JPH06241782A - Rough road judging device - Google Patents

Abstract

PURPOSE:To accurately judge a wave-shape road surface as a rough road by providing a correcting means changing the judging time and threshold value used as rough road judgment references in response the vehicle body deceleration. CONSTITUTION:A wheel acceleration detecting means 1 detects the wheel acceleration. A rough road judging means 2 judges a road as a rough road if the number of times, that the amplitude of the aging change of the detected wheel acceleration exceeds the prescribed rough road judgment threshold value within the prescribed rough road judging time, is the prescribed rough road judgment reference number of times or above. A vehicle body deceleration detecting means 3 detects the vehicle body deceleration. A judgment reference correcting means 4 changes the rough road judgment threshold value, rough road judging time, and rough road judgment reference number of times used as rough road judgment references in response to the vehicle body deceleration detected by the detecting means 3. An accurate rough road judgment can be made for the change of the road surface such as a wave-shape road surface or a gravel road surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bad road judging device for judging whether or not a road surface condition is a bad road.

[0002]

2. Description of the Related Art Conventionally, as a bad road determination device, for example, one disclosed in Japanese Patent Laid-Open No. 3-273967 is known.

In this conventional bad road judging device, the number of times that the amplitude of the temporal change of the wheel acceleration detected by the wheel acceleration detecting means exceeds a predetermined threshold value within a predetermined time is larger than the predetermined number of times threshold value. When the vehicle is not being braked based on the detection signal from the rough road determining means that determines whether the vehicle is on a bad road or not, and the braking / non-braking detection means that determines whether the vehicle is braking. And a threshold value changing means for changing the amplitude threshold value to a value larger than that during non-braking.

[0004]

However, in the above-mentioned conventional bad road judging apparatus, the wheel by braking / non-braking is changed by changing the amplitude threshold value of the wheel acceleration which is the reference of the bad road judgment. This makes it possible to accurately determine rough roads with respect to changes in acceleration amplitude, but when the amplitude of wheel acceleration is large and the fluctuation frequency is high, such as on a large uneven road surface such as a wavy road surface, or on a gravel road surface. When the amplitude of the wheel acceleration is small and the fluctuation frequency is low as in the case of a small uneven road surface, there is a problem that the rough road cannot be accurately determined.

The present invention has been made by paying attention to the conventional problems as described above, and it is possible to accurately judge a bad road even when the road surface such as a corrugated road surface or a gravel road surface changes. The purpose is to provide a device.

[0006]

In order to achieve the above object, a bad road determination device of the present invention comprises a wheel acceleration detecting means for detecting the acceleration of a wheel, and the wheel acceleration detected by the wheel acceleration detecting means over time. If the number of times that the amplitude of change exceeds the predetermined rough road judgment threshold within the predetermined rough road judgment time is equal to or larger than the predetermined rough road judgment reference number of times, the rough road judgment means for judging a bad road and the reduction of the vehicle body Vehicle body deceleration detecting means for detecting a speed, and a bad road determination time, a bad road determination threshold value and a bad road determination serving as a reference for the bad road determination in accordance with the vehicle body deceleration detected by the vehicle body deceleration detecting means. And a criterion correction means for changing the reference number.

[0007]

In the rough road judging device of the present invention, the rough road judging time serving as a rough road judging reference according to the vehicle body deceleration detected by the vehicle body deceleration detecting means in the judging standard correcting means,
The rough road judgment threshold value and the rough road judgment reference number of times are changed.By performing the bad road judgment based on each of the changed judgment reference values, the road surface such as a wavy road surface or a gravel road surface can be changed. Accurate rough road judgment is possible even with changes.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rough road judging apparatus according to an embodiment of the present invention will be described with reference to the drawings. First, FIG. 1 is a block diagram showing a rough road determination device of an embodiment of the present invention. As shown in this figure, a wheel acceleration detecting means 1 for detecting a wheel acceleration GG and a wheel acceleration detecting means 1 for detecting the wheel acceleration GG. If the number of times that the amplitude of the temporal change of the wheel acceleration GG exceeds the predetermined bad road judgment threshold value + α to −α within the predetermined bad road judgment time t is the predetermined bad road judgment reference number n or more, the bad road is judged. Bad road determination means 2 for determining
A vehicle body deceleration detecting means 3 for detecting a vehicle body deceleration G, and a bad road determination threshold + α serving as a reference for the bad road determination according to the vehicle body deceleration G detected by the vehicle body deceleration detecting means 3.
.About .-. Alpha., The rough road judgment time t, and the rough road judgment reference number n are changed.

Next, the operation contents of each of the rough road determination devices will be described.
A description will be given based on the flowchart of FIG.

First, at step 101, it is judged whether or not the vehicle body deceleration G detected by the vehicle body deceleration detecting means 1 is less than or equal to a predetermined value G _S , and if YES, the routine proceeds to step 102, and FIG. As shown in the maps of FIGS. 4 and 5, each rough road determination reference value (+ α, −α, t, n) is corrected and changed according to the value of the vehicle body deceleration G at that time, and then the process proceeds to step 104. On the other hand, if NO, the routine proceeds to step 103, where each rough road determination reference value (+ α, −α, t, n) is set to the standard value, and then the routine proceeds to step 104.

Incidentally, + α is a threshold value for determining a bad road side of the wheel acceleration, −α is a threshold value for determining a bad side of the wheel acceleration,
t is a rough road determination time indicating a reference count time of the number of times that the wheel acceleration exceeds the range of + α to −α, and n is a number of times that the wheel acceleration exceeds the range of + α to −α within the rough road determination time t. The reference number of times of rough road determination showing the reference is shown.

Then, each rough road judgment reference value (+ α, −
The standard values of α, t, n) are set as follows.

+ Α = + 5G, −α = −5G, t = 300 ms, n = 6 Step 104 is a subtraction count (BRT) of the subtraction timer.
Is 0 or more, that is, a step of determining whether or not a rough road is being determined, and if YES, step 1
If the result is NO, the routine proceeds to step 107. If NO, the routine proceeds to step 106, where the control to the good road determination control is performed, and then the routine proceeds to step 107. .

In step 107, the number of times the wheel acceleration GG used for rough road judgment exceeds + αG or falls below -αG, that is, the threshold crossing count (BRC) is equal to or larger than the rough road judgment reference count n. If YES, the process proceeds to step 108, where the wheel acceleration
The GG threshold count (BRC) and the rough road judgment timer timer count (BRCC) are both reset to 0 and the subtraction timer subtraction count (BRT) is set to 85.
After the processing for setting to 0 ms, that is, the processing for starting the rough road control is performed, the process proceeds to step 109, and if NO, the process directly proceeds to step 109. That is, step 108 is a step of extending the control at the time of the rough road determination by 850 ms when the rough road determination is made in step 107.

Step 109 is a step of determining whether or not the timer count (BRCC) of the rough road determination timer has passed the rough road determination time t. If YES, the routine proceeds to step 110, where the threshold crossing count is exceeded. The count (BRC) and the rough road judgment timer timer count (BRCC) are both 0
After resetting to NO, proceed to step 111, and NO
If so, the process directly proceeds to step 111.

Step 111 is a step of judging whether or not the plus side threshold crossing flag + GF of the wheel acceleration GG is set from 0 to 1, and if YES, the routine proceeds to step 112, where the threshold crossing is exceeded. After incrementing the number of times (BRC) by 1, proceed to step 113, and NO
If so, the process directly proceeds to step 113.

Step 113 is a step of determining whether or not the minus side threshold crossing flag -GF of the wheel acceleration GG is set from 0 to 1, and if YES, the routine proceeds to step 114 and the threshold value is set. Overcoming count (BRC)
After adding 1 to step 115, proceed to step 115
If it is O, the process directly proceeds to step 115.

In step 115, the wheel acceleration GG is + αG.
If YES, the routine proceeds to step 116, where the flag GF on the plus side threshold value of the wheel acceleration GG + GF is set to 1 and the minus side threshold value of the wheel acceleration GG is exceeded. After resetting the flag -GF to 0, the process proceeds to step 117, and if NO, the process directly proceeds to step 117.

In step 117, the wheel acceleration GG is -αG.
If it is YES, the routine proceeds to step 118, where the minus side threshold crossover flag -GF of the wheel acceleration GG is set to 1 and the plus side threshold value of the wheel acceleration GG is set. After resetting the excess flag + GF to 0, the process proceeds to step 119, and if NO, the process directly proceeds to step 119.

Step 119 is a step for judging whether or not the threshold crossing count (BRC) is 1 or more. If YES, the routine proceeds to step 120, where the rough road judgment timer timer count (BRCC). After 10 ms is added to step 121, the process proceeds to step 121. If NO, the process directly proceeds to step 121.

Step 121 is a step of subtracting 10 ms from the subtraction count (BRT) of the subtraction timer.

With the above, one flow is completed, and thereafter, the above flow is repeated.

Next, the control operation of the rough road determination device will be described with reference to the time chart of FIG. As shown in this figure, the wheel acceleration GG is a bad road determination threshold value of + 5G to -5G.
When it fluctuates beyond the range of, the threshold crossing count (BRC) is started at the first crossing.
Then, the number of times the threshold value is exceeded (BCC) of the rough road determination timer (BRCC) started from that point until the rough road determination time t = 300 ms elapses (B
RC) exceeds the rough road judgment reference number n = 6, the rough road judgment control is started, and 850 ms, which is the subtraction count (BRT) of the subtraction timer started from that time, elapses. During this period, the control is continued at the time of judging a rough road.

As described above, in the bad road determination device of the embodiment, the bad road determination serving as a reference for the bad road determination is made according to the vehicle body deceleration detected by the vehicle body deceleration detecting means 3. The threshold value + α to −α, the rough road judgment time t, and the rough road judgment reference number n are provided so that the judgment criterion correcting means 4 is provided, so that a change in the road surface such as a corrugated road surface or a gravel road surface can be achieved. Also has a feature that an accurate rough road can be determined.

For example, the control at the time of determining a bad road in step 105 includes control of an anti-skid brake for a vehicle, and at the time of determining a bad road, the control of changing the brake fluid pressure reduction timing or the like is not performed. A road determination device is used.

The embodiment has been described above with reference to the drawings, but the specific structure is not limited to this embodiment, and the present invention can be applied even if there are design changes and the like within the scope not departing from the gist of the present invention. included.

[0027]

As described above, in the rough road determination device of the present invention, the rough road determination serving as a reference for the rough road determination is made according to the vehicle body deceleration detected by the vehicle body deceleration detection means. Equipped with the judgment reference correction means for changing the time, the rough road judgment threshold value and the rough road judgment reference number, it is possible to accurately judge the bad road even when the road surface such as a wavy road surface or a gravel road surface changes. The effect of becoming

[Brief description of drawings]

FIG. 1 is a block diagram showing a rough road determination device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation content of the rough road determination device according to the embodiment of the present invention.

FIG. 3 is a map showing a variable characteristic of a rough road determination threshold value α with respect to a vehicle body deceleration.

FIG. 4 is a map showing variable characteristics of rough road determination time t with respect to vehicle deceleration.

FIG. 5 is a map showing a variable characteristic of a rough road determination reference number n with respect to a vehicle deceleration.

FIG. 6 is a time chart showing the operation contents of the rough road determination device according to the embodiment.

[Explanation of symbols]

 1 Wheel Acceleration Detection Means 2 Bad Road Judgment Means 3 Vehicle Body Deceleration Detection Means 4 Judgment Criteria Correction Means

Claims (1)

[Claims] 1. A wheel acceleration detecting means for detecting acceleration of a wheel, and an amplitude of a change with time of the wheel acceleration detected by the wheel acceleration detecting means is within a predetermined rough road determining time within a predetermined bad road determining threshold value. If the number of times exceeds the predetermined rough road determination reference number of times or more, the road is judged as a bad road, a vehicle deceleration detecting means for detecting the deceleration of the vehicle body, and the vehicle deceleration detecting means. And a judgment reference correction means for changing the rough road judgment time, the rough road judgment threshold value, and the rough road judgment reference number, which serve as a reference for the rough road judgment according to the vehicle deceleration. Bad road determination device.