JPH0714704B2 - Constant-speed running control device for vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for performing constant speed traveling control of a vehicle by controlling opening / closing of a throttle valve.

<< Conventional Technology >> In this type of conventional device shown in Japanese Patent Publication No. 53-7592,
When the driver turns on the set switch, constant speed running control is started in which the throttle valve is opened and closed in the direction in which the detected vehicle speed matches the target vehicle speed for constant speed running of the vehicle.
By this control, the vehicle speed is maintained at the target vehicle speed.

However, since the control system for constant-speed running of the vehicle includes a control delay element, when the set switch is turned on and constant-speed running is started, the vehicle speed temporarily decreases and the driver feels uncomfortable. To be

Therefore, in the conventional apparatus disclosed in Japanese Patent Laid-Open No. 6050031, the throttle valve is fully opened for a predetermined period at the start of control when the set switch is turned on, and the period is extended according to the change in vehicle speed during this period.

Here, in order to obtain the extension period, it is necessary to accurately detect the change in vehicle speed, and therefore the period is set to be long to some extent in consideration of the detection error of the sensor that detects the vehicle speed.

<< Problems to be Solved by the Invention >> Therefore, for example, even when the vehicle starts traveling at a constant speed while traveling on a downhill where the target vehicle speed can be maintained with the throttle valve fully closed, as described above. Since the throttle valve is fully opened for the period set to a certain length, when the vehicle exceeds the target vehicle speed, the throttle valve is immediately driven to be closed to cause a large fluctuation in vehicle speed. As a result, the conventional device has a rather uncomfortable feeling. There was a problem of being given to the driver.

The present invention has been made in view of the above conventional problems,
It is an object of the present invention to provide a vehicle constant speed traveling control device capable of preventing a temporary decrease in vehicle speed without causing the vehicle speed fluctuation when the vehicle starts traveling at constant speed.

<< Means for Solving Problems >> In order to achieve the above object, the device according to the present invention is
It is configured as shown.

In the figure, the traveling speed of the vehicle is detected by the vehicle speed detecting means a, and the target vehicle speed for vehicle constant speed traveling is set by the target vehicle speed setting means b.

Then, when the start of the constant speed traveling of the vehicle is instructed by the constant speed traveling start command means c, the valve control means d starts the control of opening and closing the throttle valve e in the direction in which the detected vehicle speed matches the target vehicle speed.

Here, the current running load of the vehicle is estimated by the running load estimating means f, and the opening degree calculating means g finds the opening degree of the throttle valve e at which the vehicle can maintain the target vehicle speed under the estimated running load.

Then, when the control for opening and closing the throttle valve e in the direction in which the detected vehicle speed matches the target vehicle speed is started, the throttle valve e is opened by the valve forced opening control means h to the opening obtained by the calculation means g. It is controlled to open.

<Operation> In the present invention, when the vehicle starts traveling at a constant speed, the throttle valve is opened to an opening degree at which the vehicle can maintain the target vehicle speed under the current traveling load.

<< Embodiment >> A preferred embodiment of an apparatus according to the present invention will be described below with reference to the drawings.

In FIG. 2, the throttle valve 12 in the throttle chamber 10 is driven to open and close by an accelerator pedal 16 or a throttle actuator 18 (pneumatic type, motor type or the like can be used) via a wire 14, and the throttle actuator 18 is a microcomputer. It is controlled by a throttle control circuit 20 composed of.

The throttle control circuit 20 is supplied with the switching signals of the set switch 22, the brake switch 24, and the clutch switch 26, and the brake switch 24 and the clutch switch 26 are each turned on when a brake operation or a clutch operation is performed. ing.

Further, the vehicle speed sensor 28 and the throttle opening sensor 30 respectively obtain a detection voltage according to the vehicle speed and a detection voltage according to the opening of the throttle valve 12, and these detection voltages are transmitted via the A / D converter 32. Is supplied to the throttle control circuit 20.

Further, the detection signal of the crank angle sensor 34 is also supplied to the throttle control circuit 20, and the detection signal is used for detecting the engine speed.

Then, the throttle control circuit 20 includes an engine torque table 36 and a throttle opening table 38, each of which is composed of a ROM.
Are prepared and their stored contents are shown in Tables 1 and 2 below.

Further, the gear shift of an automatic transmission (not shown) is controlled by the transmission control circuit 40, and the gear shift command is given to the transmission control circuit 40 from the throttle control circuit 20.

Next, the operation of this embodiment will be described based on the flowchart of FIG.

In the process of FIG. 3, it is first judged whether or not the set switch 22 has been turned on (step 100), and when the set switch 22 has been turned on, the flag (SETFLAG) is set and the throttle valve 12 Are fully closed (step 102).

When the set switch 22 is not turned on, it is determined whether the flag (SETFLAG) is set (step 104). When the flag (SETFLAG) is set, the flag (SETFLAG) is reset, the flag is set. (M
AINFLAG) is set and the current vehicle speed V at that time
Is set as the target vehicle speed Vs for constant-speed running of the vehicle (step 106).

Further, the control for opening the throttle valve 12 to the opening θs at which the vehicle can maintain the target vehicle speed Vs under the current traveling load D is started (step 108), and the flag (SETOFFFLAG) is set (step 110).

Then, it is determined whether or not the brake switch 24 or the clutch switch 26 is turned on by stepping on the brake pedal or the clutch pedal (step 11
2) When any of them is turned on, the flag (MAINFLAG) is reset (step 114).

When the processing for the switch operation is performed in this way, the current vehicle speed V detected by the vehicle speed sensor 28 is read and it is determined whether or not the current vehicle speed V is within the vehicle speed range of 40 Km / h to 100 Km / h. (Step 116, Step 11
8) If the current vehicle speed V is outside the speed range, a flag (M
AINFLAG) is reset (step 120).

Then, it is judged whether or not the control cycle Δt (for example, 1 sec) has elapsed (step 122), and when it has elapsed, the detected vehicle speed V ₁ in the previous control cycle is read (step 12).
4) Further, by dividing the vehicle speed difference obtained by subtracting the current vehicle speed V from the detected vehicle speed V ₁ by the control cycle Δt, the vehicle speed acceleration α
Is calculated (step 126), and the current vehicle speed V is detected vehicle speed V ₁
Is stored as (step 128).

Next, when the actual opening θ of the throttle valve 12 obtained by the throttle opening sensor 30 is read and the engine speed Ne is obtained from the detection signal of the crank angle sensor 34 (step 130), they are used to determine the engine torque Te. Is read from the engine torque table 36 (step
132 See Table 1).

Then, using the engine torque Te, the vehicle acceleration α, and the current shift position m of the automatic transmission, the current vehicle running resistance D is obtained (step 134).

In the present embodiment, the value γm is the gear ratio of each stage of the transmission, the value ηm is the transmission efficiency of each stage, the value γn is the final reduction ratio, the value ηn is the final transmission efficiency, the value R is the tire radius, and the value W is the vehicle weight and the value. g is gravitational acceleration, value J _W is wheel inertia,
The value J _P is the impeller inertia value, J _T is the turbine inertia, the value Je is the engine inertia, and the value J is J _W + γn ² · ηn · J _P + (J _T + J
e) ・ γm ²・ γn ²・ ηm ・ ηn
Te = R (D + Wα / g + Jα / R ² ) / γmηmγnηn · between the shift position m, the engine torque De, the vehicle acceleration α, and the vehicle running resistance D.
・ ・ Since the relation of the formula (1) is established, D = γm ・ ηm ・ γn ・ ηn ・ Te / R-W ・ α / g-J ・ α / R ²・ ・ ・ Value from the formula (2) The current vehicle running resistance D is obtained using m, Te and α.

When the current vehicle running resistance D is obtained in each control cycle as described above, the target opening degree θs for constant speed running at which the vehicle can maintain the target vehicle speed Vs is calculated by using the running resistance D. (See Table 2 above) (step 136).

In the present embodiment, from the equation (1) where the vehicle acceleration α is set to 0, that is, Te = R · D / γm · ηm · γn · ηn Equation (4) The engine output torque Te capable of running at a constant speed is required, and the engine speed Ne when the vehicle runs at a constant speed at the target vehicle speed Vs is Ne = γm · γn · 60 · Vs / 2πR (Equation (5)) The target target opening degree θs is read using the engine output torque Te and the engine speed Ne.

In this way, when the target target opening θs at which the vehicle can travel at the target vehicle speed Vs at a constant speed is obtained in real time based on the current estimated traveling load D, it is determined whether the flag (MAINFLAG) is reset (step 138), flag (SETOF
Judge whether FFLAG) has been reset (Step 1
40) is performed.

If the vehicle is not traveling at a constant speed, and the flag (MAINFLAG) is reset at that time, such as when the constant speed traveling is released by depressing the clutch pedal or the brake pedal, the throttle valve 12 Are fully closed (Step 14
2) In this case, the vehicle speed is adjusted according to the depression operation of the accelerator pedal 16.

Further, when the flag (MAINFLAG) is not reset and the flag (SETOFFFLAG) is reset (affirmative determination in step 140), the detected vehicle speed V is the target vehicle speed Vs.
Throttle valve 12 is opened and closed in the direction
144), the vehicle travels at a constant speed with the vehicle speed V controlled to the target vehicle speed Vs.

Further, when the flag (MAINFLAG) is not reset and the flag (SETOFFFLAG) is not reset (negative determination in step 140), that is, when the set switch 22 is turned on and then turned off, the vehicle When the start of constant-speed traveling is instructed, the control for opening the throttle valve 12 to the opening θs at which the vehicle can maintain the target vehicle speed Vs with the current traveling load D is continued (step 146).

After that, when it is confirmed that the opening degree θ of the throttle valve 12 is stable at the target opening degree θs (positive determination in step 148), the flag (SETOFFFLAG) is reset (step
150), which controls the constant speed running of the vehicle (step 144)
Is started (steps 100, 104, 106, 110, 150, 14
0, 144).

As described above, in the present embodiment, the running resistance D of the vehicle is constantly obtained, and the target opening degree θs of the throttle valve 12 that allows the vehicle to run at a constant speed is also constantly obtained from the running resistance D, and the set switch 22 is turned on. When it is instructed to start the control of the vehicle constant speed running by being turned off later, the target vehicle speed θs at which the vehicle can maintain the target vehicle speed Vs at the current traveling load D
The opening θ of the throttle valve 12 is controlled to
When the vehicle speed becomes stable at s, the control of the vehicle constant speed running is started.

For this reason, the vehicle speed V does not temporarily decrease at the time of starting the control of the vehicle constant speed traveling, and at that time, the optimal vehicle speed control without causing the fluctuation of the vehicle speed V becomes possible.

<< Effects >> As described above, according to the present invention, the throttle valve opening that allows the vehicle to run at a constant speed is constantly calculated from the current vehicle running resistance, and the opening is set when the vehicle starts running at a constant speed. Since the throttle valve is controlled to be opened, it is possible to perform optimum vehicle speed control that can prevent a temporary decrease in the vehicle without causing fluctuations in the vehicle speed, and as a result, the driving feeling of the vehicle can be greatly improved.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram, FIG. 2 is a configuration explanatory view showing a preferred embodiment of the apparatus according to the present invention, and FIG. 3 is a flowchart for explaining the operation of the embodiment in FIG. 12 …… Throttle valve 18 …… Throttle actuator 20 …… Throttle control circuit 22 …… Set switch 28 …… Vehicle speed sensor 30 …… Throttle opening sensor 34 …… Crank angle sensor 36 …… Engine torque table 38 …… Throttle opening Degree table 40 ... Transmission control circuit

Claims (1)

[Claims] 1. A vehicle speed detecting means for detecting a traveling speed of a vehicle, a target vehicle speed setting means for setting a target vehicle speed for constant speed traveling of the vehicle, and a constant speed traveling start command means for instructing start of the vehicle constant speed traveling. Valve control means for starting the control for opening and closing the throttle valve in the direction in which the detected vehicle speed matches the target vehicle speed by the command of the constant speed travel start command means, travel load estimation means for estimating the current travel load of the vehicle, and estimated travel And a valve opening control means for controlling the opening of the throttle valve to the calculated opening at the start of the control. Constant speed running control device for a vehicle.