CZ2019818A3 - Warning end element with automatic acoustic power control - Google Patents

Abstract

A single warning and notification system terminal with automatic acoustic power control to change the volume of the terminal message depending on ambient noise includes a control unit (11), power supply module (12), signal receiver (111), amplifier (114) and loudspeaker ( 21) and further comprises a noise detector (113) connected to the control unit (11), to which a noise sensor (3) is connected. The noise sensor (3) of the end element can be a microphone located outside the end element or possibly a diaphragm of the electroacoustic transducer of the loudspeaker (21).

Description

Warning end element with automatic acoustic power control

Field of technology

The invention belongs to the field of electrical communication technology, in particular to technologies for transmitting information for an emergency or urgent need.

Prior art

Warning of the population against imminent danger is usually implemented by announcing an acoustic warning signal. The warning signal is handled via the warning terminal elements of the Unified Warning and Notification System (JSVV).

The final element of a warning (KPV) is a technical device for providing a warning or transmitting warning information. It can be an electric rotary siren (RS). These are electrical devices that generate a warning signal in a mechanical manner, usually by forcing air through the rotating impeller blades through slits in the body of the acoustic siren head. Also electronic endpoint warning (EKPV). Thus, the technical device is able to issue a warning signal and provide warning and other information in audible form in a purely electronic way. The EKPV can be an electronic siren (ES). It is a self-contained device that can be used locally and remotely to warn and inform the population, including live announcements. Or the local information system (MIS). In this case, it is a set of technical devices for the transmission of voice and other acoustic information over a larger area. One MIS can ensure the environment of entire municipalities, cities, industrial areas and similar public spaces.

Sirens are acoustically very powerful means of warning, which can be used to provide warning from a relatively large area from one place. In terms of physical, MIS are a source of an acoustic signal with a relatively low sound pressure level, which is, however, distributed over a relatively large area.

From a structural point of view, electronic sirens usually consist of two basic parts, namely cabinets with electronics and acoustic heads. The electronics cabinet contains its own control part, low-frequency power amplifier, source part, including backup batteries, buttons or other elements for local control and signaling and display elements. In addition, it contains a number of interfaces for connecting external devices and other optional modules. External devices are usually means for connection to the transmission system, radio receiver, microphone for direct voice inputs, another audio signal source, remote terminal for local operation from another location, sensors and other means of environmental monitoring, etc. The control part also includes the relevant software application , which determines the main used properties of the device and controls communication with external devices. The acoustic head consists of a mast on which the baffles with electroacoustic transducers are mounted. These are usually pressure speakers. Loudspeakers are made of plastic, sheet metal or metal alloys. The number of loudspeakers on the head depends on the power of the siren. This is usually one pair of speakers per low-frequency power amplifier.

From a design point of view, MIS usually consists of a control / transmission workplace, control technology, transmission system, detectors and display devices. Control technology, which consists of hardware elements and the appropriate software solution. The hardware part consists of basic electronic components and necessary subsystems - power supply, backup power supply, interface for connection of transmission technologies, means for MIS control, inputs and interface for connection of monitoring means of dangerous phenomena, etc. The mentioned HW components and MIS subsystems are usually wardrobe. Local control of MIS is solved either from the local control panel or from a computer with the appropriate application. The software includes applications included in the MIS control technology and user applications installed in the control / transmission station or in the local control terminal. The transmission system MIS can be

-1 CZ 2019 - 818 A3 consisting of classic wired distributions, wireless technologies and technologies of television or other cable distributions.

At present, development in this area focuses mainly on wireless systems, both analog and digital. In this case, we are talking about a wireless local information system (BMIS). Modern digital technologies are characterized by analogue systems; better acoustic output from wireless detectors, higher resistance to interference, better protection against deceptive and unwanted inputs. On the other hand, in places with a weak radio signal of the MIS transmission system, the reproduction quality and reliability of operation of digital wireless detectors decreases. The quality of reproduction in digital systems is strongly influenced by the codecs used, the setting of modulation levels and the solution of the penetration of the locality of interest by the radio signal of the transmission system. Digital radio transmission can be realized as simplex or as duplex (semi-duplex). Detectors are groups of speakers for sounding the outdoor environment or home receivers. These can also be television and radio receivers. For outdoor detectors, MIS usually use pressure speakers with an output of 15 - 100 W. One detector can consist of several speakers. Thus, the circularity of (omnidirectional) radiation of sound energy is achieved. In areas with an increased noise level (eg along busy main roads), detectors with an output of 180 - 200 W are also used.

Because the warning end elements described are means that provide a warning by an acoustic warning signal, a reliable warning is conditional on the warning signal being recognizable in other sounds that commonly occur in the environment. To do this, several basic conditions need to be met:

1. The signal must be clearly identifiable. This is achieved by the acoustic shape of the warning signal, which is determined by the time course of sounds at certain frequencies, which ensure its unmistakability.

2. The signal must be audible. For reliable audibility of the signal, a minimum value of sound pressure is defined and a value by which the signal must exceed the value of ambient noise.

3. As sirens are high-performance sound devices, the level of possible exposure of people who can normally move around them must be taken into account when installing them. Permissible sound exposure values are set by hygiene standards.

Environmental noise is not locally or temporally constant. Depending on the time of day, its intensity changes significantly. Determining a sufficient and at the same time acceptable acoustic level of the warning signal is a very demanding step in the preparation of the construction of warning terminal elements in new localities. At present, the required audibility of the warning signal can only be influenced by selecting the warning terminal element of the corresponding power range.

At present, the performance of the warning end element can only be reduced for some devices, and only by the local operator, who must be physically present at the specific device. Gain reduction is only possible for locally handled activities. By remotely triggering a warning via JSVV, which is the vast majority of cases, the acoustic power of the warning end element is automatically set to maximum.

Input data on ambient noise can be obtained either from a noise map or by measurement. Current noise maps are only available for very few locations. In most cases, it is necessary to perform noise measurements before installing new warning devices. Obtaining relevant data in this way is a very time consuming matter. Incorrect determination of ambient noise values, incorrect determination of the required acoustic power of the warning end element, or a combination of both of these effects can have fatal consequences for the reliability and success of the warning.

- 2 CZ 2019 - 818 A3

The essence of the invention

The new design of the warning end element eliminates the problems described above by regulating its acoustic power according to the current noise level at the installation site. The described solution only applies to electronic terminal elements of the warning. They cannot be applied to electric rotary sirens.

The essence of the invention is noise detection, which is an integral part of the electronic terminal of the warning. Based on the measured value of the environmental noise of the warning terminal control electronics according to the algorithm specified in the control software of the terminal control unit, the power of low frequency power amplifiers is adjusted before activating the warning so as to achieve optimal acoustic performance when the above conditions are met for reliable warning audibility. In the event that the acoustic performance of the warning terminal element is not sufficient to meet a given distance of the warning signal sound from ambient noise, the warning terminal element may process the warning signal repeatedly, thereby increasing the likelihood of it being detected by the population.

A microphone can be used as an additional component as a noise sensor to detect ambient noise, or the diaphragm of the electroacoustic transducer of the electronic warning terminal can also be used for this purpose.

Ambient noise is detected by a noise sensor that converts it from mechanical to electrical energy. The output voltage of the noise sensor is sent to the noise detector to evaluate the noise level. Based on the set criteria, a command is then transmitted by the noise detector to the control unit of the warning terminal electronics, which sets the required gain level of the low-frequency power amplifier.

Advantageously, the output voltage of the noise sensor can be evaluated by the control unit based on a comparison of the level of ambient noise reported by the noise detector from the output voltage of the noise sensor when no warning is transmitted with the output voltage level of the noise sensor at the time of reporting. in the level of ambient noise compared to the acoustic power of the siren for the subsequent setting of the required volume of the acoustic signal of the siren by means of a low-frequency power amplifier.

With this solution, it is also possible to achieve a reduction in the energy requirements of the warning end elements, because it will not be necessary to use the maximum power in all cases of their use.

Explanation of drawings

Figure No. 1 shows a block diagram of an electronic siren according to Example No. 1.

Figure 2 shows a block diagram of the wireless local system detector according to Figure 2.

Examples of embodiments of the invention

Example No. 1

The example describes the basic assembly of an electronic siren with components for automatic control of acoustic power. The electronic siren consists of a housing 1 with electronics, an acoustic head 2 and a noise sensor 3 in the form of a microphone. The electronics box 1 contains basic components in the form of a control unit 11 and a power supply module 12. A receiver 111 of the JSVV signal, a radio receiver 112 are connected to the control unit 11, a noise detector 113 and a power amplifier 114. Acoustic

-3GB 2019 - 818 The A3 head 2 with speaker 21 is connected to the low frequency power amplifier 115 of the electronics cabinet 1. The noise sensor 3 is connected to a noise detector 113.

Example No. 2

The example describes the assembly of a basic wireless local system detector with components for automatic acoustic power control. The digital MIS detector consists of a power supply module 12, a radio station 16, which wirelessly receives a signal from the MIS control station, a control unit 11, to which an amplifier 114 is connected, to which a speaker 21 is further connected. when no reporting occurs, the diaphragm of the electroacoustic transducer of the loudspeaker 21 in the function of the noise sensor 3 is used to detect noise by connecting to the noise detector 113.

Industrial applicability

The final element of the warning with automatic regulation of acoustic power can be used within regional and national infrastructures by a unified system of warning and notification of the population by rescue services in the event of emergencies.

Claims (3)

PATENT CLAIMS A warning terminal element with automatic sound power control comprising a control unit (11), a power supply module (12), a signal receiver (111), an amplifier (114) and a loudspeaker (21), characterized in that it further comprises a control unit (11) a connected noise detector (113), to which a noise sensor (3) is connected. End element according to claim 1, characterized in that the noise sensor (3) is a microphone ίο located outside the end element. End element according to Claim 1, characterized in that the noise sensor (3) is the diaphragm of the electroacoustic transducer of the loudspeaker (21).