JPH07257221A - Dozing at the wheel prevention device - Google Patents

Abstract

PURPOSE:To judge dozing at the wheel securely not by correction steering cycle at the time of normal driving when falling asleep at the wheel is detected based on driver's correction steering cycle. CONSTITUTION:Steering angle data and car speed data which are detected by a steering angle sensor 10 and a car speed sensor 12 are supplied to a steering cycle calculating section 14 in an ECU to calculate driver's correction steering cycle at the time of normal driving, and it is stored in a storage section 18. A judging section 16 calculates reference cycle based on the correction steering cycle at the time of normal driving and gain determined in accordance with the correction steering cycle to compare it with the current correction steering cycle. Since gain is set to a smaller value as the correction steering cycle becomes longer, it is possible to judge dozing at the wheel securely even of a driver who provides long correction steering cycle at the time of normal driving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drowsy driving prevention device, and more particularly to a device for detecting drowsy driving from a steering cycle.

[0002]

2. Description of the Related Art Conventionally, various devices have been developed and installed for the purpose of improving the safety of vehicle running, and one of them is a doze driving prevention device that detects a driver's dozing state and issues an alarm. is there.

For example, in the doze driving detection apparatus disclosed in Japanese Unexamined Patent Publication No. 5-58192, the steering angle data for 10 minutes from the start of driving is collected as a reference value for each vehicle speed, and the reference value and the steering data are compared to make a dozing operation. Driving is detected.

[0004]

On the other hand, focusing on the fact that the driver's corrected steering cycle tends to become longer as the driver's consciousness decreases in order to detect a more accurate dozing driving,
A device for determining the dozing state based on the driver's corrected steering cycle has also been proposed. The applicant of the present application also previously filed Japanese Patent Application No. 5-2.
No. 66957 proposed a device for determining the driver's dozing state by calculating the driver's corrected steering period and comparing it with a reference period obtained by multiplying the normal corrected steering period by a predetermined gain.

However, the rate of change in the correction steering cycle of the driver when the consciousness is lowered is not constant, and particularly in the case of a driver whose correction steering cycle during normal times is extremely short or conversely long, Even if the reference period is calculated by multiplying the corrected steering period by a constant gain, there is a problem that it is not possible to accurately determine the dozing state.

That is, in the case of a driver whose correction steering cycle during normal driving is extremely long, the rate of change in the correction steering cycle during normal driving and during drowsy driving is generally small, so that the driver's consciousness actually deteriorates. However, it may be determined that the period is less than or equal to the reference period.

The present invention has been made in view of the above problems of the prior art, and its purpose is to reliably determine the dozing state of the driver and to give an alarm regardless of the driving characteristics of the driver during normal driving. (EN) It is an object to provide a drowsy driving prevention device that can be given to promote awakening.

[0008]

In order to achieve the above object, a drowsy driving prevention apparatus of the present invention comprises a steering angle detecting means and a correction steering for calculating a correction steering cycle of a driver from the detected steering angle data. Cycle calculation means, comparing the calculated correction steering cycle and a reference cycle obtained by multiplying the correction steering cycle during normal operation by a gain, determining means for determining the driver's dozing state, and the gain at normal times. The adjusting means for increasing / decreasing according to the modified steering cycle and the alarming means for giving an alarm when it is determined to be in the dozing state.

[0009]

As described above, in the doze driving prevention apparatus of the present invention, the gain for calculating the reference period is increased or decreased according to the corrected steering period during normal operation. That is, for a driver with a short correction steering cycle during normal operation, the gain is set high and adjusted so that the reference cycle is high. Conversely, for a driver with a long correction steering cycle during normal operation, Adjusts the gain so that the reference period becomes smaller.

As a result, even if the driver has an extremely long correction steering cycle during normal driving, the reference cycle for determining the dozing state is set to be relatively small, so that the correction steering cycle increases as the consciousness decreases. The period is longer than the reference period, and it can be reliably determined that the subject is in a dozing state.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a doze driving prevention apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of the configuration of this embodiment. The steering angle sensor 10 and the vehicle speed sensor 12 are respectively provided at predetermined positions of the vehicle, and sequentially output the detected steering angle data and vehicle speed data as time series data. Steering angle sensor 10 and vehicle speed sensor 12
Is connected to an electronic control unit ECU having a steering cycle calculation unit 14, a determination unit 16, and a storage unit 18, and the detected steering angle data and vehicle speed data are supplied to the steering cycle calculation unit 14 in the ECU. The steering cycle calculation unit 14 calculates a corrected steering cycle by FFT or the like from the input steering angle data. In addition, in order to calculate the corrected steering period, a method may be used in which the steering turning point is obtained and estimated from the turning pattern, or the steering angle data is differentiated to detect the zero point. On the other hand, the vehicle speed data from the vehicle speed sensor 12 is also supplied to the steering cycle calculation unit 14, and the steering cycle calculation unit 14 calculates the corrected steering cycle for each vehicle speed. That is, the corrected steering cycle data in each vehicle speed zone for 10 minutes after the start of operation, which is considered to be sufficient for the driver to wake up and to perform normal operation, is calculated, and the average value of these is used as the final corrected steering cycle. If the corrected steering period is not calculated in all vehicle speed zones, it is converted to the corrected steering period at the standard vehicle speed (for example, 80 km / h) based on, for example, a general tendency of the corrected steering period with respect to the vehicle speed. It is also possible to use a corrected steering cycle during driving. The calculated correction steering cycle is supplied to the storage unit 18 in the ECU.

After the correction steering period of 10 minutes after the start of driving is calculated and stored in the storage unit 18, the steering angle data and the vehicle speed data output from the steering angle sensor 10 and the speed sensor 12 10 minutes after the start of the driving are calculated. Are similarly supplied to the steering cycle calculation unit 14, and the corrected steering cycle is calculated. The calculated corrected steering cycle is output to the determination unit 16. The determination unit 16 compares the input correction steering cycle with the reference cycle, and when the correction steering cycle is greater than the reference cycle, determines that the driver is in a dozing state, and activates the alarm unit 20 to drive the vehicle. Give an alarm to the person.

The characteristic feature of this embodiment is that the determination unit 16 determines the reference period used when determining the dozing state based on the corrected steering period during normal operation stored in the storage unit 18. To do. That is, in the prior art, the reference cycle is determined by multiplying the correction steering cycle during normal operation by a constant gain, but the correction steering cycle during normal operation is extremely short or extremely long. When determining the state, if the gain is uniquely determined in this way, the dozing state cannot be accurately determined. Therefore, in the present embodiment, the gain by which the correction steering cycle during normal operation is multiplied is increased or decreased according to the value of the correction steering cycle during normal operation, and the reference cycle is obtained.

FIG. 2 shows the relationship between the corrected steering period during normal operation and the gain for calculating the reference period. In the figure, the horizontal axis represents the corrected steering period (sec) during normal operation, and the vertical axis represents the gain. As can be seen from the figure, the shorter the modified steering cycle during normal operation, the higher the gain. The determination unit 16 (or the storage unit 18) has such a relationship between the corrected steering cycle and the gain during normal operation as a map or as a functional relationship, and the driver's calculated in 10 minutes after the start of the operation The reference period is calculated by calculating the gain corresponding to the corrected steering period and multiplying the gain by the corrected steering period during normal operation. As a result, it becomes possible to determine the dozing state that matches the steering characteristics of the driver during normal driving, and for example, for a driver whose correction steering cycle is extremely long during normal driving, increase the correction steering cycle due to lowering of consciousness. It is possible to reliably detect and determine the dozing state.

The operation of the ECU will be described in more detail below with reference to the processing flowchart of FIG.

First, the corrected steering cycle characteristic of the driver is learned for x minutes (10 minutes as described above in the present embodiment) after the start of driving, and the average steering cycle is calculated (S101).
This calculation can be performed by detecting the FFT, the turning point, the zero point in the differential waveform of the steering data, or the like, as described above.

Next, a reference period for determining the dozing state is set based on a statistically obtained map showing the relation between the corrected steering period and the gain during normal operation, or a functional relation (S102). The reference period T _TH is determined by T _TH = G · T, where T is the corrected steering period during normal operation and G is the corresponding gain.

Then, the current correction steering cycle is compared with the reference cycle calculated in this way. If the current correction steering cycle is equal to or longer than the reference cycle, the driver's consciousness is lowered and the dozing state is reduced. It is determined that it has occurred, and an alarm is issued (S103, S104). If the driver's normal correction steering cycle is the correction steering cycle at the reference vehicle speed,
It goes without saying that the current correction steering cycle is also converted into the correction steering cycle at the reference vehicle speed and compared in the determination step in S103.

As described above, in this embodiment, the gain for determining the reference period is adjusted to be increased or decreased according to the corrected steering period during normal operation. Therefore, the corrected steering period during normal operation is extremely short or extremely low. Even for drivers who have a habit of driving for a long time, the dozing state can be reliably detected,
It becomes possible to prevent it.

In this embodiment, the relationship between the corrected steering cycle and the gain during normal operation is a linear relationship as shown in FIG. 2, but the gain is shortened as the corrected steering cycle becomes longer. Any structure may be used, and it is possible to appropriately adjust the inclination and the intercept by the driver's manual operation while maintaining the relationship shown in FIG. 2. In this case, it is more suitable for the driver. It is possible to prevent drowsiness.

[0021]

As described above, according to the doze-driving prevention device of the present invention, the driver's drowsy driving can be reliably prevented regardless of the driving characteristics in normal times.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the corrected steering cycle and the gain during normal operation in the embodiment of the present invention.

FIG. 3 is a processing flowchart in the embodiment of the present invention.

[Explanation of symbols]

 10 Steering Angle Sensor 12 Vehicle Speed Sensor 14 Steering Cycle Calculation Section 16 Judgment Section 18 Storage Section 20 Warning Section

Claims (1)

[Claims] 1. A steering angle detection means, a correction steering cycle calculation means for calculating a correction steering cycle of a driver from the detected steering angle data, and a gain for the calculated correction steering cycle and the correction steering cycle during normal operation. When a determination is made that the driver's dozing state is determined by comparing with a reference period obtained by multiplying by, an adjusting unit for increasing / decreasing the gain according to the normal correction steering period, and a dozing state. A drowsy driving prevention device, comprising: