JP4076161B2 - Horn with adaptively adjustable movement - Google Patents

Abstract

The invention relates to a signal horn upon which external influences have an effect which is as minor as possible. The inventive signal horn comprises a control circuit for adaptively modifying an operating variable in order to bring it into line with a predefinable set-point value. A switch (6);controlled by a pulse generator (6); is used to control an excitation current (I) flowing through the signal horn in relation to the pulse frequency and/or pulse-scan ratio. Switching means (11) which detect one or several characteristic variables of the excitation current (I) are provided, in addition to other switching means (12) which provide one or several manipulated variables for the pulse generator (6) from the deviation between the characteristic variable(s) derived from the excitation current (I) and one or several set-point values.

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horn having a control system that adaptively adjusts the operation amount of the horn to a preset target value. Here, an excitation current flowing through the horn is controlled by a switch controlled by a pulse generator. The pulse frequency and / or pulse duty ratio is controlled, and the above control system has circuit means by which the operation amount of the horn is detected, and the above pulse generator is controlled depending on this. The movement amount of the horn is set to take a target value.
[0002]
Such a horn having a control system for adaptively adjusting the resonance frequency is known from US Pat. No. 5,414,406. Here, an acoustic sound sensor (microphone) is used to measure the frequency of the actual sound of the horn, and the phase deviation between this measured actual signal and the pulse train formed by the pulse generator that controls the horn. (Phasenablage) is detected. The pulse frequency of the pulse generator is adjusted so as to minimize this phase deviation. When the horn is driven and controlled in this way, the optimum operating frequency, that is, the resonance frequency is achieved. It is technically relatively expensive to detect the actual amount of movement of the horn using an acoustic sound sensor. In addition to this, the functioning of an acoustic sound sensor is highly dependent on the effects of temperature and aging. That is, the frequency of the sound of the horn measured by the sound sensor changes due to the influence of temperature and aging. In this case, the control system can no longer accurately adjust the horn to its resonance frequency.
[0003]
The object of the present invention is therefore to provide a horn of the type mentioned at the outset, which can be realized as simply as possible in terms of production technology and that external influences have as little influence on the operating characteristics as possible. is there.
[0004]
Advantages of the Invention According to the features described in the characterizing part of claim 1, the above object is provided with circuit means for detecting one or more characteristic quantities of the exciting current flowing through the horn, and is derived from the exciting current. Another circuit means is provided for supplying one or more adjustment amounts to the pulse generator from the deviation between the one or more characteristic quantities and the one or more target values. This is solved by controlling the pulse frequency and / or the pulse duty ratio of the exciting current by the switch. Since the actual movement amount of the horn is derived from the excitation current in the control system, it is possible to omit a sound sensor that is susceptible to failure and that measures the frequency of the horn sound. The one or more characteristic quantities of the excitation current are a relative phase of harmonic components of the excitation current and / or a spectrum distribution of the excitation current. Here, these characteristic quantities of the exciting current can be detected by a frequency analyzer.
[0005]
Advantageous developments of the invention are described in the dependent claims.
[0006]
For the control process, it is advantageous to use the resonance frequency or an amount proportional thereto (preferably an excitation current) as the amount of movement of the horn.
[0008]
In an advantageous arrangement, a current-voltage converter is provided, by which the excitation current is converted into a voltage, an analog-digital converter is provided, the voltage is digitized by this converter, and A digital frequency analyzer is provided, which determines one or more characteristic quantities of the digitized voltage curve derived from the excitation current. A signal processor is preferably used by means of which the one or more characteristic quantities determined by the above frequency analyzer of the excitation current or the voltage derived therefrom and the one or more target values And the deviation between the one or more characteristic quantities and the one or more target values provides one or more adjustment quantities for the pulse generator. At this time, the signal processor can execute the target value comparison at time intervals that are periodically repeated.
[0009]
The signal processor may store one or more target values corresponding to a fixed amount of movement of the horn, or may supply the signal processor with one or more target values that can be changed. it can. The sound of the horn can be changed according to the last embodiment.
[0010]
In the following, the present invention will be described in detail based on two embodiments shown in the drawings. here,
FIG. 1 shows a block diagram of a control system that adaptively adjusts the amount of movement of the horn, where the control system is adjusted to a fixed resonance frequency of the horn,
FIG. 2 shows a control system that adaptively adjusts the movement amount of the horn, where the sound of the horn can be changed.
[0011]
FIG. 1 is a block diagram of a control system for adaptively adjusting the amount of movement of a horn. The horn 1 has, for example, a structure described in US Pat. No. 5,414,406, and only the exciting coil 2 is shown in FIG. This exciting coil vibrates the diaphragm of the horn when current flows. The excitation coil 2 of the horn 1 is powered by an energy source 3, for example a vehicle battery. A switch 4 is provided on the line between the energy source 3 and the exciting coil 2, and the horn is activated by operating this switch.
[0012]
The current I flowing through the exciting coil 2 is controlled by an electrically controllable switch 5 used in the current closed circuit of the exciting coil 2. A control signal for the electrically controllable switch 5 comes from a pulse generator 6, and a pulse train having a predetermined pulse train frequency and a predetermined pulse duty ratio is output by the pulse generator. By means of a driver 7 connected between the pulse generator 6 and the electrically controllable switch 5, the pulse train output from the pulse generator 6 is at a level advantageous to the electrically controllable switch 5. Is converted to The electrically controllable switch 5 is preferably a semiconductor switch, for example a field effect transistor. That is, the electrically controllable switch 5 is turned on and off in accordance with the pulse train formed by the pulse generator 6, so that the excitation current I flowing through the excitation coil 2 is set by the pulse generator 6. It has the form of a pulse train having a pulse frequency and a pulse duty ratio.
[0013]
The role of the control system described below is to drive the horn constantly at its resonant frequency without relying on aging or temperature effects or other external effects. Here, this resonance frequency depends on the overall structure of the horn, the excitation coil, the magnetic core, the diaphragm, the casing and other parts of the horn. The operation amount of the horn 1 is detected as a control amount. The amount of movement of the horn 1 is preferably its resonance frequency or an amount proportional thereto, ie the excitation current I flowing through the excitation coil 2 and the electrically controllable switch.
[0014]
In the embodiment shown in FIG. 1, the excitation current I itself is not supplied to the control system as the control amount, but the voltage U derived from the excitation current I is supplied. The conversion of the excitation current I into the voltage U is performed using a current-voltage converter, which in the simplest case is the ohmic resistor 8.
[0015]
In the circuit part 9 post-connected to the current-voltage converter 8, the voltage U is converted to a signal level which is advantageous for the analog-to-digital converter 10 connected downstream. The analog-to-digital converter 10 is necessary when further signal processing is desired to be performed digitally in this control system. In the analog signal processing, the analog-digital converter 10 can be omitted. The digitized control amount, that is, the voltage U is supplied to the digital frequency analyzer 11. One or more characteristic quantities of the voltage signal U are determined by the frequency analyzer 11. The characteristic quantity can be, for example, the spectral distribution of the signal U and / or the relative phase of a predetermined harmonic spectral component.
[0016]
One or more characteristic quantities of the signal U obtained by the frequency analyzer 11 are supplied to the signal processor 12. The signal processor 12 stores the target values of these characteristic quantities, which correspond to the desired operating quantity, i.e. the desired excitation current course I of the horn 1. The signal processor 12 determines a deviation between the one or more quantities determined by the frequency analyzer 11 and the one or more target values stored in the signal processor 12. The signal processor 12 prepares an adjustment amount proportional to these obtained deviations for the pulse generator 6. This one or more adjustment amounts are used to control the pulse duty ratio and / or the pulse frequency of the pulse generator 6. By this control process, the pulse duty ratio and / or the pulse frequency of the pulse generator 6 is adjusted to minimize the deviation between the actual amount and the target value obtained by the signal processor 12, and the horn 1 is thus set to the optimum frequency, That is, it is driven at the resonance frequency.
[0017]
The signal processor 12 receives a start signal S when the switch 4 is operated, which activates the horn. Advantageously, the signal processor 12 compares one or more stored target values with one or more actual quantities supplied from the frequency analyzer 11. That is, the control process is initiated at predetermined repeated time intervals rather than continuously. Each time a control process is started by the signal processor 12, the signal processor sends a start signal A to the analog-to-digital converter 10, on which the analog-to-digital converter sends an analog input signal U. To a digital signal for the frequency analyzer 11. It is not always necessary to activate the analog-to-digital converter 10 only at the time of the control process initiated by the signal processor 12, and the analog-to-digital conversion can be carried out continuously.
[0018]
In the embodiment shown in FIG. 2, the control system has the same circuit portion as the embodiment of FIG. 1 described above. Accordingly, all circuit blocks in FIG. 2 have the same reference numerals as in FIG. The embodiment of FIG. 2 differs from that of FIG. 1 only in that the signal processor 12 has a separate signal input 13. What has been described in the description of the embodiment shown in FIG. 1 is that one or a plurality of target values that are fixedly preset in the signal processor 12 are stored. A plurality of target values can be supplied from the outside by the signal input side 13 for the signal processor 12 shown in FIG. 2, and here, the frequency of the horn 1 can be changed from the resonance frequency by changing these target values. it can. Therefore, the frequency of the sound formed by the horn 1 or its volume can be changed. The changeable target value supplied to the signal input 13 of the signal processor 12 can be supplied from the central control unit of the vehicle. In this case, the switch 4 entered in the embodiment of FIG. 1 is also omitted. This is because, via the signal input 13, the signal processor 12 also receives a start signal for activating the horn 1. The switch-on of the horn 1 is in this case carried out via the pulse generator 6 and the electrically controllable switch 5 starting from the signal processor 12, where this switch is used to switch the current circuit of the excitation coil 2. Close.
[0019]
The above circuit blocks 5, 6, 7 and 8, 9, 10, 11, 12 need not be independent circuits, and they can also be integrated with one another in an advantageous manner.
[Brief description of the drawings]
FIG. 1 is a block diagram of a control system that adaptively adjusts the amount of movement of a horn.
FIG. 2 is a block diagram of a control system that adaptively adjusts the amount of movement of a horn capable of changing sound.

Claims (8)

A horn having a control system that adaptively adjusts a movement amount of the horn (1) to a preset target value,
The switch (5) controlled by the pulse generator (6) controls the pulse frequency and / or pulse duty ratio of the excitation current (I) flowing through the horn (1),
The control system has circuit means (8, 9, 10, 11, 12),
The circuit means detects the movement amount of the horn (1), and controls the pulse generator (6) depending on the movement amount so that the movement amount of the horn (1) takes the target value. In the type of horn,
Circuit means (11) for detecting one or more characteristic quantities of the excitation current (I) is provided;
Separately supplying one or a plurality of adjustment amounts for the pulse generator (6) from a deviation between one or a plurality of characteristic amounts derived from the excitation current (I) and one or a plurality of target values Means are provided ,
One or more characteristics of prior Symbol of the exciting current (I) is the excitation current (I) or a relative phase and / or the excitation current of the harmonic spectral components of the voltage (U) derived from the excitation current (I) or a spectral distribution of voltage (U) derived from the excitation current ,
A horn having a control system that adaptively adjusts the movement amount of the horn to a preset target value. The operating amount of the horn (1) is the resonance frequency of the horn or an amount proportional to the resonance frequency, preferably the excitation current (I).
The horn according to claim 1. The characteristic quantity of the excitation current (I) or the voltage (U) derived from the excitation current is detected by the frequency analyzer (11).
The horn according to claim 1 or 2 . A current-voltage converter (8) for converting the excitation current (I) into a voltage (U);
An analog-to-digital converter (10) for digitizing said voltage (U) is provided;
A frequency analyzer for determining one or more characteristic quantities of the digital voltage profile (U) derived from said excitation current (I), preferably the relative phase and / or spectral distribution of the harmonic spectral components ( 11) is provided,
The horn according to claim 1. A signal processor (12) is provided;
The signal processor includes one or more characteristic quantities of the excitation current (I) or the voltage (U) derived from the excitation current determined by the frequency analyzer (11), and one or more One or more adjustment amounts for the pulse generator (6) are supplied by comparing with the target value and from the deviation between the one or more characteristic values and the one or more target values. To
The horn according to claim 1, 3 or 4 . The target value comparison is performed by the signal processor (12) at time intervals that are periodically repeated.
The horn according to claim 1 or 5 . The signal processor (12) stores one or more target values corresponding to a fixed amount of movement of the horn (1),
The horn according to claim 1 or 5 . The signal processor (12) is provided with one or more variable target values;
The horn according to claim 1 or 5 .

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