JPS62140082A - Alarm apparatus for ultrasonic sensor - Google Patents

Abstract

PURPOSE:To make it possible to accurately judge the distance difference up to matter, by providing a cycle variable means continuously changing a light emitting cycle or sounding cycle corresponding to the distance up to the matter and making said cycle shorter as a detected distance is made shorter. CONSTITUTION:An oscillation circuit 7 is intermittently oscillated at a predetermined interval determined by a transmitting interval setting circuit 6 and a pulse like ultrasonic wave is intermittently sent out through a transmitter 4 and, when reflected by the matter 3 present in a detection area, the reflected wave is received by a receiver 5 to be amplified by a receiving circuit 8 and, after noise removal and detection were performed, only a reflected wave received within a range wherein the time from the transmission of the ultrasonic wave to the reception of the reflected wave thereof is a predetermined one is taken out by a detection gate circuit 9 and the distance up to matter 3 is operated from the output of the circuit 9 by a signal processing circuit 10. Next, the ON/OFF time determining the light emitting cycle of LED and the sounding cycle of a buzzer is determined by the distance from an ultrasonic sensor to the matter 3 and, as the distance up to the matter 3 becomes shorter, the cycles are shortened and the distance difference up to the matter can be accurately judged.

Description

Detailed Description of the Invention [Technical Field 1] The present invention detects a distance of 1 [distance] to an object based on the propagation time from transmitting an ultrasonic pulse signal to receiving a reflected wave from the object, and The present invention relates to a notification device for an ultrasonic sensor that provides notification by emitting light or sounding in response to the request.

[Background Art] Conventionally, there is an ultrasonic sensor of this type as shown in FIG. Multiple light emitting diodes (hereinafter referred to as LE) correspond to the detection area of
Notification was carried out by emitting light (abbreviated as D) in stages, or by emitting a buzzer with the emission period varied in steps #i corresponding to the detection area similar to the above-mentioned LED. Figure 6 shows, for example, a plurality of LEDs depending on the distance #IC to object 3.
In addition to emitting light, a buzzer is also emitted with a variable sounding cycle depending on the detection method (1) (a) similar to the above-mentioned LED. The notification by LEI is to emit light in stages according to the distance gI to the object 3, as shown in Figure (b). For example, when the object 3 is in the detection area point d, Then, the LED of the fish in the detection area d lights up. At this time, the buzzer rings at a frequency of 240 m5, as shown in FIG. 3(c). When object 3 is present in detection areas a to ``of the pond, the buzzer's ringing cycle is a continuous sound in detection area a, and a cycle of 6 (1+os,
120+as in detection area C, 48 in detection area e
0+ns, detection area "Then 960+ns, otherwise there is no sound, and the detection area a-
The buzzer sounded at a different frequency for each f.

However, according to this notification method, the distance η to the object 3 indicated by one LED has a wide range, and depending on the number of divisions of the detection area, the range of the distance e may be too large, making it difficult to know where the object 3 is located. In some cases, it is difficult to recognize the LED, and increasing the accuracy requires a large number of LEDs.

Another notification method is to digitally display the detected distance aa, but for example, with the I'I harmful object detector for vehicles that uses ultrasonic waves, the reported distance is a dangerous distance. It is necessary for the user to immediately judge whether the product is present or not, and judgments may vary depending on differences in user awareness, which can lead to unexpected disasters, and digital displays are often unsightly. There was a problem.

[Objective of the Invention 1 The present invention has been made in view of the above-mentioned points, and its purpose is to provide an ultrasonic sensor that can continuously notify the distance to an object and reduce the number of LEDs. The goal is to provide equipment.

[Disclosure of the Invention 1 (Configuration) The present invention detects the distance to an object based on the propagation time from transmitting an ultrasonic pulse signal to receiving a reflected wave from the object, and emits or emits light according to the detected distance. A notification device for an ultrasonic sensor that makes a sound to notify an object, comprising a period variable means that continuously changes a light emitting period or a sounding period according to the distance to an object, and shortens the period as the detection distance becomes shorter. Continuously announces the distance to L.
An ultrasonic sensor notification device that can reduce the number of EDs is disclosed.

(Example 1) FIGS. 1 to 4 are diagrams showing an example of the present invention,
The ultrasonic sensor 1 of this embodiment has a maximum detection pressure of #! It is capable of detecting a substantially fan-shaped detection area 2 of aO, and uses an LED, a buzzer, etc. to notify the detection distance αi of the object 3, similar to the conventional example.

First, the ultrasonic sensor 1 used in this embodiment will be explained. FIG. 3 is a diagram showing the configuration of a distance-measuring type ultrasonic sensor 1, in which an oscillation circuit 7 is intermittently oscillated at predetermined intervals determined by a transmission interval setting circuit 6, and a transmission signal is transmitted via a transmitter 4. When the ultrasonic wave is reflected by an object 3 existing in the detection area 2, the reflected wave is received by the transfer device 5, amplified by the receiving circuit 8, and noise-reduced. After removing and detecting the ultrasonic wave, the gate circuit 9 detects only those whose time from transmitting the ultrasonic wave until the reflected wave is received is within a predetermined time range.
The signal processing circuit 10 calculates the distance to the object 3 from the output of the detection date circuit 9. Here, the detection date circuit 9 performs the following steps. As shown in FIG. 4(a), the ultrasonic waves transmitted from the transmitter 4 are received by the transfer device 5 at the same time as the transmitter 4 transmits the ultrasonic waves, as shown in FIG. 4(b). Therefore, the detection date circuit 9 is set to open the date at a time such that the ultrasonic waves directly received by the transfer device 5 from the transmitter 4 are not subjected to calculation processing, as shown in FIG. 4(d). Also, the time to close the date is the maximum detection distance of 0.
The time is set according to 2. Incidentally, FIG. 4(e) shows the output of the receiving circuit 8.

Next, the period variable means 20 for changing the light emission period of the LED and the sounding period of the buzzer, which is the essence of this embodiment, will be explained. In this embodiment, the on time (l) and the off time t2, which determine the emission period of the LED and the sounding period of the buzzer, are determined by the distance α1 from the ultrasonic sensor 1 to the object 3. For example, the on time shown in FIG. 2 is the maximum detection distance α.

In this method, a predetermined value C (here, C1 is a constant time, for example, 200 m5) is set as the ratio of the distance Q+ to the off time, and 2 is a predetermined value C2 (constant). The above open time and off time L2 are calculated by the formula % formula % (1
). In this case, the on-state opening t1 is continuously controlled by the distance 0.1 to the object 3, and as the object 3 approaches, the notification period becomes shorter, and as the object 3 gets farther away, the notification period becomes longer. It is something. Therefore, based on the distance information output from the signal processing circuit 10, the above formula (IO2)
What is necessary is to provide a pulse generation circuit 21 that generates a pulse signal that satisfies the following relationship, and a drive circuit 22 that drives an LED or a buzzer using the output of this pulse generation circuit 21.

In addition, as another example, there is a method of continuously varying the off time t2, contrary to the above, in this case, t, = C,...
・(3) Cj constant L2=0. oc<10. l ・<4) If C4 is kept constant, the same operation as in the above example can be achieved. In addition to this, both the on time T1 and the off time t2 can be varied. In this case, t+= Q+Cs/Q, o
・=<5) C5 constant tz=Q, aCa/
0. + - (6) Cs may be kept constant.

(Embodiment 2) FIG. 5 is a diagram showing another embodiment of the present invention. In this embodiment, the detection area 2 is set to a narrow detection distance of 0, o, and the first embodiment has a wide detection distance. of the detection distance corresponding to the maximum detection distance. It is divided by 2. Here, the area within the detection distance fiQ,ot is, for example, a dangerous distance, and when an object 3 exists within this detection area 2, an LED is lit continuously or a buzzer is sounded. And 3. detection distance. of detection distance. If there is an object 3 in the opening of 2, the distance to the object 3 is 0 as in the first embodiment described above.
．． 1, the light emitting period and the emitting period are made variable.

Note that the above equation shows an example, and the on-time t
, and the off time L2 correspond to the distance to the object 3 of 0.1, it goes without saying that they may be obtained using arithmetic expressions other than those of this embodiment.

[Effects of the Invention] As described above, the present invention includes a period variable means that continuously varies the notification period according to the distance to the object and shortens the notification period as the detection distance becomes shorter. When the distance from the ultrasonic sensor to the object becomes short, the light emission period is shortened by the period variable means, so that the force on the object can be determined simply by watching or listening to the notification operation of the notification device. The user can judge whether the object is within the distance, and since the notification is continuous according to the distance of the object, it is possible to accurately judge the difference in distance, and the notification cycle is variable depending on the distance. The notification device can be configured with one LED without using a plurality of LEDs, etc., and therefore the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the operating state of one embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the same notification device, and FIG. 3 is the same circuit v! FIG. 4 is an explanatory diagram of the operation of the same ultrasonic sensor as described above, FIG. 15 is an explanatory diagram of the operating state of another embodiment of the present invention, and FIG. 6 is an explanatory diagram of the operation of the conventional example. . 1 is an ultrasonic sensor, 2 is a detection area, 3 is an object, is an on time, t2 is an off time, and 20 is a period variable means. Agent Patent Attorney Ishi 1) Ai 7 Figure 1 Figure 5 Figure 6

Claims (1)

[Claims] (1) Detect the distance to the object based on the propagation time from transmitting the ultrasonic pulse signal to receiving the reflected wave from the object, and change the notification operation by emitting light or sounding depending on this detected distance. A notification device for an ultrasonic sensor that performs notification by detecting an object, characterized by comprising a period variable means that continuously changes the notification period according to the distance to the object and shortens the notification period as the detection distance becomes shorter. Ultrasonic sensor notification device.