JP3206390B2 - Arousal level determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wakefulness determination device for determining the wakefulness of a human such as a driver of a vehicle.

[0002]

2. Description of the Related Art When driving for a long time on a highway or the like, fatigue may accumulate in a driver, causing drowsiness and a decrease in concentration. For this reason, conventionally, a vehicle was equipped with a dozing driving warning device, a signal for requesting a response to a driver at a certain time interval, and a decrease in arousal level was determined based on the appropriateness of the response time of the driver, and a warning was issued. is there. However, with this device, when the driver has to concentrate his nerves, such as when driving in a city area or on a curve, or when the arousal level is not reduced, a response may be required, which is troublesome for the driver. . Therefore,
In recent years, a system for judging the magnitude of an estimated awakening degree calculated using vehicle speed information or steering information and a predetermined reference value (threshold) by a judging unit and sounding an alarm is disclosed in Japanese Patent Application Laid-Open No. 60-21352.
No. 8, for example.

[0003]

However, in the above-mentioned alertness estimation system, the estimated alertness is calculated using limited information among the vehicle speed information and the steering information. There was a problem that it occurred. For example,
When driving on rough roads, despite the fact that the driver's awakening degree is actually reduced, the estimated waking degree does not decrease and an alarm is generated due to the reduction of the steering hold time due to the swing of the handle due to the unevenness of the road surface You do it. Although the steering information is used in estimating the arousal level, the arousal level is reduced even when the arousal level is not reduced, when the arousal level is reduced or vice versa. This is because the characteristics may be similar to those in the case where no driver is provided, and the characteristics of the threshold are constant regardless of the driver.

It is an object of the present invention to provide a wakefulness determination device that effectively increases the information on the wakefulness determination and reduces the occurrence of false alarms and false alarms.

[0005]

According to the present invention, there is provided a waking degree determining apparatus for detecting an awakening degree based on a detection signal of a vehicle speed sensor, a steering angle sensor for detecting a steering angle of a vehicle, and a detection signal of the vehicle speed sensor. A vehicle speed change amount detecting means for detecting a vehicle speed change amount during a certain period of time, and an awakening degree determining means for determining a decrease in a driver's awakening degree based on input data obtained from these detecting means. and a warning means for alertness in awareness determination means urging the improvement of alertness with an alarm to the driver when it is determined to be decreased, the objective
The awakening degree determining means is configured to detect the detection signal from the vehicle speed change amount detecting means.
Threshold value corrected based on the vehicle speed, the vehicle speed sensor and the steering
Estimated sense calculated based on detection signals from the angle sensor
It is characterized by comparing with the arousal level .

According to the above construction, based on each input data of the vehicle speed sensor, the steering angle sensor and the vehicle speed change detecting means,
The arousal level determination means detects the vehicle speed change amount from the
A threshold value corrected based on the signal,
Estimation calculated based on the detection signal from the steering angle sensor
By comparing the wakefulness with the wakefulness, a decrease in the wakefulness is determined with higher accuracy by effectively using the conventional sensor, and an alarm is issued when the wakefulness is reduced.

[0007]

[0008]

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the arousal level judging device according to the present invention will be described below in detail with reference to the accompanying drawings. 1 is a block diagram of the arousal level determination device, FIG. 2 is a flowchart for explaining the operation of the device of FIG. 1, FIG. 3 is a flowchart for explaining the operation of the device of FIG. 1, and FIG. FIG. 5 is a diagram showing an example of the time history of the vehicle speed change amount.

As shown in FIG. 1, a traveling speed of a vehicle (hereinafter referred to as a vehicle speed) provided on an output shaft or the like of a transmission (not shown).
A detection signal from a steering angle sensor 2 that is provided on a steering shaft (not shown) and detects a steering angle (a deviation from a steering neutral position) similarly to the vehicle speed sensor 1 that detects the vehicle speed is input to an estimated waking degree calculation unit 4 of the controller 3. You.

The estimated waking degree calculating section 4 calculates a steering time (time during which the steering angle does not change) and an average steering time (movements of the past four steering times) based on a detection signal from the steering angle sensor 2. The signal from the steering time calculating unit 5 for calculating the average is input.

The estimated waking degree calculating section 4 uses the neural network (or fuzzy inference and other control rules) which uses the above-mentioned vehicle speed, steering angle, steering time and average steering time as input information. And outputs the result to the determination unit 7. The estimated arousal level takes a value, for example, from 10 (was high) to 0 (high drowsiness).

The judging section 7 calculates the estimated arousal level from the estimated arousal level calculating section 4 and the threshold calculated by the threshold calculating section 8 from the map as shown in FIG. The threshold value corrected by the signal from the amount calculation unit 6 (see the characteristic of the dashed line in the figure) is compared, and if the estimated arousal level is smaller than these threshold values, an alarm unit such as an alarm buzzer incorporated in the instrument panel An alarm is issued at 9. Further, the determination unit 7 displays the estimated arousal level on a display unit (screen) 10 such as a bar graph incorporated in the instrument panel regardless of the determination result.

The threshold value calculation unit 8 includes a vehicle speed change amount calculation unit 6
When the average vehicle speed change per predetermined time (for example, one second) detected by the signal from the vehicle speed sensor 1 becomes equal to or less than a predetermined value (for example, 0.8 km / h / sec), the threshold value of the map is increased by n times (or a certain numerical value). Is added) to raise the threshold value so that the alarm can easily sound. As can be seen from the example of the time history of the vehicle speed change amount in the experiment of FIG. 5, when driving at a high speed for a long time, the average vehicle speed change amount becomes a certain value (for example, 0.8
Km / h / sec).

Next, the operation procedure of the controller 3 will be described with reference to the flowcharts of FIGS. First,
After reading the steering angle and the vehicle speed in step P1, the process shifts to step P2 to determine whether or not the steering angle has changed.
If NO here, the process proceeds to step P6 after adding the steering time counter in step P3. On the other hand, if yes, the value of the steering time counter is converted to seconds in step P4, and the counter value is cleared to 0 in step P5.
The average of the steering times is calculated by moving average of the steering times.
Here, steps P1 to P5 are calculated every 0.1 second.

Next, at step P7, the vehicle speed is 60 km / h.
It is determined whether or not this is the case, and if not, the estimated arousal level is fixed at 8.0 or more at or above the threshold value in Step P8, and then Step P1
Move to 0. On the other hand, if it is possible, the estimated arousal level is calculated as described above based on the information on the steering time, the average steering time, the vehicle speed, and the steering angle in step P9, and then in step P1.
Then, the average estimated arousal level is calculated by moving average of the estimated arousal level in the past 8 seconds. Here, steps P6 to P9 are calculated every 0.2 seconds.

Next, in step P11, a threshold value is calculated using a map, and then in step P12, the amount of change in vehicle speed is calculated.

Next, in step P13, it is determined whether or not the amount of change in vehicle speed is equal to or less than a predetermined value Va (0.8 km / h / sec).
Move to On the other hand, if no, step P1
Then, it is determined whether the threshold value is equal to or higher than the average estimated arousal level.

If the answer is NO in Step P15, the program shifts to Step P17. On the other hand, if yes, step P16
Then, the process goes to step P17, and the average estimated arousal level is displayed on the screen. Here, step P
The calculation from 10 to step P17 is performed every 0.2 seconds. Thereafter, this operation is repeated.

In the above embodiment, the vehicle speed change amount is used for the threshold value calculation, but may be used for the estimated arousal degree calculation.

[0021]

As described above, according to the present invention, a vehicle speed sensor for detecting a running speed of a vehicle, a steering angle sensor for detecting a steering angle of the vehicle, and a predetermined time based on a detection signal of the vehicle speed sensor. A vehicle speed change amount detecting means for detecting a vehicle speed change amount in the vehicle, and a vigilance degree judging means for judging a decrease in the degree of vigilance of the driver based on input data obtained from these detecting means; and Warning means that alerts the driver when it is determined that the arousal level has decreased, and prompts the driver to improve the arousal level. Can be reduced. In particular, the detection signal from the vehicle speed change amount detecting means
The vehicle speed sensor and the steering angle sensor.
Estimated arousal calculated based on the detection signal from the sensor
By comparing the threshold characteristics with the driving state of the driver
And is suitable.

[0022]

[Brief description of the drawings]

FIG. 1 is a block diagram of an awakening degree determination device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the apparatus of FIG. 1;

FIG. 3 is a flowchart for explaining the operation of the apparatus of FIG. 1;

FIG. 4 is a map showing characteristics of threshold values.

FIG. 5 is a diagram showing an example of a time history of a vehicle speed change amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle speed sensor 2 Steering angle sensor 3 Controller 4 Estimated arousal degree calculation part 5 Steering time calculation part 6 Vehicle speed change amount calculation part 7 Judgment part 8 Threshold value calculation part 9 Alarm part 10 Display part

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-201000 (JP, A) JP-A-60-15230 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 28/06

Claims (1)

(57) [Claims] 1. A vehicle speed sensor for detecting a running speed of a vehicle, a steering angle sensor for detecting a steering angle of the vehicle, and a vehicle speed change amount detecting a vehicle speed change amount for a predetermined time based on a detection signal of the vehicle speed sensor. Means, and a wakefulness determination means for determining a decrease in the wakefulness of the driver based on input data obtained from these detection means, and the wakefulness determination means determines that the wakefulness has decreased. Warning means for issuing a warning to the driver at the time to promote the improvement of the arousal level, wherein the arousal level determination means is provided by the vehicle speed change amount detection means.
A threshold value corrected based on the detection signals,
Calculated based on the detection signals from the sensor and the steering angle sensor.
A wakefulness determination device , which compares the estimated wakefulness with the estimated wakefulness .