JPH092100A - Constant speed cruise control device for vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent shift hunting immediately after the transition between constant speed traveling control and acceleration / deceleration control or immediately after the start of constant speed traveling control. A constant speed running control means for adjusting an engine output so that an actual vehicle speed matches a target vehicle speed based on a running resistance estimated value Fr calculated by a running resistance estimating means 52 for calculating an estimated running resistance of a vehicle. 53, a control mode command means 54 for instructing the start of constant speed traveling control or acceleration or deceleration during constant speed traveling control based on the driver's operation, and the shift position of the automatic transmission based on the traveling resistance estimated value Fr. The automatic shift control means 55 to be changed, the control state determination means 56 for determining whether the control state of the control mode command means 54 has changed, and a predetermined time from the time when this determination result determines the change in the control state. The automatic shift control means 55 is provided with a shift inhibiting means 57 for inhibiting the shift operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a vehicle constant speed traveling control device for maintaining traveling at a predetermined vehicle speed.

[0002]

2. Description of the Related Art Conventionally, there has been known a constant speed running control device for controlling an engine output and a shift position of an automatic transmission so as to maintain an arbitrary target vehicle speed, and an actuator for driving an engine throttle is provided. The target throttle opening is calculated by the vehicle speed feedback so that the actual vehicle speed matches the target vehicle speed, and the actuator is driven so that the actual throttle opening matches the target throttle opening. The shift down or shift up is instructed so that the shift position can maintain the vehicle speed.

A constant speed traveling control device for a vehicle is equipped with a set switch for starting constant speed traveling control, an acceleration switch and a deceleration switch for performing acceleration or deceleration during constant speed traveling control. When the driver operates the set switch after the vehicle speed reaches, the constant speed running control is started with this vehicle speed as the target vehicle speed, and the driver continues to press the acceleration switch or the deceleration switch during the constant speed running control. During this period, acceleration control or deceleration control is performed to control the throttle and the automatic transmission so as to follow the actual vehicle speed while increasing or decreasing the target vehicle speed at a predetermined rate.

When the actual vehicle speed reaches the desired speed, the driver releases the acceleration switch or the deceleration switch to update the target vehicle speed to the actual vehicle speed at that time and return to the constant speed traveling control again. It is a thing.

An example of such a device is Japanese Patent Laid-Open No. 5-31.
What is disclosed in Japanese Patent No. 3754 is known, which is calculated by a target driving force (or a target throttle opening) based on a deviation between an actual vehicle speed and a target vehicle speed, and a disturbance estimator using a vehicle model. The throttle opening is controlled based on the sum of the estimated traveling resistance value (or the throttle opening correction amount) so that the actual vehicle speed matches the target vehicle speed.

As a similar device, SAE93077
1 is also known.

[0007]

However, in the above-mentioned conventional constant speed running control device, the engine torque of the engine torque is calculated based on the running resistance estimated value (or the target throttle opening correction amount) estimated and calculated during the vehicle speed feedback control. Vehicle speed feedback control in which the set switch is operated when O / D cancellation (shift down from the top gear) or O / D return (shift up to the top gear) of the automatic transmission is determined by determining the allowance Immediately after the start or immediately after the acceleration / deceleration control in which the acceleration or deceleration switch is operated during the constant speed running control, the running state of the vehicle is in the transient state,
The calculated running resistance estimated value has not converged to the actual value, the above-mentioned engine torque margin cannot be accurately determined, and unnecessary shifting is performed to cause hunting of the shift position. However, there were cases where the vehicle speed temporarily dropped and smooth constant-speed running control could not be performed.

Therefore, the present invention has been made in view of the above problems, and suppresses the hunting of the shift position and the decrease of the vehicle speed immediately after the start of the constant speed running control or immediately after the start of the acceleration / deceleration during the constant speed running control. An object of the present invention is to provide a vehicle constant speed traveling control device capable of realizing smooth constant speed traveling control.

[0009]

A first aspect of the present invention is to provide a target vehicle speed setting means 50 for setting a target vehicle speed in FIG.
The actual vehicle speed matches the target vehicle speed based on the actual vehicle speed detecting means 51 for detecting the actual vehicle speed of the vehicle and the traveling resistance estimated value Fr calculated by the traveling resistance estimating means 52 for calculating the estimated value of the traveling resistance of the vehicle. Constant speed running control means 53 for adjusting the output of the engine so as to perform, and control mode command means 54 for instructing the start of the constant speed running control or the acceleration or deceleration during the constant speed running control based on the operation of the driver, In a vehicle constant speed traveling control device including an automatic shift control means 55 for changing a shift position of an automatic transmission based on the calculated traveling resistance estimated value Fr, a control state of the control mode command means 54 changes. A control state determining means 56 for determining whether or not the shift is performed, and a shift for inhibiting the shift operation of the automatic shift control means 55 for a predetermined time from when the determination result determines that the control state has changed. And a stop means 57.

As shown in FIG. 12, a second aspect of the present invention is the traveling resistance estimating means 5 according to the first aspect of the present invention.
2 calculates the running resistance estimated value Fr based on the vehicle model and the target vehicle speed, while the constant speed running control means calculates the target driving force based on the deviation between the target vehicle speed and the actual vehicle speed. And a throttle control means 59 for controlling the throttle opening degree of the engine based on the sum of the traveling resistance estimated value Fr and the target driving force.

As shown in FIG. 12, a third aspect of the present invention is the same as the first or second aspect, wherein the automatic shift control means 55 calculates a driving force required for acceleration / deceleration. A means 60, a total required driving force calculating means 61 for calculating the total required driving force by adding the running resistance estimated value Fr and the required driving force, and a maximum for calculating the maximum driving force at the current vehicle speed and a predetermined shift position. The driving force estimating means 62 is provided, and the driving force margin is calculated based on the difference between the maximum driving force and the total required driving force, and the shift position of the automatic transmission is changed according to the margin. To do.

[0012]

Therefore, according to the first aspect of the invention, when the driver operates the control mode command means to instruct the start of the constant speed traveling control during the normal traveling, the target vehicle speed is made to match based on the traveling resistance estimated value Fr. The engine output and the shift position of the automatic transmission are controlled to start the constant speed running control. Immediately after this command, the control state determination means determines the change in the control state, so the shift prohibition means performs the automatic shift control. The shift position of the automatic transmission can be held by prohibiting the speed change operation of the means for a predetermined time, and the shift due to the influence of the running resistance estimated value Fr that changes in the transitional state where the normal running shifts to the constant speed running control. Position hunting can be prevented, and smooth constant speed traveling control is realized by canceling the shift inhibition after a predetermined time when the estimated traveling resistance value Fr converges to a steady value.
Even after the control shifts from the constant speed running control to the acceleration / deceleration control or vice versa, the shift operation is prohibited for a predetermined time due to the change in the control state, and similarly, the hunting of the shift position in the transient state is prevented. be able to.

According to a second aspect of the present invention, the throttle opening is controlled in accordance with the running resistance estimated value Fr calculated based on the vehicle model and the target vehicle speed and the target driving force based on the deviation between the target vehicle speed and the actual vehicle speed. Smooth constant speed traveling control can be performed.

In the third aspect of the invention, during acceleration control or deceleration control during constant speed traveling control, the estimated driving resistance Fr is added to the required driving force (engine braking force in the case of deceleration) required for acceleration / deceleration. Since the shift position is changed according to the total required driving force plus the driving force, which is the difference between the current vehicle speed and the maximum driving force at the predetermined shift position, sufficient acceleration / deceleration cannot be obtained. Only when the shift position is changed, frequent shift position changes during acceleration / deceleration control are prevented, hunting of the shift position immediately after a change in the control state is prevented, and unnecessary shift operations during acceleration / deceleration control are performed. Is suppressed.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, reference numeral 1 denotes a constant speed traveling control unit for controlling the engine, which includes a CPU,
It is mainly composed of a microcomputer 10 provided with a ROM, a RAM, various interfaces and various timers, and a throttle actuator drive circuit 11.

Reference numerals 2 to 7 denote a group of switches operated by the driver, and the control unit 1 determines whether to start or cancel the constant speed traveling control according to the operation of these switches.

Reference numeral 2 is a main switch for constant speed running, set switch 3 is for starting constant speed running control and setting vehicle speed, and accelerator switch 4 and coast switch 5 are respectively under constant speed running control. The command to increase or decrease the target vehicle speed is to accelerate or decelerate the vehicle. The cancel switch 6 and the brake switch 7 are
The constant-speed traveling control is released, and these constitute control mode command means.

Various sensors for detecting the driving state of the vehicle are connected to the control unit 1, and the vehicle speed sensor 8 is
The control unit 1 calculates the actual vehicle speed by transmitting a pulse signal corresponding to the actual vehicle speed and counting the pulses.

The throttle sensor 9 is composed of a potentiometer or the like and sends out a signal corresponding to the actual throttle opening, and the control unit 1 controls the drive of the throttle actuator 30 based on this throttle opening and the running resistance described later. It is used for estimation calculation. Also,
The crank angle sensor 13 sends out the engine speed Ne.

A throttle for controlling the amount of intake air is provided in the intake passage of the engine, and this throttle is driven by a negative pressure type throttle actuator 30 which responds to a command from the control unit 1. This negative pressure type throttle actuator A vacuum pump 31 and an atmosphere release valve 32 shown in FIG. 2 are provided at 30, and the accelerator wire is driven according to the negative pressure generated by the vacuum pump 31 to control the opening degree of the throttle.

