JP4046777B2 - Vehicle speed control device for vehicles - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an automotive vehicle speed control device for constant speed running.
[0002]
[Prior art]
As conventional vehicle speed control apparatuses for vehicles, those described in JP-A-1-114545 and JP-A-1-114548 are known.
This is because the driving force margin is estimated from the current throttle opening, and when the throttle opening exceeds a threshold position (O / D cancellation threshold; for example, 80% of the maximum opening) when traveling uphill or the like, Judging that there is no more driving force, shift down from 4th speed (O / D) to 3rd speed (3rd), then open the throttle that is the same vehicle speed at 4th speed from the throttle opening while traveling at 3rd speed. The degree is calculated from a preset map, and when the throttle opening becomes smaller than the threshold value, it is determined that the margin has been restored, and the shift up is performed to prevent shift hunting.
[0003]
[Problems to be solved by the invention]
However, when downshifting / upshifting is performed based on the driving force requirement value in such a conventional vehicle speed control device for a vehicle, the following problems occur.
As shown in FIG. 19, when the driver removes his / her foot from the accelerator and starts constant speed running control (ASCD control), the actual vehicle speed may be slightly lower than the set vehicle speed due to the operation delay of the actuator. Then, in order to eliminate the vehicle speed deviation, the throttle opening may exceed a threshold value (for example, 80% of the maximum opening), and the vehicle may shift down even though there is still a margin in driving force.
[0004]
When the total driving force required for constant speed driving is far below the maximum driving force as shown in Fig. 20 (a), if the driver presses the acceleration switch to accelerate, the 4th speed remains. However, the actual vehicle speed can be made to follow the vehicle speed command value.
However, as shown in FIG. 20 (b), when the driving resistance increases due to the gradient resistance or the like, if the driver presses the acceleration switch, there is no margin in the driving force and the vehicle speed command value is not completely followed. In such a case, the conventional technology controls the vehicle to shift down and completely follow the vehicle speed command value. However, if the actual vehicle speed does not follow the vehicle speed command value even a little, the downshift will occur, resulting in an increase in shift changes. However, for the driver, when the running resistance is small and a predetermined acceleration is obtained, acceleration follows the vehicle speed command value, and if the running resistance increases and the acceleration slightly decreases, the frequency of shift changes decreases. It is preferable in terms of feeling.
[0005]
The present invention has been made paying attention to such conventional problems, and improves drivability by preventing unnecessary shift changes while the driver is pressing the acceleration switch or the deceleration switch. For the purpose.
[0006]
[Means for Solving the Problems]
Therefore, in the invention according to claim 1, as shown in FIG. 1, a constant speed traveling control means for controlling the output of the engine so that the actual vehicle speed coincides with the vehicle speed command value, and the control by the constant speed traveling control means. An automatic transmission means for controlling the shift position of the transmission, a running resistance estimating means for estimating the running resistance of the vehicle, an acceleration required driving force calculating means for calculating a driving force required to accelerate the vehicle, When judging the necessity of downshifting, the maximum driving force is estimated according to the current vehicle speed and the shift position before downshifting. When judging whether upshifting is necessary, the current vehicle speed and the shift position after upshifting are estimated. Estimate the maximum driving force according to The maximum driving force estimating means, the total required driving force calculating means for calculating the total required driving force required for the vehicle, the maximum driving force and the total required driving force are compared, and the difference is calculated as a margin. An acceleration switch is operated in an automotive vehicle speed control device including a driving force margin calculation unit and a shift command unit that commands a shift position to the automatic transmission unit according to the driving force margin. The vehicle speed command value setting means for increasing the vehicle speed command value and setting the vehicle speed desired by the driver as the vehicle speed command value is provided, and the all required driving force calculation means is a constant speed running by the constant speed running control means. While the acceleration switch is not being operated during control, the running resistance is set to the total required driving force, and the running resistance is set to the running resistance during operation of the acceleration switch during constant speed running control by the constant speed running control means. Addition The plus the required driving force, characterized in that said total required driving force.
[0007]
The total required driving force calculating means may calculate the total required driving force by adding a value obtained by multiplying the acceleration required driving force by a predetermined ratio to the running resistance during operation of the acceleration switch. Item 2).
The shift command means includes a downshift command means for instructing a downshift when the driving force margin falls below a first predetermined value, and after the downshifting, the driving power margin is a first predetermined value. A shift-up command means for commanding a shift-up when a larger second predetermined value is exceeded may be included.
[0008]
In the invention according to claim 4, as shown in FIG. 2, a constant speed traveling control means for controlling the output of the engine so that the actual vehicle speed coincides with the vehicle speed command value, and a speed change during the control by the constant speed traveling control means. Automatic transmission means for controlling the shift position of the machine, running resistance estimating means for estimating the running resistance of the vehicle, deceleration request engine braking force calculating means for calculating the engine braking force required to decelerate the vehicle, When judging whether a downshift is necessary, estimate the maximum engine braking force according to the current vehicle speed and the shift position before the downshift, and when judging whether a shift up is necessary, the current vehicle speed and the shift after the upshift Estimate the maximum engine braking force according to the position The maximum engine brake force estimating means, the total required engine brake force calculating means for calculating the total required engine brake force required for the vehicle, the maximum engine brake force and the total required engine brake force are compared, and the difference is calculated. In an automotive vehicle speed control device, comprising: an engine brake force margin calculating unit that calculates a margin; and a shift command unit that commands a shift position to the automatic transmission unit according to the engine brake force margin. Vehicle speed command value setting means for setting the vehicle speed command value desired by the driver as the vehicle speed command value by decreasing the vehicle speed command value while the deceleration switch is being operated. During the constant speed traveling control by the speed traveling control means, when the deceleration switch is not operated, the traveling resistance is set to the all required engine brake. The total required engine braking force is obtained by adding the deceleration request engine braking force to the traveling resistance during operation of the deceleration switch during constant speed traveling control by the constant speed traveling control means. It is characterized by that.
[0009]
The total required engine brake force calculating means calculates the total required engine brake force by adding a value obtained by multiplying the deceleration required engine brake force by a predetermined ratio to the running resistance during operation of the deceleration switch. Good (Claim 5).
The shift command means includes a downshift command means for instructing a downshift when the engine brake force margin falls below a third predetermined value, and after the downshift, the engine brake force margin has the third degree. It is preferable to include a shift-up command means for commanding a shift-up when a fourth predetermined value larger than the predetermined value is exceeded (Claim 6).
[0010]
[Action]
The operation will be described (see FIG. 3).
In the invention according to claim 1, when the acceleration switch is pressed during the constant speed traveling control, the vehicle speed command value is increased at a constant rate until the acceleration switch is released. The required driving force is added to obtain the total required driving force. Then, the maximum driving force estimated from the current vehicle speed and the shift position is compared with the total required driving force, the driving force margin is calculated, and shift determination is performed based on this.
[0011]
Therefore, when the running resistance is low, such as low speed running or flat road running, there is a considerable margin for the maximum driving force, so sufficient acceleration can be obtained without downshifting, and running resistance can be reduced during high speed running or uphill running. If it is large, even if the driver presses the acceleration switch, sufficient acceleration cannot be obtained at the current shift position, so that the driver shifts down and accelerates. Therefore, the shift is started only when sufficient acceleration cannot be obtained at the current shift position, and unnecessary shift changes are eliminated.
[0012]
In addition, since the driving force required to accelerate only while the acceleration switch is pressed is taken into account, even if the throttle opening increases immediately after the vehicle speed is set, there is no downshift if the gradient is not sharp, Necessary shift changes disappear.
In the invention according to claim 4, when the deceleration switch is pressed during the constant speed traveling control, the vehicle speed command value is decreased at a constant rate until the deceleration switch is released. The required engine braking force is added to achieve the required engine braking force. Then, the maximum engine brake force estimated from the current vehicle speed and the shift position is compared with the total required engine brake force to calculate an engine brake force margin, and a shift determination is made based on this.
[0013]
Therefore, when the running resistance is high, such as when driving at high speed or on an uphill road, there is a considerable margin with respect to the maximum engine braking force, so that sufficient deceleration can be obtained without downshifting and the running resistance is low when running downhill. If the driver presses the deceleration switch, a sufficient deceleration cannot be obtained at the current shift position, so the vehicle is shifted down and decelerated. Therefore, the shift is started only when sufficient deceleration cannot be obtained at the current shift position, and unnecessary shift changes are eliminated.
[0014]
In the invention according to claim 2 or claim 5, when calculating the total required driving force or the total required engine braking force during the operation of the acceleration switch or the deceleration switch, a predetermined ratio is set to the acceleration required driving force or the deceleration required engine braking force. The multiplication is added to the running resistance. The predetermined ratio here is determined in consideration of these factors, since the frequency of shift-down decreases if the value is reduced, but the followability to the vehicle speed command value deteriorates.
[0015]
In the invention according to claim 3 or claim 6, when the margin of the driving force or the engine braking force falls below the first predetermined value or the third predetermined value, a downshift is instructed. Hunting can be prevented by instructing upshifting when the degree exceeds the second predetermined value or the fourth predetermined value.
[0016]
【Example】
Examples of the present invention will be described below.
FIG. 4 is a system diagram showing an embodiment of the present invention.
First, the configuration will be described. Reference numeral 1 denotes a constant speed running control unit, which includes a CPU, ROM, RAM, digital port, A / D port, one-chip microcomputer incorporating various timers (or a plurality of chips realizing the same function), and It is constituted by a throttle actuator drive circuit.
[0017]
Reference numerals 2 to 7 are switch groups operated by the driver. Based on these signals, the control unit 1 determines the start or release of the constant speed traveling control (ASCD control). Reference numeral 2 denotes a main switch for supplying power to the constant speed traveling control unit 1 to start calculation. Reference numeral 3 denotes a set switch for starting constant speed traveling control and setting a vehicle speed command value. Reference numerals 4 and 5 denote acceleration (acceleration) switches and deceleration (coast) switches for increasing and decreasing the vehicle speed command value, respectively. Reference numerals 6 and 7 denote a cancel switch and a brake switch used for releasing the constant speed traveling control.
[0018]
Reference numeral 8 denotes a vehicle speed sensor using a reed switch. When the permanent magnet connected to the speedometer cable rotates, the contact of the reed switch opens and closes, and a pulse corresponding to the actual vehicle speed is output to the control unit 1. The control unit 1 counts pulses and measures the actual vehicle speed.
Reference numeral 9 denotes a potentiometer type throttle sensor, which outputs an analog signal corresponding to the actual throttle opening to the control unit 1. The control unit 1 performs A / D conversion to measure the actual throttle opening.
[0019]
A crank angle sensor 10 is used for measuring the engine rotation speed.
11 is a negative pressure type throttle actuator, which includes a vacuum pump for generating negative pressure and a solenoid valve for releasing air, and controlling the vacuum pump and solenoid valve with the duty ratio of the PWM signal output from the control unit 1 to control the throttle valve. It opens and closes.
[0020]
Reference numeral 12 denotes an automatic transmission control unit, which controls the automatic transmission 13. This corresponds to automatic transmission means. The automatic transmission control unit 12 sends the shift position (3rd or O / D) during the constant speed traveling control to the constant speed traveling control unit 1 using the signal line S1. On the other hand, the constant speed traveling control unit 1 sends a constant speed traveling control signal using the signal line S2 to the automatic transmission control unit 12 during the constant speed traveling control. Used to send an O / D cancel request signal for a shift command. During the constant speed traveling control, the automatic transmission control unit 12 performs the shift control according to the command of the constant speed traveling control unit 1, that is, the level of the O / D cancellation request signal.
[0021]
5 to 8 show flowcharts of control operations performed by the microcomputer in the constant speed traveling control unit 1.
FIG. 5 shows a main routine, which is executed every fixed control cycle (for example, 50 msec). This routine corresponds to constant speed traveling control means.
First, at P1, the average vehicle speed Vsp is measured using the count value of the vehicle speed sensor pulse counted for 50 msec. Similarly, the average engine speed Ne is measured using the count value of the crank angle sensor pulse. Further, the throttle opening Tvo is measured by A / D converting the analog signal of the throttle sensor.
[0022]
In P2, the state of the cancel switch and the brake switch is monitored. If either one is ON, the process proceeds to P13 as ASCD control cancellation, and if both are OFF, the process proceeds to P3 as ASCD control permission.
In P3, the state of the set switch is monitored. If it is ON, it is determined that ASCD control is started, and the process proceeds to P4. If it is OFF, the process proceeds to P6.
[0023]
In P4, the current actual vehicle speed Vsp is stored as the vehicle speed command value Vspr.
In P5, a flag (ASCD control flag) indicating that the ASCD control is being performed is set.
In P6, the state of the ASCD control flag is monitored, and if the flag is set, the process proceeds to P7 and P8, and if it is cleared, the process proceeds to P14.
[0024]
P7 and P8 are routines for performing acceleration control or coast control, and details are shown in FIGS.
In P9, based on the vehicle speed command value Vspr and the actual vehicle speed Vsp, a target driving force For for making them coincide is calculated.
Here, the target driving force For is calculated using a “model matching method” and an “approximate zeroing method” which are known linear control methods.
[0025]
The transfer characteristic of the controlled object is represented by the pulse transfer function P (z ^-1 ), The compensator portion is as shown in FIG. z is a delay operator, z ^-1 Multiplying the value gives the value one sample period before. C1 (z ^-1 ), C2 (z ^-1 ) Is a compensator based on the approximate zeroing method, which suppresses the influence of disturbances and modeling errors. Also, C3 (z ^-1 ) Is a compensator based on the model matching method. ^-1 ) To match the characteristics.
[0026]
When the target acceleration is input and the actual vehicle speed is output, the control object is P (z ^-1 ) Is an integral element P1 (z ^-1 ) To dead time element P2 (z ^-1 ) = Z ^-2 And can be left as a product.
P1 (z ^-1 ) = (T · z ^-1 ) / (1-z ^-1 )
T: Sample period (50msec)
At this time, C1 (z ^-1 ), C2 (z ^-1 ) Becomes the following formula.
[0027]
C1 (z ^-1 ) = [(1-γ) · z ^-1 ] / [1-γ · z ^-1 ]
(Low-pass filter with time constant Tb)
C2 (z ^-1 ) = [(1-γ) · (1-z ^-1 ]] / [T · (1-γ · z) ^-1 )]
(C2 = C1 / P1)
Where γ = exp (−T / Tb)
If the first-order low-pass filter with the time constant Ta of the reference model is ignored ignoring the dead time of the controlled object, C3 becomes the following constant.
[0028]
C3 = K = [1-exp (-T / Ta)] / T
As described above, at P9, the following calculation is performed. However, data y (k-1) indicates data y (k) one cycle before.
y2 (k) = γ · y2 (k-1) + (1-γ) · y1 (k-1)
y3 (k) = [gamma] .y3 (k-1) + (1- [gamma]) / T.Vsp (k)-(1- [gamma]) / T.Vsp (k-1)
y1 (k) = K. (Vspr (k) -Vsp (k))-y3 (k) + y2 (k-2)
y1 (k) is the target acceleration, which is multiplied by the basic vehicle weight M to calculate the target driving force For as shown in the following equation.
[0029]
For = y1 (k) ・ M
As described above, C1 (z ^-1 ), C2 (z ^-1 ) Acts as a disturbance estimator, so it can estimate disturbances during constant speed running, that is, running resistance. Therefore, if y1 = r1 + r2, C1 (z ^-1 ), C2 (z ^-1 The running resistance is calculated by multiplying the target acceleration r1 (see FIG. 9) by the basic vehicle weight M.
[0030]
Also, C3 (z ^-1 ) Calculates the driving force or engine braking force required to follow the actual vehicle speed when the vehicle speed deviation occurs or when the acceleration switch or deceleration switch is pressed and the vehicle speed command value increases or decreases. Therefore, C3 (z ^-1 ) By multiplying the target acceleration r2 (see FIG. 9) on the side by the basic vehicle weight M, the driving force or engine braking force required for acceleration / deceleration is calculated.
[0031]
In P10, first, the target engine torque Ter is calculated by the following equation based on the target driving force For. Gm is the gear ratio of the transmission, Gf is the final gear ratio, and Rt is the effective radius of the tire.
Ter = (For · Rt) / (Gm · Gf)
Next, the target throttle opening degree Tvor is calculated from the target engine torque Ter and the engine rotational speed Ne by using a non-linear characteristic data map of the engine previously stored in the memory as shown in FIG.
[0032]
In P11, a known control method such as PID control is used, and each of the vacuum pressure actuator and the air release solenoid valve of the negative pressure type throttle actuator is controlled based on the throttle opening deviation Δ (target opening Tvor−actual opening Tvo). The output pulse widths Tvac and Tvent are calculated.
Further, the vacuum pump output pulse width Tvac and the air release solenoid valve output pulse width Tvent are written in the pulse output register in the microcomputer.
[0033]
P12 is a routine for determining O / D cancellation, and details are shown in FIG.
In P13, the process comes from P2, and the ASCD control flag is cleared to cancel the ASCD control.
In P14, the target throttle opening Tvor for ASCD control is reset from P6 or P13.
[0034]
Next, the acceleration control routine of FIG. 6 will be described.
In P21, the state of the acceleration switch (acceleration switch) is monitored, and if it is ON, the process proceeds to P23 to perform acceleration control, and if it is OFF, the process proceeds to P22.
In P22, the state of a flag (acceleration control flag) indicating whether or not the acceleration control is in progress is monitored. If it is set, it is determined that the acceleration control has ended, and the process proceeds to P25. Return to.
[0035]
In P23 and P24, the acceleration control flag is set and the vehicle speed command value Vspr is set to a constant value (for example, 0.2km / h) as the vehicle speed command value Vspr (old) one control cycle before in order to perform acceleration control. The added value. Therefore, the parts P21 and 24 correspond to the vehicle speed command value setting means.
In P25, 26, in order to end the acceleration control, the vehicle speed command value Vspr is set to the actual vehicle speed Vsp at that time, the acceleration control in-progress flag is cleared, and the process returns to the main routine.
[0036]
Next, the coast control routine of FIG. 7 will be described.
In P31, the state of the deceleration switch (coast switch) is monitored. If ON, the process proceeds to P33 to perform coast control, and if OFF, the process proceeds to P32.
In P32, the state of a flag indicating whether coast control is being performed (coast control flag) is monitored. If it is set, it is determined that coast control has been completed, the process proceeds to P35, and if it is cleared, the process returns to the main routine.
[0037]
In P33 and P34, the coast control flag is set and the vehicle speed command value Vspr is subtracted from the vehicle speed command value Vspr (old) one control cycle before in order to perform coast control. Value. Accordingly, the portions P31 and P34 correspond to vehicle speed command value setting means.
In P35 and 36, in order to end the coast control, the vehicle speed command value Vspr is set to the actual vehicle speed Vsp at that time, the coast control in-progress flag is cleared, and the process returns to the main routine.
[0038]
Next, the O / D cancellation determination routine of FIG. 8 will be described.
In P41, the running resistance Fr is estimated and calculated by multiplying the acceleration component r1 of the running resistance during constant speed running obtained in P9 by the basic vehicle weight M. This portion corresponds to running resistance estimation means.
Fr (k) = r1 (k) M
In P42, based on the positive or negative of the estimated running resistance Fr, the process proceeds to P43 if it is positive, and proceeds to P47 if it is negative (downhill).
[0039]
In P43, when it is assumed that the shift position of the automatic transmission is O / D and the throttle opening Tvo is fully opened at the current vehicle speed Vsp, the expected driving force (O / D maximum driving force) Fodmax is set. calculate. Specifically, the O / D maximum driving force Fodmax is calculated from the current vehicle speed Vsp using one-dimensional table data stored in advance for each vehicle speed. This portion corresponds to the maximum driving force estimation means.
[0040]
In P44, the state of the acceleration switch (acceleration switch) is monitored. If it is ON (acceleration control), the process proceeds to P45, and if it is OFF, the process proceeds to P46, and the total required driving force Fa is equal to the running resistance Fr. (Fa (k) = Fr (k)).
In P45, the acceleration component r2 of the driving force required for acceleration determined in P9 is multiplied by the basic vehicle amount M and multiplied by a predetermined ratio β, and the result is added to the running resistance Fr. The required driving force Fa is calculated.
[0041]
Fa (k) = Fr (k) + (r2 (k) .multidot.M) .beta.
Here, the portion of P44 to 46 corresponds to the total required driving force calculation means, and in particular, the portion of calculating (r2 (k) · M) · β at P45 corresponds to the acceleration required driving force calculation means.
In P47, when it is assumed that the shift position of the automatic transmission is O / D and the throttle opening Tvo is in the fully closed state at the current vehicle speed Vsp, the expected engine braking force (O / D maximum engine braking force) ) Calculate Fodmax. Specifically, the O / D maximum engine brake force Fodmax is calculated from the current vehicle speed Vsp using one-dimensional table data stored in advance for each vehicle speed. This portion corresponds to the maximum engine brake force estimating means.
[0042]
In P48, the state of the deceleration switch (coast switch) is monitored. If it is ON (during deceleration control), the process proceeds to P49, and if it is OFF, the process proceeds to P50 and the total required engine braking force Fa is equal to the running resistance Fr. (Fa (k) = Fr (k)).
In P49, the acceleration component r2 of the engine braking force required for deceleration obtained in P9 is multiplied by the basic vehicle amount M and multiplied by a predetermined ratio β to add to the running resistance Fr, as shown in the following equation: The total required engine braking force Fa is calculated.
[0043]
Fa (k) = Fr (k) + (r2 (k) .multidot.M) .beta.
Here, the portion of P48 to 50 corresponds to the all required engine brake force calculating means, and in particular, the portion of calculating (r2 (k) · M) · β at P49 corresponds to the deceleration required engine brake force calculating means.
In P51, it is determined whether the shift position of the automatic transmission is currently in the O / D state or the 3rd state based on the Hi / Lo state of the signal line S1 from the automatic transmission control unit. If there is, proceed to P52, and if it is the 3rd state, proceed to P54.
[0044]
In P52, the difference between the absolute value of the O / D maximum driving force (or O / D maximum engine braking force) Fodmax and the absolute value of the total required driving force (or total required engine braking force) Fa is calculated as a margin. To do.
Margin = | Fodmax | − | Fa |
Then, this margin (| Fodmax | − | Fa |) is compared with a first predetermined value (a third predetermined value in the case of engine braking), and a first predetermined value (or a third predetermined value). If it is smaller than, it is determined that there is no margin in driving force (or engine braking force) for traveling at a constant speed at the current shift position (O / D), and the process proceeds to P53 for a shift down request. Otherwise, it is determined that there is a considerable margin in driving force (or engine braking force) at the current shift position (O / D), and the process proceeds to P55 to maintain the current shift position (O / D).
[0045]
In P54, the margin (| Fodmax |-| Fa |) is calculated in the same manner as P53, and then compared with a second predetermined value (fourth predetermined value in the case of engine braking), and the second predetermined value is calculated. If it is larger than the value (or the fourth predetermined value), even if it is shifted up, there is a margin in driving force (or engine braking force) for traveling at a constant speed at the shifted position (O / D) after the shifting up. The process proceeds to P55 for an upshift request. Otherwise, it is determined that there is no margin in driving force (or engine braking force) even if the gear is upshifted, and the process proceeds to P53 in order to maintain the current shift position (3rd).
[0046]
In P53, an O / D cancel flag is set to shift down from O / D to 3rd or hold 3rd.
In P55, the O / D cancel flag is cleared to shift up from 3rd to O / D or hold the O / D.
In P56, based on the ASCD control in-progress flag, a constant speed running control in-progress signal is output to the signal line S2 to the automatic transmission control unit.
[0047]
In P57, based on the O / D cancel flag, an O / D cancel signal is output to the signal line S3 to the automatic transmission control unit.
Here, the portion of P52 to P57 corresponds to the shift command means, and in particular, the portion for calculating | Fodmax |-| Fa | at P52 corresponds to the driving force margin calculating means, and at | P54, | Fodmax |-| The part for calculating Fa | corresponds to the engine braking force margin calculating means.
[0048]
Next, the operation in this embodiment will be described separately for acceleration control and deceleration control.
(Acceleration control)
If the acceleration switch is pressed during constant speed traveling control, the vehicle speed command value is increased at a constant rate (for example, 0.2 km / h) until the acceleration switch is released, but only during that time the driving force required for acceleration is increased. The product multiplied by the predetermined ratio β is added to the required driving force value (traveling resistance) required for constant speed traveling to obtain the total required driving force, and shift determination is performed based on this.
[0049]
If the running resistance is low, such as low speed running or flat road running, the total required driving force required for acceleration is as shown in Fig. 11 (when β = 0.3), and there is a considerable margin for the maximum driving force. Thus, sufficient acceleration can be obtained without downshifting.
However, as shown in FIG. 12, when traveling at high speed or traveling on an uphill road, running resistance increases, and even if the driver presses the acceleration switch, sufficient acceleration may not be obtained at the current shift position. Therefore, O / D cancellation is performed in order to make a shift determination by adding the driving force necessary for acceleration multiplied by a predetermined ratio β to the required driving force value (travel resistance) necessary for constant speed traveling. To accelerate. Therefore, it is possible to shift down only when sufficient acceleration cannot be obtained at the current shift position, and there is an effect that unnecessary shift changes are eliminated.
[0050]
In addition, because we decided to consider the driving force necessary to accelerate only while pressing the acceleration switch, The acceleration switch is not pressed During constant speed driving Compare with maximum driving force to determine if downshift is necessary The total required driving force is , Driving resistance due to road surface gradient (+ rolling resistance + air resistance) It becomes only. Therefore, even if the throttle opening increases immediately after the vehicle speed is set, there is an effect that if the gradient is not steep, the gear is not shifted down and unnecessary shift changes are eliminated.
[0051]
However, if the value of the predetermined ratio β is reduced, the frequency of downshifting is reduced, but the followability to the vehicle speed command value is deteriorated, so the value is determined by the sensory evaluation of the driver. An example is shown in FIGS. FIG. 13 shows the case where β = 0.7, and FIG. 14 shows the case where β = 0.5.
[Deceleration control]
If the deceleration switch is pressed during constant speed travel control, the vehicle speed command value is decreased at a constant rate (for example, 0.2 km / h) until the deceleration switch is released. Is multiplied by a predetermined ratio β to be subtracted from the required driving force value (traveling resistance) necessary for constant speed traveling to obtain the total required driving force, and shift determination is performed based on this.
[0052]
When the running resistance is high, such as when driving at high speeds or on an uphill road, the total required driving force required for deceleration is as shown in Fig. 15. But you can get enough deceleration.
However, when traveling downhill or the like, as shown in FIG. 16, the running resistance may decrease, and even if the driver presses the deceleration switch, sufficient deceleration may not be obtained at the current shift position. Therefore, the engine brake force required for deceleration multiplied by the predetermined ratio β is subtracted from the engine brake force required value required for constant speed travel to make a shift determination. It becomes like this. Therefore, it is possible to shift down only when sufficient deceleration cannot be obtained at the current shift position, and there is an effect that unnecessary shift changes are eliminated.
[0053]
However, if the value of the predetermined ratio β is reduced, the frequency of downshifting is reduced, but the followability to the vehicle speed command value is deteriorated, so the value is determined by the sensory evaluation of the driver. An example is shown in FIGS. FIG. 17 shows the case where β = 0.7, and FIG. 18 shows the case where β = 0.5.
[0054]
【The invention's effect】
As described above, according to the first or fourth aspect of the invention, the downshift is performed only when a sufficient acceleration / deceleration cannot be obtained when the driver performs acceleration / deceleration with the acceleration switch or the deceleration switch. There is an effect that the desired acceleration / deceleration can always be obtained without an extra shift change.
[0055]
Further, according to the invention according to claim 2 or claim 5, by setting the predetermined ratio, it is possible to obtain an effect that the frequency of the downshift and the followability to the vehicle speed command value can be taken into consideration.
Further, according to the invention according to claim 3 or claim 6, the effect that hunting can be prevented by setting the threshold value before and after the downshift is obtained.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing the configuration of the present invention.
FIG. 2 is a functional block diagram showing the configuration of the present invention.
FIG. 3 is a diagram showing the operation of the present invention.
FIG. 4 is a system diagram showing an embodiment of the present invention.
FIG. 5 is a flowchart of the main routine.
FIG. 6 is a flowchart of an acceleration control routine.
FIG. 7 is a flowchart of a coast control routine.
FIG. 8 is a flowchart of an O / D cancellation determination routine.
FIG. 9 is a block diagram of a compensator.
[Figure 10] Map of target throttle opening calculation map
FIG. 11 is a characteristic diagram when the running resistance is small and sufficient acceleration can be achieved at the fourth speed.
[Fig. 12] Characteristic diagram when running resistance is large and acceleration is not possible at 4th speed
FIG. 13 is a characteristic diagram of O / D cancellation frequency adjustment by a predetermined ratio β.
FIG. 14 is a characteristic diagram of O / D cancellation frequency adjustment by a predetermined ratio β.
FIG. 15 is a characteristic diagram when the running resistance is large and the vehicle can sufficiently decelerate at the 4th speed
FIG. 16 is a characteristic diagram when the running resistance is small and the 4th gear cannot sufficiently decelerate.
FIG. 17 is a characteristic diagram of O / D cancellation frequency adjustment by a predetermined ratio β.
FIG. 18 is a characteristic diagram of O / D cancellation frequency adjustment by a predetermined ratio β.
FIG. 19 is a characteristic diagram of a conventional example.
FIG. 20 is a characteristic diagram of a conventional example.
[Explanation of symbols]
1 Control unit for constant speed running
3 Set switch
4 Acceleration switch
5 Deceleration switch
8 Vehicle speed sensor
9 Crank angle sensor
11 Throttle actuator
12 Control unit for automatic transmission

Claims (6)

Constant speed travel control means for controlling the output of the engine so that the actual vehicle speed matches the vehicle speed command value;
Automatic transmission means for controlling the shift position of the transmission during control by the constant speed traveling control means;
Running resistance estimating means for estimating the running resistance of the vehicle;
Acceleration required driving force calculating means for calculating a driving force required to accelerate the vehicle;
When judging the necessity of downshifting, the maximum driving force is estimated according to the current vehicle speed and the shift position before downshifting. When judging whether upshifting is necessary, the current vehicle speed and the shift position after upshifting are estimated. Maximum driving force estimating means for estimating the maximum driving force according to
A total required driving force calculating means for calculating a total required driving force required for the vehicle;
A driving force margin calculating means for comparing the maximum driving force and the total required driving force and calculating the difference as a margin;
Shift command means for commanding a shift position to the automatic transmission means according to the driving force margin;
In a vehicle automobile speed control device comprising:
Vehicle speed command value setting means for increasing the vehicle speed command value while the acceleration switch is operated and setting the vehicle speed desired by the driver as the vehicle speed command value;
The total required driving force calculation means sets the running resistance as the total required driving force during the constant speed running control by the constant speed running control means and when the acceleration switch is not operated, and the constant speed running control means. The vehicle speed control device for a vehicle, wherein during the operation of the acceleration switch during constant speed traveling control by the above, the total required driving force is obtained by adding the acceleration required driving force to the traveling resistance.   The total required driving force calculating means is configured to calculate a total required driving force by adding a value obtained by multiplying the acceleration required driving force by a predetermined ratio to the running resistance during operation of an acceleration switch. The vehicle automobile speed control device according to claim 1.   The shift command means includes a downshift command means for instructing a downshift when the driving force margin falls below a first predetermined value, and after the downshifting, the driving power margin is a first predetermined value. 3. The vehicular vehicle speed control device according to claim 1, further comprising a shift-up command means for commanding a shift-up when a larger second predetermined value is exceeded. Constant speed travel control means for controlling the output of the engine so that the actual vehicle speed matches the vehicle speed command value;
Automatic transmission means for controlling the shift position of the transmission during control by the constant speed traveling control means;
Running resistance estimating means for estimating the running resistance of the vehicle;
A deceleration request engine brake force calculating means for calculating an engine brake force required to decelerate the vehicle;
When judging whether a downshift is necessary, estimate the maximum engine braking force according to the current vehicle speed and the shift position before the downshift, and when judging whether a shift up is necessary, the current vehicle speed and the shift after the upshift Maximum engine brake force estimating means for estimating the maximum engine brake force according to the position ;
All required engine braking force calculating means for calculating all required engine braking force required for the vehicle;
Engine braking force margin calculating means for comparing the maximum engine braking force and the total required engine braking force and calculating the difference as a margin;
Shift command means for commanding a shift position to the automatic transmission means according to the engine braking force margin;
In a vehicle automobile speed control device comprising:
Vehicle speed command value setting means for setting the vehicle speed command value desired by the driver as the vehicle speed command value by decreasing the vehicle speed command value while the deceleration switch is being operated;
The all-required engine braking force calculation means sets the running resistance to the all-required engine braking force during constant speed running control by the constant speed running control means and when the deceleration switch is not operated, and the constant speed running Vehicle speed control for a vehicle characterized in that, during operation of the deceleration switch during constant speed traveling control by a control means, the total required engine braking force is obtained by adding the deceleration requested engine braking force to the traveling resistance. apparatus.   The total required engine brake force calculating means calculates the total required engine brake force by adding a value obtained by multiplying the deceleration required engine brake force by a predetermined ratio to the running resistance during operation of the deceleration switch. The vehicular automobile speed control device according to claim 4.   The shift command means includes a downshift command means for instructing a downshift when the engine brake force margin falls below a third predetermined value, and after the downshift, the engine brake force margin has the third degree. 6. The vehicle automobile speed control device according to claim 4, further comprising a shift-up command means for commanding a shift-up when a fourth predetermined value larger than the predetermined value is exceeded. .

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