JPH05221254A - Constant speed running device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the cost of vehicle development by outputting fixed target acceleration, when a difference between target and actually measured while speeds is a threshold value or more, and controlling the target acceleration calculated momently, when the difference is the threshold value or less, to smooth a car speed change and to facilitate tuning. CONSTITUTION:A throttle opening table memory 207, engine torque table memory 208 and a torque ratio table memory 209, of a target value are connected to a microcomputer 210. Further, a difference between the present car speed of a car speed sensor 203 through an A/D converter 206 and a car speed set in a set switch 201 is calculated, and a lithium switch 202 is turned on to control a throttle actuator 211 to fixed target acceleration, when the difference is larger than a threshold value, and to target acceleration calculated so as to correspond to the car speed difference in each fixed period, when the difference is the threshold value or less. Accordingly, a speed change can be smoothed to the target car speed, to omit tuning labor of voltage for driving a throttle actuator 211, and the cost of development for a vehicle can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle constant speed traveling device.

[0002]

2. Description of the Related Art As a conventional vehicle constant speed traveling device, for example, there is one described in JP-A-47-35692. One of the functions of this device is resume control, which means that the driver turns on the cancel switch of the vehicle constant-speed traveling device or steps on the brake during constant-speed traveling control. After canceling the constant-speed traveling with, the driver can automatically return the vehicle speed to the target vehicle speed before the cancellation by simply turning on the resume switch, and can shift to the constant-speed traveling again.

[0003]

However, in the conventional vehicle constant-speed traveling device, when the resume control is performed and the speed difference between the target vehicle speed and the current vehicle speed is larger than a constant value, constant acceleration control is performed. However, when the speed difference is equal to or less than a constant value, the vehicle moves to the constant speed traveling control, but the vehicle speed overshoot is prevented after the constant acceleration control is switched to the constant speed traveling control, and
In order to make the transition from acceleration running to constant speed running smooth, the throttle actuator is changed depending on the characteristics of the power weight ratio, throttle actuator, etc.
It was necessary to tune the time to output the voltage for driving the vehicle by vehicle type and engine type installed, and this tuning had to spend a lot of time.

In order to solve this problem, a running resistance estimation type feedforward control method in which tuning is unnecessary is disclosed in, for example, Japanese Patent Laid-Open No. 62-261545. When this method is used, the running resistance of the vehicle is estimated during constant-speed running control, and the target throttle opening is determined based on the estimated value and the vehicle speed, etc., so there is no tuning for smoothing the constant-speed running. You will need it. But,
Even in this method, tuning is unnecessary only for constant speed running control, and there is still a need for tuning for resuming control.

The present invention has been made to solve the above-mentioned problems, and is intended to realize a smooth and quick transition from acceleration running to constant speed running during resume control.
The object of the present invention is to provide a constant-speed traveling device for a vehicle that does not require tuning, shorten the time required to develop a vehicle equipped with this device, and reduce the development cost.

[0006]

In order to achieve such an object, according to the invention described in claim 1, as shown in the diagram corresponding to the claim of FIG. A vehicle speed setting means 101 for setting a target vehicle speed Vs, a vehicle speed detecting means 103 for detecting a current vehicle speed V, an engine speed detecting means 105 for detecting an engine speed Ne.
Resume control start means 107 for sending a control start signal for returning to the vehicle speed before cancellation after the constant speed running control of the vehicle is canceled, and throttle opening detection means for detecting the opening θ of the throttle valve of the engine. 109
And a vehicle speed difference calculation means 111 for obtaining a difference Vs-V between the target vehicle speed Vs set by the vehicle speed setting means 101 and the current vehicle speed V detected by the vehicle speed detection means 103.
Acceleration calculation means for obtaining the acceleration α by reading the vehicle speed V detected by the vehicle speed detection means 103 at every predetermined cycle t, and dividing the difference between two continuously read vehicle speeds in the vehicle speed V by the cycle t. 113, the vehicle speed V detected by the vehicle speed detecting means 103, the engine speed Ne detected by the engine speed detecting means 105, and the opening θ of the throttle valve detected by the throttle opening detecting means 109. , Driving force calculation means 115 for calculating the driving force F transmitted from the engine to the tires
Then, when a control start signal is sent from the resume control start means 107, the magnitude relationship between the vehicle speed difference Vs-V calculated by the vehicle speed difference calculation means 111 and a predetermined threshold value Vc is judged, While the vehicle speed difference Vs-V is larger than the threshold value Vc, a predetermined constant target acceleration is output, and when the vehicle speed difference Vs-V becomes equal to or less than the threshold value Vc, the magnitude of the vehicle speed difference. Target acceleration determining means 117 for determining the target acceleration αs, vehicle acceleration α calculated by the acceleration calculating means 113, driving force F calculated by the driving force calculating means 115, and the target acceleration determining means. Target acceleration α determined by 117
running resistance calculation means 119 for calculating the running resistance D of the vehicle from s, the vehicle speed V detected by the vehicle speed detection means 103, the engine speed Ne detected by the engine speed detection means 105, and the running resistance calculation. Means 119
The target engine torque TE, which is the engine torque to be output to the engine, from the running resistance D calculated by
A target engine torque calculation means 121 for obtaining S, a target engine torque TES calculated by the target engine torque calculation means 121, and an engine rotation speed Ne detected by the engine rotation speed detection means 105. The throttle opening degree determining means 123 for determining θs and the throttle valve opening degree θ detected by the throttle opening degree detecting means 109 match the target opening degree θs of the throttle valve determined by the throttle opening degree determining means 123. The constant-speed traveling device for a vehicle is constituted by the throttle control means 125 for controlling the throttle valve so as to operate.

[0007]

The vehicle speed difference Δ between the target vehicle speed Vs set by the driver in the vehicle speed setting means 101 calculated by the vehicle speed difference calculating means 111 and the current vehicle speed V detected by the vehicle speed detecting means 103.
V (= Vs-V) is the threshold value Vc (this threshold value Vc
Is a predetermined value, for example Vc = 2 km / h
(About 0.56 m / s)), the target acceleration determining means 117 determines a predetermined constant target acceleration α.
When the vehicle speed difference ΔV becomes equal to or smaller than the threshold value Vc, the target acceleration determining means 117 outputs the vehicle speed difference ΔV.
The target acceleration is calculated every moment according to the magnitude of V,
The vehicle speed smoothly reaches the target vehicle speed Vs without overshooting or undershooting, that is, the vehicle speed difference ΔV =
The acceleration α of the vehicle is determined so that the target acceleration αs = 0 when 0.

The running resistance calculation means 119 calculates the current vehicle acceleration α calculated by the acceleration calculation means 113.
And the driving force F calculated by the driving force calculation means 115.
And the running resistance D of the vehicle is calculated from the target acceleration αs determined by the target acceleration determining means 117.

The target engine torque calculating means 121 is a vehicle speed V detected by the vehicle speed detecting means 101, an engine speed Ne detected by the engine speed detecting means 105, and a vehicle calculated by the running resistance calculating means 119. The target engine torque TES, which is the torque to be output to the engine, is obtained from the running resistance D of the above.

The throttle opening determining means 123 is detected by the vehicle speed detecting means 102 and the running resistance D of the vehicle calculated by the target engine torque TES running resistance calculating means 109 obtained by the target engine torque calculating means 121. Vehicle speed V and the engine speed detection means 1
Based on the engine speed Ne detected by 03, the target opening degree θs of the throttle valve is determined so that the vehicle reaches the target acceleration αs calculated by the target acceleration determining means 110.

The throttle control means 112 includes the present throttle opening θ of the vehicle detected by the throttle opening detection means 111 and the throttle opening determination means 111.
The opening degree θ of the throttle valve is controlled so as to match the target opening degree θs of the throttle valve determined by.

[0012]

2 is a block diagram showing a first embodiment of the present invention, and a first embodiment will be described below with reference to the block diagram of FIG.

First, the structure will be described.

A set switch 2 which is a vehicle speed setting means for arbitrarily setting a target vehicle speed Vs within a certain range.
01, a resume switch 202 which is a resume control starting means, a vehicle speed sensor 203 which detects a vehicle speed, a throttle sensor 204 which detects a throttle opening, and a crank angle sensor 205 which is an engine speed detecting means.
And the vehicle speed sensor 203 and the throttle sensor 20.
A / D that converts analog signals from 4 to digital signals
The converter 206 and the vehicle speed sensor 203 and the A / D converter 206 constitute a vehicle speed detecting means 103, and the throttle sensor 204 and the A / D converter 206 constitute a throttle opening detecting means 109. ), A throttle opening table memory 207 for storing a target throttle opening θs which has an engine speed Ne and a target engine torque TES as variables, and a throttle opening θ and an engine speed Ne as variables. Engine torque table memory 208 for storing the engine torque Te
And a torque ratio table memory 209 for storing a torque ratio t having a speed ratio e as a variable, which will be described later, a micro computer 210, and a micro computer 210.
And a throttle actuator 211 that changes the opening of the throttle valve in accordance with the output of

Next, the operation will be described according to the flow chart showing the execution contents of the microcomputer 210 of FIG.

First, it is determined whether a control start signal is sent from the resume switch 202, that is, whether the resume switch 202 is on or off (step 305). When it is turned on, that is, when a control start signal is input, a vehicle speed difference ΔV (= Vs-V) between the target vehicle speed Vs set by the set switch and the current vehicle speed V detected by the vehicle speed sensor 203 is calculated. (Step 310). (This step 310 constitutes the vehicle speed difference calculation means described in claim 1.) Whether (ΔV-Vc) is positive or negative, that is, the magnitude relationship between the vehicle speed difference ΔV and the threshold value Vc is determined. (Step 3
15) If the vehicle speed difference ΔV is larger than the threshold value Vc, the constant acceleration αs1 is set as the target acceleration, and step 325 described later is performed.
(Step 317).

On the other hand, if the vehicle speed difference ΔV is less than or equal to the threshold value Vc, the target acceleration αs is calculated and output according to the following equation (step 320). (Step 305, Step 315, Step 317, and Step 320
And the target acceleration determining means according to claim 1 is configured. Αs = K (Vs−V) ... where K is a constant and is determined by K = αs1 / Vc.

Next, the vehicle speed V read every predetermined period t
Among these, the acceleration α is obtained by dividing the difference between the current vehicle speed Vm and the vehicle speed Vm−1 read one cycle before by the cycle t (that is, the following equation) (step 325). (This step 325 constitutes the acceleration calculating means described in claim 1) α = (Vm-Vm-1) / t ... The throttle valve opening θ detected by the throttle sensor 204 and the crank angle Based on the engine speed Ne detected by the sensor 205, the current engine torque Te is read from the engine torque table memory 208 (step 330). Table 1 below is an example of the engine torque table.

[0019]

[Table 1]

The input speed Ne of the torque converter (= engine speed) and the output speed Nt of the torque converter (gear ratio Gm of the transmission which is predetermined based on the data of the vehicle).
And the final gear ratio Gn, the tire radius R, and the vehicle speed V detected by the vehicle speed sensor 203), and the torque ratio t of the torque converter with the speed ratio e (= Nt / Ne) obtained as a variable. The data is read from the ratio table memory (step 335). Table 2 below is an example of the torque ratio table.

[0021]

[Table 2]

From the transmission gear ratio Gm, the final gear ratio Gn, the tire radius R, the engine torque Te read in the step 330, and the torque ratio t read in the step 335, the tire moves to the road surface. The transmitted driving force F is calculated by the following equation (step 34)
0). (The engine torque table memory 208, the torque ratio table memory 209, and the step 330
-335 and 340 constitute the driving force calculation means described in claim 1) F = Te * t * Gm * Gn / R ... The current vehicle acceleration α obtained in step 325 and the step Based on the driving force F obtained at 340, the target acceleration .alpha.s obtained at step 320, and the vehicle total weight M input in advance based on the data of each vehicle, the running resistance D of the vehicle is calculated by the following equation. Is calculated (step 345). (This step 345 constitutes the running resistance calculating means described in claim 1) D = FM (α-αs) / g ... However, g is a gravitational acceleration.

The torque ratio t read in the step 335 and the running resistance D read in the step 345.
From the transmission gear ratio Gm, the final gear ratio Gn, and the tire radius R, which are input in advance based on the data of each vehicle, the target engine torque TE is calculated by the following equation.
S is calculated (step 350). (This step 350
Then, the target engine torque calculating means described in claim 1 is configured) TES = D * R / (t * Gm * Gn) ... The target engine torque T obtained in step 350.
Target throttle opening θ with ES and engine speed Ne detected by the crank angle sensor 205 as variables
s is read from the throttle opening table memory 207 (step 355). (This step 355 and the throttle opening table memory 207 constitute the throttle opening determining means described in claim 1) Table 3 below
Is an example of the target throttle opening table.

[0024]

[Table 3]

The difference Δθ (= θ) between the target throttle opening degree θs read in step 355 and the throttle valve opening degree θ detected by the throttle sensor 204.
s-θ) is calculated and output (step 360).

The above is the description of the flowchart showing the execution contents of the microcomputer 210.

The throttle actuator is a throttle valve of an engine, and is connected to the microcomputer 21.
Open and close by Δθ output from 0. (The step 360 and the throttle actuator constitute the throttle control means described in claim 1.) FIG. 4 shows the vehicle speed V / time T when the system according to the present invention is used and when the prior art is used. And a graph of vehicle acceleration α and time T. The graph of A shows the changing state of the speed of the vehicle equipped with the device according to the present invention (a is the changing condition of its acceleration), and the graph of B shows the undershoot of the vehicle equipped with the conventional device. (B is the state of change of the acceleration), and the graph of C shows how the vehicle equipped with the conventional device overshoots (c is the state of change of the acceleration). Vs is a target vehicle speed, and Vc is a threshold value. The vehicle equipped with the conventional device approaches the target vehicle speed Vs while overshooting or undershooting, whereas the vehicle equipped with the device according to the present invention smoothly reaches the target vehicle speed Vs. ing.

[0028]

As described above, according to the present invention, it is predetermined that the target acceleration determining means determines that the vehicle speed difference ΔV calculated by the vehicle speed difference calculating means 111 is larger than the threshold value Vc. When a constant target acceleration is output and the vehicle speed difference ΔV becomes equal to or less than the threshold value Vc,
The target acceleration deciding means 117 calculates the target acceleration corresponding to the vehicle speed difference ΔV every moment so that the vehicle speed smoothly reaches the target vehicle speed Vs without overshooting or undershooting. That is, since the vehicle acceleration α is controlled so that the target acceleration αs = 0 when the vehicle speed difference ΔV = 0, the vehicle speed is prevented from overshooting during the resume control, and the vehicle is accelerated. In order to achieve a smooth and quick transition from to constant speed, the throttle actuator
Of the time for outputting the voltage for driving the
Since it is possible to save the trouble of carrying out the training, it is possible to reduce the time required for developing a vehicle equipped with this device and to reduce the development cost.

[Brief description of drawings]

FIG. 1 is a diagram of a claim corresponding to claim 1 of the present invention.

FIG. 2 is a functional block diagram showing a first embodiment of the present invention.

FIG. 3 is a flow chart showing the execution contents of the microcomputer.
Chart

FIG. 4 is a graph of a vehicle speed V / time T and a vehicle acceleration α / time T when the present system is used and when the prior art is used.
Graph of

[Simple explanation of symbols]

101 ... Vehicle speed setting means 103 ... Vehicle speed detecting means 105 ... Engine speed detecting means 107 ... Resuming control starting means 109 ... Throttle opening detecting means 111 ... Vehicle speed difference calculating means 113 ... Acceleration calculating means 115 ... Driving force calculating means 117 Target acceleration determining means 119 Running resistance calculating means 123 Throttle opening determining means 125 Throttle control means 201 Set switch 202 Resume switch 203 Vehicle speed sensor 204 Throttle sensor 205 Crank angle sensor 206 A / D
Converter 207 ... Throttle opening table memory 208 ... Engine torque table memory 209 ... Torque ratio table memory 210 ... Micro computer 211 ... Throttle actuator

Claims (1)

[Claims] 1. A vehicle speed setting means for a driver to set a target vehicle speed when the vehicle is traveling at a constant speed, a vehicle speed detecting means for detecting a current vehicle speed, and an engine speed detecting means for detecting an engine speed. A resume control starting means for sending a control start signal for returning to the vehicle speed before the cancellation after the constant speed running control of the vehicle is canceled, and a throttle opening degree detecting means for detecting the opening degree of the throttle valve of the engine. A vehicle speed difference calculating means for obtaining a difference between a target vehicle speed set by the vehicle speed setting means and a current vehicle speed detected by the vehicle speed detecting means; and a vehicle speed detected by the vehicle speed detecting means for each predetermined cycle. Acceleration calculating means for obtaining the acceleration of the vehicle by dividing the vehicle speed difference obtained by taking the difference between the two vehicle speeds read continuously in the vehicle, and the vehicle. From the vehicle speed detected by the speed detecting means, the engine speed detected by the engine speed detecting means, and the opening of the throttle valve detected by the throttle opening detecting means, the driving force transmitted from the engine to the tire. When a control start signal is sent from the driving force calculation means for calculating, and the resume control start means, the magnitude of the vehicle speed difference calculated by the vehicle speed difference calculation means and a predetermined threshold value are determined, While the vehicle speed difference is larger than the threshold value, a predetermined constant target acceleration is output, and when the vehicle speed difference becomes equal to or less than the threshold value, the target acceleration corresponding to the magnitude of the vehicle speed difference is set. Target acceleration determining means for determining, vehicle acceleration calculated by the acceleration calculating means, driving force calculated by the driving force calculating means, and target acceleration determining means Running resistance calculating means for calculating running resistance of the vehicle from the target acceleration determined by the above, vehicle speed detected by the vehicle speed detecting means, engine speed detected by the engine speed detecting means, and running resistance calculating means Target engine torque calculating means for obtaining a target engine torque, which is the engine torque to be output to the engine, from the running resistance calculated by, and the target engine torque calculated by the target engine torque calculating means and the engine speed detecting means. Throttle opening determining means for determining the target opening of the slot valve from the engine speed detected by the throttle opening determining means, and the throttle opening determining means for determining the throttle valve opening detected by the throttle opening detecting means. The throttle valve so that it matches the target opening of the throttle valve. Throttle control means for controlling the rottle valve,
A constant-speed traveling device for a vehicle, comprising: