JPH0512170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a vehicle alarm system that detects that the driver is not awake, such as when falling asleep, and issues a warning to the driver.

[Background technology]

Conventional devices of this type have been developed based on driver responsiveness,
It is possible to detect whether a driver is not awake by testing the accuracy of the vehicle before starting driving, or by equipping the driver with a measuring device connected to measuring electrodes.

However, with the above-mentioned device, there is an inconvenience in using the device that the driver cannot start driving immediately because a test must be conducted in advance before starting operation, and the driver must connect measurement electrodes and wear a measuring device. Ta.

Another problem was that some drivers felt uncomfortable using the device.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a vehicle warning device that can be easily used by a driver.

[Structure of the invention]

In order to achieve the above object, the present invention includes a steering angle detector that detects a steering angle, a high frequency component of a steering angle detection signal, and a steering monitoring value obtained from the high frequency component within a predetermined monitoring period. The vehicle includes an alarm signal generation circuit that generates an alarm signal when the determined monitoring reference value is exceeded, and an alarm device that issues an alarm to the driver using the alarm signal.

The alarm signal generation circuit generates an integral value obtained by integrating the absolute value of the high frequency component of the steering angle detection signal or an integral value obtained by integrating the absolute value of the differential high frequency component obtained by differentiating the steering angle detection signal. As the monitoring value, the monitoring reference value may be determined based on an average value of the integral values and a standard deviation value of the integral values, which are continuously determined when the vehicle starts driving.

Further, the alarm signal generation circuit calculates the frequency of occurrence of the high frequency component or the frequency of occurrence of a differential high frequency component obtained by differentiating the high frequency component for each preset range, and multiplies the frequency of occurrence for each range by a weighting coefficient. The monitoring value is the integrated value obtained by integrating the frequencies of each occurrence, and the monitoring reference value is determined based on the average value of the integrated values continuously obtained at the start of operation and the standard deviation value of the integrated value. It's okay.

[Effect]

A driver performs steering to correct the direction of the vehicle depending on the shape of the road, such as unevenness (undulations) of the road, and steering to ensure the directionality of the vehicle.

When the steering state of the vehicle is detected by detecting the steering angle, the low frequency component of the signal obtained by detecting the steering angle is caused by a signal detected according to the shape of the road and the like.

Therefore, when attempting to determine the driver's wakefulness state by detecting the steering angle, the low frequency components of the detected signal become noise. As a result, it may be erroneously determined whether or not the person is awake. Therefore, high frequency components are extracted from the signal that detects the steering angle, and S/
It is necessary to improve N.

On the other hand, among the high-frequency components of the detected signals, the signals due to fine steering below a certain steering angle are large when the driver is in an alert state, and therefore, this fine steering decreases when the driver is not in an alert state. do. When the driver is not in an alert state, such fine steering is rare, so the direction of the vehicle fluctuates greatly due to external factors such as crosswinds and road undulations that are applied to the vehicle. In order to correct this, the driver has to make a quick and large correction maneuver on the steering wheel. The signal detected when the steering is fast and the corrective steering is large becomes a high frequency component with a large absolute value.

Therefore, in the present invention, a steering angle is detected by a steering angle detector, and a high frequency component is extracted from a steering angle detection signal detected by an alarm signal generation circuit. Further, the alarm signal generation circuit obtains a monitoring value from high frequency components within a predetermined monitoring period, and generates an alarm signal when the obtained monitoring value exceeds a predetermined monitoring reference value. This alarm signal causes the alarm to give a warning to the driver. In this way, by determining the driver's wakefulness based on the high frequency component of the steering angle detection signal, a warning is not given when the driver is awake and driving normally.
An alert will be given only if the person is not awake.

The monitoring value in the above alarm signal generation circuit is obtained by integrating the absolute value of the high frequency component of the steering angle detection signal or by integrating the absolute value of the differential high frequency component obtained by differentiating the steering angle detection signal. It may also be an integral value. Furthermore, the monitoring reference value is based on the average value of the integral values continuously obtained at the start of vehicle operation and the standard deviation value of the integral values, for example, by adding the average value and the standard deviation value doubled. It can be found by By determining the monitoring value and the monitoring reference value in this manner, a signal with less noise can be used to determine whether the driver is awake.

In addition, the monitoring value is obtained by calculating the occurrence frequency of high frequency components or the differential occurrence frequency of high frequency components obtained by differentiating the high frequency components for each preset range, and multiplying the occurrence frequency of each range by a weighting coefficient. It may also be an integrated value obtained by Also,
The monitoring reference value is determined by, for example, adding the average value and the standard deviation value doubled, based on the average value of the integrated values and the standard deviation value of the integrated values continuously determined at the start of operation. You can also ask for it.

As described above, by determining the monitoring reference value at the start of driving, the wakefulness state can be determined in a way that is suitable for the driver, without causing individual differences between drivers.

[Embodiments of the invention]

Embodiments of the apparatus according to the present invention will be described below based on the drawings.

In FIG. 1, a gear 14 is fitted onto the steering shaft 12 of a steering wheel 10, and a gear 16 is driven by the gear 14.
This gear 16 is attached to a detection shaft of a steering angle detector 18, and therefore, this detection shaft is driven in response to steering operation.

In FIG. 2, the steering angle detector 18 is constructed by connecting a variable resistor 20 to a battery 22, and the variable resistor 20 generates a voltage corresponding to the steering angle by driving the detection shaft. A detection signal 100 is generated.

The steering angle detection signal 100 is supplied to the alarm signal generation circuit 24 shown in FIG.
4 determines whether or not the driver is awake by monitoring the steering angle detection signal 100, and sends an alarm signal 10 to the alarm 26 when the driver is not awake.
Supply 2.

The above-mentioned alarm signal generation circuit 24 of this embodiment is mainly composed of a microcomputer.
In FIG. 3, the configuration is shown divided into blocks according to their functions.

The alarm signal generating circuit 24 includes a first arithmetic circuit 2
8 and a second arithmetic circuit 30 are provided, and the steering angle detection signal 100 of the steering angle detector 18 is supplied to these, respectively.

The first calculation circuit 28 extracts the high frequency component 104 (not shown in FIG. 3) from the steering angle detection signal 100, and extracts the high frequency component absolute value 106 (the third
(not shown in the figure) integral value 108
is determined as a monitoring value.

This integral value 108 is supplied to a comparison circuit 32, and the comparison circuit 32 compares the integral value 108 with a monitoring reference value 110, which will be described later, to obtain a deviation 112 of the integral value 108 with respect to the monitoring reference value 110. 1 determination circuit 34.

Then, the first determination circuit 34 determines whether or not the integral value 108 exceeds the monitoring reference value 110 by determining the magnitude of the deviation 112.
When it is determined that the value exceeds the monitoring reference value 110, an alarm signal 114 is generated.

In this way, the alarm signal generation circuit 24 of this embodiment extracts the high frequency component 104 from the steering angle detection signal 100, and when the integral value 108 of the absolute value of the high frequency component 106 exceeds the monitoring reference value 110 within the predetermined monitoring period t. An alarm signal 114 is generated.

Here, the monitoring reference value 110 is supplied from the monitoring reference value storage circuit 36 to the comparison circuit 32, and the monitoring reference value 110 obtained by the second calculation circuit 30 is supplied to this monitoring reference value storage circuit 36. .

This second arithmetic circuit 30 includes the first arithmetic circuit 2
Continuously perform the calculation operation similar to step 8 only at the start of operation, calculate the average value and standard deviation value of the integral value 108 continuously obtained during the continuous calculation operation period T, and double this average value. The monitoring reference value 11 is determined by adding the standard deviation value
Find 0.

In this way, the alarm signal generating circuit 24 of this embodiment generates the integral value 10 continuously obtained at the start of driving of the vehicle.
The monitoring reference value 110 is determined based on 8.

As a result, in this embodiment, the monitoring reference value 110 is determined from the steering angle detection signal 100 at the start of driving.
Thereafter, this monitoring reference value 110 is compared with the integral value 108 determined by the first arithmetic circuit 28, and when the integral value 108 exceeds the monitoring reference value 110, an alarm signal 114 is generated.

In FIG. 3, the alarm signal 114 generated in the first determination circuit 34 in this manner
is fed to one AND input of .

This AND circuit 38 is for stopping the erroneous generation of the alarm signal 102, and for this purpose, the judgment signal 116 is supplied from the second judgment circuit 40 to the other AND input of the AND circuit 38.

The second determination circuit 40 includes the steering angle detector 1
A steering angle detection signal 100 is supplied from 8, a vehicle speed detection signal 118 from a vehicle speed detector 42, a shift lever operation detection signal 120 from a shift lever operation detector 44, and a brake operation detection signal 122 from a brake operation detector 46.

The second determination circuit 40 uses these steering angle detection signals 10.
0, the vehicle speed detection signal 118, shift lever operation detection signal 120, and brake operation detection signal 122 indicate that the steering angle is not greater than the set angle, there is no brake operation, the vehicle speed does not change by more than the set value, and the shift lever is The determination signal 116 is supplied to the AND circuit 38 when there is no operation, and is not supplied in other cases.

The AND circuit 38 outputs the alarm signal 116 only when the judgment signal 116 is supplied from the second judgment circuit 40.
is supplied to the alarm device 26 as an alarm signal 102, and the alarm device 26 uses this alarm signal 102 to give an alarm consisting of an alarm sound and an alarm light to the driver.

In this way, even if the alarm signal generation circuit 24 of this embodiment determines that the driver is not in an awake state by monitoring the steering operation and generates the alarm signal 114, when the steering wheel is turned at a angle greater than or equal to the set angle. , when there is a change in vehicle speed greater than a predetermined value, when there is a shift lever operation, or when there is a brake operation, the warning signal 1 is issued despite this determination.
02 is not supplied to the alarm 26. Therefore, the warning issued to the driver up to that point is stopped.

The operation of this embodiment will be further explained below with reference to a flowchart.

When the engine is started in step 200 of FIG. 4, it is determined in step 202 whether the monitoring reference value storage circuit 36 has been cleared.

In this step 202, the monitoring reference value storage circuit 36
If it is determined that the reference value storage circuit 36 is not cleared, the monitoring reference value storage circuit 36 is cleared in step 204 and the process proceeds to step 206, where each internal circuit is enabled.

In this manner, the monitoring reference value storage circuit 36 is cleared and each internal circuit is started at the same time as the engine is started.

Thereafter, at step 208 in FIG. 5, measurement of the steering angle detection signal 100 is immediately started.

Then, in step 210, it is determined whether or not the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36. Here, since the monitoring reference value storage circuit 36 is cleared at the same time as the operation starts, the monitoring reference value storage circuit 36 is cleared. It is determined that the monitoring reference value 110 is not stored in 36, and the process advances to step 212 in FIG.

In this step 212, the steering angle detection signal 100 measured over the continuous calculation period T is read every time t.

Furthermore, the high frequency component 104 of the steering angle detection signal 100 is extracted by the processing in steps 214 and 216.

That is, in step 214, step 2
The steering angle detection signal 100 in FIG. 7 read in at step 12
Only the low frequency component 124 is extracted, and its waveform becomes as shown in FIG.

Further, in step 216, the low frequency component 124 is subtracted from the steering angle detection signal 100, and the high frequency component 104 is extracted from the steering angle detection signal 100, and its waveform becomes as shown in FIG.

Also, in the next step 218, step 2
The absolute value 106 of the high frequency component of the high frequency component 104 obtained in step 16 is determined, and its waveform becomes as shown in FIG.

Further, in step 220, the high frequency component absolute value 106 obtained in step 218 is time-integrated every monitoring period t, as shown in FIG. 11, and the integral value 108 is continuously obtained.

In this way, the alarm signal generation circuit 24 of this embodiment extracts the high frequency component 104 from the steering angle detection signal 100, and the absolute value of the high frequency component 104 within the monitoring period t.
The integral value 108 of 6 is continuously calculated over a continuous calculation operation period T from immediately after the start of operation.

Then, in step 222, the alarm signal generating circuit 24 of this embodiment calculates the average value and standard deviation value of the integral values 108 continuously determined in step 220.

Further, in step 224, the average value and the doubled standard deviation value are added to obtain the monitoring reference value 110, and the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36.

In this way, in this embodiment, the integral value 10 is continuously determined during the predetermined period T immediately after the start of operation.
The monitoring reference value 110 is obtained from 8.

In other words, in this embodiment, since it is empirically understood that the driver is in an awake state immediately after starting driving, the monitoring standard is used to determine whether or not the driver is in an awake state by monitoring the steering operation. The value 110 can be obtained from the steering angle detection signal 100 measured within a predetermined period T immediately after the start of driving.

When the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36 in this manner, the step 208
After the steering angle detection signal 100 is measured in step 210, the process returns to step 210.

In step 210, since the monitoring reference value 110 has already been stored in the monitoring reference value storage circuit 36,
An affirmative determination is made and the process advances to step 226.

In step 226, the steering angle detection signal 100 is read during the monitoring period t, and in step 228, its low frequency component 124 is extracted.

Furthermore, in step 230, the low frequency component 124 obtained in step 228 is subtracted from the steering angle detection signal 100 read in step 226 to obtain the high frequency component 104.

Further, in step 232, the absolute value 106 of the high frequency component 104 is determined, and in step 234, the high frequency component absolute value 106 is time-integrated to determine the integral value 108.

Then, in step 236, step 23
The integral value 108 obtained in step 4 is compared with the monitoring reference value 110 read from the monitoring reference value storage circuit 36, and it is determined in step 238 whether the integral value 108 is larger than the monitoring reference value 110.

If it is determined in this step 238 that the integral value 108 does not exceed the monitoring reference value 110,
Return to step 208 and repeat the above process.
No alarm will be issued.

In other words, in this device, the integral value 108 is the monitoring reference value 1.
If it does not exceed 10, it is determined that the driver is awake, and no warning is given to the driver.

Also, in step 238, the integral value 108
If it is determined that is greater than the monitoring reference value 110, the device determines that the driver is not awake and proceeds to step 240, where a warning signal 114 is issued.

This alarm signal 114 (ie, alarm signal 102) causes the alarm 26 to provide a warning to the driver.

Next, the process shown in FIG. 12 is started, and in step 244 of the same figure, it is determined whether or not the brake is operated, and in step 2
In step 46, whether or not the shift lever is operated, step 24
In step 8, it is determined whether the vehicle speed has changed by more than a set value, and in step 250, it is determined whether or not there has been a change in the steering angle by more than the set angle.

These steps 244, 246, 248, 2
If all 50 results are negative, the process proceeds to step 252, where an alarm is issued again, and the process returns to step 244.

Also, these steps 244, 246, 248,
If any one of 250 is determined to be affirmative, the process advances to step 254, and the alarm is canceled.

In other words, in this embodiment, when it is determined that the driver is not in an alert state, the presence or absence of brake operation, the presence or absence of shift lever operation, the presence or absence of a change in vehicle speed greater than a set value, and the presence or absence of a change in steering angle greater than a set value are determined. The presence or absence of the driver is monitored, and if it is determined that there are no changes in these operations, it is determined that the driver is not yet awake, and a warning is repeatedly given.

Also, when there is a brake operation, a shift lever operation, a change greater than the set value, or a change in the steering angle greater than the set angle,
It is determined that the driver is awake, and the generation of the warning is stopped.

When the alarm is canceled in step 254, the process proceeds to step 256 in FIG. 13, where it is determined whether the vehicle is stopped.

If it is determined in step 256 that the vehicle is not stopped, the vehicle continues to be driven, so the process returns to step 208 in FIG. 5 and the above process is repeated.

If it is determined in step 256 that the vehicle is stopped, the program proceeds to step 258 where it is determined whether the engine is stopped.

If it is determined in step 258 that the engine has not stopped, the apparatus determines that operation is continued, and the process returns to step 256.

If it is determined in step 258 that the engine is stopped, the apparatus determines that the operation has ended, and in step 260 the monitoring reference value storage circuit 36 is cleared and the process is terminated.

As explained above, according to this embodiment, it is determined whether or not the driver is awake by monitoring the steering operation, so it is tested whether the driver is awake or not before driving the vehicle. There is no need to attach measuring electrodes, measuring instruments, etc. to the body, and operation can therefore be started immediately, which is extremely suitable for the use of the device.

Furthermore, since there is no need to wear electrodes, measuring instruments, etc., the driver does not feel uncomfortable.
Therefore, it is possible to promote the use of the device.

Furthermore, according to this embodiment, the high frequency component is extracted from the steering angle detection signal, and it is determined that the driver is not in an alert state when the integral value of the absolute value of the high frequency component within a predetermined monitoring period exceeds the monitoring reference value. is carried out, it is possible to reliably detect that the driver is not in an alert state without error.

Furthermore, according to this embodiment, a reference value (monitoring reference value) for determining whether or not the driver is in an alert state is generated every time the vehicle starts driving. It is possible to always make constant and stable judgments regardless of the state.

According to this embodiment, even if it is determined that the driver is not in an alert state and a warning is issued, the process shown in FIG. The alarm will be stopped when it is confirmed that the
Unnecessary warnings do not cause discomfort to the driver.

In this example, the high frequency component is differentiated, the frequency of occurrence of the differential high frequency component is determined for each preset range, and the frequency of occurrence of the differential high frequency component for each range is multiplied by a weighting coefficient. The monitoring value is the integrated value obtained by integrating the frequency of occurrence of each differential high-frequency component, and the monitoring reference value is determined based on the average value and standard deviation of the integrated values continuously obtained at the start of operation. It is also possible to configure the alarm signal generation circuit similarly.

In this case, it is preferable to modify the flowcharts in FIGS. 5 and 6 as shown in FIGS. 14 and 15, which will be explained next.

If it is determined in step 210 of FIG. 14 that the monitoring reference value 110 is not stored in the monitoring reference value storage circuit 36, in step 212 of FIG.
A steering angle detection signal 100 as shown in FIG. 6 is read, and in step 214 a low frequency component 124 as shown in FIG. 17 is obtained.

Then, in step 216, the low frequency component 124 shown in FIG. 17 is subtracted from the steering angle detection signal 100 shown in FIG. 16 to obtain the high frequency component 104 having a waveform as shown in FIG.

The steps up to this point are the same as in the previous embodiment, but in the next step 260, time differentiation is performed on the high frequency component 104 to obtain a differential high frequency component 126 as shown in FIG.

Furthermore, in step 262, as shown in FIG. 20, each range R1, R2, R3, R4, . . . is preset for the differential high frequency component 126.
The frequency of occurrence of differential high frequency components at Rn is determined.

Further, in step 264, the frequency fn (n=1, 2,
3, 4...) with a weighting coefficient kn (n=1, 2,
3, 4...) are respectively multiplied by the weighting coefficient kn
The frequency of occurrence of each differential high frequency component 126 multiplied by
The score S is obtained by integrating fn.

S=f1×k1+f2×k2+f3×k3+f4×k4+……fn
×kn ...Equation (1) In the above equation, the subscripts 1, 2, 3, 4...n for the frequency f and coefficient k represent the values for each range, and the term for range 0 is ignored. has been done.

The above calculations are performed continuously over the period T for each monitoring period t, and in the next step 266, the average value and standard deviation value of these scores S are determined.

Further, in step 224, the average value and the doubled standard deviation are added to obtain the monitoring reference value 110, and the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36.

When the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36 as described above, it is determined in step 210 that the monitoring reference value 110 is stored in the monitoring reference value storage circuit 36, and steps 212 and 21 are performed.
4, 216, 260, 262, 264 are performed in steps 268, 270, 272, 274,
276 and 278, respectively, and step 278
The score S during the monitoring period t is determined. Note that in step 268, the steering angle detection signal 100 during period t is read.

Further, in step 280, the score S
is treated as a steering monitoring value, and this score S is compared with a monitoring reference value 110.

Then, in step 282, it is determined whether or not the score S is greater than the monitoring reference value 110;
If it is determined that
If it is determined otherwise, the process returns to step 208.

In this way, the high frequency components are differentiated, the frequency of occurrence of the differential high frequency components is determined for each preset range, the frequency of occurrence of the differential high frequency components in each range is multiplied by a weighting coefficient, and each differential high frequency component is multiplied by the weighting coefficient. The alarm signal generating circuit is configured to use the integrated value obtained by integrating the frequency of occurrence as the monitoring value, and to obtain the monitoring reference value based on the average value and standard deviation value of the integrated values continuously obtained at the start of operation. 24
It is also possible to configure this, and with this, the same effects as in the above embodiment can be seen, and it is possible to reliably detect that the driver is not in an alert state.

In addition, the absolute value of the differential high-frequency component is integrated, and this integral value is used to detect a dozing state, and the frequency of occurrence of the high-frequency component for each preset range is calculated, and the frequency of occurrence is integrated. It is also possible to detect a dozing state using the integrated value.

〔Effect of the invention〕

As explained above, according to the present invention, it is determined whether or not the driver is in an awake state based on the high frequency component of the steering angle detection signal, so it is determined without error that the driver is not in an awake state. In addition, there is no need to test whether the driver is awake or not before driving the vehicle, and there is no need to attach measuring electrodes or measuring instruments to the body, so the driver can start driving immediately. be.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the mounting position of the steering angle detector, Figure 2
FIG. 3 is an explanatory diagram of the circuit configuration of the steering angle detector, FIG. 3 is an explanatory diagram of the overall configuration of the device according to the present invention, FIG. 4 is a flowchart diagram illustrating the operation start procedure of the device according to the present invention, and FIG. 6 is a flowchart illustrating the procedure for determining the presence or absence of wakefulness in the apparatus according to the present invention, FIG. 6 is a flowchart illustrating the procedure for generating monitoring standards in the apparatus according to the present invention, and FIG. FIG. 8 is a waveform explanatory diagram of a low frequency signal, FIG. 9 is a waveform explanatory diagram of a high frequency component, FIG. 10 is a waveform explanatory diagram of the absolute value of a high frequency component, and FIG. 11 is a waveform explanatory diagram of the high frequency component absolute value. FIG. 12 is a flowchart illustrating the alarm cancellation processing operation of the device according to the present invention, and FIG. 13 is a diagram illustrating the operation termination procedure of the device according to the present invention. Flowchart diagram for explaining, No. 14
15 is a flowchart illustrating another procedure for determining the presence or absence of wakefulness in the apparatus according to the present invention, FIG. 15 is a flowchart illustrating another monitoring standard generation procedure in the apparatus according to the present invention, and FIG. FIG. 17 is an explanatory diagram of the waveform of the steering angle detection signal. FIG. 17 is an explanatory diagram of the waveform of the low frequency signal. FIG. 18 is an explanatory diagram of the waveform of the high frequency component.
FIG. 20 is an explanatory diagram of the waveform of a differential high-frequency component, and FIG. 20 is an explanatory diagram of the signal processing operation for generating monitoring criteria of the alarm signal generation circuit in the apparatus according to the present invention. 18...Steering angle detector, 24...Alarm signal generation circuit, 26...Alarm device.

Claims (1)

[Scope of Claims] 1. A steering angle detector that detects a steering angle, a high frequency component of the steering angle detection signal is extracted, and a monitoring value of the steering determined from the high frequency component within a predetermined monitoring period is a predetermined monitoring reference value. A vehicle alarm device includes an alarm signal generation circuit that generates an alarm signal when the alarm exceeds the threshold, and an alarm that issues a warning to a driver using the alarm signal. 2. The alarm signal generation circuit generates the integral value obtained by integrating the absolute value of the high frequency component of the steering angle detection signal or the integral value obtained by integrating the absolute value of the differential high frequency component obtained by differentiating the steering angle detection signal. Claim 1, characterized in that the monitoring reference value is determined based on an average value of the integrated values and a standard deviation value of the integrated values, which are used as monitoring values and are continuously obtained when the vehicle starts driving. The vehicle alarm device described. 3. The alarm signal generation circuit calculates the frequency of occurrence of the high frequency component or the frequency of occurrence of a differential high frequency component obtained by differentiating the high frequency component for each preset range, and multiplies the frequency of occurrence for each range by a weighting coefficient. The integrated value obtained by integrating the respective occurrence frequencies is used as the monitoring value, and the monitoring reference value is determined based on the average value of the integrated values continuously obtained at the start of operation and the standard deviation value of the integrated value. A vehicle alarm system according to claim 1, characterized in that: