JPH11148396A - Vehicle running controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply limit to a throttle opening upon request of deceleration by exactly-discriminating control abnormality due to failure of an accelerator opening sensor or the like even if braking operation is conducted with a left foot concurrently with the accelerator operation with a right foot, in a vehicle engine having a constitution whose throttle opening is electronic-controlled according to the accelerator opening. SOLUTION: The variance in accelerator opening is detected (S1), and whether such a condition as the opening variation quantity is a prescribed value or lower is continued for more than a prescribed time or not is discriminated (S2, S3). If the condition of the opening variation quantity of the prescribed value or lower continues for more than the prescribed time, it is discriminated that a possibility of the occurrence of an accelerator opening sensor failure is high. If the brake has been operated with a brake switch being ON (S4, S5) at this time, the throttle opening control amount is limited so as to become the maximum throttle opening for emergency or lower (S6), in order to meet the driver's deceleration request.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device, and more particularly, to a vehicle travel control device having a structure for electronically controlling a throttle opening of an engine in accordance with a result of detecting an accelerator opening.

[0002]

2. Description of the Related Art Conventionally, a vehicle engine having a structure in which a target throttle opening is set from an accelerator opening and an actuator such as a motor is controlled in accordance with the target throttle opening to open and close a throttle valve is known. Have been. In the above-described vehicle engine, for example, an abnormality occurs in a system for detecting an accelerator opening (an accelerator opening sensor and a mechanism for transmitting the movement of an accelerator pedal to the sensor), and the opening differs from the actual accelerator opening. Is detected, the throttle valve is controlled to an opening that does not correspond to the accelerator opening, which causes a problem that acceleration and deceleration do not occur against the driver's will.

[0003] As a fail-safe technique against abnormal throttle opening, for example, Japanese Patent Application Laid-Open No. 4-203244 discloses a technique.
JP, JP-A-1-102451, JP-A-6-2
47188 and JP-A-7-19077. JP-A-4-20324
Japanese Patent Application Laid-open No. 4 (1994) discloses a configuration in which a throttle valve opening is restricted when a driver requests a deceleration (when a brake switch is ON).

In Japanese Utility Model Laid-Open Publication No. 1-102451,
A configuration is disclosed in which when the opening degree of the first throttle valve is equal to or more than a predetermined value and the braking force is equal to or more than a predetermined value, the second throttle valve is closed to forcibly reduce the engine output. JP-A-6-247188 discloses a configuration in which the throttle valve opening is limited according to the amount of brake operation.

[0005] Japanese Patent Application Laid-Open No. Hei 7-19077 discloses that when a brake operation is detected and the vehicle is decelerating at that time, the throttle opening is adjusted to an opening corresponding to the deceleration of the vehicle. There is a disclosure of a restrictive configuration.

[0006]

In general, the operation of depressing the accelerator pedal and the brake pedal with the right foot is common.
There is a case where the brake pedal is operated by the left foot (hereinafter referred to as left foot brake running), and when the brake switch is ON as in the method disclosed in Japanese Patent Application Laid-Open No. Hei 4-203244, the throttle is operated. With the configuration in which the opening is limited, when the left foot brake travel is performed, even if the system operates normally, the throttle opening is all limited, and the left foot brake is substantially reduced. There was a problem that the device would not be allowed to run.

Further, in the case where the throttle opening is limited on the condition of the throttle opening and the braking force as in the method disclosed in Japanese Utility Model Application Laid-Open No. 1-102451, a large throttle valve is opened with a large opening. Steep slope start to give braking force, cornering by sports driving,
In order to allow all left-foot brake running such as stall start, it is necessary to set the threshold value of the throttle opening near the full opening and set the threshold value of the braking force to be high. There is a problem that a fail-safe cannot be executed even when a driver with weak leg strength steps on the brake. Furthermore, since it is necessary to accurately detect the braking force, there is a problem that the sensor cost is high.

As disclosed in JP-A-6-247188,
Even when the brake operation amount is used as a condition, it is necessary to increase the threshold value of the brake operation amount in order to allow all the left foot brakes to travel, similar to the one disclosed in Japanese Utility Model Application Laid-Open No. 1-102451. In addition, there is a problem that fail-safe may not be executed even when a driver with weak leg force steps on the brake, and there is a problem that sensor cost is required because it is necessary to accurately detect a brake operation amount.

Further, Japanese Patent Application Laid-Open No. 7-19077 aims to suppress deterioration of fuel efficiency due to excessive depression of an accelerator when the left foot brake is running. Because of the limitation, there is a problem that it is not possible to cope with acceleration (do not decelerate) contrary to the driver's will. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a vehicle travel control device capable of reliably functioning as a throttle opening limit for a control abnormality due to a failure of an accelerator opening sensor or the like, while permitting all left foot brake traveling. The purpose is to provide.

[0010]

According to the present invention, a throttle opening control amount corresponding to an accelerator opening is output to an actuator for opening / closing a throttle valve of an engine to control the throttle valve. In the vehicle travel control device configured to control the opening, at least one of the opening of the throttle valve and the opening of the accelerator pedal is substantially constant for a predetermined time or more, and the brake is operated. In this case, the throttle opening control amount is limited and output to the actuator.

With this configuration, the throttle opening is electronically controlled based on the accelerator opening, but the state in which the throttle opening and / or the accelerator opening is substantially constant continues for a predetermined time or more, and the brake Is operated, the throttle opening control amount is limited. When the accelerator is operated during left foot brake travel, the accelerator opening generally fluctuates, and the throttle opening also fluctuates accordingly.For example, if an abnormality occurs in the accelerator opening sensor, Since the detection result of the accelerator opening becomes constant and the throttle opening is controlled to be constant thereby, the same brake operation state may be caused by the left foot brake running, or the throttle control system may be abnormal. It can be determined whether the request is a driver's deceleration request (the same applies to claim 2).

The throttle opening control amount is limited by fixing the throttle opening control amount to a fixed value, by limiting the throttle opening control amount by a limiter so as to be controlled to a predetermined maximum opening or less, by controlling the throttle opening control amount. It is assumed that this includes a limitation on the detected value of the accelerator opening, which is a condition for determining the degree control amount (target throttle opening) (the same applies to claim 2).

Further, the throttle opening control amount according to the accelerator opening is set in accordance with a configuration that uniquely converts the accelerator opening into a target throttle opening, and a target output that is set according to the accelerator opening. It is assumed that a configuration for setting the target throttle opening based on the torque is included (the same applies to claim 2). The invention according to claim 2 is configured as shown in FIG.

In FIG. 1, the actuator is for opening and closing the throttle valve of the engine, and the control means supplies a throttle opening control amount corresponding to the accelerator opening detected by the accelerator opening detecting means to the actuator. Output. On the other hand, the opening change amount detecting means detects the opening change amount of at least one of the throttle valve and the accelerator pedal per unit time, and the brake operation detecting means detects the brake operation.

[0015] The throttle opening limit means may include a state in which the opening change amount detected by the opening change amount detecting means is equal to or less than a predetermined value for a predetermined time or more, and the brake operation detecting means may control the brake operation. When an operation is detected, a throttle opening control amount output to the actuator by the control means is limited. According to this configuration, the throttle opening control amount according to the detection result of the accelerator opening is output to the actuator, and the throttle opening is electronically controlled, but the throttle opening and / or the accelerator opening is substantially constant. Continues for a predetermined time or more,
If a brake operation is detected at that time, the throttle opening control amount is limited.

Here, the actuator is, for example, a motor, and a brake switch generally provided in a vehicle can be used as the brake operation detecting means.
According to a third aspect of the present invention, the throttle opening limiting means limits the throttle opening control amount so that the throttle opening is equal to or less than a predetermined maximum opening.

According to this configuration, when the state in which the opening change amount is equal to or less than the predetermined value continues for the predetermined time or more and the brake operation is detected, the opening is controlled to exceed the predetermined maximum opening. Is prohibited, and control is performed within an opening range equal to or less than a predetermined maximum opening. According to a fourth aspect of the present invention, the throttle opening limiting means changes the maximum opening smaller with time.

According to such a configuration, when the state in which the opening change amount is equal to or less than the predetermined value continues for a predetermined time or more and the limit condition for detecting the brake operation is satisfied, the opening degree is reduced to a predetermined maximum opening or less. Although the restriction is added, the predetermined maximum opening is gradually reduced in accordance with the elapsed time from the satisfaction of the restriction condition, and the throttle opening is restricted to be smaller as the restriction applying time becomes longer.

[0019]

According to the first and second aspects of the present invention, it is possible to reliably limit the throttle opening in the event of a failure in the accelerator opening detection system while permitting all left foot brake running. In addition, there is no need to detect the amount of brake operation or the braking force, so that an increase in sensor cost can be avoided.

According to the third aspect of the present invention, it is possible to respond to a driver's deceleration request for a control abnormality while permitting control in the low opening range and securing the minimum required traveling performance. effective. According to the fourth aspect of the invention, there is an effect that the throttle opening can be restricted more safely on the driver's deceleration request for the control abnormality.

[0021]

Embodiments of the present invention will be described below. FIG. 2 is a diagram illustrating a system configuration of the vehicle engine according to the embodiment. Engine 1 shown in FIG.
A throttle valve 3 for adjusting the amount of intake air is interposed in the intake passage 2, and a combustion air-fuel mixture is formed by the air passing through the throttle valve 3 and the fuel injected from the injector 4.

The injector 4 may have either a configuration for injecting fuel into the intake passage 2 or a configuration for injecting fuel directly into the combustion chamber. A drive mechanism including a reduction gear 5 and a motor 6 as an actuator is provided at one end of the rotation shaft 3a of the throttle valve 3.
The rotation of the motor 6 is transmitted to the rotating shaft 3a via the reduction gear 5, and the opening of the throttle valve 3 changes.

On the other hand, a throttle opening sensor 7 for detecting the opening of the throttle valve 3 and a return spring 8 for urging the throttle valve 3 in the closing direction are provided at the other end of the rotary shaft 3a. ing. When the driver depresses the accelerator pedal 9 against the urging force of the accelerator return spring 10, the accelerator drum 12 is driven to rotate via the accelerator wire 11, and the rotation angle of the accelerator drum 12 is used as an accelerator opening sensor 13 ( The accelerator opening detecting means) detects the accelerator opening.

A control unit 14 for controlling the motor 6 and the injector 4 receives detection signals from the throttle opening sensor 7 and the accelerator opening sensor 13 and outputs an ON signal when the brake pedal 15 is operated. A detection signal is input from the brake switch 16 (brake operation detecting means). FIG. 3 is a control block diagram showing a configuration of the throttle opening control by the control unit 14. As shown in FIG.

In FIG. 3, a throttle opening control section is shown.
14a (control means) is an accelerator opening detected by the accelerator opening sensor 13 (the amount of depression of the accelerator pedal 9).
, A target throttle opening is set, and a control amount (throttle opening control amount) corresponding to the target throttle opening is output. The setting of the target throttle opening according to the accelerator opening may be performed by converting the accelerator opening into the target throttle opening according to a table stored in advance, or by setting the target throttle opening based on the accelerator opening, vehicle speed, and the like. The configuration may be such that the torque is set and the target throttle opening at which the target torque is obtained is calculated.

On the other hand, the throttle opening control amount changing section 14b
(Throttle opening limiting means) is an accelerator opening sensor
13, the presence or absence of a control abnormality is determined based on detection signals from the throttle opening sensor 7 and the brake switch 16, and when an abnormality occurs, the throttle opening control amount output from the throttle opening control unit 14a is limited. In addition, the output is output to a throttle drive mechanism including the reduction gear 5 and the motor 6.

FIG. 4 is a flow chart showing the control in the throttle opening control amount changing section 14b. In S1 (opening change detecting means), the accelerator opening change amount (and / or throttle opening degree) is determined. Change amount).
The amount of change is calculated as the amount of change in the opening degree per unit time (per execution cycle of this routine) as the opening degree of the present time minus the opening degree of the previous time.

In S2, it is determined whether or not the amount of change in the opening is equal to or less than a predetermined value (for example, 0.1 to 0.3 deg / 100 ms) to determine whether the accelerator opening (and / or the throttle opening) varies. It is determined whether or not the vehicle is in the traveling state. Here, when it is determined that the opening change amount is equal to or less than the predetermined value and the opening is substantially constant, the process proceeds to S3. on the other hand,
If the amount of change in the opening exceeds the predetermined value, the accelerator opening is normally detected, and it is determined that the throttle opening is properly controlled in response to this, and this routine is terminated. Let it.

That is, when a mechanical failure such as a failure of the accelerator opening sensor 13 or a sticking of the accelerator wire 11 (hereinafter referred to as a failure of the accelerator opening detection system) occurs, the actual accelerator opening varies. However, a constant value is input to the control unit 14 as a detection result, and in a configuration in which the accelerator opening is converted to a target throttle opening in a table, the throttle opening is also controlled to a constant value. become. Therefore, when the opening change amount is equal to or less than a predetermined value, it is determined that there is a possibility that the accelerator opening detection system has a failure, and the process proceeds to S3 and thereafter to limit the throttle opening control amount. This is to determine whether there is a need.

Therefore, in the case of a configuration in which the accelerator opening is converted into a target throttle opening in a table, at least one of the accelerator opening change amount and the throttle opening change amount may be detected. In addition, when the target torque is set from the accelerator opening and the target throttle opening at which the target torque is obtained is set, a failure occurs in the accelerator opening detection system, and the detection result of the accelerator opening is constant. Even if
Since the throttle opening may fluctuate, it is preferable to detect the accelerator opening change amount.

When it is determined that the opening change is equal to or less than the predetermined value and the process proceeds to S3, the state in which the opening change is equal to or less than the predetermined value continues for a predetermined time (for example, about 2 to 5 seconds). Is determined. When the driver operates the accelerator pedal 9, a slight change actually occurs even if the driver intends to depress the accelerator pedal 9, so that the state in which the opening change amount is equal to or less than a predetermined value continues for a predetermined time or more. It is determined whether or not there is a failure in the accelerator opening detection system by making a determination as to whether or not the accelerator operation has been performed.

In S3, when it is determined that the state in which the opening change amount is not more than the predetermined value has not continued for the predetermined time or more, it can be determined that there is no abnormality in the accelerator opening detection system. This routine ends without limiting the amount. On the other hand, when it is determined that the state in which the opening change amount is equal to or less than the predetermined value has continued for the predetermined time or more, it is highly likely that the accelerator opening detection system has a failure. In this case, the process proceeds to S4. , Brake switch 16
Is detected, and in S5, ON / OFF of the brake switch 16 is determined to determine a driver's deceleration request.

When the brake switch 16 is ON and the driver is performing a brake operation, the process proceeds to S6 (throttle opening restriction means) to limit the throttle opening control amount in response to the deceleration request. Add. When the brake switch 16 is turned off or a change in the opening is detected after proceeding to S6, the restriction on the throttle opening control amount is released, but the restriction state is maintained until then. .

The control of the throttle opening control amount in S6 is based on the maximum throttle opening (for example, 4 deg.
) And a limiter is provided for the throttle opening control amount so as not to exceed the maximum throttle opening. By limiting by the limiter, even if a large target throttle opening that does not correspond to the actual accelerator opening is set as the target throttle opening due to a failure of the accelerator opening detection system, the control opening of the throttle valve is set. , And the vehicle can be decelerated according to the driver's intention to decelerate.

The maximum throttle opening is preferably set to such an extent that a normal slope start can be performed. As a result, even if the throttle opening control amount is limited even if there is no failure in the accelerator opening detection system, it is possible to guarantee the minimum running performance.
That is, it is determined that the state in which the amount of change in the accelerator opening is equal to or less than the predetermined value has continued for the predetermined time or more when the vehicle starts on a slope due to the left foot brake running, and the throttle opening is limited to the maximum throttle opening. Can be started,
If there is no abnormality in the accelerator opening detection system, the restriction is released by further depression of the accelerator, and the vehicle can be driven normally.

Further, the maximum throttle opening is determined after the restriction condition that the amount of change in the opening is equal to or less than a predetermined value has continued for a predetermined time or more and the brake operation is being performed is first determined. May be gradually reduced in accordance with the elapsed time of, so that the driver's deceleration request can be more reliably satisfied. According to the above configuration, the deceleration request for the failure of the accelerator opening detection system is distinguished from the time of left foot brake running based on the characteristic that the accelerator opening is rarely continued for a predetermined time or more in a substantially constant state. Therefore, it is possible to reliably respond to a deceleration request for a failure of the accelerator opening degree detection system while allowing the left foot brake running, and since the deceleration request is determined based on the presence or absence of the brake operation, even if the leg force is weak Even if there is a driver, it is possible to reliably limit the throttle opening.

In the above embodiment, the throttle opening control amount is limited. However, the accelerator opening detection value, which is the basis of the throttle opening control amount, may be limited. Further, in the case where the target torque is calculated from the accelerator opening and the throttle opening control amount (target throttle opening) is determined in accordance with the target torque, the target torque may be limited. Therefore, any configuration may be used as long as the throttle opening control amount is consequently limited.

In the case of a vehicle engine having a structure in which the throttle valve is opened and closed by an actuator based on the detection result of the accelerator opening, the transmission combined with the engine may be manually operated,
Any of automatic may be used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle travel control device according to claim 2;

FIG. 2 is a system configuration diagram of the embodiment.

FIG. 3 is a control block diagram according to the embodiment;

FIG. 4 is a flowchart showing control contents according to the embodiment.

[Explanation of symbols]

 Reference Signs List 1 engine 2 intake passage 3 throttle valve 5 reduction gear 6 motor 7 throttle opening sensor 9 accelerator pedal 13 accelerator opening sensor 14 control unit 15 brake pedal 16 brake switch

Claims (4)

[Claims] 1. A vehicle travel control device configured to output a throttle opening control amount according to an accelerator opening to an actuator that opens and closes a throttle valve of an engine to control the opening of the throttle valve. When a state in which at least one of the opening degree of the throttle valve and the opening degree of the accelerator pedal is substantially constant has continued for a predetermined time or more and the brake is operated, the throttle opening control amount is limited. The vehicle travel control device is configured to output the signal to the actuator. 2. An actuator for opening and closing a throttle valve of an engine, an accelerator opening detector for detecting an accelerator opening, and a throttle opening control amount corresponding to the detected accelerator opening is output to the actuator. Control means; opening degree change amount detecting means for detecting an opening degree change amount per unit time of at least one of the throttle valve and the accelerator pedal; brake operation detecting means for detecting a brake operation; When the state in which the opening change amount detected by the detecting means is equal to or less than a predetermined value continues for a predetermined time or more, and the brake operation is detected by the brake operation detecting means, the control means outputs an output to the actuator. Throttle opening limiting means for limiting the throttle opening control amount to be controlled. Both travel control device. 3. The vehicle travel control device according to claim 2, wherein said throttle opening limit means limits the throttle opening control amount so that the throttle opening is equal to or less than a predetermined maximum opening. . 4. The vehicle travel control device according to claim 3, wherein said throttle opening restriction means changes said maximum opening smaller as time elapses.