JPS6322735A - Constant-speed travel control device for vehicle - Google Patents

Abstract

PURPOSE:To perform the smooth transition by determining the opening of a throttle valve allowing the constant acceleration of a vehicle and the opening allowing the constant-speed travel based on the estimated value of the current travel load and controlling the throttle valve to the latter opening at the time of transition from the constant-acceleration control to the constant-speed control. CONSTITUTION:A constant-speed travel throttle valve control means (d) driving a throttle valve (c) so that the detected vehicle speed by a vehicle speed detecting means (a) coincides with the target vehicle speed by a target vehicle speed setting means (b) is provided. Also, arithmetic means (f), (g) calculating the target opening for constant acceleration allowing the constant acceleration of a vehicle based on the current estimated travel load by a travel load estimating means (e) and the target opening for control transition allowing to keep the vehicle at the target speed are provided. When constant acceleration is directed by a directing means (h), the throttle valve (c) is controlled by a constant-acceleration throttle valve control means (i). At the time of transition from the constant-acceleration control to the constant-speed travel control, the throttle valve (c) is controlled by a control transition throttle valve control means (j).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a constant speed driving control device for a vehicle that controls constant speed driving of a vehicle, and particularly to a constant speed driving control device for a vehicle that is capable of controlling constant acceleration of a vehicle. Regarding a control device.

(Prior Art) As shown in Japanese Patent Application Laid-Open No. 60-71341, in this type of conventional device, vehicle speed is controlled by opening/closing control of a throttle valve, and constant speed running control of a vehicle is performed based on the target vehicle speed. This is done by opening and closing the throttle valve in the direction that matches the detected vehicle speed.

The constant acceleration control of the vehicle is started by the ON operation of the accelerator switch 1, and the control is performed by the feedback control that opens and closes the rotary valve in the direction in which the actual acceleration of the vehicle matches the set acceleration. It is being done.

When the accelerator switch is turned off, constant-speed driving control of the vehicle is started with the current vehicle speed as the target vehicle speed, and when the actual acceleration of the vehicle becomes equal to or higher than the fixed acceleration at the time of control transition, the vehicle speed is changed. The control gain is corrected, thereby preventing vehicle speed overshoot.

(Problem to be Solved by the Invention) Conventionally, however, constant acceleration control of the vehicle is performed by the feedback control, so when constant acceleration control of the vehicle is performed on a road with many ups and downs, the vehicle speed depends on the road gradient. There is a problem in that a delay occurs in vehicle speed control in response to a large change in the vehicle speed, making it difficult to accurately control the constant acceleration of the vehicle.

Furthermore, when vehicle speed control shifts from constant acceleration control to constant speed driving control due to the acceleration switch being turned off while driving on a road with many ups and downs, the feedback control and vehicle speed control gain are corrected. This causes overshoot and undershoeing of the vehicle speed, resulting in a problem of large vehicle speed fluctuations relative to the target vehicle speed when the vehicle is traveling at a constant speed.

The present invention has been made in view of the above-mentioned conventional problems,
The purpose is to provide a constant speed cruise control device for a vehicle that can perform optimal vehicle speed control that always enables accurate constant acceleration control and smooth transition to constant speed cruise control regardless of the ups and downs of the vehicle travel road. There is a particular thing.

(Means for Solving the Problems) In order to achieve the above object, an apparatus according to the present invention is configured as shown in FIG.

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

The throttle valve C is opened and closed by the constant speed running throttle valve control means d in the direction in which the detected vehicle speed matches the target vehicle speed, thereby controlling the vehicle speed to the target vehicle speed.

Here, the current vehicle running load is estimated by the running load estimating means e, and the target opening degree for constant acceleration allows the vehicle to accelerate at a constant rate with the current estimated running load, and the vehicle maintains the target vehicle speed with the estimated running load. The possible target opening degree for control transition is determined by the constant acceleration target opening degree calculation means f and the control transition target opening degree calculation means q.

From the time when the start of constant acceleration of the vehicle is commanded by the constant acceleration command means until the end is commanded, the opening degrees of the throttle valves 1 to 3 C are controlled by the constant acceleration throttle valve 1 to valve control hand Qi. The opening is controlled to the target opening.

At the time of transition from the throttle valve control for rough constant acceleration to the throttle valve control for constant speed running, the opening degree of the throttle valve C is controlled to the target opening degree for the time of control transition by the throttle valve control means j for the time of control transition. has been done.

(Operation) In the present invention, the current vehicle running load is estimated, and a target opening degree that allows the vehicle to accelerate at a constant rate with the estimated running load and a target opening degree that allows the vehicle to maintain the target vehicle speed are determined.

Then, during vehicle constant acceleration control and when control transfers from that control to constant speed traveling control, the target opening degree is controlled to each of these target opening degrees.

(Embodiments of the Invention) Hereinafter, preferred embodiments of the apparatus according to the present invention will be described with reference to the drawings.

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

This throttle control circuit 20 includes a set switch 22,
Accelerate switch 24, brake switch 26,
A switching signal for the inhibit switch 28 is supplied, and the brake switch 26 and the inhibit switch 28 are turned on when the brake is operated or the select lever is operated.

Further, the vehicle speed sensor 30 and the throttle opening sensor 32 each obtain a detection voltage corresponding to the vehicle speed V and a detection voltage corresponding to the opening degree θ of the throttle valve 12, and these detection voltages are Throttle control circuit 20 via converter 34
is supplied to.

Further, a detection signal from the crank angle sensor 38 is also supplied to the throttle control circuit 20, and the detection signal is used to detect the engine rotation speed Ne.

The throttle control circuit 20 includes engine torque tables 40, each configured with a ROM. A throttle opening degree table 42 is prepared, and the stored contents thereof are shown in the following Tables 1 and 2, respectively.

Further, an automatic transmission (not shown) is controlled by a transmission control circuit 1 to 44, and a speed change command is given to the transmission control circuit 44 from the throttle control circuit 20.

Next, the operation of this embodiment will be explained based on flowcharts 1 to 1 in FIG.

In the process of FIG. 3, it is first determined whether or not the set switch 22 has been turned on (step 100), and when the set switch 22 has been turned on, a flag (MAIN
FLAG) is set, and the current vehicle speed V detected by the vehicle speed sensor 30 at that time is set as the target vehicle speed Vs for fixed speed driving (step 102).

Then, it is determined whether the brake switch 26 or the inhibit 1 to 28 switches have been turned on (step 1).
04>, when either the brake pedal or the select lever is operated and any of the switches 26 and 28 is turned on, the flag (MAINFLAG) is reset to 1 (step 106).

It is roughly determined whether or not the acceleration switch 24 has been turned on (step 108), and if the acceleration switch 24 has been turned on, a flag (ACCE
LFLAG> is set (step 110).

If the acceleration switch 24 is not turned on at that time, it is determined whether or not a flag (ACCELFLAG) is set (step 112>; if it is set, the flag (ACCELFLAG) is set.
> is reset and the flag (MAINFL
AG) is set, and the current vehicle speed ■ at that time is set as the target vehicle speed Vs for constant speed vehicle running (step 114).
), a flag (ACCELOFFFLAG) is set (step 116).

When the switch operation is processed in this way, the current vehicle speed V detected by the vehicle speed sensor 30 is read and the current vehicle speed is 40 Km/h to 1100 Km/h.
/h within the vehicle speed range (step 11).
8, step 120), when the current vehicle speed is outside the speed range, the flag (MAINFLAG) is reset (
Step 122).

Then, it is determined whether the control period Δt (for example, 1 SeC) has elapsed (step 124>, and when it has elapsed, the detected vehicle speed 1 in the previous control period is read out (step 126). Roughly speaking, the detected vehicle speed 1 is calculated from the current vehicle speed. The vehicle acceleration α is calculated by dividing the vehicle speed difference from which V is subtracted by t.
is determined (step 128), and the current vehicle speed V is stored as the detected vehicle speed v1 (step 130).

Here, the actual opening θ of the throttle valve 12 obtained by the throttle opening sensor 32 is read, and the engine rotation speed Ne is determined from the detection signal of the crank angle sensor 38 (step 132). is read from the engine torque table 40 (step 134, see Table 1).

Then, the running resistance of the vehicle is determined using the engine torque Te, the vehicle acceleration α, and the current shift position m of automatic 1 to transmission (step 136).

In this example, the value γm is the gear ratio of each stage of the automatic 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, the value W is the vehicle weight, The value q is the gravitational acceleration, the value Jw is the wheel/one member, tamp is the bellows inertia, the value JT is the turbine inertia, the value Je is the engine inertia, (direct J is Jw ten Tn
2・ηnJp ten (JT ten Je)・γTn2・γn2・η
■°ηn, the relationship between gear shift position m, engine torque Te, vehicle acceleration α, and vehicle running resistance is,
Te=R・(D1W・α/q+J・α/R2)71m・
ηm・γn・ηn ...Since the relationship of equation (1) holds, D=TTIl・ηtn"γn"ηn-Te/R-W・α
/C1-J・α/R2... From equation (2), the value m, Te
, α are used to find the vehicle running resistance.

When the vehicle running resistance is determined in this way, the target opening θS1 for constant acceleration that allows the vehicle to accelerate at a constant speed, and the target opening Os2 for constant speed running that allows the vehicle to maintain the target vehicle speed S are determined based on the above running resistance. Based on the throttle opening table 42 (
(see Table 2 above) (step 138)
.

Among these, regarding the target opening degree θs1 for constant acceleration, the equation (1) above is obtained by replacing the vehicle acceleration α with the set acceleration a, that is, Te=R(D+Wa/q+Ja/R2)/γmηm? ”
nηn -... From equation (3), the engine output torque Te that allows the vehicle to accelerate at a constant acceleration a is determined, and the target opening O5, which corresponds to the engine output torque Te and the engine rotational speed Ne, is determined by the throttle [... It is read from the opening degree table 42.

Regarding the target opening degree θs2, use the formula (1) above in which the vehicle acceleration α is O, that is, Te=RD/γm''
f) rnTT1r/n - From equation (4), the engine output torque Te that allows the vehicle to travel at a constant speed at the target vehicle speed VS is determined, and the engine rotation speed Ne when the vehicle travels at a constant speed at the target vehicle speed VS is Ne= '7'm・γn・60・V s/27rR・
... is obtained from equation (5), and the target opening degree θs2 is read out from these engine output torque Te and engine rotational speed Ne.

In this way, the target opening degree θs1 allows the vehicle to accelerate at a constant rate of acceleration a, and the target opening degree θ allows the vehicle to travel at a constant speed at the target vehicle speed S.
When s2 is determined in real time based on the current estimated running delivery, the flag (MAINFLAG) is reset.
(Step 140), determines whether the acceleration switch 24 is turned on (Step 142), and sets the flag (ACCELOFFFLA).
G) has been reset (step 14)
4) is performed.

At that time, if the flag (MAINFLAG) has been reset to 1 or higher (that is, if the vehicle is not running at a constant speed and if the control is canceled by pressing the brake pedal or clutch pedal), , the throttle valve 12 is fully closed (step 146), and the vehicle speed is adjusted according to the depression operation of the accelerator pedal 16.

Further, when the ON operation of the acceleration switch 24 is confirmed (affirmative determination in step 142), the opening degree of the throttle valve 12 is maintained at the target opening degree θS1 (step 148>, and as a result, the current running load The engine generates a torque Te that allows the vehicle to accelerate at a constant rate.

When the rough flag (ACCELOFFFLAG> is reset (affirmative determination in step 144), the throttle valve 12 is opened and closed in the direction in which the detected vehicle speed ■ matches the target vehicle speed VS (step 150), and the vehicle speed V becomes the target vehicle speed. The vehicle runs at a constant speed controlled by the vehicle speed VS.

When it is confirmed that the flag (ACCELOFFFLAG) is set (negative determination in step 144), that is, the acceleration switch 24 is turned on and then turned off, instructing the vehicle to shift to constant speed driving. When the opening degree θ of the throttle valve 12 is maintained at the target opening degree θs2 (step 152).

As a result, the engine generates a torque Te that allows the vehicle to maintain the target vehicle speed VS under the current running load.

Thereafter, when it is confirmed that the opening degree θ of the throttle valve 12 has stabilized at the target opening degree θs2, the flag (ACCELOFFFLAG) is reset (step 156), and constant speed running control of the vehicle is started (step 154). 108.112.114.116.142.144
．． 150).

As explained above, according to this embodiment, the running resistance of the vehicle is constantly determined, the target opening degree θs1 of the throttle valve 12 that allows the vehicle to accelerate at a constant speed, and the target opening degree of the throttle valve 12 that allows the vehicle to travel at a constant speed. θs2 is also always determined, and the opening θ of the throttle valve 12 is set to the former target opening θS1 during vehicle constant acceleration control, and the latter target opening θs2 when transitioning from constant acceleration control to constant speed driving control. controlled.

Therefore, even if the vehicle is traveling on a road with many ups and downs and its running resistance changes greatly depending on the road gradient, the vehicle will accurately accelerate at a constant speed relative to the set acceleration a, and from this control, constant speed driving will be controlled. When transitioning to , the vehicle speed ■ is the target vehicle speed Vs for constant speed vehicle driving.
will be maintained. Therefore, regardless of the ups and downs of the vehicle travel path, it is possible to perform accurate constant acceleration control of the vehicle and optimal vehicle speed control that allows smooth transition from that control to constant speed driving control.

(Effects) As explained above, according to the present invention, the throttle valve opening that allows the vehicle to accelerate at a constant speed with the current vehicle running resistance and the throttle valve opening that allows the vehicle to travel at a constant speed are determined. Since the opening of the throttle valve is controlled to the former opening and the latter opening when transitioning from that control to constant speed driving control, accurate constant acceleration control I is possible despite changes in the slope of the vehicle road. This enables optimal vehicle speed control that allows a smooth transition to constant-speed driving control, and greatly improves the driving feeling of the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a diagram corresponding to the claims, FIG. 2 is a configuration explanatory diagram showing a preferred embodiment of the apparatus according to the present invention, and FIG. 3 is a flowchart 1 for explaining the operation of the embodiment shown in FIG. 12... Throttle valve 18... Throttle actuator 20... Throttle control circuit 22... Set switch 24... Acceleration switch 30... Vehicle speed sensor 32... Throttle opening sensor 38... ... Crank angle sensor 40 ... Engine torque table 42 ... Throttle opening table 44 ... Transmission control circuit Mi'J Fig. 1 Q Department J Fig. 2

Claims (1)

[Claims] (1). A vehicle speed detection means for detecting the running speed of the vehicle; a target vehicle speed setting means for setting a target vehicle speed for constant speed running of the vehicle; and a constant speed running valve control means for opening and closing a throttle valve in a direction in which the detected vehicle speed matches the target vehicle speed. a running load estimating means for estimating the current vehicle running load; a constant acceleration target opening calculation means for calculating a constant acceleration target opening at which the vehicle can be constantly accelerated with the current estimated running load; A target opening calculation means for control transition for calculating a target opening for control transition that allows the vehicle to maintain a target vehicle speed under load; constant acceleration command means for commanding the start and end of vehicle constant acceleration; constant acceleration valve control means for controlling the opening degree of the throttle valve to a target opening degree for constant acceleration from when the start is commanded until the end is commanded; and constant acceleration valve control to constant speed running valve control. 1. A constant speed cruise control device for a vehicle, comprising: a valve control transition means for controlling a throttle valve to a target opening for the control transition when the control transitions to the target opening.