JPH0240800A - Running controller for vehicle - Google Patents

Abstract

PURPOSE:To improve the safety by executing a response by discriminating a way of curving and acceleration of a front vehicle, based on a variation of an inter-car distance which has been detected. CONSTITUTION:It is assumed that a creeping run is being executed under the conditions of steps S4-S6. By front, left and right sonars, inter-car distances LC, LR and LL are detected and inputted, respectively (S7). In S8, in the case of LC>30m, it is decided that there is no car ahead, and in S9, in the case of LR and LL>30m, it is decided that there is no car on the right and the left sides. In S10, in the case of an inter-car distance BLR which has been detected by the previous control or BLL<=30m, it is decided that a front vehicle has curved, and in S11, a steering angle AH is inputted. In S12, whether a handle operation is being executed or not is decided, and in the case of AH=0, by proceeding to S13, a buzzer is sounded and a driver's attention is called, and in S14, a corner flag FC is set, and in S15, BLC, BLR and BLL are updated to LC, LR and LL, respectively. The foregoing has explained with regard to the case when the vehicle has curved, and in the case of acceleration, it is decided and a response is executed, based on the inter-car distance. In accordance with the inter-car distance, brake force and a throttle opening can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a travel control device that controls vehicle speed so as to maintain a predetermined inter-vehicle distance from a vehicle in front.

(Prior Art) Current road conditions are steadily deteriorating, and the occurrence of vehicle traffic jams has become a daily occurrence. Driving in such traffic jams causes considerable pain and psychological irritation to drivers, and is one of the causes of traffic accidents. In order to reduce the burden on the driver, a following distance control device has been proposed that uses ultrasonic sonar to control the speed of the own vehicle so as to maintain a certain safe distance from the vehicle in front. Publication No. 163733/1983).

By the way, when driving at low speed while maintaining a certain distance from the vehicle in front, vehicles equipped with automatic transmissions have a creeping phenomenon caused by the torque converter, so it is necessary to control the brakes only to automatically control the vehicle in front of the vehicle. It is possible to track. In this case, only the stop direction is controlled,
As long as the driver's attentiveness does not decrease, safety is high.

However, in reality, this may lead to a decline in the driver's attentiveness, leading to new problems. For example, during traffic jams,
When entering automatic driving mode using forward sonar and tracking the vehicle in front while maintaining a predetermined following distance, if the vehicle in front of you turns to the left or right when you reach a curved point on the road, your vehicle will also operate the steering wheel. Also, if the vehicle in front accelerates, if you do not immediately stop creeping and start accelerating, there is a risk that another vehicle will get between the vehicle in front and your own vehicle.

(Object of the Invention) Therefore, the present invention provides a vehicle travel control device that is capable of determining a curve in a road when automatically tracking a vehicle in front, and determining when the vehicle in front accelerates, and responding to the acceleration. The purpose is to provide

(Structure of the Invention) The present invention provides distance detection means provided at the front of the vehicle body.
When a vehicle travel control device detects the distance between the vehicle in front and the vehicle in front during traffic congestion, and controls the vehicle speed based on this detection signal to automatically travel, when it becomes unable to detect an object in front of the vehicle. The present invention is characterized in that the automatic travel control is canceled.

(Effects of the Invention) According to the present invention, when the vehicle in front turns to the left or right while tracking the vehicle in front by automatic driving control,
Or even if the vehicle accelerates, it is possible to respond immediately, thereby avoiding danger and improving safety.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a power train of a vehicle to which the present invention is applied, where 2 is an engine, 2 is a throttle valve provided in its intake passage 3, and 4 is a drive mechanism for the throttle valve 2. 5 is an electronically controlled automatic transmission (EAT) attached to the rear end of the engine 1, and the output of this transmission 5 is:
The left and right drive wheels 9 are connected through the propeller shaft 6, the differential gear W7, and the left and right drive shafts 8L and 8R, respectively.
It is designed to be transmitted to L and 9R. Each drive wheel 9L
, 9R are equipped with a brake device 10L and an IOR, respectively.

On the other hand, the control unit includes an accelerator pedal sensor 12 that detects the amount of depression of the accelerator pedal, a steering angle sensor 13 that detects the steering angle of the steering wheel, a brake switch l4 that detects that the brake pedal is depressed, and an EAT 5 set to N. The throttle opening, ignition timing, and air-fuel ratio are controlled for the engine l based on inputs from the N range switch 15 that detects that the vehicle is in the range, the vehicle speed sensor 16, etc., and the brake device 10L
, 10R, the brake force is controlled via the brake pressure servo unit 17.
The powertrain automatically adapts to the road conditions and the driver's wishes.

Furthermore, as shown in FIG. 2, the front part of the vehicle body is equipped with a front sonar 18, a right side sonar 19, and a left side sonar 20.
An ultrasonic pulse train as shown in the figure is transmitted at predetermined time intervals, and after transmission, it is switched to reception, and creeping driving is performed while measuring the distance between the vehicle and the vehicle in front using the reverse time Tr.

L = Vs * Tr/ 2 (Vs s vehicle speed)
Then, the control unit 11 detects that the vehicle in front is the sonar 1.
When the detection is no longer possible between 8 and 20, the buzzer 21 is sounded to issue a warning, or the braking force or throttle opening is controlled depending on the distance between the vehicle and the vehicle in front.

Next, the control executed by the control unit 11 will be explained with reference to FIGS. 4 and 5.

First, in step S1 of FIG. 4, initialization is performed, and in the next step S2, the accelerator pedal depression 1lPA is input from the accelerator pedal sensor 12.Next, in step S3, the basic throttle opening PB is calculated from the accelerator pedal depression 1lPA. 0th order steps 84 to S6
indicates a creeping driving condition, and creeping driving is when the accelerator is OFF (PA=0), the brake is OFF (no input to the brake switch 140), and it is not in the N range (no input to the N range switch 15). Proceeding to the next step S7, the inter-vehicle distance 11Lc detected by the front sonar 18 and the inter-vehicle distances L++ and Lt detected by the right sonar 19 and left sonar 20, respectively, are input. Then, in the next step S8, Lc>30
If m, it is determined that there is no car ahead, and in step S9 L
If llSLL>30m, it is determined that there are no cars on the right or left side. Furthermore, in step SlO, the inter-vehicle road 1 detected in the previous control! ! IIB L or BLL is determined, and if BLR or BLL≦30m, it is determined that the vehicle ahead has turned either to the right or left, and in the next step 311, the vehicle is turned to the right or left. The steering angle AH from the angle sensor 13 is input. Furthermore, in step S12, it is determined whether or not the steering wheel is being operated. If AH=0, the process proceeds to step S13, where the buzzer 21 is sounded to call the driver's attention, and in the next step 314, the corner flag FC is set. Then, proceed to step S15 and set the previous inter-vehicle distances BLc, BLe, and BLL, respectively, as LC1Lll1.
% Update to LL.

On the other hand, when it is determined in step S8 that Lc≦30m, it is determined that there is a car ahead and the process directly proceeds to step S15.
Update the following distance. Further, if it is determined in step S8 that there is no vehicle ahead, and it is determined in step S9 that there is a vehicle on the right or left side, the process proceeds to step 516, and the inter-vehicle road jlfLc is determined from the difference between Lc and BLc. It is determined whether or not there has been a sudden change, and if the determination is rYEsJ, the process proceeds to step 311, but if it is rNOJ, the process proceeds to step 315.
Further, if it is determined in step 310 that BL8 or BLL≦30m was also determined last time, the process advances to step S17, and it is determined whether the corner flag FC is set. The process proceeds to S16, but in the case of rYEsJ, the steering angle AH is input in step 318, and the corner flag FC is cleared in step S19. If it is determined in the next step S20 that the steering wheel is being operated, the process proceeds to step 315, but if it is determined that the steering wheel is not being operated, the brakes are applied in step S21 to stop the vehicle. After that, the process proceeds to step 315.

After updating the previous inter-vehicle distance in step S15, control moves to FIG. 5. In FIG. 5, first, in step S22, the vehicle speed Vs is input from the vehicle speed sensor 16, and then in the next step S2.
3, determine whether Vs>201um/h, and VS ≦2
When the speed is 0 km/h, the vehicle stops at step S24 (Vs = O
) Determine whether or not. If the vehicle is running, the inter-vehicle road 11 measured by the forward sonar 18 is determined in step S25.
It is determined whether Lc exceeds 7 m. Inter-vehicle road ji
If lLc exceeds 7 m, it is determined in the next step S26 whether or not the brake is applied, and if the brake is applied, the brake force BK is weakened in step S27.
The process proceeds to step S39. If the vehicle speed Vs is determined to be zero in step S24, the process proceeds to step 328 to determine whether the inter-vehicle lane jilLc exceeds 5 m, and determine whether the inter-vehicle road 11Lc exceeds 5 m. If so, step S
After weakening the brake force in step S29, proceed to step S39,
If the inter-vehicle distance Lc is within 5m, proceed directly to step S3.
9, while in the running state and step S2
If it is determined in step S30 that the inter-vehicle distance Lc is within 7 m, the process advances to step S30, and the inter-vehicle distance Lc is 5 m or less.
Determine whether or not the value is less than or equal to the value. And this judgment is rYE
sJ, the throttle correction opening degree P is determined in step S31.
Determine whether C is greater than zero, and this determination is rYE
sJ, the throttle correction opening degree P is set in step S32.
Clear C and proceed to step 339, step 331
If the determination is rNOJ, the brake force BK is increased in step S33, and the process proceeds to step S39. Furthermore, if 5m≦L
When c≦7m, the process proceeds to step 334, where it is determined whether or not the throttle correction opening degree PC is greater than zero, and when this determination is rYEsJ, the throttle correction opening degree is reduced in step S35. Also, the determination in step S34 is r
If NOJ, it is determined in step 836 whether or not the brake is applied, and if the brake is not applied, the brake is left as is, and if the brake is applied, the brake is weakened in step S37, and then the process proceeds to step S39.

In this way, when the inter-vehicle distance Lc is within the range of 5 m≦Lc≦7 m, both the speed increasing side and decelerating side controls are stopped. Further, when it is determined in step S26 that the brake is not applied, the auxiliary throttle correction opening degree PC is increased in step 338, and step S39
Move to.

In step 339, the final throttle opening PT is calculated, and in the next step 340% 341, the throttle opening is controlled and the brake force is controlled, and the process returns to step S2 in FIG.

The above is a description of the configuration and operation of the embodiment of the travel control device according to the present invention.As is clear from the above description, according to this embodiment, the vehicle automatically tracks the vehicle in front by creeping travel. Even if the vehicle ahead turns to the left or right or accelerates, it is possible to respond immediately, thereby avoiding danger and improving safety.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a power train of a vehicle to which the present invention is applied, FIGS. 2 and 3 are explanatory diagrams of a method for measuring an inter-vehicle distance, and FIGS. 4 and 5 are control flowcharts thereof. 1- Engine 2- Throttle valve 4...
- Throttle valve drive IJJ Rm5 - Electronically controlled automatic transmission (EAT) 10L, 10R - Brake device 11 - Control unit 16 - Vehicle speed sensor 17 - Brake pressure servo unit 18 - Front sonar 19 - Right side sonar 20 - left side sonar

Claims (1)

[Claims] A distance detecting means provided at the front of the vehicle body detects the distance between the vehicle and the vehicle in front during traffic congestion, and based on this detection signal, the vehicle speed is controlled to automatically drive the vehicle. A vehicle travel control device according to the present invention, characterized in that the automatic travel control is stopped when an object cannot be detected in front of the vehicle.