This throttle is provided with a throttle sensor 9 composed of a potentiometer or the like, which sends a signal corresponding to the actual throttle opening to the control unit 1, and the control unit 1 produces a negative signal based on this throttle opening. Pressure type throttle actuator 30
It is used for driving control of the vehicle and estimation calculation of running resistance described later. In addition, the crank angle sensor 1 installed in the engine
3 sends out the engine speed Ne.

An automatic transmission control unit 20 for controlling the automatic transmission is connected to the control unit 1 via signal lines 41 to 43.

The automatic transmission control unit 20 is
The shift position (3rd speed or OD) of the automatic transmission under constant speed traveling control is sent to the constant speed traveling control unit 1 via the signal line 41, while the constant speed traveling control unit 1 transmits via the signal line 42. And sends a constant speed travel control signal through the signal line 43, and an automatic transmission control via the signal line 43 an OD cancel signal requesting a shift down from the O / D position or a shift up to the O / D position during constant speed travel control. It is sent to the unit 20. The communication between the control units 1 and 20 by the signal lines 41 to 43 is shown as a parallel type.

3 to 7 are flowcharts showing an example of control performed by the control unit 1, which is executed at predetermined time intervals, for example, every 50 msec by a timer interrupt or the like, and FIG. 3 shows a main routine. 4 and 5 show subroutines for acceleration control and deceleration control, FIG. 6 shows an O / D cancel routine, and FIG. 7 shows a shift inhibition determination routine, which will be described in detail below with reference to these flowcharts.

First, in step S1, the vehicle speed sensor 8,
The signals of the throttle sensor 9 and the crank angle sensor 13 are read, and the average value of the vehicle speeds counted during the predetermined time is set as the actual vehicle speed Vsp based on the respective signals counted during the predetermined time (for example, 50 msec), Similarly, the average value of the engine speed is calculated as the engine speed Ne, and the actual throttle opening Tvo is measured by A / D converting the output of the throttle sensor 9.

In step S2, the cancel switch 6
Also, it is determined whether one of the brake switch 7 and the brake switch 7 is on, and it is determined whether to continue (start) or cancel the constant speed traveling control. In the case of cancellation, the process proceeds to step S15 and subsequent steps, while continuing (or In the case of (start), the process proceeds to step S3.

In step S3, it is determined whether or not the set switch 3 is on, and if it is on, the target vehicle speed Vsp is reached.
Since r is set and the constant speed traveling control is started, step S
On the other hand, while proceeding to step 4, if not, proceeding to step S6.

In step S4, the current actual vehicle speed Vsp is stored as the target vehicle speed Vspr, and in step S5, the constant speed traveling control flag indicating that the constant speed traveling control is being performed is set to 1.

If the set switch 3 is turned off in step S3, the processing from step S6 is performed, and constant speed running control and acceleration control or deceleration control based on the target vehicle speed Vspr set up to the previous time are performed. .

In step S6, it is determined whether or not the constant speed traveling control flag indicating that the constant speed traveling control is being executed is set state = 1, and if it is set, it is determined that the constant speed traveling control is continued. While proceeding to step S7, if not, proceeding to step S16.

In step S7, acceleration control during constant speed traveling control is performed in response to the operation of the accelerator switch 4 as will be described later, and in step S8, as described below, a constant speed in response to operation of the coast switch 5 is performed. Deceleration control during traveling control is performed.

In step S9, in order to match the actual vehicle speed Vsp with the target vehicle speed Vspr, the target driving force For of the engine is calculated using a known linear control method such as a model matching method and an approximate zeroing method.

First, the outline of the compensator for performing the feedback control of the vehicle speed will be described.

The transfer characteristic of the controlled object is represented by the pulse transfer function P
With (z ^-1 ), the compensator is as shown in FIG.

In FIG. 8, z is a delay calculation element,
When multiplied by z ⁻¹ , the value becomes one sample period before. Also,
C1 (z ⁻¹ ) and C2 (z ⁻¹ ) are disturbance estimators based on the approximate zeroing method and suppress the influence of disturbance and modeling errors.

C3 (z ^-1 ) is a compensator based on the model matching method, and matches the response characteristic of the controlled object with the characteristic of the reference model H (z ^-1 ).

When the target acceleration is input and the portion that outputs the actual vehicle speed Vsp is set as a control target, P (z ⁻¹ ) is an integral element P1 (z ⁻¹ ) and a dead time element P2 (z ^{− 1} ) = z
Can be set to the product of ^-2 .

P1 (z ⁻¹ ) = T · z ⁻¹ / (1−z ⁻¹ ) (1) where T; sample period = 50 msec At this time, C1 (Z ⁻¹ ) and C2 (Z ⁻¹ ) ) Are as follows.

C1 (Z ⁻¹ ) = (1−γ) · z ⁻¹ / (1−γ · z ⁻¹ ) (2) (Low-pass filter with time constant Tb) C2 (Z ⁻¹ ) = (1 −γ) · (1-z ⁻¹ ) / T · (1−γ · z ⁻¹ ) ... (3) (C2 = C1 / P1) where γ = exp (−T / tb) the dead time of the controlled object , And the reference model with a time constant t
If the first-order low-pass filter of a is used, C3 becomes the following constant.

C3 = K = {1-exp (-T / ta)} / T (4) Based on the above, the following calculation is performed. However, the data y (k-1) indicates the data y (k) one sample period before.

Y2 (k) = γ · y2 (k-1) + (1-γ) · y1 (k-1) (5) y3 (k) = γ · y3 (k-1) + (1- γ) / T · Vsp (k)-(1-γ) / T · Vsp (k-1) (6) y1 (k) = K · {Vspr (k) -Vsp (k)}-y3 (k ) + Y2 (k-2) ... (7) = r2 (k) -r1 (k) ... (7) 'However, r1 (k) = y3 (k) -y2 (k-2) r2 (k) = k {Vspr (k) -Vsp (k)} Here, y1 (k) is the target acceleration, and the target driving force For is calculated by multiplying the basic weight M of the vehicle as follows.

For (k) = y1 (k) · M (8) As described above, since C1 (z ⁻¹ ) and C2 (z ⁻¹ ) in FIG. 8 function as a disturbance estimator, constant speed running is performed. The disturbance in the inside, that is, the running resistance can be estimated. Therefore, the running resistance is calculated by multiplying the acceleration component r1 of the running resistance during constant speed running by the basic vehicle weight M.

Further, C3 (z ^-1 ) is necessary to follow the actual vehicle speed when a vehicle speed deviation occurs or when the target vehicle speed Vspr is increased or decreased by pressing the accelerator switch 4 or the coast switch 5. Calculate the driving force or engine braking force.

Therefore, the driving force or engine braking force required for acceleration / deceleration is calculated by multiplying the basic vehicle weight M by the acceleration component r2 of the driving force required for acceleration / deceleration.

Then, in step S10, the target engine torque Ter is calculated by the following equation, and then the target throttle opening Tvor is calculated.

Ter = (For · Rt) / Gm · Gf (9) However, Gm mission gear ratio, Gf is the final gear ratio, and Rt is the effective radius of the tire.

Further, as shown in FIG. 9, a target throttle opening Tvor is calculated by a table from the engine speed Ne and the target engine torque Ter using a preset engine nonlinear data map.

In step S11, the duty ratios Dvac and Dv of the vacuum pump 31 of the negative pressure type throttle actuator 30 and the solenoid valve 32 for opening to the atmosphere according to the target throttle opening Tvor thus obtained.
ent is calculated by a known control method such as PID control. The duty ratio is calculated according to the deviation Δ of the throttle opening (target throttle opening Tvor−actual throttle opening Tvo), and the vacuum pump 31 and Each duty ratio is set in each output register (not shown) to the atmosphere opening solenoid valve 32 to drive the negative pressure type throttle actuator 30.

In step S12, after a process for prohibiting shift of the automatic transmission described later is performed, it is determined in step S13 whether or not a shift prohibit flag for prohibiting shift is set (= 1). , If it is set, the process ends, while if it is not set,
In step S14, the O / D cancel routine for controlling the automatic transmission as described later is executed, and then the process ends.

If the cancel switch 6 is operated in step S2, step S1
In step 5, the constant speed running control flag is cleared to 0, and flags A, B, and C used in the later-described shift prohibition determination are cleared, and then in step S16, the target throttle opening Tvor is reset to run at constant speed. Control ends.

If the constant speed running control flag is not set in step S6, only the process of step S16 is performed.

Next, the acceleration control performed in step S7 will be described in detail with reference to the flowchart of FIG.

In the acceleration control subroutine performed in step S7, first, in step S21, it is determined whether or not the accelerator switch 4 is ON, and if it is ON, the process proceeds to step S23 for acceleration control. , OF
In the case of F, the process proceeds to step S22.

After setting the acceleration control flag in step S23, the target vehicle speed Vspr is set to the previous value, that is, the target vehicle speed Vspr one cycle before is set in step S24.
Set it to the value obtained by adding a predetermined value to (old), and here, +
After adding 2 km / h, the process returns to the main routine of FIG.

On the other hand, if the acceleration switch 4 is OFF in the determination in step S21, step S2
In step 2, it is determined whether or not the acceleration control flag is set, and if it is not set, the process returns to the main routine, while if it is set, the acceleration control is ended, so that the target vehicle speed Vspr is set in step S25. The current actual vehicle speed Vsp is set, the acceleration control flag is cleared in step S26, and the process returns to the main routine.

Similarly, in the deceleration control performed in step S8, as shown in FIG. 5, first, in step S31, it is determined whether or not the coast switch 5 is ON, and if it is ON, the deceleration control is performed. In order to do so, the process proceeds to step S33, while if OFF, the process proceeds to step S32.

After the deceleration control flag is set in step S33, the target vehicle speed Vspr is set to the previous value, that is, the target vehicle speed Vspr one cycle before is set in step S34.
It is set to a value obtained by subtracting a predetermined value from (old), and here, 2 km / h is subtracted as the predetermined value.

On the other hand, if the coast switch 5 is off in the determination in step S31, it is determined in step S32 whether or not the deceleration control flag is set. If not, the process returns to the main routine. On the other hand, if set, the deceleration control is ended, so the current vehicle speed Vsp is set to the target vehicle speed Vspr in step S35, the deceleration control in progress flag is cleared in step S36, and the process returns to the main routine.

By the above control, when the accelerator switch 4 or the coast switch 5 is pressed during the constant speed running control, the target vehicle speed Vspr is maintained at a predetermined rate until the switch is turned off, in this case, 2 km / h. Acceleration / deceleration is performed by increasing / decreasing every predetermined period (50 msec).

Next, the O / D cancel routine executed in step S14 will be described in detail with reference to the flowchart of FIG.

O / in steps S41 to S57 of FIG.
In the D cancel routine, the O / D cancel flag for selecting the shift position between O / D (for example, 4th speed) and another shift position (for example, 3rd speed) is set according to the traveling state, and communication is performed. Is transmitted to the automatic transmission controller 20.

In step S41, the running resistance Fr is estimated by the following equation by multiplying the basic vehicle weight M by the acceleration component r1 of the running resistance obtained in step S9 of FIG.

Fr (k) = r1 (k) · M (10) In step S42, determination is made according to whether the running resistance Fr estimated in step S41 is positive or negative, and if positive, the process proceeds to step S43. On the other hand, if negative, step S
Go to 47.

In step S43, an expected driving force Fod _max is calculated, assuming that the shift position of the automatic transmission is O / D and the throttle opening Tvo is in the fully open state at the current vehicle speed Vsp.

The driving force Fod _max is calculated based on the one-dimensional data table preset for each vehicle speed and the current vehicle speed Vsp, as shown in FIG.

Next, in step S44, the state of the accelerator switch 4 is monitored, and if it is ON, the process proceeds to step S45, and if it is OFF, the process proceeds to step S46 to calculate the total required driving force according to the acceleration state. To do.

In step S45, the total required driving force is calculated by the following equation from the acceleration component r2 of the driving force required for acceleration obtained in step S9.

Fr (k) + (r2 (k) · M) · β → Fr (k) (11) where β is a predetermined ratio.

On the other hand, in step S46, since the vehicle is traveling at a constant speed, the total required driving force = running resistance estimated value Fr.

In step S47, which is executed when the running resistance Fr is negative in the determination in step S42, the shift position of the automatic transmission is O / D and the throttle opening Tvo is fully closed at the current vehicle speed Vsp. Assuming the case of 1), the expected engine braking force Fod _max is calculated.

The engine braking force Fod _max is
It is calculated for each vehicle speed based on a preset one-dimensional data table and the current vehicle speed Vsp.

Next, in step S48, the state of the coast switch 5 is monitored, and if it is ON, step S49.
If OFF, the process proceeds to step S50 to calculate the total required engine braking force according to the deceleration state.

In step S49, the total required engine braking force is calculated from the acceleration component r2 of the driving force required for deceleration obtained in step S9 by the equation (11).

On the other hand, in step S50, since the vehicle is traveling at a constant speed, the total required engine braking force = running resistance estimated value F
r.

Thus, steps S45, S46, S4
9. Through S50, the total required driving force Fr obtained by dividing the positive / negative of the running resistance estimated value Fr and the situation of acceleration / deceleration
(K) or the total required engine braking force and the O / D position maximum driving force or O determined in steps S43 and 47 above.
Based on the / D position maximum engine braking force FOD _max , the O / D cancel flag is set after step S51.

In step S51, it is determined whether or not the shift position of the automatic transmission is O / D. If the shift position is in the O / D position, the process proceeds to step S52 and a position other than O / D (for example, 3
If so, the process proceeds to step S54.

In step S52, the driving force which is the difference between the absolute value of the O / D position maximum driving force FOD _max or the O / D position maximum engine braking force FOD _{max and} the absolute value of the total required driving force Fr (k) is calculated. If the margin is smaller than the predetermined value 1 (predetermined value 3 in the case of engine braking), it is determined that there is no room in the driving force or engine braking force for traveling at a constant speed at the current shift position, and the process proceeds to step S53. On the other hand, if the above-mentioned difference is equal to or larger than the predetermined value 1, it is determined that there is sufficient margin for the driving force or the engine braking force, and the process proceeds to step S55 to hold the O / D position.

On the other hand, if the shift position is other than O / D, the maximum O / D position driving force F is determined in step S54.
OD _max or O / D position Maximum engine braking force FO
If the driving force margin, which is the difference between the absolute value of D _{max and} the absolute value of the total required driving force Fr (k), is smaller than the predetermined value 2 (the predetermined value 4 in the case of engine braking), the current shift position Since it is determined that the driving force or the engine braking force does not have enough margin for traveling at constant speed, the process proceeds to step S53 and the current shift position is maintained, while if the difference is equal to or more than the predetermined value 2, the O / D is performed. It is judged that there is sufficient margin for the driving force or the engine braking force even if the shift is up, and the step S
Proceed to 55 and request an upshift to the O / D position.

In step S53, the O / D cancel flag is set to request the shift position of the automatic transmission to be a position other than O / D (for example, the third speed). Similarly, in step S55, O / D is set. The cancel flag is reset and the shift position of the automatic transmission is requested to be O / D.

Then, in step S56, a constant speed traveling control signal is sent to the automatic transmission control unit 20 via the signal line 42 based on the constant speed traveling control flag, and the O / D cancel flag is set in the step S57. Based on the signal line 43, an O / D cancel signal is output to the automatic transmission control unit 20 to request the automatic transmission to shift up, down, or hold.

The O / D cancel routine of steps S41 to S57 is the same as the Japanese Patent Application No. 7-4 proposed by the applicant of the present application.
Although it is similar to No. 7123 and is not described in detail here, during the acceleration or deceleration by the operation of the accelerator switch 4 or the coast switch 5 when performing the shift operation of the automatic transmission based on the running resistance estimated value Fr, The running resistance estimated value F is obtained by multiplying the basic vehicle weight M and a predetermined ratio β by the acceleration component r2 of the driving force or engine braking force required for acceleration / deceleration.
r, and the added running resistance estimated value Fr and O /
Since the margin of the driving force, which is the difference from the D maximum driving force (or engine braking force), is compared with the predetermined value 1 or 2 (the predetermined value 3 or 4 during deceleration) to determine the shift position,
When the driver accelerates or decelerates by operating the accelerator switch 4 or the coast switch 5, the driver only shifts down if sufficient acceleration / deceleration cannot be obtained, and the desired acceleration / deceleration is suppressed while suppressing unnecessary downshifting. You can get speed.

Next, step S of the main routine of FIG.
The shift prohibition determination subroutine executed in 12 will be described in detail with reference to the flowchart of FIG.

In step S61, it is determined whether or not the constant speed traveling control flag has changed from 0 to 1 (OFF to ON) and the constant speed traveling control has been started. And the flag A indicating the previous value of the constant speed traveling control flag is 0, it is determined that the set switch 3 is pressed and the constant speed traveling control is started, and step S6 is performed.
On the other hand, while proceeding to step 4, when the constant-speed traveling control in which the constant-speed traveling control flag does not change is being executed, the routine proceeds to step S62.

In step S62, in order to judge the start or end of the acceleration control, the acceleration control flag is compared with the flag B indicating the previous value of the acceleration control flag. When it is determined that the acceleration control is started or ended by the operation, step S
On the other hand, while proceeding to 64, if the acceleration control in which the acceleration control flag does not change is being continued, the routine proceeds to step S63.

In step S63, in order to determine the start or end of the deceleration control, the deceleration control flag is compared with the flag C indicating the previous value of the deceleration control flag. If they are not equal, the coast switch 5 is operated. It is determined that the deceleration control has been started or ended, and the process proceeds to step S64. On the other hand, if the deceleration control flag is not changed and the deceleration control is continuing, the process proceeds to step S64.

In steps S61 to S63, the change in the state of the constant speed traveling control is determined, and the constant speed traveling control is started.
When the acceleration / deceleration control is started or ended, the process proceeds to step S64, and a predetermined value corresponding to the time during which the shift of the automatic transmission is prohibited is set in the prohibit timer. This predetermined value is set to, for example, 60, and when one cycle of the constant speed traveling control is 50 msec, it becomes a time corresponding to 3 seconds.

Next, in step S65, a predetermined value (for example, 1) is subtracted from the prohibit timer, and then it is determined in step S66 whether the predetermined time (= 3 seconds) set by the prohibit timer has elapsed. In this determination, if the value of the prohibit timer is greater than 0, it is judged that the predetermined time has not elapsed, and it is judged that the shift is prohibited, and the process proceeds to step S67 to set the shift prohibit flag to 1, while the value of the prohibit timer is If 0 or less, it is determined that the predetermined shift inhibition time has elapsed, and the shift inhibition flag is cleared to 0 in step S68.

In step S69, the current control state is stored for the next shift inhibition determination, and the values of the constant speed running control flag, the acceleration control flag and the deceleration control flag are set to the flags A, B and C. To the main routine of FIG. 3 to complete the shift inhibition determination routine.

The above control is performed in a predetermined cycle (50 mse
c) by changing the control state for a predetermined period of time to inhibit the shift, suppress the influence of the disturbance of the running resistance estimated value Fr that occurs after the change of the control state, and frequently shift down or shift. The operation will be described in detail below with reference to FIG. 11.

When the driver presses the set switch 4 at time A in FIG. 11 when the driver normally operates the accelerator pedal, the above step S3 is performed.
The constant speed traveling control flag is set to 1 by S5 and the constant speed traveling control is started.

In the gear shift prohibition determination in step S12, since the previous value and the current value of the constant speed traveling control flag are different in step S61, the prohibit timer is set to a predetermined time and the gear shift prohibit flag is set. To be done.

Therefore, immediately after the start of the constant speed running control, the shift inhibition flag is set, so that the operation in step S14 becomes O.
The / D cancel routine is not executed, the shift position of the automatic transmission is not changed during the predetermined time (about 3 seconds), and the shift position immediately before the start of the constant speed traveling control is maintained.

Immediately after the start of the constant speed traveling control, the vehicle speed,
The physical quantity such as the throttle opening and the running resistance estimated value Fr calculated in step S9 and step S41 converge to a steady value while repeating undershoot and overshoot.

That is, in this transient state, the running resistance estimated value Fr generally contains a large error, and is different from the actual running resistance, and steps S41 to S5 are executed.
In the O / D cancel routine of No. 7, the shift position is determined based on the running resistance estimated value Fr. Therefore, the shift hunting in which unnecessary shifts are repeated according to the disturbance of the running resistance estimated value Fr is performed as in the conventional example. In contrast to this, in the present embodiment, the shift is prohibited for a predetermined time from the change of the control state and the start of the constant speed traveling control, and the calculated values such as the estimated traveling resistance value Fr converge to a steady value. Since the shift operation of the automatic transmission is permitted after the predetermined time, the smooth constant speed traveling control can be realized while suppressing the shift hunting of the automatic transmission immediately after the control state changes.

Further, in FIG. 11, the acceleration switch 5 is pressed from time B to time C to perform acceleration control. Immediately after shifting from the constant speed running control to the acceleration control and from the acceleration control to the constant speed running control. Immediately after the transition, the running resistance estimated value Fr is disturbed as in the above. However, when the acceleration control state changes in step S62, the prohibit timer and the shift prohibit flag are set, so that the automatic shift within the predetermined time period is performed. It is possible to prevent gear shifting of the machine and perform smooth constant speed traveling control, and the same applies to deceleration control from time D to time E when the coast switch 5 is operated.

As described above, when there is a change in the control state such as the start of the constant speed running control or the acceleration / deceleration control during the constant speed running control, the shifting operation of the automatic transmission is prohibited until a predetermined time elapses. Thus, it is possible to prevent shift hunting of the automatic transmission due to the disturbance of the calculated values such as the estimated traveling resistance value Fr. Since the shift operation is permitted after a predetermined time has elapsed, smooth constant speed traveling control can be performed. You can do it.

Further, control of the automatic transmission is performed in step S4.
1 to S57, the driving force or the engine braking force required for acceleration / deceleration multiplied by a predetermined ratio β is added to the running resistance estimated value Fr to determine the shift position. In acceleration / deceleration control during constant-speed traveling control, it is possible to obtain the desired acceleration / deceleration at all times while suppressing unnecessary shift-down, and shift hunting due to changes in the control state and unnecessary shift during acceleration / deceleration control. It is possible to suppress the down and further improve the drivability.

Although the model matching is used for the vehicle speed feedback control in the above embodiment, the present invention is not limited to this, and similar effects can be obtained even when a known control method such as PI control (proportional integral control) is used. , The effect can be obtained.

[0100]

As described above, according to the first aspect of the present invention, when the driver operates the control mode command means to instruct the start of constant speed traveling control during normal traveling, the target is estimated based on the traveling resistance estimated value Fr. The engine output and the shift position of the automatic transmission are controlled so as to match the vehicle speed, and constant-speed traveling control is started. Immediately after this command, the control state determination means determines the change in the control state, so the shift prohibition is prohibited. The means can prohibit the gear shifting operation of the automatic gear shift control means for a predetermined time, can hold the shift position of the automatic gearbox, and the running resistance estimated value that fluctuates in the transitional state in which the normal running shifts to the constant speed running control. It is possible to prevent hunting of the shift position due to the influence of Fr, and to realize smooth constant speed running control by releasing the shift inhibition after a predetermined time when the estimated running resistance value Fr has converged to a steady value. Even after the control shifts from the row control to the acceleration / deceleration control, or vice versa, the shift operation is prohibited for a predetermined time due to the change in the control state, and it is possible to prevent the hunting of the shift position in the same manner. A constant speed traveling control can be realized.

In the second aspect of the invention, the throttle opening is controlled according to the running resistance estimated value Fr calculated based on the vehicle model and the target vehicle speed and the target driving force based on the deviation between the target vehicle speed and the actual vehicle speed. Smooth constant speed traveling control can be performed.

The third aspect of the present invention prevents hunting of the shift position immediately after the control state changes, and also unnecessary shift operation during acceleration control or deceleration control during constant speed running control. Since this is suppressed, smoother constant speed traveling control can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a constant speed traveling control device showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a negative pressure type throttle actuator.

FIG. 3 is a flowchart of a main routine showing an example of control.

FIG. 4 is a flowchart showing an example of a subroutine of acceleration control.

FIG. 5 is a flowchart showing an example of a deceleration control subroutine.

FIG. 6 is a flowchart showing an example of a subroutine that similarly sets an O / D cancel flag.

FIG. 7 is a flowchart showing an example of a subroutine for similarly determining shift inhibition.

FIG. 8 is a configuration diagram of a feedback control compensator.

FIG. 9 is a map showing the non-linear characteristic of the engine, showing the relationship between the throttle opening and the engine torque.

FIG. 10 is a map showing the driving force expected when the shift position of the automatic transmission is O / D and the throttle opening is in the fully open state, showing the relationship between the driving force and the vehicle speed.

FIG. 11 is a graph showing a relationship between a state of a shift inhibition flag and a vehicle speed, a throttle opening, and an estimated value Fr of running resistance when acceleration control and deceleration control are performed from the start of constant speed running control.

FIG. 12 is a claim correspondence diagram corresponding to any one of the first to third inventions.

[Explanation of symbols]

 1 constant speed running control unit 3 set switch 4 accelerator switch 5 coast switch 20 automatic transmission control unit 30 negative pressure type throttle actuator 50 target vehicle speed setting means 51 vehicle speed detecting means 52 running resistance estimating means 53 constant speed running control means 54 control Mode command means 55 Automatic gear shift control means 56 Control state determination means 57 Gear shift prohibiting means 58 Target driving force calculation means 59 Throttle control means 60 Driving force calculation means 61 Total required driving force calculation means 62 Maximum driving force calculation means

Claims (3)

[Claims] 1. A target vehicle speed setting means for setting a target vehicle speed, an actual vehicle speed detecting means for detecting an actual vehicle speed of a vehicle, and a running resistance estimation means for calculating a running resistance estimating means for calculating an estimated value of the running resistance of the vehicle. Based on the value Fr, a constant speed traveling control unit that adjusts the output of the engine so that the actual vehicle speed matches the target vehicle speed, and a constant speed traveling control start or constant speed traveling control based on a driver's operation. A vehicle constant speed traveling control device comprising: a control mode command means for commanding acceleration or deceleration; and an automatic shift control means for changing a shift position of an automatic transmission based on the calculated traveling resistance estimated value Fr. A control state determining means for determining whether or not the control state of the control mode commanding means has changed, and a shift of the automatic shift control means for a predetermined time from when the determination result determines the change of the control state. A constant speed running control device for a vehicle, comprising: a shift inhibiting means for inhibiting an operation. 2. The running resistance estimating means calculates a running resistance estimated value Fr based on a vehicle model and a target vehicle speed, while the constant speed running control means comprises a target driving force based on a deviation between the target vehicle speed and the actual vehicle speed. Target driving force calculation means for calculating
The vehicle constant speed traveling control device according to claim 1, further comprising: throttle control means for controlling a throttle opening degree of the engine based on the sum of the traveling resistance estimated value Fr and the target driving force. 3. The automatic shift control means calculates a total driving force by adding a driving force calculating means for calculating a required driving force required for acceleration / deceleration and the running resistance estimated value Fr and the required driving force. A total driving force calculation means and a maximum driving force estimation means for calculating the maximum driving force at the current vehicle speed and a predetermined shift position are provided, and driving is performed based on the difference between this maximum driving force and the total required driving force. While calculating the power margin,
The vehicle constant speed traveling control device according to claim 1 or 2, wherein a shift position of the automatic transmission is changed according to the margin.