JPS5991793A - Ultrasonic wave remote controller - Google Patents

Abstract

PURPOSE:To reduce the effect of missing of an ultrasonic wave at a remote distance by transmitting the ultrasonic wave having a very short pulse width and taking the repetition of two kinds of pulse interval until the next ultrasonic wavepulse is oscillated as a channel code. CONSTITUTION:The ultrasonic wave having a very short pulse width t7 is transmitted, the time until the next ultrasonic wave pulse is transmitted is provided with two kinds; one is taken as a basic pulse interval t5 and the other as a channel discriminating pulse interval t6, and the plural alternate repetition of the two kinds of the pulse intervals t5, t6 is taken as one channel code. Thus, the effect of missing of an echo and the ultrasonic wave at a remote distance is made scarce because of pulse transmission and malfunction between channels is avoided by the plural repetition.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an improvement in a transmission code in an ultrasonic remote control.

Conventional configuration and its problems Conventional ultrasonic remote controls have been carefully devised to prevent the receiving side from malfunctioning due to ultrasonic noise that exists in nature. In general, noise ultrasound in the natural world (
For example, the sounds produced by a telephone ring or a set of keys), with the exception of some sounds, lack continuity (the property of continuing stably and continuously) and regularity (the property of the same thing occurring regularly), and are remote. For control purposes, most of the transmission codes utilize these two properties to regularly and continuously transmit ultrasonic waves. An example of this is shown in FIG. 1, where the t1 interval is an interval in which ultrasonic waves are being transmitted, and the t2 interval is an interval in which ultrasonic transmission is stopped. The longer the t1 interval, the more distinguishable it is from noise in the natural world, but if it is completely continuous, the amount of information that can be sent using one frequency becomes one, and the effectiveness of remote control becomes weaker. Also, at this point in the case of continuous sound waves, time constraints come into play depending on whether this is distinguished as a continuous wave. Also, if it is too fast, it will be impossible to distinguish it from noise at all, and if recognition is extended indefinitely, the response will be delayed, which also becomes a problem. For this reason, the ultrasonic transmission period is set to several milliseconds to several tens of milliseconds, and the stopping period is also roughly the same.
Many types of codes were constructed by changing these times. However, observing the time of the ultrasonic transmission period and the time of the stop period in this way may cause the sound wave to drop out (not be continuously received) within the transmission period at the last minute distance where the ultrasonic wave can barely reach the ultrasonic wave. ) occurs, making it impossible to recognize the signal, and the apparent distance becomes shorter and longer.

In addition, in the case of a small room, even if the transmission of ultrasound is stopped on the transmitting side, the ultrasound emitted earlier reflects off walls etc. and enters the receiving side (hereinafter referred to as echo), so the ultrasound On the receiving side, it is observed with a long tail. For this reason, the transmission period and stop period on the υ receiving side differ depending on the structure of the room, so even if the ultrasonic wave is sent coded at an accurate time, it does not mean anything. Conventionally, a common method to solve this problem was to send ultrasonic waves of a different frequency to the stop section than the transmit section to eliminate the echo phenomenon, but due to the frequency characteristics of the receiving microphone, it was necessary to use two frequencies. How far apart should it be? Also, due to the directivity of the microphone, the reflected waves may be observed more strongly on the receiving side than the direct waves, so the reflected waves of one transmission section should be canceled out by the ultrasonic waves of the stop section. Because of the inability to do so, we could not expect much improvement in terms of accuracy.

In both cases, the major drawback was the complexity of the circuit when using multiple frequencies. By the way, as I mentioned earlier, noise in the natural world lacks regularity and continuity, but some noises, especially those that are somewhat intentional, are very regular. An example of this is the ring tone of a manual telephone. An example of this is shown in FIG. 2, where it can be seen that an extremely thin pulse sound t3 is regularly continuous with t4. In this way, unlike general external noise, certain types of noise have extremely regularity, and this regularity often repeats at short intervals. Previously, some devices had adopted such a pulse transmission method, but the repetition time was extremely long to avoid interference with regular natural noise.

(Because the code shown in Figure 2 does not last very long), it took a long time to recognize the code, and the recognition time was extremely different between each code.

OBJECTS OF THE INVENTION The present invention relates to improvement of a transmission code in ultrasonic remote control, and aims to improve reliability.

Structure of the Invention The ultrasonic remote control of the present invention emits ultrasonic waves with an extremely short pulse width and has two types of time until the next ultrasonic pulse is emitted, one of which is the basic pulse interval, and the other is the basic pulse interval. is the pulse interval for determining channel selection, and the repetition of these two alternating Nords intervals is
0 Description of Embodiment The present invention solves the above-mentioned conventional drawbacks, and an embodiment thereof will be explained below based on FIG. 3.0 FIG. 3 shows the present invention. 2 is a code signal of one embodiment of the present invention. t6 is a basic pulse interval, t6 is a pulse interval for channel discrimination, and the pulse width t7 is extremely short compared to these pulse intervals. The transmission is continuous alternating transmission of these two types of pulse intervals. Further, in this method, the channel is changed by changing only the channel discrimination pulse interval t6.

If such a transmission method is used, the following characteristics can be obtained.

Because it is a pulse transmission, compared to a code with an extremely long transmission period as shown in Figure 1, there is less influence of echoes and drop-off of ultrasonic waves over long distances.In particular, since the pulse rise point is used as the time base, the end of the pulse is less affected. Even if the initial echo continues for some time, the echo can be completely ignored as long as the rise of the next pulse is clear. Furthermore, compared to the conventional pulse method, it is difficult to create the ring tone of a manual telephone as mentioned earlier because the pulse interval is completely continuous, and malfunctions can be completely eliminated by repeating it several times. Since the pulse interval and the channel discrimination pulse interval alternate, even if a pulsed sound wave were to drop due to long distances, the mistake could be detected quickly and the timing for starting new recognition could be easily determined. ’) To avoid interference with external noise, repeat this multiple times, but just by checking the interval between two consecutive pulses, you can determine if it is a signal from the channel 9, and then it will be sent repeatedly. Just check to see if it is. Furthermore, since one of the pulse intervals is a common pulse interval regardless of the channel, dropout of sound waves and effects of echoes can be determined by checking at most two intervals. This covers the situation where code recognition is delayed due to omissions and echoes peculiar to ultrasonic waves, and if it fails, it is easy to reconfirm by starting from the beginning again, and the responsiveness is also extremely good. - Also, as mentioned earlier, in this code system, the channel can be changed by simply changing the channel discrimination pulse interval, so the transmitter only needs to be a simple oscillation circuit.

Furthermore, since this code presets the reference pulse interval, in the event that an ultrasonic pulse is dropped, this reference pulse interval will no longer appear, and therefore there will be no interference between channels. In other words, since the reference pulse interval and the channel discrimination pulse interval are repeated, no matter which pulse disappears, the reference pulse does not appear. This is a feature not found in conventional pulse code systems. In the conventional pulse code method, if one pulse disappears by chance, the pulse interval becomes 2.
As with twice the channel, there was a possibility of malfunction. In order to avoid this, conventionally a special type has been selected that does not cause interference between channels no matter how many pulses disappear. This limits the number of codes and extremely reduces code usage. In the above embodiments, the shorter pulse interval is the basic pulse interval.

Although it was closed, there is no problem in using the longer one as the basic pulse interval. The point is that it is sufficient that each channel has a common pulse interval.

Effects of the Invention As described above, according to the present invention, ultrasonic waves with an extremely short pulse width are emitted, and there are two types of time until the next ultrasonic pulse is emitted, one of which is the basic pulse interval, and this 2
This is a channel code that consists of multiple repetitions of alternating pulse intervals.It improves the reduction in recognition response speed due to the influence of echoes in narrow rooms, where ultrasonic waves fall off over long distances, and It can be expected to have great effects such as eliminating malfunctions in equipment.

[Brief explanation of drawings]

Figure 1 is a diagram of the transmission waveform of conventional ultrasound waves, Figure 2 is a diagram of the waveform of the ultrasound waves that generate the ring tone of a manual telephone that generates highly regular ultrasound waves that are distorted in external noise. The figure is a waveform diagram of a transmission code according to an embodiment of the present invention. t7... extremely short pulse width ultrasound, t5...
...Basic pulse interval, t6...Pulse interval for channel discrimination. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] It has a circuit that oscillates ultrasonic waves and a coding circuit that intermittents the oscillation, and has two types of time periods for emitting ultrasonic waves with an extremely short pulse width and emitting the next ultrasonic pulse, one of which An ultrasonic remote control device in which one is a basic pulse interval, the other is a pulse interval for determining channel selection, and a plurality of repetitions of these two types of pulse intervals are one channel code.