JP3911738B2 - Vehicle control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control apparatus, and more particularly to control of a gear ratio of an automatic transmission including a stepped transmission and a continuously variable transmission.
[0002]
[Prior art]
For example, Japanese Patent Publication No. 6-58141 has been proposed as a control device for an automatic transmission provided with a shift means for changing the control pattern of the automatic transmission according to road information about the current position of the vehicle.
[0003]
[Problems to be solved by the invention]
However, in the above technique, there is a problem that acceleration / deceleration due to downshifting and upshifting is limited in order to prohibit shifting when traveling on a curve. In other words, before entering the curve, downshift and apply the engine brake, reduce the vehicle speed to a speed that can smoothly pass the curve, and apply a large driving force to the wheels at a low gear position, so that it is stable. You can no longer pass the curve. In addition, even after passing through a point with the highest curvature of the curve, if the shift up is limited, the engine speed may become too high.
[0004]
For this reason, the present inventor uses a navigation device to detect in advance that there is a curve ahead of the course, and when entering the curve, the inventor controls the automatic transmission so as to shift down like a manual shift. In addition, the inventors have devised a technique that allows the vehicle to pass through the curve stably by applying a large driving force to the wheels at a low gear position.
[0005]
However, even if the downshift is performed before the curve using this technique, the automatic transmission performs the upshift according to the vehicle speed and the throttle opening. It will shift up and down. For this reason, unnecessary shifts are repeated while passing the curve, and in addition to the transmission of the driving force being interrupted during shifting, the powerful driving force required to pass the curve is shifted up to a higher shift stage. When you hit, you will not be able to get. For this reason, it is necessary to limit the upshifting until the curve is completed.
[0006]
Here, the shift-up limitation needs to be continued until the vehicle finishes running on the curve. However, it becomes a problem at what timing this cancellation is performed. Here, for example, if the restriction is released after driving a fixed distance from a point with the largest curvature of the curve, the shape of the curve, the curvature of the curve, the bank angle of the curve, the road surface condition, the slope of the road, Since there are various curve conditions such as road width, the release of the restriction is too late and it is not possible to shift up properly, giving the driver a sense of incongruity, or the release is too early and shifting up in the middle of the curve It is expected that a large driving force cannot be transmitted to the wheels.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that can appropriately switch from a shift speed control for curve travel to a normal shift speed control. There is.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, in the vehicle control device according to claim 1, a current position detecting means for detecting a current position;
  Road data storage means for storing road data;
  A curve detection means for detecting a forward curve based on the current position detected by the current position detection means and the road data stored in the road data storage means;
  Downshift determination means for determining whether or not a downshift is necessary based on road data relating to a forward curve detected by the curve detection means and the current position detected by the current position detection means and the vehicle speed at the current position;
When it is determined by the downshift determining means that downshifting is necessary,Downshift means for downshifting before passing through a predetermined position of the curve;
  Predetermined position passage determination means for determining whether or not the vehicle has passed a predetermined position of the curve based on the current position detected by the current position detection means and road data stored in the road data storage means;
  Vehicle speed memory for storing the vehicle speed when the curve passes through a predetermined positionmeansWhen,
  While it is determined by the predetermined position passage determining means that the predetermined position has not been passed, the gear ratio is limited to be shifted up, and after passing the predetermined position, until the vehicle speed at the predetermined position becomes higher than the predetermined speed. It is a technical feature to have a shift-up limiting means for limiting the shift-up.
[0010]
  In the vehicle control device according to claim 2, current position detecting means for detecting a current position;
  Road data storage means for storing road data;
  A curve detection means for detecting a forward curve based on the current position detected by the current position detection means and the road data stored in the road data storage means;
  Downshift determination means for determining whether or not a downshift is necessary based on road data relating to a forward curve detected by the curve detection means and the current position detected by the current position detection means and the vehicle speed at the current position;
  Downshift means for downshifting the gear ratio before passing through a predetermined position of the curve when the downshift judging means judges that downshifting is necessary;
  Predetermined position passage determination means for determining whether or not the vehicle has passed a predetermined position of the curve based on the current position detected by the current position detection means and road data stored in the road data storage means;
  Vehicle speed storage means for storing the vehicle speed when the curve passes a predetermined position;
  While the predetermined position passage determining means determines that the predetermined position has not been passed, the gear ratio shift-up is restricted, and after the predetermined position has passed, the predetermined position is determined.SaidUpshift limiting means for limiting upshifting when the increase amount of the vehicle speed relative to the vehicle speed when passing through the predetermined position is equal to or less than a predetermined value until it is determined that the current position detected by the current position detection means is a predetermined distance apart. And having a technical feature.
[0013]
  In the vehicle control device according to the first aspect, the current position detecting means detects the current position, and the curve detecting means detects the forward curve based on the road data stored in the road data storage means. And the shift down meansIn placeShift down before passing. The shift-up limiting means limits the shift-up of the gear ratio while the predetermined position passage determining means determines that the predetermined position has not passed, and after the predetermined position has passed,In placeUpshifting is limited until a predetermined speed higher than the speed at the time of passage.
[0014]
  Claim1Then, the shift down means shifts so that it can decelerate appropriately with engine brake when entering the curve.ratioHowever, in normal control of an automatic transmission, even if the gear is once shifted down, the gear is shifted up based on the vehicle speed and the throttle opening. This is limited by the up-shifting limiting means, so that a low speed change is possible.ratioThe vehicle can pass through the curve in a state where a large driving force is applied to the wheels and the vehicle is stabilized.
[0015]
  In the vehicle control device according to the second aspect, the current position detecting means detects the current position, and the curve detecting means detects the forward curve based on the road data stored in the road data storage means. Then, the shift down means shifts down before passing a predetermined position on the curve. And the upshift limiting meansPlaceAfter it is determined that a predetermined interval has passed after passing through the fixed position, the upshift is permitted at the normal vehicle speed.
[0016]
  According to the second aspect of the present invention, the shift-down means shifts so that the engine brake can appropriately decelerate when entering the curve.ratioHowever, in normal control of an automatic transmission, even if the gear is once shifted down, the gear is shifted up based on the vehicle speed and the throttle opening. By limiting this by the shift-up limiting means, it is possible to maintain a low gear ratio and pass the curve in a state where a large driving force is applied to the wheels and the vehicle is stabilized. In addition, after passing a predetermined positionintervalSince the upshift at the normal vehicle speed is permitted when the vehicle is separated, the normal gear ratio control can be resumed when the vehicle is away from the curve even if the vehicle speed is not so high.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.
FIG. 1 shows a control mechanism of a vehicle control device according to a first embodiment of the present invention. In this vehicle, the vehicle navigation device 10 that detects the position of the vehicle and performs route guidance and selects a gear position when traveling on a curve, and the automatic transmission 60 based on a preset control pattern are controlled. An automatic control unit 20 for controlling the engine 50 and an engine control unit 30 for controlling the engine 50 are provided.
[0018]
The navigation device 10 receives a radio wave (GPS signal) from an artificial satellite through the antenna 12 using GPS (Global Positioning System), calculates the current position, reads out the road data recorded in the CDROM 14, and maps Identifies the current position above. Furthermore, as will be described later, the shift stage selected based on the curve in the road data and the gradient of the connection path to the curve is sent to the automatic control unit 20.
[0019]
The engine control unit 30 controls the throttle opening signal from the throttle 70, the engine speed from the engine 50 and others (cooling water temperature, 0₂The engine 50 is controlled by giving a fuel injection command to the engine 50 based on the sensor signal and the like.
[0020]
The automatic control unit 20 is configured to give a gear shift command to the automatic transmission 60 according to a selected control pattern based on the throttle opening signal from the throttle 70 and the vehicle speed from the automatic transmission 60. . The shift lever 74 is a 6-position type having six ranges, ie, a drab range, a second range, a low range, a neutral range, a parking range, and a reverse range. Select the most appropriate speed among the 3rd speed, 2nd speed, 1st speed based on the throttle opening and the vehicle speed, and set the 2nd speed or 1st speed when the second range is set, When the low range is set, it is fixed at the first speed. On the other hand, the automatic transmission 60 having a four-speed gear stage switches the gear stage according to a command from the automatic control unit 20 according to the operation of the shift lever 74. Further, the automatic transmission 60 is configured to shift to a gear stage according to a command from the navigation device 10 in accordance with a curve curvature and a road gradient, which will be described later, in a state where the drive range is selected.
[0021]
Here, prior to the description of the shift speed control by the automatic control unit 20 of the present embodiment, the contents of the road data recorded in the CD ROM 14 will be described with reference to FIG.
FIG. 3 schematically shows the contents of the road data. In the figure, a solid line R indicates a road. Here, in the road data, the road is converted into data as a locus defined by a plurality of node points N1, N2,. That is, the coordinates (latitude / longitude) of each node point shown in the figure are held as data, and the road is processed as a series of line segments (hereinafter referred to as links) connecting the node points. . This method of converting roads into data based on node points is generally employed as navigation data. Here, the link connecting the node points N1 and N2 having a relatively large interval is a substantially straight road, and the node points N3, N4... N9 having a small interval are S-shaped curved roads. .
[0022]
On the other hand, in the first embodiment, not only the node points for conceptualizing the road described above, but also the altitudes are held in a matrix. The matrix points are provided at intervals of 250 m. For example, the altitude point indicated by 10-10 in the figure is an altitude of 20 m, and the altitude point indicated by 10-11 is an altitude of 22 m.
[0023]
In the first embodiment, the road gradient is obtained from the position of the node point indicating the inflection point of the conventional road and the relative position of the altitude data in a matrix surrounding the node point. In this embodiment, in order to reduce the amount of data, the road gradient is obtained by holding the matrix elevation points in the road data, but it is also possible to add gradient data for each node point. is there.
[0024]
Next, the control concept of the shift speed by the automatic control unit 20 of this embodiment will be described.
In this embodiment, the shift speed control corresponding to the curve is started from the front side of the curve. In other words, in curve-compatible shift speed control, when the foot is released from the accelerator pedal before the curve and the throttle opening is lowered, downshifting is performed opposite to normal control, and the engine brake is effectively applied. Therefore, the vehicle speed can be reduced so that the car can run smoothly.
[0025]
Here, on the uphill road, since the running resistance is high and the vehicle speed is greatly reduced by the engine brake, the curve-corresponding speed control is started from a position close to the curve. On downhill roads, since the running resistance is low and the decrease in vehicle speed due to engine braking is small, the curve-corresponding speed control is started at a position far from the curve.
[0026]
Next, the curve-corresponding shift speed control will be described with reference to FIGS. 4 to 8 showing flowcharts of the control. Here, the upper side of FIG. 4 shows a main routine of processing of the navigation apparatus 10 that performs curve-related shift speed control. The lower side of FIG. 4 shows the processing of the automatic control unit 20 according to the processing by the navigation device 10.
[0027]
First, the navigation device 10 determines whether or not the vehicle has entered and exited at a position where curve-related shift speed control is to be started (curve control start cancellation process: S10). Next, the optimum shift speed is calculated based on the curve-corresponding shift speed control, and the selected optimal shift speed is sent to the automatic control unit 20 side at the timing when the accelerator pedal is turned off and the brake pedal is turned on (there is an event) ( Event control by accelerator-off / brake-on: S40). Finally, downshifting is also performed when there is no accelerator-off event (shift stage standby control: S80).
[0028]
On the other hand, as shown in the lower side of FIG. 4, the automatic control unit 20 determines that the gear position switching command from the navigation device 10 side is the gear position selected by itself (S210), and selects the gear position switching actuator. It is driven to actually switch the gear position of the automatic transmission 60 (S220).
[0029]
First, the curve control start / cancel process (S10) for determining whether the vehicle has entered the position to start or cancel the curve corresponding gear position control will be described with reference to FIG. 5 showing the subroutine of the process. .
First, the purpose of the curve control start / release process will be described. As will be described later, the automatic control unit 20 performs gear shift switching that is contrary to normal gear shift switching during execution of curve-corresponding gear shift control. In other words, during normal driving, when the throttle opening is lowered by turning off the accelerator pedal, the shift is upshifted, whereas when performing curve-related shift speed control during curve driving, as described above, the accelerator pedal is Control is performed to shift down the gear position when the throttle opening is reduced by turning off.
[0030]
Here, if the upshift is performed in the same way as usual while passing through the curve, the upshift is immediately performed and the downshift is performed immediately after the downshift is temporarily performed by the curve corresponding gear position control. For this reason, unnecessary shifts are repeated while passing the curve, and in addition to the transmission of the driving force being interrupted at the time of shifting, the powerful driving force required to pass the curve is obtained during the selection of a high shift stage. I can't. For this reason, in this embodiment, it is determined whether or not the vehicle has passed the curve by the curve control start / release process, and control for suppressing the shift-up of the gear stage is performed until the vehicle exits the curve.
[0031]
First, the navigation device 10 determines whether a drive range is set for the automatic shift lever 74 (S12). Here, when the second range and the low range are set (No in S12), in order to respect the driver's intention, the flag for performing the curve-compatible shift speed control is folded (S37), and the process is terminated.
[0032]
On the other hand, when the drive range is set (S12 is Yes), the radio wave from the artificial satellite is received via the antenna 12 using GPS (Global Positioning System), and the current position is calculated and recorded in the CDROM 14. The road data is read out, the current position on the map is identified, and the node points within the predetermined range described above with reference to FIG. 3 are detected (S14). Further, from the node point, it is determined whether a curve exists in the traveling direction, and a node point at a specific point (a point having the largest curvature) that is the peak of the curve is detected (S16). For example, at three consecutive node points, the angle between the side formed by the first node point and the second node point and the side formed by the second node point and the third node point is If it is 170 ° or less, it is recognized that there is a curve, and a node that forms the largest angle among consecutive node points forming the curve is defined as a specific node point (specific point).
[0033]
Thereafter, it is determined whether or not the flag indicating the curve corresponding shift speed control is set (S18). Here, when the curve-corresponding speed control is not yet started and the flag is not set (No in S18), the distance from the specific point to the current vehicle position is calculated (S20). Then, it is determined whether the current vehicle is within a predetermined distance before the curve (for example, 500 m before) (S21). Here, when the current vehicle is within a predetermined distance before the curve (Yes in S21), a flag indicating curve-corresponding shift speed control is set (S22), and the process is terminated. On the other hand, until the predetermined distance before the curve is reached (No in S21), the process ends without setting the flag.
[0034]
In this embodiment, whether it is in front of the curve or in front of a fixed predetermined distance is determined, but it is also possible to make it different according to the curvature of the curve and the gradient of the connection path to the curve. . For example, it is possible to make a judgment based on whether it is 700 m before the curve that has a small curvature and cannot pass smoothly unless the speed is reduced. .
[0035]
In determining whether or not the flag in step 18 is set, curve-corresponding shift speed control has already been started, and if the flag is set (Yes in S18), has the curve peak (specific point) passed? It is determined whether or not it is necessary to cancel the curve-corresponding speed control (S23). Here, until it passes through the peak (No in S23), the process ends after the determination in Step 24 (No in S24).
[0036]
On the other hand, when the vehicle passes the peak (S23 is Yes), first, a peak flag indicating the peak passage is set (S25), and the vehicle speed at the time of the peak passage is input (S26). Thereafter, the curve-corresponding speed control is canceled by the following processing. On the other hand, after the passage of the peak and before the release of the curve-corresponding shift speed control, the determination of whether the peak is in step 23 is No, the determination of whether the peak flag is set in Step 24 is Yes, and Step 27 Migrate to
[0037]
In this embodiment, the process for canceling the curve-corresponding speed control is started based on whether or not the peak (specific node point) has been passed, but this process is performed at various positions on the curve. Can start. For example, starting at the time when the vehicle travels 2/3 of the curve, or when the vehicle travels a predetermined distance after passing the peak, or when a predetermined time has elapsed, a predetermined point corresponding to the radius of the curve. You can also start with
[0038]
Subsequently, the navigation apparatus 10 inputs the shift stage selected by the automatic control unit 20 (S27), and compares the shift stage selected by the automatic control unit 20 with the shift stage selected by the navigation apparatus 10 itself. (S28). Here, when the selections of the automatic control unit 20 and the navigation device 10 match (Yes in S28), it is not necessary to continue the curve-compatible shift speed control, that is, the special shift speed control for passing the curve. The process proceeds to step 37, where the flag is folded and the shift control corresponding to the curve is released. On the other hand, when the selection between the automatic control unit 20 and the navigation device 10 does not match (No in S28), the process of limiting the upshifting according to the vehicle speed is continued.
[0039]
Here, first, vehicle information such as the current vehicle speed Vnow and the vehicle speed at the time of passing the peak is input (S29), and then it is determined whether the second speed is currently selected as the gear position (S30). Here, when the second speed is currently selected (S30 is Yes), it is determined whether the current vehicle speed Vnow is equal to or higher than the release vehicle speed 1 that restricts the shift-up from the second speed to the third speed (S31). The release vehicle speed 1 is set to a value obtained by adding a specified vehicle speed (for example, 10 km / h) to the vehicle speed based on the vehicle speed when passing the peak point of the curve. For example, if the vehicle speed at the peak passage is 35 km / h, the release vehicle speed 1 is 45 km / h. Here, the release vehicle speed 1 is set to be higher than the vehicle speed that is the reference for the upshifting from the second speed to the third speed in the shift speed control according to the normal shift pattern.
[0040]
Here, the vehicle speed at the time of passing the peak point is used as a reference, but it is also possible to use the vehicle speed at the time of releasing the brake pedal while passing the curve as a reference instead. Note that when the brake pedal is depressed, the gear is shifted down to the second speed as described later).
[0041]
Furthermore, as a release vehicle speed 2 to be described later for permitting upshifting from the 3rd speed to the 4th speed, a value obtained by adding a specified vehicle speed (for example, 25 km / h) to the vehicle speed based on the vehicle speed when passing the peak point is used as a reference. It is set. For example, if the vehicle speed at the time of peak passing is 35 km / h, the release vehicle speed 2 is 60 km / h. The release vehicle speed 2 is set to be higher than the vehicle speed that is the reference for the upshifting from the 3rd speed to the 4th speed in the shift speed control according to the normal shift pattern in the same manner as the release vehicle speed 2.
[0042]
Here, until the current vehicle speed Vnow exceeds the release vehicle speed 1 (No in S31), a command with the second speed as the upper limit is sent (S32). That is, downshifting to the first speed is permitted, but upshifting to the third speed is prohibited, and the automatic control unit 20 selects the gear position accordingly (see the lower stage in FIG. 4). Thereafter, a distance from the specific point (specific node point) is calculated (S35), and it is determined whether the calculated distance is a predetermined distance or more (for example, 300 m) (S36). Here, until the distance from the peak is a predetermined distance or more (S36 is No), the process is terminated. On the other hand, if it is more than the predetermined distance from the peak (S36 is Yes), the vehicle has completely escaped from the curve, and the curve-corresponding speed control is not necessary, so the flag is folded (S37). Here, apart from the determination based on the vehicle speed, the restriction is released by moving away by a predetermined distance or more, so it is possible to reliably end the curve-corresponding speed control regardless of the vehicle speed.
[0043]
Thereafter, when the vehicle speed further increases and the current vehicle speed Vnow becomes equal to or higher than the release vehicle speed 1 (S31 is Yes), a command for setting the third speed as the upper limit is sent through the determination in step 33 (S34). In accordance with this command, the automatic control unit 20 selects a gear position according to the vehicle speed and the throttle opening. That is, the automatic control unit 20 follows a command on the navigation device 10 side when the selected shift speed and the commanded shift speed do not match. Here, in the curve, by shifting up at a vehicle speed higher than the second to third shift up in the shift speed control according to the normal shift pattern, a high driving force is applied to the wheels, and the curve traveling is stabilized. By increasing the rotation speed of the engine 50 and increasing the output, a high acceleration force can be obtained when escaping from the curve.
[0044]
Here, until the current vehicle speed Vnow exceeds the release vehicle speed 2 (No in S33), the sending of the command with the third speed as the upper limit is continued (S34). That is, downshifting to the second speed is allowed, but shifting up to the fourth speed is prohibited. Then, when the current vehicle speed Vnow exceeds the release vehicle speed 2 and the shift up is further limited, the driver feels uncomfortable (Yes in S33), the flag for limiting the shift up is folded (S37), and the peak passage is indicated. The flag is folded (S38), the curve-corresponding shift speed control is canceled, the upshift to the fourth speed is permitted, and the process is terminated.
[0045]
Subsequently, the event control (S40 shown in FIG. 4) by accelerator-off / brake-on following the above-mentioned shift stage hold control (S20 shown in FIG. 4), that is, the control for the downshift performed before the curve passes the peak. The process will be described with reference to the flowcharts of FIGS.
First, the navigation device 10 searches for the curvature of the specific node point (curve peak point) detected in step 16 of the curve control start process (S42), and the recommended vehicle speed according to the curvature of the node point (curve). V0 is searched (S44). FIG. 2A shows the relationship between the curve curvature and the recommended vehicle speed V0. Here, when the curvature decreases, the recommended vehicle speed V0 that can pass smoothly decreases, and conversely, when the curvature increases, the recommended vehicle speed V0 increases. The navigation device 10 is provided with a recommended vehicle speed search map having the contents shown in FIG. 2A, and the recommended vehicle speed V0 is obtained by searching the map.
[0046]
Next, after calculating the road gradient from the current position to the specific node point of the curve from the road data as described above with reference to FIG. 3 (S45), the road gradient is taken into consideration and the automatic transmission 60 is operated at the third speed. The deceleration acceleration G3 and the deceleration acceleration G2 at the second speed are searched from the map (S46). The contents of the map for searching for the deceleration accelerations G3 and G2 are shown in FIG. Deceleration acceleration G2 due to engine braking when switching to the 2nd speed up to the recommended vehicle speed V0 at the peak position of the curve (specific node point) and running resistance on the uphill or downhill road is less than the deceleration acceleration G3 at the 3rd speed It is getting bigger. The navigation apparatus 10 holds a map having the contents shown in FIG. 2B corresponding to the road gradient, and searches for the deceleration accelerations G3 and G2 based on the map.
[0047]
Next, the navigation apparatus 10 calculates a distance L to a specific node point (a position at which the vehicle speed needs to be lowered most at the peak point of the curve, that is, a position passing at the recommended vehicle speed V0) (S48). Then, decelerable vehicle speeds V4-3 and V3-2 to the recommended vehicle speed V0 are calculated from the distance L, deceleration accelerations G3 and G2, and the recommended vehicle speed V0. This decelerable vehicle speed V4-3 is the vehicle speed at which the accelerator pedal is turned off at the current position, the 4th speed is switched to the 3rd speed, the engine brake is applied at the 3rd speed, and the vehicle speed can be lowered to the recommended vehicle speed V0 at the peak point (specific node point). Means. Similarly, V3-2 refers to the vehicle speed that can be switched from the 3rd speed to the 2nd speed when the accelerator pedal is off (zero slot opening) and the engine brake is applied at the 2nd speed to decrease to the recommended vehicle speed V0 at the peak point. . Thereafter, the current vehicle speed Vnow is detected from a vehicle speed sensor (not shown) (S51).
[0048]
Next, it is determined whether the decelerable vehicle speed V4-3 at the third speed is lower than the current vehicle speed Vnow (S52). That is, unless the vehicle is decelerated at the third speed, it is determined whether the vehicle speed can be reduced to the recommended vehicle speed V0 at the peak point. Decelerate that the optimum gear position is 4th while the decelerable vehicle speed V4-3 is lower than the current vehicle speed Vnow, that is, while it can be decelerated to the recommended vehicle speed V0 without downshifting to 3rd gear at present (S52: No) (S58), the process proceeds to step 62 shown in FIG. On the other hand, if the decelerable vehicle speed V4-3 exceeds the current vehicle speed Vnow and cannot be decelerated to the recommended vehicle speed V0 unless the vehicle is shifted down to the third speed at this time and decelerated (S52 is Yes), then the second speed higher than the current vehicle speed Vnow. It is determined whether the decelerable vehicle speed V3-2 is low (S53). That is, it is determined whether the vehicle speed can be lowered to the recommended vehicle speed V0 at the peak point unless the vehicle is shifted down from the third speed to the second speed and decelerated. Deceltable vehicle speed V3-2 is lower than current vehicle speed Vnow, that is, while it is possible to decelerate to the recommended vehicle speed V0 while maintaining 3rd speed without decelerating at 2nd speed (No in S53), 3rd speed is determined as the optimum gear stage (S56), the process proceeds to step 62 shown in FIG. On the other hand, if the decelerable vehicle speed V3-2 exceeds the current vehicle speed Vnow and the vehicle cannot be decelerated to the recommended vehicle speed V0 unless it is decelerated at the second speed (S53 is Yes), the second speed is determined as the optimum gear position (S54). Then, the process proceeds to step 62 shown in FIG.
[0049]
In step 62 shown in FIG. 7, the navigation apparatus 10 determines whether the optimum gear stage N determined in the above process is 4th speed, 3rd speed, or 2nd speed (S62). Here, when the 4th speed is selected, the 4th speed is commanded to the automatic control unit 20 side as the upper limit of the gear position (S78), and the process is terminated. On the other hand, when the third speed is selected, the routine proceeds to step 64, where it is determined whether the previous shift speed command is the third speed or less. Here, when the previous gear command exceeds the third speed, that is, when the fourth speed is commanded (No in S64), it is determined whether the accelerator pedal is turned off or the brake pedal is turned on (S68). Then, unless the accelerator pedal is turned off or the brake pedal is turned on (No in S68), the process is terminated. On the other hand, when the accelerator pedal is turned off or the brake pedal is turned on (Yes in S68), a command is given to set the third speed as the upper limit (S77), and the downshift is performed from the fourth speed to the third speed as described later. Let's do it. Similarly, when the previous shift speed command is 3rd gear or less (S64 is Yes), a command is given to set the 3rd speed upper limit (S77).
[0050]
In this specification, the fact that the accelerator pedal is turned off or the brake pedal is turned on is referred to as “there is an event”. In this embodiment, downshifting is performed when there is an event. That is, if it is not possible to decelerate to the recommended vehicle speed V0 unless it is decelerated at the third speed in the above step 52, it is possible to immediately shift down from the fourth speed to the third speed. This will make the driver feel uncomfortable. For this reason, when the intention of deceleration is positively expressed by the driver, that is, when the accelerator pedal is turned off or the brake pedal is turned on, the downshift from the fourth speed to the third speed is performed.
[0051]
Here, in the determination of whether the shift speed N in step 62 is the third speed or the second speed, when the second speed is selected, that is, the engine brake is applied at the third speed and the vehicle is decelerated. When approaching and downshifting to the second speed is selected, the process proceeds to step 66, and it is determined whether the brake pedal is turned on after determining whether the previous shift speed command is the second speed or less (S70). Then, unless the brake pedal is turned on (S70 is No), the previous shift command stage n is determined (S72), and when the third speed is commanded, the routine proceeds to step 77 and the third speed is maintained. Here, when the brake pedal is turned on (S70 is Yes), first, it is determined whether or not the current gear position is the fourth speed (S74). Shift to 77 and command upper limit 3rd speed. On the other hand, when the speed is not the fourth speed but the third speed (No in S74), the routine proceeds to step 76, and a command is issued to set the second speed as the upper limit. On the other hand, when it is determined in step 66 that the previous instruction is the second speed or less (S66 is Yes), or when it is determined in step 72 that the second speed is instructed, step After judging 74, the routine proceeds to step 76 where the upper limit 2nd speed is maintained.
[0052]
In step 72, it is determined whether or not the previous command is the third speed, and in step 74 whether or not the current gear is the fourth speed is changed from the fourth speed to the third speed first. In order to prevent the so-called jump gear shift and smooth deceleration by lowering the gear stage and further reducing from the 3rd gear to the 2nd gear, and to prevent the driver from feeling uncomfortable and uncomfortable with the engine brake being too powerful It is. Further, as described above, when the accelerator pedal is turned off or the brake pedal is turned on (Yes in S68), the speed is reduced to the third speed (S77). Thereafter, only when the brake pedal is turned on (S70). However, the reason why the speed is lowered to the second speed (S76) is that the gear is strongly shifted to the second speed where the engine brake is applied only when the driver's intention of strong deceleration is confirmed.
[0053]
After the end of the event control (step 40 shown in FIG. 4) by accelerator-off / brake-on described above with reference to FIGS. 6 and 7, the routine proceeds to the shift stage standby process of step 80 shown in FIG. First, the reason for performing the shift stage standby process will be described. In the event control described above, a downshift is performed when the brake pedal is turned on or the accelerator pedal is turned off (there is an event) after the curve-corresponding shift speed control is started. For this reason, when the accelerator pedal is turned off before the start of the event control, that is, when the accelerator pedal is turned off from a position substantially before the curve and the vehicle enters the curve at a low speed, the event control shifts down. I can't do that.
[0054]
Here, when the downshift is not performed by the event control, the automatic control unit 20 controls the gear position according to a normal shift pattern. However, the normal shift stage control by the automatic control unit 20 is that the downshift from the 4th speed is compared with the vehicle speed when shifting up from the 3rd speed to the 4th speed after passing the curve in order to avoid unnecessary shock. This is done at a very low vehicle speed. For this reason, when downshifting according to a normal shift pattern, the timing is delayed, a large driving force is transmitted to the wheel at the peak point of the curve and it can not pass stably, and when accelerating after passing the curve, High acceleration force cannot be obtained. In order to cope with such a situation, when the accelerator pedal is turned off and the vehicle enters the curve, the shift down is performed at an appropriate timing even if the accelerator pedal is not turned off (there is an event).
[0055]
The shift stage standby process will be described with reference to the flowchart of FIG. 8 showing a subroutine of the process.
First, the navigation device 10 determines whether the accelerator pedal is kept off (S81). Here, when the accelerator pedal is turned on (S81 is No), the driver has a willingness to actively accelerate, or the accelerator pedal is turned off again for deceleration, and the shift command process shifts. Since the down is made, the process is terminated.
[0056]
Here, when the accelerator pedal is kept off (S81 is Yes), standby vehicle speeds V3 and V2 are calculated (S82). This standby vehicle speed V3 is higher than the vehicle speed that normally shifts down from the fourth speed to the third speed with the accelerator pedal off (throttle opening = 0), in this case, after passing through the peak point of the curve, When the pedal is depressed (throttle opening = several tens of percent), the vehicle speed when shifting up from the 3rd speed to the 4th speed, that is, a higher vehicle speed than during normal downshifting is set. Similarly, the standby vehicle speed V2 is higher than the vehicle speed at which the accelerator pedal is turned off (throttle opening = 0) and is normally shifted down from the third speed to the second speed, in this case, after passing through the peak point of the curve, When the pedal is depressed (throttle opening = several tens of percent), the vehicle speed when shifting up from the 2nd speed to the 3rd speed, that is, a higher vehicle speed than during normal downshifting is set. Thus, by making the vehicle speeds of the downshift and the accelerator pedal substantially equal, acceleration / deceleration is performed in contrast to the peak point of the curve.
[0057]
Subsequently, it is determined whether the current vehicle speed is higher than the standby vehicle speed V3 (S83). While the current vehicle speed is lower than the standby vehicle speed V3 (No in S83), the shift stage standby process is terminated.
[0058]
On the other hand, when the current vehicle speed is equal to or higher than the standby vehicle speed V3 and it is desirable to shift down to the third speed in timing (Yes in S83), the process proceeds to step 87 through the determination of step 84 and the third speed. After instructing the downshift to 1, the process is terminated.
[0059]
In step 84, it is determined whether the current vehicle speed is higher than the standby vehicle speed V2. Here, while the current vehicle speed is lower than the standby vehicle speed V2 and the third speed is desirable (No in S84), the process proceeds to step 87 and the third speed is commanded. On the other hand, if the current vehicle speed is higher than the standby vehicle speed V2 and it is desirable to switch to the second speed in time (Yes in S84), it is further determined whether the brake pedal has been depressed (S85). When the brake pedal is depressed (S85 is Yes), a shift to the second speed is instructed (S86), and the process ends. Here, when the brake pedal is only turned on, the speed is lowered to the second speed because the gear is strongly shifted to the second speed where the engine brake is applied only when the driver's intention of strong deceleration is confirmed.
[0060]
Next, an example of the above control of the present embodiment when the vehicle passes the curve will be described with reference to FIG.
9A schematically shows an actual road, FIG. 9B shows control in accordance with the curvature of the road (curve), FIG. 9C shows vehicle speed, and FIG. (D) represents switching of the gear position of the present embodiment.
[0061]
Here, the control when entering the curve shown in FIG. In FIG. 9, the points where the accelerator pedal is turned off, the brake pedal is turned on, the brake pedal is turned off, and the brake pedal is turned on are indicated by solid lines.
As described above with reference to FIG. 2 (B), the navigation device 10 starts the third-speed distance limitation that is performed when the accelerator pedal is turned off from the curve to the third speed at a predetermined point ( (See FIG. 9B). Here, when the driver removes his / her foot from the accelerator pedal for deceleration, the gear position is switched to the third speed as shown in FIG. As a result, the engine brake is strongly applied, and the vehicle speed indicated by the chain line in FIG. 9C decreases. In addition, since the downshift is performed when the accelerator pedal is turned off, the driver does not feel uncomfortable.
[0062]
When the curve further approaches the peak of the curve, the gating device 10 starts the second speed distance limitation that is performed when the brake pedal is turned on (see FIG. 9B). Here, when the driver depresses the brake pedal for further deceleration, the gear position is switched to the second speed (see FIG. 9D). As a result, the engine brake is applied more strongly, and the vehicle speed indicated by the chain line in FIG. In addition, since the downshift to the second speed to which a large engine brake is applied is performed at the timing when the brake pedal is turned on, the driver is not uncomfortable.
[0063]
Even when the accelerator pedal is kept off after the curve peak, the upshift is suppressed by the second speed upper limit command (S22) of the curve control start / release process described above with reference to FIG. That is, as long as the current vehicle speed Vnow does not exceed the release vehicle speed 1, traveling at the second speed continues. When the driver depresses the accelerator pedal and the current vehicle speed Vnow exceeds the release vehicle speed 1, the third speed upper limit command is sent from the navigation device 10 to the automatic control unit in the process of step 34 described above with reference to FIG. 20 is sent out. At this time, the automatic control unit 20 has already selected the gear position (3rd speed or 4th speed) to be shifted up according to the speed change pattern based on the vehicle speed and the throttle opening, and immediately according to the 3rd speed upper limit command. Shifting up to the third speed is performed (time t1 in FIG. 9D).
[0064]
Subsequently, the third speed upper limit command is issued in the above process, and the vehicle goes through the curve while smoothly accelerating in a state where the upshift to the fourth speed is prohibited. Thereafter, when the current vehicle speed Vnow exceeds the release vehicle speed 2, the third speed upper limit command is released in the process of step 37 described above with reference to FIG. At this point, since the automatic control unit 20 has already selected the shift stage (fourth speed) to be shifted up according to the shift pattern based on the vehicle speed and the throttle opening, immediately following the cancellation of the third speed upper limit command, the automatic control unit 20 Shifting up to speed is performed (time t2 in FIG. 9D).
[0065]
In the above-described embodiment, when the vehicle exits the curve, the vehicle is shifted up on the condition that the vehicle speed is higher than the normal speed change condition. No discomfort is felt, or the release is too early and a shift up occurs in the middle of the curve, so that an appropriate driving force cannot be transmitted to the wheels. Further, in this embodiment, the release vehicle speeds 1 and 2 are based on the vehicle speed at the time when the brake pedal is released. However, as the release vehicle speeds 1 and 2, as long as a higher value than the normal shift condition is set. Various values can be used.
[0066]
In this embodiment, a four-speed automatic transmission is illustrated as an example, but the configuration of the present invention is a three-speed or five-speed automatic transmission, and further a gear ratio of a stepless automatic transmission using an endless belt. It can also be suitably applied to the switching.
[0067]
【effect】
As described above, in the vehicle control device according to claims 1 and 2, the gear stage is shifted down so that the engine brake can appropriately decelerate when entering the curve. However, in the normal automatic transmission control, Is shifted up based on the vehicle speed and the throttle opening even if it is once shifted down. By limiting this, it is possible to maintain a low gear position and pass the curve with a large driving force applied to the wheels and the vehicle being stabilized.
[0068]
Further, according to the third aspect of the present invention, the gear position is shifted down so that the engine brake can be appropriately decelerated when entering the curve. However, in the normal automatic transmission control, even if the gear is shifted down, the vehicle speed is reduced. The upshift is performed based on the throttle opening. By limiting this, it is possible to maintain a low gear position and pass the curve in a state where a large driving force is applied to the wheels and the vehicle is stabilized. Further, when a predetermined distance is passed after passing through a predetermined position, a shift-up at a normal vehicle speed is permitted, so that normal gear stage control can be reliably resumed when the vehicle speed is not too high and the vehicle speed is away from the curve.
[Brief description of the drawings]
FIG. 1 is a block diagram of a vehicle control apparatus that performs gear position control according to a first embodiment of the present invention.
FIG. 2A is a graph showing the relationship between the curvature of the reference vehicle speed curve and FIG. 2B is a graph showing the relationship between deceleration acceleration and distance.
FIG. 3 is an explanatory diagram showing the contents of road data according to the first embodiment.
FIG. 4 is a flowchart showing a main routine of curve-related shift speed control according to the first embodiment.
FIG. 5 is a flowchart showing a subroutine of a curve control start / cancel process shown in FIG.
6 is a flowchart showing the first half of an event control subroutine by accelerator-off / brake-on shown in FIG. 4; FIG.
7 is a flowchart showing the latter half of the subroutine for event control by accelerator-off / brake-on shown in FIG. 4; FIG.
FIG. 8 is a flowchart showing a subroutine of a shift stage standby process shown in FIG. 4;
9A is an explanatory diagram schematically showing an actual road, and FIG. 9B is an explanatory diagram showing control in accordance with the curvature of the road. FIG. ) Is a graph showing the vehicle speed, and FIG. 9D is an explanatory diagram showing switching of the gear position of this embodiment.
[Explanation of symbols]
10 Navigation device
20 Automatic control unit
30 E / G ECU
50 engine
60 Automatic transmission
70 Accelerator pedal
72 Brake pedal
74 Shift lever

Claims (2)

Current position detecting means for detecting the current position;
Road data storage means for storing road data;
A curve detection means for detecting a forward curve based on the current position detected by the current position detection means and the road data stored in the road data storage means;
Downshift determination means for determining whether or not a downshift is necessary based on road data relating to a forward curve detected by the curve detection means and the current position detected by the current position detection means and the vehicle speed at the current position;
Downshift means for downshifting before passing through a predetermined position of the curve when the downshift judging means judges that downshifting is necessary,
Predetermined position passage determination means for determining whether or not the vehicle has passed a predetermined position of the curve based on the current position detected by the current position detection means and road data stored in the road data storage means;
Vehicle speed storage means for storing the vehicle speed when the curve passes a predetermined position;
While it is determined by the predetermined position passage determining means that the predetermined position has not been passed, the gear ratio is limited to be shifted up, and after passing the predetermined position, until the vehicle speed at the predetermined position becomes higher than the predetermined speed. A vehicle control apparatus comprising: a shift-up limiting unit that limits the shift-up. Current position detecting means for detecting the current position;
Road data storage means for storing road data;
A curve detection means for detecting a forward curve based on the current position detected by the current position detection means and the road data stored in the road data storage means;
Downshift determination means for determining whether or not a downshift is necessary based on road data relating to a forward curve detected by the curve detection means and the current position detected by the current position detection means and the vehicle speed at the current position;
Downshift means for downshifting the gear ratio before passing through a predetermined position of the curve when the downshift judging means judges that downshifting is necessary;
Predetermined position passage determination means for determining whether or not the vehicle has passed a predetermined position of the curve based on the current position detected by the current position detection means and road data stored in the road data storage means;
Vehicle speed storage means for storing the vehicle speed when the curve passes a predetermined position;
Wherein while it is judged that the predetermined position passing at a predetermined position passing determination means, while restricting the shift-up of the gear ratio after a predetermined position passing the current position detected by said present position detecting means and a predetermined position A shift-up limiting means for limiting a shift-up when an increase in the vehicle speed with respect to the vehicle speed when passing through the predetermined position is equal to or less than a predetermined value until it is determined that the predetermined distance has elapsed.

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