JPH10227855A - Apparatus and method for sensing of abnormal operation in side collision alarm system of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense the abnormal operation of an ultrasonic sensor without adding a component by a method wherein two kinds of reference voltage waveforms are generated alternately at constant time intervals by one reference voltage generator. SOLUTION: When an ultrasonic sensor is disconnected, an exciting waveform from a point of time T2 to a point of time T3 in Fig. (a) does not exist. Consequently, a detection received signal becomes a waveform as shown in Fig. (c), and it is input to the inverting terminal of a comparator. On the other hand, by means of a microprocessor, a reference voltage generator inputs a waveform whose time is shorter than that of a reference voltage waveform from a point of time T1 to a point of time T4 and which is a waveform from the point of time T1 to the point of time T2 in Fig. (b) is input to the noninverting terminal of the comparator at constant time intervals. At this time, when the output waveform of the comparator at the point of time T3 is in a low-level state as shown in Fig. (e), it is judged that the exciting waveform exists normally. However, when the output waveform at the point of time T3 is in a high-level state as shown in Fig. (d), it is judged that the exciting waveform does not exist and that the sensor is not operated normally, and an alarm is issued. Consequently, the abnormal operation of a system can be sensed without adding a component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for detecting an abnormal operation of a side collision warning system of a vehicle, and more particularly to a collision prevention warning system using an ultrasonic sensor without adding another component. The present invention relates to a device and a method for detecting an abnormal operation of a vehicle side collision warning system capable of detecting an abnormal operation such as disconnection or malfunction of an acoustic wave sensor.

[0002]

2. Description of the Related Art Generally, a side collision warning system for a vehicle is used to ensure the safety of a vehicle and a driver in a blind spot where the driver's visual field cannot be seen when the traveling lane of the vehicle is changed, parked, or driven. Things.

As shown in FIG. 1, a general vehicle side collision warning system has an ultrasonic sensor 11 for generating ultrasonic waves for detecting an obstacle, an input terminal of the ultrasonic sensor 11, A sensor driving unit 12 connected to drive the ultrasonic sensor 11 and an oscillating unit 1 connected to an input terminal of the sensor driving unit 12 to generate a resonance frequency of 40 KHz
3. a preamplifier 14 connected to an output terminal of the ultrasonic sensor 11 for amplifying an output signal of the ultrasonic sensor 11, a partial region of an amplified signal band connected to an output terminal of the preamplifier 14 A bandpass filter 15 for passing only the signal, a detector 16 connected to the bandpass filter 15 for detecting an output signal of the bandpass filter 15, and a reference voltage to be compared with the output signal of the detector 16 to determine the presence or absence of an obstacle. A reference voltage generator 17 to be generated; a comparator 18 for comparing an output signal of the detector 16 with a voltage signal of the reference voltage generator 17; the oscillating unit 13 and the reference voltage generator 1
7, a microprocessor 19 for receiving the output signal of the comparator 18 to determine the presence or absence of an obstacle, a buzzer 20 for generating an alarm sound when an obstacle is detected, and an alarm lamp 2.
1. Buzzer-2 under the control of the microprocessor 19
0 and an alarm drive unit 22 for driving the alarm lamp 21.

FIG. 2 shows another conventional collision prevention and warning system in which the general vehicle side collision warning system shown in FIG. 1 is further provided with an abnormal state detecting unit 30 for detecting an abnormal state of the system. Show.

First, the operation of the conventional collision prevention alarm system shown in FIG. 1 will be described with reference to FIGS. 3 (a) to 3 (d). It is applied and driven, but T1 to T in FIG.
The waveforms in the two sections are oscillation waveforms generated while the ultrasonic sensor 11 oscillates, and the waveforms in the sections T2 to T3 in FIG. 3A indicate the excitation waveforms generated while the ultrasonic sensor 11 oscillates. FIG. 3B shows the output waveform of the reference voltage generator 17, and FIG. 3C shows the output of the detector 16 after the signal received by the receiver of the ultrasonic sensor 11 is detected by the detector 16. The waveform in the section T1 to T3 is a waveform generated by driving and excitation of the ultrasonic sensor 11, and the waveform in the section T4 is reflected by an obstacle and then received by the receiving unit of the ultrasonic sensor 13. The reflected input signal. FIG. 3D shows an output waveform of the comparison unit 18 in which the output waveform of the reference voltage generator 17 is compared with the input waveform of the detector 16. The presence / absence of an obstacle and the distance between the obstacle and the vehicle are calculated.

The reference voltage (see FIG. 3) generated by the reference voltage generator 17 which is operated in response to a predetermined control signal by the microprocessor 19 is supplied to the other terminal of the comparator 18.
(B)) is applied, and this is applied to the ultrasonic sensor 1
Microprocessor 1
9 outputs the comparison result to the microprocessor 1 to which a predetermined signal is input based on the comparison result from the comparator 18.
9 judges the presence or absence of an obstacle by judging the input signal, and if there is an obstacle, outputs a signal to the alarm drive unit 22 to drive the buzzer 20 and the alarm lamp 21 to cause an obstacle to the user. Let them know if something is present.

However, the conventional system shown in FIG. 1 which performs the above-mentioned operation does not have a means for checking an abnormal state of the system such as a disconnection of the ultrasonic sensor, so that the faulty part in the abnormal state of the system is provided. This could pose a fatal danger to the driver because of possible sensing problems.

In order to improve this, as shown in FIG. 2, an abnormal state detection for detecting that an abnormal state occurs in the system due to disconnection of the ultrasonic sensor 11 and abnormalities of other parts in the configuration of FIG. A part 30 is further provided. The abnormal state detection unit 30 includes a reference voltage generator 31 and a comparator 3
Consists of two.

In the system shown in FIG. 2, when the ultrasonic sensor 11 is disconnected or malfunctions due to other components,
As shown in FIG. 4A, the ultrasonic sensor 11 does not oscillate even if the control signal of the microprocessor 19 is input and the sensor driving unit 12 is driven, so that the interval between T2 and T3 as shown in FIG. In this case, no excitation waveform is generated by driving the ultrasonic sensor 11. At this time, the abnormal state detection unit 3
The second reference voltage generator 31 of 0 outputs a signal as shown in FIG.
2 and the output of the detector 16 is shown in FIG.
Is input to the inverting terminal of the comparator 32.

Accordingly, the output terminal of the comparator 32 becomes low from the time point T3, and the microprocessor 19 determines that the ultrasonic sensor 11 does not operate normally in accordance with the output signal of the comparator 32, and issues an alarm drive. A control signal is output to the buzzer 20 to drive the buzzer 20 and the alarm lamp 21 in a manner different from the normal state, so that the driver can recognize an abnormal state such as disconnection of the ultrasonic sensor 11.

[0011]

However, according to the abnormal operation sensing device of the conventional vehicle side collision warning system shown in FIG. 2 as described above, an abnormal state such as disconnection of an ultrasonic sensor is sensed. Therefore, there is a problem that the system size is increased and the cost is increased by adding an abnormal state detecting unit including a reference voltage generator and a comparator to the existing configuration of FIG. Accordingly, the present invention has been devised in view of the above-described circumstances, and has as its object the purpose of an anti-collision warning system using an ultrasonic sensor, such as disconnection and malfunction of the ultrasonic sensor without adding another component. It is an object of the present invention to provide a device and a method for detecting an abnormal operation of a side collision warning system for a vehicle, which can detect such an abnormal operation.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, an abnormal operation sensing device for a side collision warning system for a vehicle according to the present invention checks the time from when an ultrasonic wave is emitted to when it returns. In the side collision warning system of a vehicle that is to issue a warning when the distance to the obstacle is calculated within a predetermined warning section distance,
One reference voltage generator is provided for generating and emitting a first reference waveform and a second reference waveform to check for an abnormality in the system.

In the method for detecting an abnormal operation of a vehicle side collision warning system according to the present invention, a distance from an obstacle to an obstacle is calculated by checking a time from when an ultrasonic wave is emitted to when it returns. In a vehicle side collision warning system that issues a warning when the distance is within a predetermined warning section distance, (1) an ultrasonic excitation waveform and a reflection waveform corresponding to a normal operation of the system; Generating and launching a first reference waveform to be compared; and (2) intermittently generating and launching a second reference waveform to be compared with an excitation waveform of a corresponding ultrasonic wave when the system malfunctions. , (3)
If the result of the comparison in the step (2) is that the system operates abnormally, the step of warning the abnormal operation is performed.

[0014]

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 5 is a block diagram of a vehicle side collision warning system to which the sensing method according to the present invention is applied.

As shown in FIG. 5, the vehicle side collision warning system of the present invention includes an ultrasonic sensor 33 for generating an ultrasonic wave for detecting an obstacle, and a sensor driving unit for driving the ultrasonic sensor 33. An oscillating unit 35 connected to the sensor driving unit 34 to generate a resonance frequency of 40 KHz;
A preamplifier 36 connected to the output end of the ultrasonic sensor 33 for amplifying an output signal; a bandpass filter 37 connected to the preamplifier 36 and passing only a part of the amplified signal; And a detector 38 for detecting the output signal of the bandpass filter 37 and the detector 3
8, a reference voltage generator 39 for sequentially generating a first reference voltage waveform and a second reference voltage waveform for determining the presence or absence of an obstacle, an output signal of the detector 38 and the reference voltage generator 39. The comparator 40 compares the output signal of the ultrasonic sensor 33 with the output signal of the comparator 40, detects the presence or absence of an obstacle, determines disconnection of the ultrasonic sensor 33, and determines abnormal operation of other components. A microprocessor 41 that outputs a drive signal to operate the ultrasonic sensor 33;
It comprises a buzzer 42 and an alarm lamp 43 for generating an alarm sound when an obstacle is detected and an error of the ultrasonic sensor 33, and an alarm drive unit 44 for driving the buzzer 42 and the alarm lamp 43 under the control of the microprocessor 41. , FIG. 2
Is not required. Further, as compared with the vehicle side collision warning system shown in FIG. 1, only the function of the reference voltage generator is different.

Hereinafter, a method for detecting an abnormal operation of the vehicle side collision warning system according to the present invention having the above-described configuration will be described in detail.

FIGS. 6 (a) to 6 (d) are signal waveform diagrams during normal operation of the vehicle side collision warning system to which the present invention is applied, and FIGS. 7 (a) to 7 (e). FIG. 4 is a signal waveform diagram at the time of an abnormal operation of the vehicle side collision warning system to which the present invention is applied.

First, a case where the side collision warning system operates normally will be described. When the ultrasonic sensor 33 is driven by the sensor driving unit 34, as shown in FIG.
The ultrasonic wave of 0 KHz is oscillated. Here, the waveform in the section T1 to T2 in FIG. 6A is the oscillation waveform of the ultrasonic sensor 33, and the waveform in the section T2 to T3 in FIG. 6 is an excitation waveform of the sound wave sensor 33. If the waveform of FIG. 6A sequentially passes through the preamplifier 36, the bandpass filter 37, and the detector 38, the waveform becomes as shown in FIG. 6C. FIG.
In (c), the waveform in the section from T1 to T4 is the ultrasonic sensor 3
3 is output through a detector 38, and the waveform in the section T5 to T6 is reflected by an obstacle, and the reflected input signal received by the receiving unit of the ultrasonic sensor 33 is output from the detector 38. Is the signal output through The waveform shown in FIG. 6C is thereafter input to the inverting terminal of the comparator 40.

On the other hand, the microprocessor 41 transmits a reference voltage waveform (waveform whose section extends from T1 to T4) as shown in FIG. Input. Here, if the waveform of FIG. 6B and the waveform of FIG. 6C in the section from T1 to T4 are compared, it is understood that the ultrasonic sensor 33 is operating normally. For this reason, the reference voltage generator 39 forms a waveform extending from T1 to T4 in the waveform of FIG.

Next, when the reflected signal Vdet that returns after hitting the object in the waveform of FIG. 6C is input to the inverting terminal of the comparator 18, the reference voltage Vref of FIG.
Since the voltage difference is larger, the comparator 40 inputs a low signal to the microprocessor 41 in that section. When a low signal is input, the microprocessor 41 detects the sensor driving unit 3.
The distance is calculated using the time difference between the time point T1 when the driving signal is driven through the line 4 and the time point T5 when the low signal is input (L
= C * t / 2, where L is distance, c is velocity of ultrasonic wave, t
Indicates the time), and if there is an object within the warning distance section,
The buzzer 42 and the warning lamp 43 are driven through the warning drive unit 44 to warn the driver that there is an obstacle at a short distance behind the driver.

Next, when the ultrasonic sensor 33 is disconnected, the excitation waveform in the section T2 to T3 in FIG. 7A does not exist. Accordingly, the received signal detected through the detector 38 is also input to the inverting terminal of the comparator 40 as a waveform shown in FIG. On the other hand, the microprocessor 41 outputs a waveform (waveform from T1 to T2) having a shorter time than the waveform of FIG. , The abnormal operation of the ultrasonic wave 33 is checked.

More specifically, when the microprocessor 41 generates the reference voltage waveform shown in FIG. 7B, the microprocessor 41 checks the output waveform of the comparator 40 at the time T3. If the output waveform of the detector 40 is in a low level state as shown in FIG. 7 (e), it is determined that the excitation waveform exists normally.

However, if the output waveform of the comparator 18 is at a high level as shown in FIG. 7D at the time T3, it is determined that there is no excitation waveform, that is, it is determined that the ultrasonic sensor 33 is not operating normally. And a buzzer-4 which is different from the method of warning that there is an obstacle in the case of normal operation.
2 and the alarm lamp 43 is driven to notify the driver that the system is abnormal. That is, the microprocessor 41 alternately generates two types of reference voltage waveforms at a fixed time interval in one reference voltage generator, and checks for an abnormality in the system.

[0024]

As described above, according to the method for detecting an abnormal operation of a vehicle side collision warning system according to the present invention, one reference voltage generator can be used without adding another component to the existing configuration. By using the system to detect abnormal operation of the system, costs can be reduced. The present invention is not limited to the above-described embodiment, and can be variously modified and implemented within a range permitted by the technical idea of the present invention.

[Brief description of the drawings]

FIG. 1 is a block diagram of a general vehicle side collision warning system.

FIG. 2 is a block diagram of another conventional alarm system further provided with an abnormal state detection unit for detecting an abnormal state of the system in the general vehicle side collision alarm system shown in FIG. 1; is there.

3 (a) to 3 (d) are signal waveform diagrams of the conventional vehicle side collision warning system shown in FIG. 2 during normal operation.

FIGS. 4A to 4D are signal waveform diagrams at the time of an abnormal operation of the conventional vehicle side collision warning system.

FIG. 5 is a block diagram of a vehicle side collision warning system to which an abnormal operation detection method according to an embodiment of the present invention is applied.

FIGS. 6A to 6D are signal waveform diagrams of a side collision warning system of a vehicle to which the abnormal operation sensing method according to an embodiment of the present invention is applied during normal operation.

FIGS. 7A to 7E are signal waveform diagrams of an abnormal operation of a side collision warning system for a vehicle to which an abnormal operation detection method according to an embodiment of the present invention is applied.

[Explanation of symbols]

 Reference Signs List 30 abnormal state detecting unit 31 reference voltage generator 32 comparator 33 ultrasonic sensor 34 sensor driving unit 35 oscillation unit 36 preamplifier 37 bandpass filter 38 detector 39 reference voltage generator 41 microprocessor 42 buzzer 44 alarm driving unit

Claims (6)

[Claims] 1. A distance from an obstacle to an obstacle is calculated by checking a time from when an ultrasonic wave is emitted to when the ultrasonic wave returns, and an alarm is issued when the distance from the obstacle is within a predetermined alarm section distance. The vehicle side collision warning system according to the above, further comprising one reference voltage generator for generating and firing the first reference waveform and the second reference waveform to check whether the system is abnormal. Abnormal operation detection device of side collision warning system. 2. The method according to claim 1, wherein the first reference waveform of the reference voltage generator is generated when the system operates normally, and the second reference waveform is generated intermittently to judge whether the system is abnormal. An abnormal operation sensing device for a vehicle side collision warning system according to claim 1. 3. The apparatus as claimed in claim 1, wherein the second reference waveform of the reference voltage generator has a shorter period than the first reference waveform. . 4. The distance from the emission of the ultrasonic wave to the return is checked to calculate the distance to the obstacle, and an alarm is issued when the distance to the obstacle is within a predetermined alarm section distance. (1) generating and launching a first reference waveform that is compared with an excitation waveform and a reflected waveform of an ultrasonic wave corresponding to a normal operation of the system; (2) when the system operates abnormally, a step of intermittently generating and emitting a second reference waveform to be compared with the excitation waveform of the corresponding ultrasonic wave; and (3) a result of the comparison in the step (2). A method for detecting an abnormal operation of a side collision alarm system for a vehicle, comprising a step of alarming the abnormal operation when the abnormal operation is performed. 5. The system according to claim 4, wherein the first reference waveform is generated when the system is operated normally, and the second reference waveform is generated intermittently to judge whether the system is abnormal. A method for detecting an abnormal operation of the side collision warning system for a vehicle according to the above. 6. The method as claimed in claim 4, wherein the second reference waveform has a shorter period than the first reference waveform.