JPS60154921A - Car driving controller - Google Patents

Abstract

PURPOSE:To make accurate automatic follow-up driving performable even in driving on a curved road, by calculating a car speed holding time according to a steering angle of a steering wheel at a time when a car-to-car distance is so suddenly changed, while making a device so as not to control a car speed during the car speed holding time after the sudden change of the car-to-car distance is over. CONSTITUTION:An adjustable speed ratio control device 11 regulates a self-car speed via a throttle valve opening control device 13 so as to cause car-to-car distance with a preceding car detected by a car-to-car distance calculated by a safety car-to-car distance calculating device 9 according to the self-car speed detected by a car speed detecting device 3 to be accorded with each other. And, a steering angle detecting device 5 and a distance variation detecting device 7, which outputs a distance sudden change signal at a time when it detects a fact that a variation in the car-to-car distance reaches the specified value, both are installed in a controller. In addition, a car speed holding command device 15 calculates a car speed holding time according to a steering angle in time of inputting the distance sudden change signal, and as long as a portion for this time, a car speed holding command signal is outputted to the adjustable speed ratio control device 11 after the input of the distance sudden change signal is over, thus the self-car speed is kept up.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention detects the distance between the vehicle in front and the vehicle in front, and controls the speed of the own vehicle according to the distance between the vehicles in front. The present invention relates to a device that automatically follows a vehicle, and relates to a vehicle travel control device that accurately controls vehicle speed when traveling on a curved road.

[Technical background of the invention and its problems] In recent years, as vehicles have been equipped with constant-speed running devices that allow vehicles to run at a fixed set speed, this has been done with the aim of preventing rear-end collisions with preceding vehicles and improving driving operability. , a vehicle running control device has been proposed that allows the own vehicle to follow the preceding vehicle by detecting the distance between the own vehicle and the preceding vehicle and controlling the vehicle speed according to the detection result (for example, Japanese Patent Laid-Open No. 1983-1999) No. 86000).

By the way, in such a vehicle running control device, as described above, the distance between the vehicle and the preceding vehicle is measured, and the vehicle speed is controlled based on the measurement result. Therefore, when the measurement result of the inter-vehicle distance is an abnormal value, inaccurate vehicle speed control is performed based on the abnormal value.

In order to solve such problems-1, the present inventor first solved the problem of sudden changes in the distance between vehicles and the distance between vehicles.

We would like to propose a method of maintaining the vehicle speed for a certain period of time after the end of a sudden change.
On a curved road, the preceding vehicle W is in the radar area (first
At the same time, curved roadside bodies R such as road signs and guardrails enter the radar area.

Therefore, the vehicle speed is erroneously controlled to decelerate by using the distance between the vehicle M and the curved roadside body R as the inter-vehicle distance. That is, on a curved road, after losing sight of the preceding vehicle W, the distance between the vehicles suddenly changes as the vehicle loses sight of the object to be measured, and then the curved roadside body R is detected and the distance to the curved roadside body R is measured. There is a tendency for the state to remain stable (see Figure 2 (A)). If this situation continues, the vehicle speed will be maintained for a certain period of time after the sudden change in distance, but after the elapse of that period, deceleration control will be performed according to the distance to the curved roadside body R (see Figure 2). (See (B))
As a result, the vehicle speed gradually decreases due to unnecessary vehicle speed control (see FIG. 2(C)).

Therefore, in such a vehicle running control device, it is necessary to prevent inappropriate vehicle speed control caused by erroneous measurement of inter-vehicle distance, especially when the vehicle is traveling on a curved road. On the other hand, when the steering angle of the steering wheel exceeds a predetermined angle using a conventional steering angle sensor, it is determined that the vehicle is traveling on a curved road, and by maintaining the vehicle speed before entering the curved road, it is possible to prevent incorrect driving on a curved road. A device for preventing the occurrence of vehicle speed control has been proposed (for example, Japanese Patent Laid-Open No. 58-43009). However, this device maintains the vehicle speed by simply detecting whether the vehicle is traveling on a curved road based on the magnitude of the steering angle, but since curves on expressways are generally gentle, the device cannot be used even on such curves. In order to operate reliably, it is necessary to set a small reference steering angle for determining whether the vehicle is traveling on a curved road. By setting the standard steering angle small in this way, steering that exceeds the standard steering angle will occur more frequently even when driving on a straight road rather than a curved road.As a result, the vehicle speed will be maintained more often than it should have been. Even when there is no need to maintain the vehicle speed, there is a risk that the vehicle speed will be maintained. This may result in a delay in response when there is an interruption, or, especially when driving on a curved road, the vehicle speed may be maintained even though the distance between the preceding vehicle and the preceding vehicle can be detected, causing the preceding vehicle to respond to the acceleration or deceleration of the preceding vehicle. This appears as a problem such as the inability to accurately follow the vehicle.

[Purpose and Summary of the Invention] The present invention has been made in view of the above, and its purpose is to detect the distance between the vehicle in front and the vehicle in front, and control the speed of the own vehicle according to the distance between the vehicles in front and maintain a safe distance between the vehicles. An object of the present invention is to provide a vehicle running control device that can accurately maintain and control the vehicle's speed on a curved road in a device that automatically follows the vehicle in front while maintaining the speed of the vehicle.

In order to achieve the above object, as shown in FIG. In a vehicle running control device that adjusts the own vehicle speed via a throttle valve opening control means 13 so as to match the safe inter-vehicle distance calculated by the safe inter-vehicle distance calculation means 9 according to the vehicle speed, the steering angle of the steering wheel is detected. A steering angle detection means 5 and a distance change detection means 7 that outputs a sudden distance change signal when detecting that a change in the inter-vehicle distance has reached a predetermined value are provided, and the vehicle speed maintenance command means 15 detects a sudden change in distance. Calculating the vehicle speed holding time according to the steering angle when the signal is input manually, and outputting the vehicle speed holding command signal to the acceleration/deceleration rate control means 11 after inputting the sudden distance change signal. The gist is that the speed of the vehicle is maintained.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 4 shows an embodiment of the present invention, in which an inter-vehicle distance detection device 1, a vehicle speed sensor 18 constituting the vehicle speed detection means 3,
Based on the output signals of the set switch 19 that commands constant speed running, the throttle valve opening sensor 21, and the steering angle sensor 22, the micro combi coater 23 processes the output signals according to the flowchart described later to control the throttle valve opening control means 1.
The configuration is such that the vehicle speed is controlled by changing the opening degree of a throttle valve (not shown) via 3. In addition, the microcomputer 234; t, CPU 25, ROM 27, R
This configuration includes an AM 29 and an input/output port 31.

Next, the operation of this embodiment will be explained with reference to FIG. 5, which shows the processing flowchart of the poly-microcomputer 23. Note that this process is started by six interrupt signals that occur at a constant period during medium-height running.

When an interrupt signal is input, the operating state of the set switch 19 is first determined, and if it is not in the operating state, that is, if the vehicle is in the vehicle running control state, the current interrupt processing is executed via step 150, which will be described later. On the other hand, if the set switch 19 is in the active state, and it was not in the active state in the previous interrupt processing, that is, it is determined that it is in the active state for the first time in the current interrupt processing. Then, the own vehicle speed S at that time is stored as the set vehicle speed SO for constant speed driving when there is no vehicle in front, and the throttle is adjusted so that the set vehicle speed SO can be maintained without the driver having to operate the accelerator. A transmission clutch (not shown) that enables the output of the valve opening control means 13 to be transmitted to a connecting rod (not shown) that changes the opening of the throttle valve is turned on, and the opening of the throttle valve is set at the vehicle speed So. Adjust the opening θSo corresponding to
A vehicle travel control flag indicating that the vehicle is in operation is set, and the process proceeds to step 150 (steps 100 to 140).

When the process proceeds to step 150, it is confirmed that the vehicle is under control and that the brakes and clutches are not in the OFF state, and acceleration/deceleration rate control processing is performed (step 15).
0-190). In addition, in step 160, when it is detected that the brake is operated or that the clutch is in the OFF state, the vehicle travel control flag is reset to 1-1 to stop the vehicle travel control, and the transmission clutch is turned off and the present operation is performed. Ends the interrupt processing.

Next, the process of acceleration/deceleration rate control (step 19o) will be explained using flowchart 17-t- in FIG. The own vehicle speed S at the current Samurai point is within a certain vehicle speed range (30km/h≦$≦120
km/l+), the vehicle stops at a safe inter-vehicle distance Do corresponding to the own vehicle speed S, and proceeds to step 250 (steps 200 to 240). Regarding own vehicle speed S, S
< 30km/h (As > 1201un/h), the vehicle running control is stopped, the vehicle running control flag is reset, the transmission clutch is set to A), and the time from the sudden change in inter-vehicle distance is indicated. Clear count register N (steps 220-235). Proceeding to step 250, the inter-vehicle distance 1i1tDi from the preceding vehicle at the time of the previous interrupt processing and the current inter-vehicle distance On
After eliminating the distance difference (lDn-Dil), the current steering angle is detected and the vehicle speed maintenance determination process (step 2) described below is performed.
80-306) (steps 250-275).

This vehicle speed maintenance determination process (steps 280 to 306) is performed for a predetermined period of time (steps 280 to 306) when a sudden change in the inter-vehicle distance is detected.
N1 x Interrupt Interval Time) [The vehicle speed is maintained, and before the predetermined time elapses, the magnitude of the steering angle is determined, and when the steering angle is greater than or equal to the predetermined angle, the vehicle speed is maintained for the predetermined time. (T+X interrupt interval time) (processing is performed in such a way that the interrupt continues).The details are as explained below.

In step 280, the distance difference calculated in step 270 is compared with a predetermined distance Dk (for example, 5 In ).

As a result, if 1Dn-Dil<1k, the process proceeds to step 300, and if 1Dn-Dil≧[)k, it is determined that a rapid change in the inter-vehicle distance has occurred, and the contents of the count register N are set. After setting the value N1 (step 290
>, proceed to step 300.

In step 300, it is determined whether the contents of the register N in the first register are in a clear state. Here, once a sudden change in the following distance occurs (step 280), the contents of the count register N are set to the set value N1 (step 290), so in order for the contents of the count register N to be in the reset state, , even if a sudden change in the inter-vehicle distance does not occur, or even if the occurrence is detected, the set value N1 is decremented to 0 every time an interrupt is processed as described later (step 306), so the predetermined time (N+X interrupt interval time) Somehow it has passed. Therefore, step 30
0, if it is N to O, it is determined that the predetermined time 111 (N+X interrupt interval time) has not elapsed since the occurrence of a sudden change in the inter-vehicle distance was detected and that the vehicle speed holding time is still within the vehicle speed holding time, and step 303
On the other hand, if N=O, it means that no sudden change in inter-vehicle distance has occurred, or even if the occurrence is detected, the predetermined time (N1×
It is determined that the interrupt interval time (interruption interval time) has elapsed, and the process proceeds to step 301.

Proceeding to step 303, it is determined whether the content of the count register N is 1 or not, and if N~1, the process proceeds to step 306 where the content of the count register N is decremented and the state waits for the next interrupt processing. If N=1, Ste.
Proceed to whelk 304. In step 304, step 2
The steering angle Z of the steering wheel detected at step 75 is compared with the reference steering angle ZO for determining the time extension for maintaining the vehicle speed. As a result, if Z≧Zo, it is determined that the vehicle is traveling on a curved road, and after setting the contents of the count register ``to the set value ``1'', the contents of the count register N (1 in this case) are decremented and set to 0, and the next interrupt is executed. It will be in a waiting state for processing, and conversely, Z
<Zo, the process proceeds to step 306, zeros the contents of the count register N, and enters a standby state (step 304
~306).

On the other hand, if the determination result in step 300 is N=0 and the process proceeds to step 301, it is determined whether the contents under the count register are in a reset state.

Here, in order to be in the state of T ~ 0, a predetermined time ((N-1)X interrupt interval time) is required from the detection of the sudden change in the inter-vehicle distance.
After the lapse of time, it is determined that 7≧ZO holds true and that it is necessary to extend the vehicle speed maintenance (steps 304 and 305).
This is a case where a predetermined time (TX interrupt interval time) has not yet elapsed since this determination. For this reason, step 301
Then, if T=O, there is no need to maintain the vehicle speed, so proceed to step 310 to control the vehicle speed, and if T=0, it is determined that it is within the extended time for maintaining the vehicle speed, and the contents of the count register T are decremented. After that, it enters a standby state for the next interrupt processing (step 302).

Proceeding to step 310, the difference ΔD between the current inter-vehicle distance Dn and the safe inter-vehicle distance Do is calculated, and if the absolute value of the difference ΔD is 1 m or less and a negative value, that is, the own vehicle is in front of the preceding vehicle. If the vehicle is approaching beyond the vehicle distance (Do -1), the deceleration rate Δθ is set to a set value (for example, -3°) and the process proceeds to step 400 (steps 310 to 3), which will be described later.
40).

On the other hand, in the determination at step 330, if ΔD>0 holds true, that is, the inter-vehicle distance to the preceding vehicle is (Do+1
), the difference (speed deviation) ΔS between the host vehicle speed S and the set vehicle speed So is calculated (step 350).
, the speed deviation ΔS is a constant speed (for example, 5 km/ll
) or above, or whether the absolute value of the speed deviation ΔS is above a predetermined speed (for example, 0.5 kn+/h). If it is determined in this judgment that ΔS≧5 km/h, that is, the distance to the preceding vehicle is at least (Do+1) and the own vehicle speed S is at least 5 km/h slower than the set vehicle speed So. In some cases, in order to accelerate the own vehicle at a constant acceleration rate, the acceleration rate Δθ is kept constant (for example, 2°) and the process proceeds to step 400 (steps 350 to 370), which will be described later.
If △S l ≧0.5km/h holds, that is,
When the inter-vehicle distance to the preceding vehicle is (Do+1) or more and the speed deviation △S is in the range of 0.5 ki/h≦△S≦5 ka+/h, a value proportional to the deviation speed △S (e.g. 3ΔS) is calculated as the acceleration rate Δθ, and the process proceeds to step 400, which will be described later (steps 380 and 390). Note that if 1ΔD1≦1m1 is established in step 320 and 1ΔS I <0.5km/h is established in step 380, that is, if the inter-vehicle distance to the preceding vehicle is within (Do±1m), and the own vehicle speed S is set. If the vehicle speed is within the constant vehicle speed range (0, 51 v/l+) with respect to the vehicle speed SO, there is no particular need to control the vehicle speed, and the process ends.

Proceeding to Step 100, step 340.
In order to control the vehicle speed at the acceleration rate or deceleration rate determined by either 370 or 390, the current throttle valve opening θ
From the detection results, the target throttle valve opening θ0
is calculated using the following formula (steps 400, 410).

θo=0+Δθ Then, in order to set the opening of the throttle valve to the target opening θ0 based on this calculation result, the process proceeds to the throttle valve opening control process as shown in FIG. 7, and the throttle valve avoids rotation of the connecting rod. If the previously set value Δθ is positive r, that is, if the value Δθ satisfies the acceleration rate, the motor constituting the opening control means 13 is rotated in the forward direction to widen the openings of the throwers 1 to 1. , if it is negative, that is, if the 〇 indicates the deceleration rate, the throttle valve is rotated in the opposite direction to narrow the opening, and the opening θ of the throttle valve becomes the target opening 0.
When the angle θT with respect to 0 is exceeded, the motor drive is stopped and the current interrupt processing is terminated (step 4).
20 and steps 500-550).

Further, in the embodiment, the holding time is reset when the steering angle is equal to or greater than a predetermined angle, but it goes without saying that the holding time may be determined continuously according to the steering angle.

[Effects of the Invention] As explained above, according to the present invention, the distance between the vehicle in front and the vehicle in front is detected, and the speed of the own vehicle is controlled according to the distance between the vehicles in front, so that the vehicle can move toward the vehicle in front while maintaining a safe distance between the vehicles in front. In an automatic tracking device, when the distance between vehicles suddenly changes, the vehicle speed holding time is calculated according to the steering angle at this time, and the vehicle speed holding time is calculated from the end of the rapid change in the following distance. Since the vehicle speed is not controlled, compared to conventional devices that simply detect whether the steering wheel is large or small when traveling on a C-curve road and maintain the vehicle speed, it is possible to suppress the occurrence of unnecessary vehicle speed holding states, thereby ensuring that the vehicle speed is accurately adjusted to the own vehicle speed. Holding control can be performed. As a result, it is possible to prevent a delay in the response of vehicle speed control to the cutting-in vehicle, and also to ensure that the vehicle automatically follows the preceding vehicle even when traveling on a curved road.

[Brief explanation of drawings]

1 and 2 are supplementary explanatory diagrams of conventional vehicle running control, FIG. 3 is a diagram corresponding to claims, FIG. 4 is a block diagram of the configuration of an embodiment of the present invention, and FIGS. FIG. 4 is an operation flowchart diagram of FIG. 4; (Represents the main parts of the figure (explanation of symbols) 1... Inter-vehicle distance detection device 3... Vehicle speed detection means 5... Steering angle detection means 7...
・Distance change detection means 9...Safe inter-vehicle distance calculation means 11...Acceleration/deceleration rate control means 13...Thrower valve opening control means 15...
Vehicle speed maintenance command means

Claims (1)

[Scope of Claims] Inter-vehicle distance detection means for detecting the inter-vehicle distance between the own vehicle and the preceding vehicle, vehicle speed detection means for detecting the own vehicle speed, and safe inter-vehicle distance calculation for calculating the safe inter-vehicle distance according to the own vehicle speed. means and
Acceleration/deceleration rate control means calculates an acceleration rate or deceleration rate to adjust the own vehicle speed so that the following distance matches the safe following distance; A vehicle running control device having a throttle valve opening degree control means for changing an opening degree, a steering angle detection means for detecting a steering angle of a steering wheel, and a steering angle detection means for detecting a change in an inter-vehicle distance reaching a predetermined value. When the sudden distance change signal is input, the distance change detection means outputs a sudden distance change signal, calculates the vehicle speed holding time according to the steering angle when the sudden distance change signal is input, and calculates the vehicle speed hold command signal after the input of the sudden distance change signal is completed. 1. A vehicle running control device comprising: a vehicle speed maintenance command means for outputting a vehicle speed maintenance command to the acceleration/deceleration rate control means for a vehicle speed maintenance time corresponding to the vehicle speed.