KR960007327B1 - Collision preventing device and method - Google Patents

Abstract

In a collision preventing device using ultrasonic wave, with an ultrawave generating circuit, an ultrasonic receiving circuit, a central processing unit, and an alarm device, including an ultrawave generating circuit, an ultrasonic wave generating clock part, an ultrawave control signal part, an ultrasonic generation sensor, an ultrasonic wave receiving part, a first amplifying part, a bandpass filter, a second amplifying part, a detecting circuit part, a comparing circuit part, a reference time operating circuit part, a time comparator, and a signal control/processing part.

Description

Vehicle collision prevention device and method using ultrasonic wave

1 is an exemplary view of the blind spot of the vehicle side back mirror,

2 is an overall configuration diagram of the present invention,

3 is a detailed configuration diagram of the ultrasonic transmitting circuit unit of the present invention,

4 is a detailed configuration diagram of the ultrasonic transmitting circuit unit of the present invention,

5 is a signal loss timing diagram of the present invention,

6 is an operational flowchart of the present invention;

7 is a noise generation path diagram.

* Explanation of symbols for main parts of the drawings

10: ultrasonic transmission circuit unit 11: ultrasonic transmission clock unit

12: ultrasonic control signal unit 13: ultrasonic transmission sensor unit

20: ultrasonic receiving circuit portion 21: ultrasonic receiving sensor portion

22: first amplifier 23: band pass filter

24: second amplifier 25: detection circuit

26: comparison circuit portion 27: reference time operation circuit portion

28: time comparison unit 29: signal adjustment and processing unit

30: central processing unit 40: alarm unit

The present invention relates to an apparatus and method for preventing a vehicle collision using ultrasonic waves, by attaching an ultrasonic sensor to a rear surface of a vehicle, and informing a driver of the distance detected by the ultrasonic sensor so that the vehicle can serve as an auxiliary role for the blind spot behind the vehicle. In particular, the present invention relates to an apparatus and a method for changing a minimum detection distance and a maximum detection distance of the present invention by varying the length of an ultrasonic transmission signal.

Accidents in automobiles are directly related to the lives of drivers and passengers, so car accidents are a serious problem behind the convenience of automobiles. Therefore, various safety equipments are being developed for automobile accidents, which are intended to save lives in the event of an accident. However, the risk of accidents may be reduced, but there is no function to prevent accidents.

In a conventional vehicle, side back mirrors are used on the left and right sides of the vehicle to determine the situation of the side and rear of the vehicle. In general, the side back mirror of the vehicle is a side view when viewed from the driver's seat, as shown in FIG. Since there are blind spots that are not identified by the rearview mirror, drivers must turn their heads to check the blind spots in the case of lane changes. There was a problem in that the side back mirror was hard to see.

The present invention for solving the conventional problems as described above by attaching an ultrasonic transmitting sensor and a receiving sensor to the rear of the vehicle to inform the driver of the distance detected by the ultrasonic sensor to serve as a secondary role for the rear blind spot and In particular, the detection distance can be varied by varying the length of the ultrasonic transmission signal.

That is, in the case of a system in which the length of the ultrasonic transmission signal is fixed, the minimum detection distance is fixed, but the present invention changes the minimum detection distance and the maximum detection distance within a short time by periodically changing the length of the ultrasonic transmission signal. will be.

When described in detail with reference to the drawings as follows.

2 is a block diagram of the present invention, which generates a clock to drive ultrasonic waves and transmits ultrasonic waves toward an object, and an ultrasonic transmitting circuit unit 10 that receives the reflected ultrasonic waves hitting an object and processes the received ultrasonic waves to a center. Ultrasonic receiving circuit unit 20 output to processing unit 30, central processing unit for controlling the entire operation of the ultrasonic transmitting circuit unit 10, ultrasonic receiving circuit unit 20 and the alarm device 40, and the central Alarm device 40 for outputting an alarm when the distance calculated by the processing device 30 is a dangerous distance.

As shown in FIG. 3, the ultrasonic transmitting circuit unit 10 includes an ultrasonic transmitting clock unit 11 for generating a clock for driving the ultrasonic wave, and an ultrasonic wave outputting a control signal for controlling the ultrasonic wave in a transmitting or standby state. The control signal unit 12 and the ultrasonic signal transmitting unit 13 for transmitting or waiting the clock generated by the ultrasonic signal transmitting unit 11 by the control signal of the ultrasonic control signal unit 12.

In addition, as illustrated in FIG. 4, the ultrasonic receiving circuit unit 20 includes an ultrasonic receiving sensor unit 21 and an ultrasonic receiving sensor unit 21 that receive ultrasonic waves transmitted from the ultrasonic transmitting circuit unit 10 and reflected on an object. A first amplifier 22 for amplifying the received signal input from 21, a bandpass filter 23 for removing noise of the signal amplified by the first amplifier 22, and the bandpass filter A second amplifier 24 for amplifying the signal filtered in (23), a detection circuit section 25 for detecting a signal amplified in the second amplifier 24 and making a digital signal, and the detection circuit section 25 Compared to the ultrasonic control signal generated by the ultrasonic transmitting circuit unit 10 and outputs a signal detected by the comparison circuit 26 and the ultrasonic control signal generated by the ultrasonic transmitting circuit unit 10 to operate only for a predetermined time Base time to determine operating time The circuit part 27 and the time comparison part 28 which compares and outputs the signal compared and output by the comparison circuit part 26 with the time set by the reference time operation circuit part 27, and this time comparison part 28 compares. And a signal adjusting / processing unit 29 for adjusting the voltage and the signal so as to process the output signal.

A to f in FIG. 5 are the outgoing signal timing diagram of the present invention, a is an ultrasonic outgoing clock, b is an ultrasonic control signal, c is an output signal of the ultrasonic outgoing sensor, and d and e are output signals of an ultrasonic outgoing sensor whose length is adjusted. And f denotes an output signal of a periodically variable ultrasonic transmitting sensor, and FIG. 6 is an operation flowchart of the present invention.

Hereinafter, the operation of the present invention will be described with reference to FIGS. 5, 6 and 7.

The ultrasonic transmission clock unit 11 of the transmission signal circuit unit 10 generates a periodic oscillation signal at a predetermined frequency suitable for the characteristics of the ultrasonic waves as shown in a of FIG. 5. However, in the ultrasonic system that finds the distance to the object by using the return time to hit the object, the oscillation signal cannot be applied to the ultrasonic oscillation sensor as it is because the ultrasonic wave is transmitted from the transmission sensor 13 in FIG. This is because the ultrasonic signal propagated through the air or other medium toward the ultrasonic receiving sensor 21 is often larger than the signal oscillated by the transmitting sensor and hitting and returning to the object.

For this reason, in general, a method of oscillating for a certain time and not oscillating for a predetermined time is often used. Accordingly, the signal from the oscillation circuit is processed by a logical product with a signal controlled by the processor to generate an output signal of the ultrasonic transmitting sensor as shown in FIG. 5 by the ultrasonic transmitting sensor 13. At this time, the ultrasonic transmitting sensor 13 is oscillated during the time t1, and the signal waits for the signal to return to the object during the time t2.

Here, t1 is the transmission time and t2 is the time to wait until the transmitted signal is received, and this time determines the detectable distance, which is determined by the following equation (Equation 1). do.

At this time, the movement speed of the sound waves in the air is 340m / sec.

Therefore, the waiting time t2 is adjusted to fit the maximum detection distance.

In this case, the ultrasonic receiving circuit unit 20 uses the same signal as b in FIG. 5 generated by the ultrasonic control signal unit 12 of the ultrasonic transmitting circuit unit 10 to make these basic signals for error cancellation. Therefore, during the transmission time t1, the receiving end processes the signal received by the ultrasonic receiving circuit unit 20 to prevent the signal propagating directly from the transmitting end, and during this time, the object cannot be detected. Detection distance.

In addition, since the outgoing power is an area during the outgoing time t1, the longer the length of the t1, the greater the power capable of detecting a long distance object. That is, if the output signal of the ultrasonic transmitting sensor is reduced by t3 as in d of FIG. 5, the minimum detection distance by the distance corresponding to the time t3 is reduced, and when the length is increased as in e in FIG. 5, the distance corresponding to t4 is reduced. Increases the minimum detection distance but increases the maximum detection distance. Therefore, the present invention uses a method of periodically varying the transmission length as in the signal f of FIG. 5, where A1, A2... An is the origination length and B1, B2... Bn is the reception wait time after the ultrasonic transmission. The signal has an improved minimum detection distance in A1 and an improved maximum detection distance in An. After the transmission, the reception wait time is changed to the same length according to the transmission length.

By the combination of these signals, the ultrasonic wave is oscillated, and the signal from which the oscillated signal hits the object and returns is input to the central processing unit 30 by the signal processed by the ultrasonic receiving circuit 20 of FIG. The measurement distance is determined by the following equation (Equation 2).

The reason for dividing by 2 in the above formula (Equation 2) is that the moving distance is actually a round trip distance.

6 is a flowchart illustrating the operation of the present invention, comprising: a first step (S1) which makes the ultrasonic oscillation length the shortest (A1) when first started in an initial step; A second step S2 of determining whether or not an object exists after performing the first step S1; If the object is not detected after performing the second step (S2), the oscillation length is increased by one space (A2 if the oscillation length is A1, A3, etc. if the oscillation length is A2, etc.) by one space from the shortest (A1) to the oscillation length (An). Increasing) the third step S3; A fourth step S4 of determining whether or not an object exists again after performing the third step S3 and entering the sixth step S6 if it is determined that the object exists; If the object is not detected after performing the fourth step (S4), it is determined whether the oscillation length is the maximum (An) .If the oscillation length is the maximum (An), the process returns to the first step (S1), and the maximum (An). Otherwise, the fifth step (S5) to enter the third step (S3) again; When the object is detected after performing the second step S2, it is determined whether or not the distance to the object is a preset dangerous distance, and when it is determined that the distance is not the dangerous distance, the sixth step S6 that enters the fifth step S5. )Wow; If it is determined that the dangerous distance after the sixth step S6 is performed, the alarm device is driven, and the operation of the alarm device is sequentially performed in the order of the seventh step S7 to enter the fifth step S5, and the third step S3. The reception wait time after the ultrasonic transmission is varied from the minimum reception waiting time B1 to the maximum reception waiting time Bn in the same length as the transmission length according to the transmission length.

The present invention configured and operated as described in detail above prevents a dangerous situation by monitoring whether an object exists in a blind spot of the side back mirror while driving a vehicle, and also varies the length of the ultrasonic transmission signal according to the distance of the object. By doing so, the minimum and maximum detection distances can be improved to increase the reliability of the detection distance.

Claims (3)

Ultrasonic transmitting circuit unit 10 which generates a clock to drive ultrasonic waves and transmits ultrasonic waves toward the object, and ultrasonic waves that receive and reflect ultrasonic waves reflected on the object, and process the received ultrasonic waves to output to the central processing unit 30. A receiving circuit section 20; A central processing unit (30) for controlling the overall operation of the ultrasonic transmitting circuit unit (10), the ultrasonic receiving circuit unit (20), and the alarm device (40); And an alarm device (40) for outputting an alarm when the distance calculated by the central processing unit (30) is a dangerous distance; The ultrasonic transmitting circuit unit 10 generates an clock to generate an clock for driving the ultrasonic wave generating unit 11 and the ultrasonic control signal unit 12 for outputting a control signal for controlling the ultrasonic wave in the outgoing or standby state. And an ultrasonic transmitting sensor unit (13) for transmitting or waiting the clock generated by the ultrasonic transmitting clock unit (11) by the control signal of the ultrasonic control signal unit (12); The ultrasonic receiving circuit unit 20 is an ultrasonic receiving sensor unit 21 for receiving the ultrasonic wave transmitted from the ultrasonic transmitting circuit unit 10 to the object and reflected, and to amplify the received signal input from the ultrasonic receiving sensor unit 21 A first amplifying section 22, a band pass filter section 23 for removing noise of the signal amplified by the first amplifying section 22, and amplifying a signal filtered by the band pass filter section 23 A second amplifier 24, a detection circuit section 25 for detecting a signal amplified by the second amplifier section 24 to create a digital signal, and the signal detected by the detection circuit section 25 ultrasonic transmission circuit (10) A comparison circuit unit 26 for comparing and outputting the ultrasonic control signal generated by the control unit; and a reference time operation circuit unit for determining an operation time to operate only for a predetermined time by the ultrasonic control control signal generated by the ultrasonic transmitting circuit 10; 27 and the comparison circuit The time comparison section 28 for comparing and outputting the signal compared and output by the reference time operation circuit section 27 with the predetermined time, and the time comparison section 28 so as to be able to process the signal compared and output. Vehicle collision prevention device using ultrasonic waves, characterized in that consisting of a signal adjusting / processing unit 29 for adjusting the voltage and signal. A first step S1 which makes the ultrasonic oscillation length the shortest A1 when it is first started in the initial step; A second step S2 of determining whether or not an object exists after performing the first step S1; A third step S3 of increasing the oscillation length by one space if the object is not detected after performing the second step S2; A fourth step S4 of determining whether or not an object exists again after performing the third step S3 and entering the sixth step S6 if it is determined that the object exists; If the object is not detected after performing the fourth step (S4), it is determined whether the oscillation length is the maximum (An) .If the oscillation length is the maximum (An), the process returns to the first step (S1), and the maximum (An). Otherwise, the fifth step (S5) to enter the third step (S3) again; When the object is detected after performing the second step S2, it is determined whether or not the distance to the object is a preset dangerous distance, and when it is determined that the distance is not the dangerous distance, the sixth step S6 that enters the fifth step S5. )Wow; If it is determined that the dangerous distance after the sixth step S6 is performed, the warning device is driven, and the vehicle collision is performed sequentially in the order of the seventh step S7 to enter the fifth step S5. Prevention method. The oscillation length of the third step (S3) is increased by one space from the shortest (A1) to the maximum oscillation length (An) of the oscillation length (A1) if the oscillation length is A1. Vehicle collision prevention method using ultrasonic waves, characterized in that increasing.