JPH08207619A - Automatic speed controller for vehicle - Google Patents

Abstract

PURPOSE: To prevent accumulation of errors so as to control a vehicle speed to a target vehicle speed by estimatively computing a running resistance value on the basis of corrected final target driving force and an actual vehicle speed. CONSTITUTION: In constant speed travel control, a control unit 1 for constant speed travel transmits a constant speed travel control signal to a control unit 12 for an automatic transmission via a signal wire B and a constant speed travel OD(overdrive) cancel demand signal to the control unit 12 via a signal wire C. The control unit 1 for constant speed travel is provided with a final target driving force correcting means, a running resistance computing means, and the like as software. In this way, vehicle speed control can be carried out without any error accumulation in the inside of the running resistance computing means even when a vehicle speed greatly exceeds a target value on a steep downward slope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle automatic speed control device for automatically controlling the traveling speed of a vehicle (hereinafter, also referred to as vehicle speed).

[0002]

2. Description of the Related Art A conventional vehicle automatic speed control device is disclosed in Japanese Patent Laid-Open No. 4-132845 (first prior art example). This is to calculate the target driving force that matches the target vehicle speed and the actual vehicle speed based on the deviation between the target vehicle speed and the actual vehicle speed, and control the throttle valve opening so that the actual driving force matches the target driving force. Then, it improves the vehicle speed control performance. "

Also, an "approximate zeroing control method" is known as a known general control method (second conventional example). This is based on the manipulated variable to the controlled object and the output of the controlled object, and estimates the disturbance applied to the controlled object using a disturbance estimator (disturbance observer) that uses a dynamic model of the controlled object. By correcting the operation amount based on the result, the influence of disturbance is eliminated.

Further, there is one disclosed in JP-A-1-313136 (third conventional example). In order to achieve the target engine torque, the target throttle valve opening is determined using the engine performance data stored in advance, and the actual throttle valve opening is controlled to match the target throttle valve opening. is there.

[0005]

In order to control the vehicle speed to the target vehicle speed with higher accuracy in the vehicle automatic speed control device, a case in which the first conventional example and the second conventional example are combined is described. Considering it, the disturbance estimator estimates the running resistance (the sum of gradient resistance, air resistance, and rolling resistance) that is the disturbance applied to the vehicle, and the target driving force calculated from the vehicle speed deviation is calculated based on the estimation result. By performing the correction, the vehicle speed control performance that is not affected by the change in the running resistance can be achieved.

However, the above combination has the following problems. That is, since the driving force of the vehicle to be controlled is finite, when a driving force exceeding the driving force (engine braking force in the case of a negative value) is required during vehicle speed control, an error is generated inside the disturbance estimator. Accumulation continues, and the vehicle speed control performance after that continues to deteriorate. That is, for example, assume a situation in which, during constant vehicle speed control, a steep uphill is entered and the driving force is insufficient even with the maximum driving force of the vehicle so that the vehicle speed falls below the target value. Under this circumstance, errors continue to accumulate inside the disturbance estimator, the target driving force is largely corrected to the positive side, and this effect remains for a while even after the road gradient returns to flat, resulting in a reverse vehicle speed. It will overshoot (see FIG. 9A).

On the other hand, during automatic speed control (hereinafter also referred to as constant vehicle speed control), a sudden downhill is entered, and even if the vehicle has the maximum engine braking force, the engine braking force is insufficient and the vehicle speed is the target. Imagine a situation where the value is exceeded. Under this circumstance, errors continue to accumulate inside the disturbance estimator, the target driving force is largely corrected to the negative side, and this effect remains for a while even after the road gradient returns to flat, resulting in a reverse vehicle speed. Undershooting will occur (see FIG. 9B).

Further, considering the combination of the first conventional example and the third conventional example, there are the following problems. That is, due to the non-linear characteristic of the engine performance, there is an operating region where the maximum engine output torque is generated even if the throttle valve opening is not fully opened. When the target throttle valve opening is determined from the target engine torque using this non-linear engine characteristic data, the throttle valve opening becomes a value that is equal to or greater than the value that is assumed in advance to obtain the maximum engine output torque. Don't Therefore, even if there are variations in the actual engine characteristics of the vehicle and there is a difference in the maximum torque, the maximum engine torque of that engine,
That is, the maximum driving force may not be obtained (see FIG. 10).

The present invention has been made in view of the above circumstances, and a vehicle in which a target driving force is calculated so as to obtain a target vehicle speed and an engine is controlled so as to obtain this target driving force. In a vehicle speed control device for a vehicle, it is possible to suppress an error in estimation calculation of running resistance that occurs when the target driving force is set to a value that cannot be actually achieved, and thereby perform highly accurate automatic vehicle speed control. A first object of the present invention is to provide an automatic speed control device for a vehicle capable of performing the above.

Further, in a vehicle speed control device for a vehicle, a target driving force is calculated so as to obtain a target vehicle speed, and a throttle valve opening is controlled so as to obtain this target driving force. When setting the valve opening, the target throttle valve opening is set using the engine characteristic data that is expanded so that the engine torque always has a one-to-one correspondence over the entire throttle valve opening, instead of the conventional non-linear engine characteristic data. By setting it, the target throttle valve opening can be set with high accuracy even if there are variations in the actual engine characteristics, so that highly accurate automatic speed control of the vehicle can be performed. It is a second object of the present invention to provide an automatic vehicle speed control device.

It is another object of the present invention to further improve the accuracy and simplification of the vehicle automatic speed control device.

[0012]

Therefore, according to the invention described in claim 1, as shown in FIG. 1, based on the actual vehicle speed of the vehicle and the target vehicle speed, the target driving force for making them substantially coincide with each other. The target driving force calculating means for calculating the final target driving force based on the calculated target driving force and the estimated running resistance of the vehicle, and the final driving force calculating means for calculating the final target driving force. By limiting the final target driving force by the upper limit value and the lower limit value, the final target driving force correction means for obtaining the corrected final target driving force, the corrected final target driving force, and the actual vehicle speed, based on the vehicle And a traveling resistance calculating means for estimating and calculating a traveling resistance value.

According to a second aspect of the present invention, as shown in FIG. 2, target driving force calculating means for calculating a target driving force that substantially matches the actual vehicle speed of the vehicle and the target vehicle speed is provided. , At least based on the calculated target driving force and engine characteristic data expanded so that the engine torque corresponds to one-to-one in the entire throttle valve opening,
A first target throttle valve opening setting means for setting a target throttle valve opening; and a throttle valve control means for controlling the throttle valve so that the actual throttle valve opening matches the target throttle valve opening. Configured.

According to a third aspect of the present invention, as shown in FIG. 3, target driving force calculating means for calculating a target driving force that substantially matches the actual vehicle speed of the vehicle and the target vehicle speed is provided. A final target drive force calculating means for calculating a final target drive force based on the calculated target drive force and a vehicle running resistance estimated value; and an upper limit value and a lower limit of the calculated final target drive force. A running resistance for estimating and calculating a running resistance value of the vehicle based on the final target driving force correcting means for obtaining the modified final target driving force by limiting the value, the modified final target driving force, and the actual vehicle speed. Based on the calculating means, the final target driving force calculated by the final target driving force calculating means, and the engine characteristic data expanded so that the engine torque has a one-to-one correspondence over the entire throttle valve opening,
Second target throttle valve opening setting means for setting a target throttle valve opening, and throttle valve control means for controlling the throttle valve so that the actual throttle valve opening substantially matches the target throttle valve opening. Composed of.

According to a fourth aspect of the present invention, the upper limit value and the lower limit value are set based on the engine torque when the throttle valve is fully opened and when the throttle valve is fully closed, which is set for each engine speed. The invention according to claim 5 is a model matching vehicle speed control for calculating the target driving force such that the actual vehicle speed substantially matches the target vehicle speed according to the response characteristic of a predetermined reference model. It was made to calculate using a means.

[0016]

In the invention according to claim 1 having such a configuration, the final target driving force used for the estimation calculation of the running resistance in the running resistance calculating means is corrected by the upper limit value and the lower limit value obtained from the engine characteristics and the like. (Limit) is added so that an error does not occur in the running resistance estimation calculation even when the final target driving force is set to a value that cannot be actually obtained. As a result, for example, during automatic speed control, when a vehicle enters a steep uphill slope and the driving force is insufficient even with the maximum driving force of the vehicle, the vehicle speed may fall below the target value. , On a steep downhill,
Even if the vehicle has the maximum engine braking force, even if the engine braking force is insufficient and the vehicle speed greatly exceeds the target value, no error is accumulated in the running resistance calculating means, Even after the slope returns to a flat level, the running resistance calculating means can quickly function to control the vehicle speed to the target vehicle speed without overshooting or undershooting. Therefore, highly accurate automatic speed control of the vehicle can be performed.

According to the second aspect of the present invention, by providing the first target throttle valve opening setting means, when setting the target throttle valve opening, the engine torque always corresponds to the entire throttle valve opening one to one. The target throttle valve opening is obtained using the extended engine characteristic data (linear). As a result, for example, on a steep uphill slope where the vehicle speed decreases from the target vehicle speed, the throttle valve can be fully opened until it is fully opened. The maximum driving force of the engine can be extracted. Therefore, highly accurate automatic speed control of the vehicle can be performed. The first target throttle valve opening degree setting means may set the target throttle valve opening degree by using a target driving force in consideration of the traveling resistance value in order to improve the setting accuracy.

According to a third aspect of the invention, in addition to the configuration of the first aspect of the invention, the first target throttle valve opening setting means of the invention of the second aspect (actually, the final target driving force calculation is performed). Since the second target throttle valve opening degree setting means using the final target driving force calculated by the means) is added, the action of the invention described in claim 1 and the claim 2 described above are added. The effect of the invention and the effect of the invention can be achieved at the same time.

According to the fourth aspect of the present invention, it is possible to set the upper limit value and the lower limit value with high accuracy with a relatively simple structure. In the invention according to claim 5, the target driving force can be calculated with high accuracy by a relatively simple configuration.

[0020]

EXAMPLES Examples of the present invention will be described below. FIG.
FIG. 1 is a system configuration diagram of an automatic speed control device according to an embodiment of the present invention. In FIG. 4, an automatic transmission 30 is provided on the output side of an engine 20 mounted on a vehicle (not shown). The automatic transmission 30 includes a fluid type torque converter 40 interposed on the output side of the engine 20, a gear type transmission 50 connected to the engine 20 via the fluid type torque converter 40, and the gear type transmission 50. And a hydraulic actuator (not shown) for performing connection / disengagement operations of various transmission elements therein.

The working hydraulic pressure for the hydraulic actuator (not shown) is controlled via various electromagnetic valves (not shown), and the CPU, ROM, RAM, digital port, A
/ D control, control unit for automatic transmission 12 consisting of microcomputer with built-in timer
Shifts to a target gear position by a combination of ON / OFF of the various electromagnetic valves.

The automatic transmission control unit 12 runs at a constant speed through the signal line A at a gear position (3rd or OD [overdrive]) during constant vehicle speed control (that is, during automatic speed control). For sending to the control unit 1. On the other hand, the constant-speed traveling control unit 1 to be described later sends a constant-speed traveling control-in-progress signal to the automatic transmission control unit 12 via the signal line B during the constant-speed traveling control, and also transmits the signal line C. An OD (overdrive) cancel request signal is sent via the vehicle at a constant speed. Then, the automatic transmission control unit 12 performs gear shift control based on a command from the constant speed traveling control unit 1 during constant speed traveling control. That is, the control unit 12 for the automatic transmission controls the signals from various sensors (TV
O, Vsp, etc.) to determine the target shift speed, output a shift signal for turning on / off the electromagnetic valve according to the target shift speed, control the shift operation in the automatic transmission 2, and control the constant speed running. In the middle, the target shift speed is determined based on the signal from the constant speed traveling control unit 1 and a shift signal for turning on / off the electromagnetic valve is output according to the target shift speed, and the shift in the automatic transmission 2 is changed. The operation will be controlled. Regarding the communication between the constant speed traveling control unit 1 and the automatic transmission control unit 12, the simplest parallel type is used in this embodiment, but other types may be used.

By the way, the constant-speed traveling control unit 1 includes a one-chip microcomputer (or a plurality of chip microcomputers for realizing the same function) including a CPU, a ROM, a RAM, a digital port, an A / D port, various timers, and the like. It is composed of a throttle actuator drive circuit 1-3. As in the present embodiment, it is preferable to include a fail-safe cutoff circuit 1-2 that cancels the constant speed traveling control when an abnormality occurs.

Various signals are input to the constant speed traveling control unit 1. The various signals are signals from the switches 2 to 7 operated by the driver, the vehicle speed sensor 8, the throttle sensor 9, and the crank angle sensor 10, and the like. It is designed to judge whether to start or cancel the high speed traveling control.

Here, the main switch (MAIN S
W) 2 is a constant speed traveling permission switch for permitting power supply to the constant velocity traveling control unit 1 and the throttle actuator drive circuit 1-3. The set switch (SET SW) 3 is a switch for starting the constant speed traveling control and setting the set vehicle speed. The accelerator switch (ACC SW) 4 is a switch for increasing the set (target) vehicle speed, and is a coast switch (COAS).
T SW) 5 is a switch for lowering the set (target) vehicle speed. Cancel switch (CANSEL SW)
Reference numeral 6 denotes a switch for canceling the constant speed running control, and a brake switch (BRAKE SW) 7 is a switch for canceling the constant speed running control when the driver depresses the brake pedal.

The vehicle speed sensor 8 is a vehicle speed sensor using an electromagnetic pickup, and generates a pulse signal in synchronization with the output shaft of the automatic transmission 30. In the constant speed traveling control unit 1, the pulse signal is generated. The output shaft rotation speed is detected by counting or measuring the cycle, and the actual vehicle speed Vsp is detected based on the detection result and the final reduction ratio. The actual vehicle speed Vsp detected in this manner is used for calculation of the operation amount of the throttle actuator 11, determination of shift timing during constant speed traveling control, and the like.

The throttle sensor 9 is a potentiometer type sensor for detecting the opening of the throttle valve 21 which is inserted in the intake system of the engine 20 and opens and closes in conjunction with an accelerator pedal (not shown). The analog signal corresponding to is output to the constant-speed traveling control unit 1, A / D conversion is performed in the unit 1, and the actual throttle valve opening TVO can be detected. The throttle valve opening TVO detected in this way is used for servo control of the throttle actuator 11 and estimation of running resistance.

The crank angle sensor 10 is a sensor used for measuring the engine speed. The throttle actuator 11 is a negative pressure type throttle actuator, and adjusts the negative pressure of a vacuum pump driven by a motor or the like by an open / close combination of a plurality of solenoid valves (not shown) capable of communicating with the atmosphere. The throttle valve 21 can be forcibly operated depending on the size of the throttle valve regardless of the accelerator operation.

Here, the constant speed traveling control performed by the constant speed traveling control unit 1 in this embodiment will be described with reference to the flow chart of FIG. In the present embodiment, the constant-speed traveling control unit 1 includes the target driving force calculating means, the final target driving force calculating means, and the target driving force calculating means according to the present invention.
Functions as final target driving force correction means, running resistance calculation means, first target throttle valve opening setting means, second target throttle valve opening setting means, throttle valve control means, model matching vehicle speed control means are provided by software. ing.

First, at P1, calculation is performed based on the count value of the number of pulses from the vehicle speed sensor 8 counted during 100 msec to measure the average actual vehicle speed VSP during 100 msec. Further, calculation is performed based on the count value of the number of pulses from the crank angle sensor 10 counted in 100 msec to measure the average engine rotation speed Ne in 100 msec. Furthermore, the analog signal value from the throttle sensor 9 is read using the A / D conversion function in the microcomputer to perform a predetermined calculation to measure the throttle valve opening TVO.

At P2, the state of the digital I / O port connected to the cancel switch 6 and the brake switch 7 is monitored, and when either one is in the ON state, constant speed traveling control (control by ASCD [AUTO SPEED CONTOROL DEVICE]) In order to cancel the above, the process proceeds to P8, and when both are OFF, the process proceeds to P3 to permit the constant speed traveling control. At P3, the status of the digital I / O port connected to the set switch 3 is monitored, and if ON, the process proceeds to P4, where OF
If F, proceed to P7.

At P4, the current actual vehicle speed Vsp is stored as the target vehicle speed Vspr. At P5, constant speed running control is in progress (A
The ASCD operation flag indicating that the SCD is operating is set (= 1). In P6, fail-safe power cutoff circuit 1
Corresponding digital I / O so that the -2 is energized
Set the specified bit in the register of the port.

At P7, the ASCD operation flag is checked, and if it is in the set state (= 1), it is determined that constant speed traveling control is in progress, and the routine proceeds to P10. If it is not set (= 0), the process proceeds to P8. At P8, each flag and variable are initialized. In P9, fail-safe power cutoff circuit 1
Clear a predetermined bit of the register of the corresponding digital I / O port so that -2 is turned off.

At P10 to P14, the target vehicle speed Vspr is
In order to match the actual vehicle speed Vsp, the final target driving force y1 is calculated by using the known model control method “model matching method” and “approximate zeroing method”. First, an outline of the vehicle speed feedback compensator will be described using a pulse transfer function. The transfer characteristic of the controlled object is defined by the pulse transfer function P
With (z ^-1 ), the controller becomes as shown in FIG. z is a delay operator, and when multiplied by z ⁻¹ , the value becomes one sample period before. 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 makes the response characteristic of the controlled object match the characteristic of the reference model H (z ^-1 ).

Assuming that a portion for inputting the target driving force and outputting the actual vehicle speed is a control object, P (z ^-1 ) is an integral element P1 (z ^-1 ) and a dead time element P2 ( z ^-1 ) = z ^-2
The product of

[0036]

[Equation 1]

If the reference model is a first-order low-pass filter with a time constant Ta, ignoring the dead time of the controlled object, C
3 is the following constant. C3 = K = [1−exp (−T / Ta)] · M / T P10 performs the following calculation corresponding to the model matching compensator to obtain the target driving force y4. However, the data y (k
-1) indicates the data y (k) one sample period before.

Y4 (k) = K · (Vspr (k) −Vsp (k)) In P11, the robust compensator C that is a part of the disturbance estimator
The following calculation corresponding to 2 (z ^-1 ) is performed. y3 (k) = γ ・ y3 (k-1) + (1-γ) ・ M / T ・ V
sp (k)-(1- [gamma]) * M / T * Vsp (k-1) In P12, the target driving force y4 is corrected by the following equation to obtain the final target driving force y1 (k). However, y2 (k-2) is P14
It is the data two sampling periods before y2 (k) obtained by Incidentally, y2 (k-2) -y3 (k) is the estimated running resistance value.

Y1 (k) = y4 (k) -y3 (k) + y2 (k-2) In P13, the table data in which the engine torque values at the time of fully opening and fully closing the throttle valve are stored for each engine speed are stored. Then, the maximum engine torque Temax and the minimum engine torque Temin are obtained. Further, the maximum driving force Fmax and the minimum driving force Fmin are calculated using the following formulas. Gm is
The mission gear ratio, Gf is the final gear ratio, and Rt is the effective radius of the tire.

Fmax = (Temax.Gm.Gf) / Rt Fmin = (Temin.Gm.Gf) / Rt Further, the final target driving force y1 (k) is set to the upper limit value F of these.
y5 (k) is obtained by limiting with max and the lower limit value Fmin. That is, if y1 (k)> upper limit value Fmax, then y5 (k) = upper limit value Fmax, and if y1 (k) <lower limit value Fmin, then y5 (k)
(k) = lower limit value Fmin, and if upper limit value Fmax ≧ y1 (k) ≧ lower limit value Fmin, then y5 (k) = y1 (k).

At P14, the following calculation corresponding to the compensator C1 (z ^-1 ) as a low-pass filter which is a part of the disturbance estimator is performed. y2 (k) = γ · y2 (k-1) + (1-γ) · y5 (k-1)) In P15, the target engine torque Ter is calculated from the final target driving force y1 (k). Gm is the transmission gear ratio,
Gf is the final gear ratio, and Rt is the effective radius of the tire.

Ter = (y1.Rt) / (Gm.Gf) Furthermore, using the engine non-linear characteristic data map stored in advance for each engine speed, the target throttle valve opening is plotted from the target engine torque Ter. Calculate
For example, as shown in FIG. 7, an expanded data map is used so that the engine torque always corresponds to the entire throttle valve opening. In FIG. 7, the solid line part is the original engine characteristic data, and the dotted line part is the expanded data.

At P16, a known control method such as PI (proportional integral) control is used to eliminate the deviation Δ based on the throttle valve opening deviation Δ (= target opening TVOR-actual opening TVO). The output (driving) pulse widths (Tvac, Tvent) of the vacuum pump of the negative pressure type throttle actuator 11 and the solenoid valve for releasing the atmosphere are calculated.

At P17, the vacuum pump output pulse width Tvac and the atmosphere release solenoid valve output pulse width Tvent are written in the pulse output register in the constant speed traveling control unit 1. With this flow, the following operational effects are exhibited. That is, the disturbance estimator configured by the "approximate zeroing method" accurately estimates the disturbance (running resistance) based on the difference between the output of the controlled object model inside and the actual output of the controlled object.

In particular, even when it is assumed that the vehicle speed falls below the target value due to insufficient driving force even with the maximum driving force of the vehicle due to a steep uphill climbing during constant vehicle speed control. , The final target driving force input to the disturbance estimator is limited so as not to exceed the actual maximum driving force, and the target driving force value that cannot be actually obtained does not reach a large value. Is never accumulated. Therefore,
Even after the road gradient returns to a flat level, the disturbance estimator can quickly function to control the vehicle speed to the target vehicle speed without overshooting (see FIG. 8A).

On the contrary, during constant vehicle speed control, even if the vehicle enters the steep downhill and has the maximum engine braking force of the vehicle, the engine braking force is insufficient and the vehicle speed greatly exceeds the target value. Even if it is assumed, the final target driving force value input to the disturbance estimator is limited so as not to fall below the actual minimum driving force value, and a small target driving force value (large engine braking Since it does not reach the target value), no error is accumulated inside the disturbance compensator. Therefore, even after the road gradient returns to a flat surface, the disturbance estimator can quickly function and the vehicle speed can converge to the target vehicle speed without undershooting (FIG. 8B).
reference).

Further, based on the target engine torque obtained from the final target driving force value whose upper and lower limits are not restricted, the engine torque value and the throttle valve full opening range are expanded so as to correspond one-to-one. Since the target throttle valve opening is calculated using the engine non-linear characteristic data map (Fig. 7), the throttle valve can be completely opened until the throttle valve is fully opened even on a steep climb where the vehicle speed decreases from the target vehicle speed. Can be opened. Therefore, the maximum driving force of the engine can be extracted without being affected by variations in engine characteristics.

In the above embodiment, the engine speed may be estimated from the engine load such as the throttle valve opening and the basic fuel injection amount Tp. Further, instead of the engine torque, a parameter (Tp, intake air flow rate, etc.) representing the engine load other than the throttle valve opening can be used. Further, in the above-described embodiment, a configuration (corresponding to claim 3) having both the traveling resistance calculation means of the present invention and the first target throttle valve opening setting means (actually the second target throttle valve opening setting means) As described above, a device provided with only the running resistance calculating means of the present invention (corresponding to claim 1. In this case, the throttle valve may not be forcibly controlled. For example, a throttle valve bypass passage may be provided, and the bypass passage may be provided. The engine torque may be controlled by a flow control valve (so-called ISD) or the like described above.) The first object of the present invention can be achieved. Further, even a device provided with only the first target throttle valve opening setting means (claim 2) can achieve the second object of the present invention.

[0049]

As described above, according to the first aspect of the present invention, the upper limit of the final target driving force used for the calculation of the running resistance in the running resistance calculating means can be obtained from the engine characteristics and the like. Corrected by and the lower limit (limit)
Therefore, even when the final target driving force is set to a value that cannot be obtained in practice, no error occurs in the running resistance estimation calculation. The error does not accumulate, and the running resistance calculating means can quickly function even after the road gradient returns to a flat level to control the vehicle speed to the target vehicle speed without overshooting or undershooting. Highly accurate automatic speed control of the vehicle can be performed.

According to the second aspect of the present invention, by providing the first target throttle valve opening setting means, when setting the target throttle valve opening, the engine torque always corresponds to the entire throttle valve opening one to one. Since the target throttle valve opening is calculated using the extended engine characteristic data (linear), the throttle valve can always be fully opened until it is fully opened. The maximum driving force of the engine can be extracted without being affected by the influence, and thus highly accurate automatic speed control of the vehicle can be performed.

