JPS595634Y2 - Obstacle warning device for automobiles - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an obstacle warning device for a motor vehicle that detects an obstacle present in the blind spot of the driver's seat and gives a warning to the driver.

Large vehicles with larger blind spots than before often cause accidents involving pedestrians and motorcycles when turning left.

In order to prevent this type of accident, a conventional method has been used to alert pedestrians and the like by sounding a warning device such as a chime when a large vehicle turns left.

However, with this type of device, it is impossible to notify the driver himself/herself that an obstacle such as a pedestrian exists in the blind spot of the driver's seat.

The present invention was developed to solve the above problems, and uses a relative speed detection section using a top radar to detect the relative speed to an obstacle that exists in the blind spot of the driver's seat of a car. The detection unit detects that the magnitude of the relative speed is equal to or greater than a predetermined value, and the magnitude of the traveling speed is less than a predetermined value, the determination alarm unit determines this and issues an alarm. By doing so, even if there are obstacles such as pedestrians or motorcycles in the blind spot of the driver's seat when turning left, the driver can easily recognize them. The object of the present invention is to provide an obstacle warning device for automobiles that can hardly cause malfunctions caused by other vehicles when the magnitude of the relative speed is less than the predetermined value or the magnitude of the running speed is greater than the predetermined value. .

The present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 1, 100 is a relative speed detection unit that detects the relative speed between the vehicle and the obstacle 1 using the dot radar 10, 200 is a vehicle speed detection unit that detects the traveling speed of the vehicle with respect to the road surface, and 300 is the relative speed between the vehicle and the obstacle 1. When the magnitude of the relative speed of the vehicle is greater than or equal to a predetermined value (2 km/h in this example) and the traveling speed is less than a predetermined value (20 km/h in this example), this is determined and an alarm is issued. This is the discrimination alarm section that emits the alarm.

The relative velocity detection unit 100 utilizes the Doppler effect of approximately 20 GHz electromagnetic waves from the oscillator 3. The electromagnetic waves emitted from the sun antenna 2 of the Doppler radar 10 hit the obstacle 1 and are reflected. The frequency is biased by a frequency proportional to the relative velocity, and this reflected wave is received by the antenna 2 and mixed with the original oscillation wave by the mixer 4 to extract the biased wave.

After this is amplified by the amplifier 5, it is modulated into a change in current by the modulation circuit 6, and is output to the relative speed signal processing circuit 20.

The vehicle speed detection unit 200 uses a known rotation sensor 30 that opens and closes four times per rotation of the wheel, and a vehicle speed signal processing circuit 40 that converts the signal from the rotation sensor 30 into a logic signal of "1" or "0" level. Become.

The discrimination alarm unit 300 includes a discrimination circuit 50 that discriminates whether the relative speed is above a predetermined value and the traveling speed is less than the predetermined value, and an alarm that issues an alarm using a lamp and a speaker in response to a signal from the discrimination circuit 50. It consists of a circuit 60.

Next, the detailed structure and operation will be explained according to the electric circuit diagram shown in FIG.

70 is a power supply circuit that generates a constant voltage and supplies it to each part;
1 is a well-known Motorola voltage regulator Ito MC 7
Reference numerals 808 and 702 are batteries installed in the vehicle.

20 is a relative speed signal processing circuit that supplies current to the Doppler radar 10 and converts changes in the supplied current into logic signal levels of "0" and "L"; 51 receives the logic pulse signal from terminal 20a; This is a counting circuit.

40 converts the signal from the rotation sensor 30 into a logic signal of "1" or "0".
A vehicle speed signal processing circuit 52 that converts the signal into a level is a circuit that inputs the logic pulse signal from the terminal 40a and counts it.

53 generates a clock pulse, which serves as a time reference for the operation of each circuit, at the terminal 53a, and sends a control signal to the terminals 53b, 53b,
53 The circuit generated at C, 54 is the flip-flop 5
A hold circuit using 41 and 542, 55 a circuit for generating a reset signal when the power is turned on, and 60 an alarm circuit.

A frequency divider 531 divides the frequency of the clock pulse to the sampling period.

532 is a decade counter which is reset at each sampling period, and flip-flops 541, 5
42 control signal to the terminal 53b, the counter 511,
Reset signals 512 and 521 are sequentially generated at the terminal 53C.

A signal having a frequency proportional to the relative speed of the obstacle is generated at the terminal 20a of the relative speed signal processing circuit 20, and is counted by counters 511 and 512.

This counter performs sampling at the period of the signal at the terminal 53C.

When the counters 511 and 512 count, for example, 32 pulses (corresponding to a relative speed of 2 km/h) within the sampling time, the Q2 output of the counter 512 becomes "L" level,
Counters 511 and 512 maintain a state in which they have counted 32 pulses.

That is, the terminal 51a maintains the "1" level.

The terminal 51a is connected to the data input terminal of the flip-flop 541, and the signal from this terminal 51a is the control signal for the flip-flop 541, that is, the terminal 53b.
At the rising edge of the signal, the data is taken in all at once, and the Q output becomes the "0" level.

Further, a logic pulse signal having a frequency proportional to the traveling speed is generated at the terminal 40a of the vehicle speed signal processing circuit 40, and is counted by a counter 521.

This force counter 521 performs sampling at the period of the reset signal at the terminal 53C.

When the counter 521 counts, for example, 8 pulses (corresponding to a running speed of 20 km/h) within the sampling time, the Q output of the counter 521 goes to the "1" level, and the counter 521 maintains the state in which it has counted 8 pulses.

That is, the terminal 52a maintains the "1" level.

The terminal 52a is connected to the data input terminal of the flip-flop 542, and is taken in as data at the rising edge of the control signal of the flip-flop 542, that is, the signal at the terminal 53b, and the Q output becomes "1" level.

The Q output of the flip-flop 541 and the Q output of the flip-flop 542 are logically determined by a NOR gate 543, and the output terminal 54a of the NOR gate 543 becomes "1" only when the outputs of both flip-flops 541 and 542 are at "0" level. level.

That is, the signal from the relative speed signal processing circuit 20 is 32
pulse or more, and the signal from the vehicle speed signal processing circuit 40 is 8
When the pulse is less than a pulse, the terminal 54a becomes "1" level.

When the terminal 54a reaches the "L" level, the lamp 601 of the alarm circuit 60 lights up and the speaker 602 emits an intermittent sound to give an alarm.

In this embodiment, as described above, the relative speed with respect to the obstacle 1 is 2.
km/h or more, and the traveling speed is 20 Jan/h
An alarm will be issued if the

In this embodiment, a lamp and a speaker are used to issue the alarm, but an LED, a fluorescent display tube, a liquid crystal, etc. may be used in addition to the lamp, and a buzzer, chime, etc. may also be used in addition to the speaker.

As explained in detail above, the present invention detects the relative speed with respect to an obstacle that exists in the blind spot of the driver's seat of a car using a relative speed detection section using a Doppler radar, and also detects the traveling speed of the car using a vehicle speed detection section. Therefore, when the magnitude of the relative speed is greater than a predetermined value and the magnitude of the traveling speed is less than a predetermined value, the discrimination alarm section determines this and issues a warning, so when turning left, etc. If there are obstacles such as pedestrians or motorcycles in the blind spot of the driver's seat, the driver can easily recognize them, and as a result, accidents can be prevented. When the magnitude of the speed is less than the predetermined value or the magnitude of the traveling speed is greater than or equal to the predetermined value, the warning is prohibited, and this has the excellent effect of almost preventing malfunctions caused by other vehicles or the like.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is an electric circuit diagram showing details of the embodiment. 1... Obstacle, 10... Doppler radar, 100... Relative speed detection unit, 200...
...Vehicle speed detection unit, 300...Discrimination alarm unit.

Claims (1)

[Scope of utility model registration request] a relative speed detection section that detects the relative speed between the vehicle and an obstacle present in the blind spot of the driver's seat of the vehicle using a top radar; a vehicle speed detection section that detects the traveling speed of the vehicle; a discrimination alarm section that discriminates and issues an obstacle warning when the magnitude of the relative speed detected by the vehicle speed detection section is greater than or equal to a predetermined value and the magnitude of the traveling speed detected by the vehicle speed detection section is less than a predetermined value; An obstacle warning device for an automobile, characterized by comprising: