JPH11348601A - Automobile control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile control device for controlling engine torque, transmission gear ratio, and brake pressure to eliminate a difference between target acceleration/deceleration and actual acceleration/deceleration by computing driver-intended target acceleration/deceleration. SOLUTION: This device is provided with a target acceleration/deceleration computing and comparing means 6 for computing target acceleration/deceleration by referring to accelerator operation opening and brake actuating force. Control is applied to the transmission gear ratio of an automatic transmission 10, the throttle opening of an engine 11, fuel supply quantity, or ignition timing, and an automobile brake device 12 so that a difference between the computed target acceleration/deceleration and actual acceleration/deceleration may be zero. The result can obtain driver-intended acceleration/deceleration, for enhancing drivability. In addition, frequent use of the neutral shift position enhances fuel economy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a motor vehicle provided with at least one of an engine torque adjusting means, a gear ratio adjusting means and a braking force adjusting means.

[0002]

2. Description of the Related Art The prior art is disclosed in JP-A-63-24043.
As described in Japanese Patent Application Publication No. 7, the driving force of the vehicle is calculated from the engine load and the shift position of the transmission, and the engine output is controlled so that the actual and estimated driving forces match.

[0003]

In the prior art, since the driving force is calculated based on the engine load and the shift position of the transmission, the target driving force (target acceleration) and the target braking force intended by the driver are intended. (Target deceleration) cannot be obtained.

It is an object of the present invention to calculate a target acceleration / deceleration as intended by a driver and to control an engine torque, a gear ratio and a brake pressure in a direction to eliminate a difference between the target acceleration / deceleration and the actual acceleration / deceleration. It is in.

[0005]

In order to achieve the above object, there is provided target speed calculating means for calculating a target speed from an accelerator operation opening and a brake depressing force. The speed ratio of the automatic transmission, the throttle opening of the engine, the fuel supply amount,
Alternatively, it controls the ignition timing and the brake device of the automobile.

[0006] In order to calculate a target speed required by the driver, signals from the accelerator opening detection means and the brake depression force detection means are input to the speed comparison means. Then, a signal from a speed detecting means such as a speed sensor is input to a comparing means, and the target speed is compared with an actual speed. If there is a difference between the speeds, one of the shift position calculating means, the engine torque calculating means and the brake pressure calculating means is used to make the speed difference close to zero. Thereby, the speed as intended by the driver can be obtained, so that the drivability is improved.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a vehicle control system according to the present invention. FIG.
Is an embodiment of the present invention. The accelerator opening detecting means 1, the brake pedal force detecting means 2, the vehicle speed detecting means 3, the shift position detecting means 4, the acceleration / deceleration detecting means 5, the acceleration / deceleration calculation comparing means 6,
It comprises a shift position calculating means 7, an engine torque calculating means 8, and a brake pressure calculating means 9. Here, the acceleration / deceleration calculation / comparison means 6, the shift position calculation means 7, the engine torque calculation means 8 and the brake pressure calculation means 9 are shown in separate blocks, respectively. It becomes.

First, the acceleration / deceleration detection calculating means 6 calculates a target acceleration / deceleration based on signals from the accelerator opening detecting means 1, the brake pedal force detecting means 2, the vehicle speed detecting means 3 and the shift position detecting means 4. At the same time, the actual acceleration / deceleration at that time is obtained by the acceleration / deceleration detecting means 5,
The difference between the target acceleration / deceleration and the actual acceleration / deceleration is calculated by the acceleration / deceleration comparing means 6. If there is a difference between these accelerations / decelerations, any one of the shift position calculation means 7, the engine torque calculation means 8 and the brake pressure calculation means 9 is used to automatically shift the acceleration / deceleration to zero. Machine 10
, The throttle valve opening of the engine 11, the fuel supply amount, the ignition timing, or the brake device 12.

The control at this time is performed according to a target acceleration / deceleration map shown in FIG.
0 ", and if the driver requests an acceleration, as shown on the right side of the acceleration map in FIG changes the target acceleration by the shift position, is proportional to the accelerator opening α and the acceleration G _0. When the brake depression force β is “β ≧ 0”, first, “β =
If 0 ", to control the brake pressure so that any deceleration beta _0. However, when the deceleration becomes equal to or more than β ₀ even when the brake pressure is set to 0 as in the case of traveling uphill, the state is maintained.

[0010] Next, when the vehicle speed v is a certain velocity v ₀ is less than the control deceleration G ₀ relative to the brake pedal force β is performed by the brake pressure control, this time, the shift position is left in the neutral. Then, the vehicle speed v becomes the predetermined speed v ₀
As described above, when “β ≧ β ₀ ”, the engine brake control and the brake pressure control are used together to prevent wear of the brake pad.

Next, the control operation of the control device C will be described. FIG. 3 is a main control flowchart.
4 to 6 are subroutine control flowcharts. In the main control routine of FIG. 3, first, at step 30, the accelerator opening α, the brake pedal force β, and the vehicle speed v are read, and then at step 31, the accelerator opening α is set to “α>
0, and if “α> 0”, then in a step 32, it is determined whether “dα / dt> 0”.
If “dα / dt> 0”, the driver determines that acceleration is required, and executes the acceleration control process of FIG.

In the acceleration control shown in FIG. 4, first, at step 40, the accelerator opening α, the shift position i, and the acceleration sensor signal G are read. Next, in step 41, the target acceleration / deceleration map of FIG. 2 is searched, and in step 42, the target acceleration G ₀ = f
(α, i) is calculated. Then, in step 43, "G-
G ₀ ”, and if it is 0, then in step 44“ dα ”
It is determined whether or not / dt <0. If Yes, the process returns. If No, it is determined that the driver requires acceleration, and the process returns to the start and repeats the same process. On the other hand, if “G−G ₀ ” is not ₀ in step 43, step 4
Engine torque 5 determines whether or not the maximum (throttle opening is maximum), running the engine torque control process of step 46 if the maximum, the "G-G _0" is to close to zero.

Further, in the main control routine of FIG. 3, when the accelerator opening "alpha ≦ 0" in step 31, the vehicle speed is any speed v ₀ or more in step 34,
If it is determined in step 35 that the brake pedal force is “β ≧ β ₀ ”, deceleration control processing based on brake control + engine brake control in step 36 is executed. FIG.
Shows the deceleration control process by the brake control + engine brake control in step 36. First, in step 50, the brake depression force β and the acceleration sensor signal G are read, and in step 51, the target acceleration / deceleration map is searched. At step 52, a target deceleration G ₀ = g (β) is obtained.
And "G ₀ -G" is to determine whether the 0 in step 53, to return here if it is 0. On the other hand, “G ₀ −
If "G" is not 0, the brake pressure and the shift position are controlled in steps 54 and 55, and the difference between the decelerations is reduced to 0 using the brake and the engine brake. Further, in the main control routine of FIG. 3, when the vehicle speed v is smaller than v ₀ in step 34, the deceleration control processing by only the brake control in step 37 is executed. FIG. 6 shows a deceleration control process based on only the brake control in step 37. First, in step 60, the shift position (neutral) is output.
In a succeeding step 61, the brake depression force β and the acceleration sensor signal G are read. In a step 62, a target acceleration / deceleration map is searched. In a step 63, a target deceleration G ₀ = g (β) is calculated. The "G ₀ -G" is not 0 in step 64, controls only braking pressure in step 65, "G ₀ -
G "converges to zero.

Therefore, according to this embodiment, the acceleration / deceleration intended by the driver is estimated from the operation state of the accelerator pedal and the brake pedal by the driver, and the engine, the transmission, or the brake is operated in accordance with the calculation result. Since the control is performed, the acceleration / deceleration as intended by the driver is automatically obtained, and it is possible to always sufficiently improve the drivability. Further, since the neutral shift position is frequently used, fuel efficiency is improved.

[0015] By the way, as the demand for higher performance of automobiles increases, automobiles equipped with a high-output engine have been frequently used. As a result, an excessively large amount of power at the time of starting is independent of the driver's intention. A technique for reducing and controlling the torque has been adopted. This will be described with reference to FIG. This FIG.
Is, for example, (expressed which in N-D signal) from the state where the engine rotational speed is maintained at 3000 rpm, when the transmission at time t ₀ has transmission to N (neutral) → D (1 speed), throttle If the opening increases relatively slowly, as indicated by the broken line, the changes in engine torque and rotation speed will also be indicated by the broken line, and there is no particular problem. If the degree is suddenly increased to a maximum, an excessive torque as shown by a solid line is generated, and there is a possibility that the driving wheels idle and the driving torque transmission system is damaged. Therefore, in such a case, the engine torque (throttle opening, fuel amount, ignition timing), clutch operating oil pressure, and the like are controlled so that the target torque (broken line) and the actual estimated torque match. If the traction control is applied, idling of the drive wheels is suppressed, so that the acceleration / deceleration intended by the driver is eventually obtained.

An embodiment of the present invention to which the traction control function is added will be described with reference to a control flowchart shown in FIG. The process of FIG. 8 is also executed by the microcomputer in the control device C of FIG. 1. First, at step 80, the ND signal, the throttle opening θ, the vehicle speed v, and the engine speed _Ne are read. In the following steps 81, 82 and 83, the shift position is in the D range,
If “θ> θ ₀ ” and “v> v ₀ ”, the engine torque reduction control (combination of throttle control, fuel control and ignition timing control) in step 84 and step 85
Of the clutch operating oil pressure lowering control is executed.

Next, at step 86, the acceleration G appearing on the vehicle is read from an acceleration sensor (not shown), and at step 87, the estimated torque T is calculated by the function of "T = F (G)". Thereafter, it is determined in step 88 whether the target torque T ₀ and the estimated torque T match, and if they match, the end engine speed “N _end = N _e ” in step 89 or the end torque in step 90 It returns with "T _end = T". On the other hand, if “T ₀ = T” is not satisfied in step 88, first, the magnitude of the estimated torque T and the target torque T ₀ is determined in step 91, and the torque is reduced in step 92 or the torque is increased in step 93 according to each of them. It controls.

Therefore, according to the embodiment shown in FIG. 8, even if the friction coefficient μ between the traveling road surface and the driving wheels of the vehicle changes, the torque is always controlled to the optimum value in accordance with the change.
The occurrence of slip and damage in the drive system is sufficiently suppressed, and as a result, the acceleration / deceleration intended by the driver can be easily obtained.

In the embodiment of FIG. 8, the estimated torque T is obtained as a function of the acceleration G obtained from the acceleration sensor. Instead, the estimated torque T may be estimated from the brake depression force signal. Hereinafter, the embodiment of the present invention will be described.If the brake pedal force β or the brake pressure (brake fluid pressure) is maximum, and the throttle opening θ is maximized, Since the car does not start, the longitudinal acceleration G
Becomes 0. However, the engine speed _Ne and the torque T increase. This is the stall operation of the automatic transmission having the hydraulic torque converter.

However, to estimate the torque in this state, torque estimating means other than the acceleration sensor is required.
In the embodiment of FIG. 10, this is obtained from the brake pedal force signal as shown in FIG. 9, and it can be said that this is a control flowchart for the processing of FIG. 10, first, the brake pedal force beta in step 100, the throttle opening theta, the longitudinal acceleration G, reads the engine speed N _e and N-D signal, shift position in the subsequent step 101 and 102 D-range, and "beta>
If "0", the estimated torque T is calculated in step 103 by the sum of the function i (G) of the acceleration G and the function j (β) of the brake pressing force β. Then, in step 104, the estimated torque T is output and used as the estimated torque T in FIG. In addition,
At this time, as is clear from FIG.
Therefore, the estimated torque T = j (β).

Next, FIG. 11 is a comparison diagram of the longitudinal acceleration G and the torque, wherein (a) shows the characteristics when the tire (driving wheel) idles, (b) shows the characteristics when the tire does not idle, In the case of (a), the vibration cycle of the torque during tire idling and the longitudinal acceleration is different, whereas in the case of (b), the longitudinal acceleration is proportional to the torque. That is, if it is possible to determine whether or not the drive wheels are idling, as in an automobile with traction control, it is possible to estimate the torque based on the longitudinal acceleration.

FIG. 12 shows the estimated torque T based on the characteristics shown in FIG.
In the control flowchart of one embodiment of the present invention in the case where is obtained, first, at step 120, it is determined whether or not the driving wheel is idling, and if not, at step 121, the signal G ₀ from the acceleration sensor is determined. reading is calculated as follows the estimated torque T as a function of G ₀ h (G ₀₎ in the subsequent step 122. T = h (G ₀ ) = k · I · G ₀ + μWr where k: constant I: inertia of the vehicle μ: number of friction systems between the running road surface and the driving wheels of the vehicle W: weight of the vehicle r: driving wheels At this time, the closer the mounting position of the acceleration sensor is to the position of the center of gravity of the vehicle, the more the accuracy of the torque estimation is improved. This is because yaw, roll, pitch and the like are not affected.

By the way, when the present invention is implemented, if the control is performed according to the road gradient θ _L , the accuracy of the control to the acceleration / deceleration intended by the driver can be further improved. The road gradient estimating process using this acceleration sensor will be described with reference to FIG. 13. In this embodiment, first, at step 130, the accelerator opening α and the acceleration sensor signal G are read. Next, in step 131, it is determined whether or not the accelerator opening α is “α> 0”. In the case of Yes, the engine load _Te is calculated in step 132, and the function f (T _e , i) with the shift position i is calculated. The estimated torque T is obtained, and the actual torque T ₀ is obtained from the function g (G) of the acceleration sensor signal G in the following step 133. Thereafter, it is determined at step 134 whether or not "T-T ₀ = 0", and if it is 0, a road gradient θ _L = 0 is output at step 135.

In step 134, "T-T ₀ " is set to 0.
If not, in step 136, the road gradient θ _L is output by the function of θ _L = h (T−T ₀ ). At this time, if “T−T ₀ > 0”, the road gradient is determined to be an ascending gradient. On the other hand, if “T−T ₀ <0”, it can be determined that the vehicle is descending. On the other hand, if “α = 0” in step 131, the shift position is set to neutral, and in step 137, the estimated torque T = i (G) is calculated, and the road gradient θ _L is calculated as a function j ( T, W).

FIG. 14 shows still another embodiment of the present invention, in which signals from an acceleration request means 20 such as an accelerator opening and a deceleration request means 21 such as a brake pedal force are transmitted to a target acceleration / deceleration calculating means 22. Input and calculate the target acceleration / deceleration. Then, the target opening degree deceleration is compared with the actual acceleration / deceleration detected by the acceleration / deceleration detecting means 23, and the engine, the transmission, and the brake device are transmitted through the target driving force control means 24 so that the deviation converges to zero. At this time, the actual acceleration / deceleration detected by the acceleration / deceleration detecting means 23 is supplied to the road gradient calculating means 25, and the current road gradient is obtained as described above. The driving force is controlled by judging whether the request is for constant speed driving or decelerating driving.

FIG. 15 is a flowchart for explaining the operation, the acceleration G, the accelerator opening α First, in step 150, the brake pedal force beta, throttle opening theta, engine speed N _e, it leads the vehicle speed v In step 151 and step 152, whether the accelerator is stepped on,
It is sequentially determined whether or not the brake is depressed, and the acceleration process in step 153 and the deceleration process in step 154 are executed. When both the accelerator opening α and the brake depression force β are both zero, the routine proceeds to step 155, where the previous acceleration g _n-1 is compared with the current acceleration g, and the result is “g ≧ g _n-1 ”. That is, when it is determined that the current traveling road has a downward slope, the vehicle speed control is further performed in step 156 and 157 by using both the engine brake and the brake device, and the previous speed v _n-1 and the current speed v _n-1 are executed. Is controlled to be equal. Then, in step 158, the current acceleration g and velocity v are stored as the next previous acceleration g _n-1 and the previous velocity v _n-1 , and the process ends.

[0027]

According to the present invention, the acceleration / deceleration as intended by the driver can be obtained, so that the drivability is improved. Further, since the neutral shift position is frequently used, fuel efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle control device according to the present invention.

FIG. 2 is an explanatory diagram of a shift map used in one embodiment of the present invention.

FIG. 3 is a flowchart illustrating a main control process according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating an acceleration control process according to an embodiment of the present invention.

FIG. 5 is a flowchart showing deceleration control processing by brake control + engine brake control in one embodiment of the present invention.

FIG. 6 is a flowchart showing deceleration control processing by brake control in one embodiment of the present invention.

FIG. 7 is a characteristic diagram illustrating excessive torque reduction control at the time of starting.

FIG. 8 is a flowchart showing the operation of another embodiment of the present invention.

FIG. 9 is a characteristic diagram illustrating a process of estimating a torque from a brake pedal force signal.

FIG. 10 is a flowchart illustrating a process of estimating a torque from a brake pedal force signal.

FIG. 11 is a characteristic diagram showing a relationship between longitudinal acceleration and torque.

FIG. 12 is a flowchart illustrating a process for obtaining an estimated torque in one embodiment of the present invention.

FIG. 13 is a flowchart illustrating an embodiment of a road gradient estimation process using an acceleration sensor according to the present invention.

FIG. 14 is a block diagram showing still another embodiment of the present invention.

FIG. 15 is a flowchart for explaining the operation of the embodiment in FIG. 14;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Accelerator opening detection means 2 Brake depression force detection means 3 Vehicle speed detection means 4 Shift position detection means 5 Acceleration / deceleration detection means 6 Acceleration / deceleration calculation comparison means 7 Shift position calculation means 8 Engine torque calculation means 9 Brake pressure calculation means 10 Automatic transmission 11 Engine 12 Brake device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshimochi Oyama 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (2)

[Claims] In an automobile control apparatus provided with at least one of an engine torque adjusting means, a gear ratio adjusting means and a braking force adjusting means, a target speed is set from an accelerator operation state and a brake operation state. Target speed setting means, and speed detecting means for detecting a speed appearing on the vehicle, so that the detected value of the speed converges to the set value of the target speed, the torque adjusting means and the gear ratio adjusting means, An automobile control apparatus characterized in that at least one kind of braking force adjusting means is controlled. 2. The invention according to claim 1, further comprising means for calculating a road gradient from a detection result of the acceleration, wherein the at least one kind of adjusting means is controlled based on the calculation result of the road gradient. An automobile control device, comprising: