accelerator opening sensor (not shown). Next, a threshold value for the accelerator opening fluctuation amount is calculated (step S7). This threshold value is set as the upper limit value of the gentle accelerator pedal operation that the driver performs regardless of the will of rapid acceleration or rapid deceleration (engine braking). It can be set to both. As will be described below, the accelerator opening is judged whether the driver is accelerating or decelerating to perform an accelerator operation, or a change in accelerator opening that does not particularly require acceleration or deceleration (or The thresholds e and f for the accelerator opening can be determined experimentally or empirically so that the determination can be made accurately, or simulation is performed. Can be determined as appropriate. An example of the threshold values e and f is shown in FIG. The example shown here is an example in which the threshold values e and f are constant regardless of the accelerator opening.

  After calculating the threshold values e and f for the fluctuation amount of the accelerator opening as described above, whether or not the fluctuation amount of the accelerator opening calculated in step S6 is within the range of the threshold values e and f. Is determined (step S8). If the accelerator pedal is returned to the return side threshold value e or more, and if the accelerator pedal is depressed to the depression side threshold value f or more, a negative determination is made in step S8. Thus, when a negative determination is made in step S8, the driver is demanding a large engine braking force or a large driving force, and therefore there is a high possibility that a downshift or an upshift will occur. The above-described forced shift is not performed. That is, if a negative determination is made in step S8, the process returns without performing any particular control.

  On the contrary, if the determination in step S8 is affirmative, that is, if the amount of change in the accelerator opening is within the range of the threshold values e and f, the threshold values c and d for the acceleration. Is calculated (step S9). This is to determine the magnitude of the acceleration that is currently occurring or the currently required acceleration, and the magnitude of the acceleration is to determine whether or not a shift is necessary or whether a shift is likely to occur. It is. FIG. 5 shows examples of acceleration (acceleration / deceleration) threshold values c and d. The example shown here is an example in which the threshold values c and d are constant regardless of the magnitude of the acceleration / deceleration G. is there.

  Therefore, in step S10 following step S9, it is determined whether or not the current acceleration is within the range of the threshold values c and d, that is, the vehicle state is suddenly accelerated (rapid descent or sudden depression of the accelerator pedal). ) Or sudden deceleration (sudden climbing or braking) is determined. The current acceleration is the current actual acceleration (including deceleration that is a negative acceleration) or the acceleration required at the present time, and may be obtained as the rate of change of the vehicle speed, or the accelerator opening or road gradient. Alternatively, it may be obtained from load / load. When the current acceleration is smaller than the deceleration-side threshold c, that is, when the deceleration is greater than or equal to the threshold c, and when the current acceleration is greater than the acceleration-side threshold d, the driver is large. Since the engine braking force or a large driving force is demanded, and therefore there is a high possibility that a downshift or an upshift will occur, the above-mentioned forced shift in consideration of fuel efficiency is not performed. That is, if a negative determination is made in step S10, the process returns without performing any particular control.

  On the contrary, if the current acceleration is within the range of the acceleration / deceleration threshold values c and d and the determination is affirmative in step S10, the driver does not particularly require acceleration / deceleration. In this case, a threshold value g for the elapsed time from the previous shift is calculated (step S11). This threshold value g is for preventing the above-described forced shift itself taking into account fuel efficiency from being a busy shift, and is set to a value according to the driving state and traveling state of the vehicle. The value can be determined by experiment or based on simulation and experience, an example of which is shown in FIG. In the example shown here, the threshold value g is set to a larger value as the vehicle speed is higher and the accelerator opening is larger. Then, the threshold value g is compared with the elapsed time after the shift (step S12). If it is determined negative in step S12 because the elapsed time after the shift is less than or equal to the threshold value g, the process returns without performing any particular control. In order to avoid the above-described forced shift itself considering the fuel consumption from becoming a busy shift, the forced shift is prohibited. On the other hand, if the elapsed time after the shift exceeds the threshold value g and a positive determination is made in step S12, the fuel speed is optimized (or the fuel efficiency is improved from the current level). Is selected (step S13). That is, the above-mentioned forced shift in consideration of fuel consumption is executed.

  In addition, it is possible to add control for determining whether or not to perform constant speed traveling control (auto cruise control) for maintaining the vehicle speed at the set vehicle speed is selected by a switch (SW) operation. An example thereof is shown in FIG. 7, and it is determined whether or not the auto-cruise switch is OFF following step S12 described above (step S12a). If the determination result is affirmative, that is, if auto-cruise control is not being executed, the routine proceeds to step S13, where a gear stage that improves fuel efficiency is selected, and another gear shift following the gear shift to that gear stage is performed. Suppression control is executed so as not to cause a busy shift.

  Therefore, the above-mentioned forced shift considering the fuel consumption, that is, the shift to the shift stage (gear stage) with the optimum fuel consumption is determined by the above-described step S3 and step S5 and step S8, step S10, step S12, and step S12a. It becomes executable after it is broken. In each of these determination steps S3, S5, S8, S10, S12, and S12a, the shift to the optimal fuel efficiency gear stage itself is newly interspersed with the shift accompanying the request for driving force or acceleration / deceleration, etc. If it is determined that the busy shift will not occur, a shift to the optimum fuel efficiency shift stage is executed or becomes possible. It should be noted that making such a determination also prohibits gear shifting that may hinder smooth changes in driving force.

  In addition to the determination of the busy shift described above or the prohibition based on the determination, the control device of the present invention determines the relationship with the shift following the shift to the optimal fuel efficiency shift stage, and permits the shift to the optimal fuel efficiency shift stage. And is configured to do bans. An example of the control is shown in the flowchart of FIG. The example shown here is the subroutine of step S13 described above. First, the time for permitting the next shift is read (step S101). Here, the “next shift” is a shift that occurs after the forced shift, assuming that a forced shift to the optimal fuel efficiency gear stage has been executed at the present time, and “permitted time” Is a time interval in which the next shift after the forced shift is not felt as a busy shift. Therefore, this time can be obtained based on the map shown in FIG. 6 described above or a similar map.

  Next, a change in the driving load in the near future is estimated (step S102). This load is an engine load, and there are various fluctuation factors. For example, the load increases due to a relatively close uphill road, the load changes due to braking due to traffic jam ahead, and the accelerator pedal is returned to reduce the load when entering the front corner, reducing the load Fluctuations, an increase in load due to an acceleration operation when exiting a corner, a load fluctuation due to a decrease in vehicle speed due to an intersection, a traffic light, or a stop instruction. As an example of these load fluctuations, the load fluctuations due to the uphill road will be described. FIG. 9 shows the subroutine of step S102 described above. First, various information (data) is acquired (step S201). Examples of the information include information on the driving environment by the navigation system (NAVI information), acceleration / deceleration information by the acceleration sensor (G sensor), steering angle, turn signal indicator signal, auto cruise switch ON / OFF information. Information on distance sensors in radar cruise control systems.

  The uphill road ahead can be acquired by the navigation system as road information related to the planned travel road, and first, a passing point after h seconds is calculated (step S202). Specifically, the horizontal distance A from the present time to a point after h seconds is obtained. This is obtained by multiplying the vehicle speed by h seconds. Further, an altitude difference is calculated by subtracting the current altitude from the altitude after h seconds (step S203). Then, the altitude difference B is divided by the horizontal distance A and the value (quotient) is multiplied by the vehicle weight to calculate the travel load fluctuation (step S204).

  When decelerating by braking due to traffic congestion or approaching or entering a corner, the braking load is calculated, and when accelerating when exiting a corner, the load from the accelerator opening or vehicle speed is calculated. What is necessary is just to calculate an increase.

In the control example shown in FIG. 8, the traveling load (more precisely, the variation of the traveling load) obtained as described above is changed to the acceleration / deceleration α (step S103). Based on the acceleration / deceleration α, an average value i of the pre-read acceleration / deceleration is calculated (step S104). this is,
i = current acceleration−α / 2
Can be calculated. The average acceleration / deceleration i is used to calculate the vehicle speed j after h seconds (step S105). Next, based on the average acceleration / deceleration value i, it is determined whether the upshift or the downshift is to be performed. That is, it is determined whether or not the average value i of acceleration / deceleration is “0” or more (step S106). If an affirmative determination is made in step S106, the vehicle is accelerating. Conversely, if a negative determination is made in step S106, the vehicle is decelerating.

  If the vehicle is accelerating as determined affirmatively in step S106, whether or not the vehicle speed j estimated as the vehicle speed after h seconds is equal to or higher than the vehicle speed defined by the upshift line in the shift diagram (upline vehicle speed). Is determined (step S107). Further, when a negative determination is made in step S106, that is, when it is estimated that the average acceleration i is negative and the vehicle decelerates, the vehicle speed j estimated as the vehicle speed after h seconds is a shift diagram. It is determined whether the vehicle speed is equal to or lower than the vehicle speed defined by the downshift line (downline vehicle speed) (step S108). If the vehicle speed j estimated as the vehicle speed after h seconds exceeds the up-line vehicle speed and is determined negative in step S107, the routine of FIG. 8 is temporarily terminated. Similarly, if the vehicle speed j estimated as the vehicle speed after h seconds is less than the down line vehicle speed and a negative determination is made in step S108, the routine of FIG. 8 is temporarily terminated. This is because it is estimated that the driving state or the traveling state of the vehicle does not stay in the above-described hysteresis region but changes across the shift line.

  As shown in FIG. 2 described above, the substantial hysteresis region for performing so-called forced shift is a region away from the upshift line and the downshift line to some extent, so the upline in step S107 described above. The vehicle speed may be lower by a predetermined vehicle speed than the vehicle speed at which the upshift line is set. Similarly, the down line vehicle speed in step S108 may be a vehicle speed higher by a predetermined vehicle speed than the vehicle speed for which the downshift line is set.

  If the vehicle speed j estimated as the vehicle speed after h seconds is equal to or less than the up line vehicle speed, a positive determination is made in step S107, and the vehicle speed j estimated as the vehicle speed after h seconds is greater than or equal to the downshift line vehicle speed. If the determination is affirmative in step S108, the shift stage (gear stage) k when the shift is performed based on a normal shift line prepared in advance is calculated (step S109). As shown in FIG. 2 or FIG. 11 described above, the downshift line is set so as to be shifted to the low vehicle speed side with respect to the upshift line. In the hysteresis region, the shift speeds that can be set on the shift map are the current gear position and the gear position that is one speed higher than that. Accordingly, the gear stage k calculated in step S109 is either the current gear stage or a gear stage on the higher vehicle speed side than that.

  Next, the driving force I at the gear stage k calculated in step S109 is calculated (step S110). Since the torque output from the engine 1 is transmitted to the wheel 5 through the drive system shown in FIG. 10 and generates driving force, the output torque of the engine 1 and the speed change between the engine 1 and the wheel 5 are changed. Based on the ratio, the diameter of the wheel 5, the transmission efficiency, and the like, the driving force I can be calculated by a conventionally known method or arithmetic expression.

  The automatic transmission 2 that is the subject of the present invention is configured so that a plurality of forward gears can be set, and therefore there are a plurality of gears that can obtain the driving force I calculated in step S110 described above. . Therefore, in step S111 following step S110, an engine torque and a gear position that satisfy the driving force I are calculated. In performing the calculation, two variables of the engine torque and the shift speed are obtained. However, the shift speed is limited to a speed that can be set by the automatic transmission 2, and the respective gear ratios are known. Therefore, the engine torque may be obtained for each gear ratio. Further, the engine speed and torque of the engine 1 are limited in terms of mechanism and limited so as not to generate vibrations and noise that impair the riding comfort of the vehicle. Of the gears, the engine torque and gears that can be actually used are limited to those that are not subject to these restrictions.

  Then, the gear position having the best fuel efficiency, that is, the minimum fuel consumption gear position is selected from the actually-adopted gear positions calculated in step S111 (step S112). The engine speed can be obtained based on the gear position and the vehicle speed, and the engine torque is calculated. Based on these values and the map, the engine speed that provides the best fuel efficiency and the What is necessary is just to obtain | require a corresponding gear stage.

  Therefore, in the control shown in FIG. 8 executed by the control device according to the present invention, in step S101 to step S108 described above, there is a possibility of a busy shift, so a predetermined time for the future in which shifting is prohibited. If a change in travel load or vehicle speed within the width h is estimated and it is determined that a shift based on the normal shift diagram does not occur within the time width h, it is not based on the shift diagram. In addition, a forced shift to the minimum fuel consumption gear position is executed. Therefore, by performing the control as described with reference to FIGS. 1 to 9, not only the so-called forced shift itself becomes a busy shift but also the next shift by executing the so-called forced shift. Can be avoided in advance. Further, since the driving force does not particularly change even after so-called forced shifting, it is possible to prevent or suppress the driver from feeling uncomfortable in combination with avoiding the busy shift.

  If the determination in step S12a shown in FIG. 7 is negative, that is, if the switch for executing auto-cruise control is ON, the process immediately proceeds to step S109 shown in FIG. The minimum gear position is selected. The reason for this is that the auto-cruise control state is basically a state in which the driver is not actively accelerating / decelerating, so the possibility of a busy shift is low, and the minimum fuel consumption gear position. It is because it is more advantageous to move to.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means for executing the control in steps S101 to S108 shown in FIG. 8 corresponds to the shift prediction means in the present invention. The functional means for executing the control corresponds to the gear selection means in the present invention.

  The specific example described above is an example of forcible shift when hysteresis is provided in the shift line for shift control, but the hysteresis is set for various controls in the vehicle. It is also set for clutch engagement / release control or slip control (flex lock-up control), and when performing such control as forced lock-up or release in the hysteresis region in such control, The control described above can be applied. The present invention can also be applied to a control device for an automatic transmission of a hybrid vehicle having an internal combustion engine and a motor as power sources. Furthermore, the automatic transmission according to the present invention may be a transmission configured to change the transmission ratio of a continuously variable transmission such as a belt-type continuously variable transmission stepwise.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 3 ... Output shaft, 5 ... Wheel, 6 ... Torque converter, 7 ... Electronic control device for engines, 8 ... Electronic control device for automatic transmissions

Claims (5)

A region in which a shift is executed based on a shift diagram in which a predetermined hysteresis is set between an upshift line and a downshift line, and the vehicle driving state or running state is set to the hysteresis in the shift diagram If you are staying first place constant time or more, the control system for an automatic transmission for a vehicle that is configured to perform a shift to the good gear position of the fuel economy,
Second place constant time set so as to prohibit busy shift from the current time when the driving state or the running state of the vehicle has remained first place constant time or more in a region where the hysteresis in the shift diagram is set Shift prediction means for predicting that a shift based on the shift map will occur before the passage of time;
And a shift speed selection means for executing a shift to a shift speed with good fuel efficiency when the shift prediction means does not predict that the shift based on the shift diagram will occur. Automatic transmission control device.   The shift stage having the best fuel consumption includes a shift stage having the best fuel consumption among the shift stages that generate a driving force equivalent to that when the shift is performed based on the shift diagram. The control apparatus of the automatic transmission for vehicles as described.   The shift prediction means includes means for predicting that a vehicle load or a vehicle speed changes according to a road condition of a planned traveling road ahead of the vehicle, and predicting whether or not a shift based on the prediction occurs. The control device for an automatic transmission for a vehicle according to claim 1 or 2.   4. The control device for an automatic transmission for a vehicle according to claim 3, wherein the road condition includes any one of a slope, presence / absence of traffic congestion, a corner entrance or exit, a stop signal, or a stop instruction. The shift prediction unit, the shifting occurs if the previous SL driving state or the running state of the vehicle after the second place constant time is in a state of change across the upshift line or a downshift line in the shift diagram 5. The control device for an automatic transmission for a vehicle according to claim 1, further comprising means for establishing the prediction.

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