According to the invention described in claim 3, the effect of the invention described in claim 1 and the effect of the invention described in claim 2 can be simultaneously achieved. In the invention according to claim 4, the upper limit value and the lower limit value can be set with high accuracy by a relatively simple configuration. Claim 5
In the invention described in (1), the target driving force can be calculated with high accuracy by a relatively simple configuration.

[Brief description of drawings]

FIG. 1 is a block diagram of the invention according to claim 1.

FIG. 2 is a block diagram of the invention according to claim 2.

FIG. 3 is a block diagram of the invention according to claim 3.

FIG. 4 is a system configuration diagram of an automatic speed control device according to an embodiment of the present invention.

FIG. 5 is a flowchart showing automatic speed control in the embodiment.

FIG. 6 is a diagram illustrating an outline of a vehicle speed feedback compensator according to the above-described embodiment using a pulse transfer function.

FIG. 7 is a diagram showing extended engine characteristic data according to the embodiment.

FIG. 8A is a diagram for explaining the function and effect of the above-described embodiment on an ascending slope. (B) is a figure explaining the operation effect in the above-mentioned example in a downhill.

FIG. 9A is a diagram illustrating a problem on an uphill in the conventional device. (B) is a figure explaining the problem on the downhill in the conventional apparatus. 9 is a flowchart showing shift control at the time of changing the shift range in the conventional example.

FIG. 10 is a diagram showing conventional engine characteristic data.

[Explanation of symbols]

 1 Control unit for constant speed driving 8 Vehicle speed sensor 9 Throttle sensor 10 Crank angle sensor 11 Throttle actuator 12 Control unit for automatic transmission 20 Engine 21 Throttle valve 30 Automatic transmission

Claims (5)

[Claims] 1. A target driving force calculation means for calculating a target driving force that substantially matches the actual vehicle speed and the target vehicle speed of the vehicle, the calculated target driving force, and a running resistance of the vehicle. A final target driving force calculation means for calculating a final target driving force based on the estimated value, and a corrected final target driving force is obtained by limiting the calculated final target driving force with an upper limit value and a lower limit value. A final target driving force correcting means, and a running resistance calculating means for estimating and calculating a running resistance value of the vehicle based on the corrected final target driving force and an actual vehicle speed. Automatic speed control device for vehicles. 2. Target driving force calculating means for calculating a target driving force that substantially matches the two based on the actual vehicle speed of the vehicle and the target vehicle speed, and at least the calculated target driving force and engine torque. A first target throttle valve opening setting means for setting a target throttle valve opening based on engine characteristic data expanded so as to correspond one-to-one over the entire throttle valve opening, and the target throttle valve opening An automatic speed control device for a vehicle, comprising: throttle valve control means for controlling the throttle valve so that the actual opening degree of the throttle valve coincides with each other. 3. A target driving force calculating means for calculating a target driving force that substantially matches the actual vehicle speed and the target vehicle speed of the vehicle, the calculated target driving force, and a running resistance of the vehicle. A final target driving force calculation means for calculating a final target driving force based on the estimated value, and a corrected final target driving force is obtained by limiting the calculated final target driving force with an upper limit value and a lower limit value. Final target driving force correction means, running resistance calculation means for estimating and calculating a running resistance value of the vehicle based on the corrected final target driving force, and actual vehicle speed, and is calculated by the final target driving force calculation means. Second, the target throttle valve opening is set based on the final target driving force and the engine characteristic data expanded so that the engine torque has a one-to-one correspondence over the entire throttle valve opening.
A target throttle valve opening setting means, and a throttle valve control means for controlling the throttle valve so that the actual throttle valve opening substantially matches the target throttle valve opening. Automatic speed control device. 4. The upper limit value and the lower limit value are set based on the engine torque when the throttle valve is fully opened and when the throttle valve is fully closed, which is set for each engine speed. The automatic speed control device for a vehicle described. 5. A model matching vehicle speed control means for calculating a target driving force such that the actual vehicle speed substantially matches the target vehicle speed according to the response characteristic of a predetermined reference model. The automatic speed control device for a vehicle according to any one of claims 1 to 4, which is calculated.