Diagnostic procedure for a receiving antenna and system

Abstract

The invention relates to a diagnostic method for an antenna (3) configured as a receiving antenna and installed in a vehicle part of a vehicle by means of a radio tuner module (4) with at least one receiver (9) and a digital interface, which is configured as a digital signal generator (5) that generates at least one defined test signal with at least one fundamental frequency, which is directed to an antenna (2) configured as a transmitting antenna and installed in a vehicle part of the vehicle, which is electromagnetically coupled to the antenna (3) configured as a receiving antenna, which is connected to the receiver (9), wherein the receiver (9) and the digital signal generator (5) are controlled by a microcontroller (15) or microprocessor (15) such thatthat the test signal of the signal generator (5) is received by the receiver (9) via the antenna (3) and its magnitude is measured, and on the basis of this the function of the antenna (3) configured as a receiving antenna and optionally the function of the antenna (2) configured as a transmitting antenna and / or the electromagnetic coupling of the antennas (2, 3) is evaluated.

Description

The invention relates to a diagnostic method for an antenna of a vehicle configured as a receiving antenna according to claim 1 and to a system comprising two antennas installed in a vehicle part of a vehicle and a radio tuner module according to the preamble of claim 4.EP 0 816 859 A2 describes a diagnostic method and a diagnostic system for motor vehicle antenna disks having at least one antenna, in particular having antennas which are configured for diversity operation and are each selected by a diversity processor and connected to the receiver, wherein a test signal is applied to the antennas by means of a transmitting antenna for diagnostic purposes and the antenna signals which are thereby produced are evaluated. For the rapid, reliable and cost-effective diagnosis of the antennas, the test signal is generated with the aid of a transmitting antenna integrated into the antenna pane and the antenna signals arising on the basis of this test signal in the one and / or the other antenna(s) are evaluated.DE 200 19 677 U1 describes an antenna system having a plurality of antennas which can be connected in predetermined combinations via a combination unit to at least two receivers, having a signal processing unit for evaluating the output signals of the receivers and having a control unit by means of which at least one of the antennas can be switched to transmit operation for carrying out a self-test, wherein this antenna transmits test signals with a test frequency predetermined via a first receiver, which test signals are coupled into at least one further antenna which is connected via the combination device to the second receiver, the frequency of which is tuned to the test frequency, and wherein, for carrying out the self-test, the reception levels of the second receiver are detected as actual values and compared with predetermined setpoint values.DE 10 2017 108 638 A1 describes a tuner for the mobile reception of high-frequency signals in vehicles, having a housing formed by a first housing part and at least one further housing part, and a printed circuit board arranged in the housing, wherein at least one heat-critical electronic component for realizing at least one subfunction of the tuner is arranged on the printed circuit board, wherein at least one region of a housing part consists of a thermally conductive material having high thermal conductivity and the at least one heat-critical electronic component is connected to this region in a heat-transferring manner.The object of the invention is to specify a novel diagnostic method for an antenna of a vehicle configured as a receiving antenna and a novel system comprising two antennas installed in a vehicle part of a vehicle and a radio tuner module.The object is achieved according to the invention by a diagnostic method for an antenna of a vehicle configured as a receiving antenna having the features of claim 1 and a system comprising two antennas installed in a vehicle part of a vehicle and a radio tuner module having the features of claim 4.Advantageous embodiments of the invention are the subject matter of the dependent claims.According to the invention, a diagnostic method for an antenna configured as a receiving antenna and installed in a vehicle part of a vehicle by means of a radio tuner module having at least one receiver and a digital interface is proposed, which is configured as a digital signal generator which generates at least one defined test signal having at least one fundamental wave. The test signal is conducted to an antenna configured as a transmitting antenna and installed in a vehicle part of the vehicle, which antenna is electromagnetically coupled to the antenna configured as a receiving antenna, which antenna is connected to the receiver, wherein the receiver and the digital signal generator are controlled by a microcontroller or microprocessor such that the test signal of the signal generator is received via the antenna from the receiver and its magnitude is measured and on the basis of which the function of the antenna configured as a receiving antenna and optionally the function of the antenna configured as a transmitting antenna and / or the electromagnetic coupling of the antennas is evaluated. An antenna can also be used as the transmitting antenna, which serves as a receiving antenna outside the diagnostic function and can also be used as the transmitting antenna because of the approximate reciprocal trace of antennas.In one embodiment, the defined test signal is further generated by the digital signal generator with at least one harmonic.In one embodiment, two receivers are provided, each connected to one of the antennas, wherein first both receivers are muted, wherein in a loop for each test frequency from a plurality of defined test frequencies the receiver is set to a current test frequency, a field strength value is read out of the receiver and stored as a reference measurement, wherein subsequently the test signal is activated, optionally amplified and fed to the antenna, wherein in a further loop for each test frequency from a plurality of defined test frequencies the receiver is set to the test frequency, a field strength value is read out from the receiver and stored as a diagnostic measurement, wherein subsequently the test signal is deactivated and the values of the diagnostic measurements are evaluated and compared and evaluated with the values of the reference measurements.According to one aspect of the present invention, a system is proposed, comprising an antenna configurable as a receiving antenna and installed in a vehicle part of a vehicle, an antenna configurable as a transmitting antenna and installed in a vehicle part of the vehicle, which antenna is electromagnetically coupled to the antenna configured as a receiving antenna, and a radio tuner module having at least one receiver connected to the antenna configured as a receiving antenna, and a digital interface configurable as a digital signal generator in order to generate at least one fixed test signal having at least one fundamental wave and to conduct it to the antenna configured as a transmitting antenna, and furthermore a microcontroller or microprocessor. The microcontroller or microprocessor is configured to control the receiver and the digital signal generator and to perform the method described above. The radio tuner module is disposed at or near at least one of the antennas and may be miniaturized.In one embodiment, a further receiver is arranged in the radio tuner module or in another control device which is connected to the radio tuner module via a communication interface. The further receiver can be connected to the antenna configured as a transmitting antenna.In one embodiment, the digital signal generator is part of one of the receivers or part of the microprocessor or microcontroller.In one embodiment, the vehicle part in which at least one of the antennas is arranged is a window, in particular a front window, rear window or side window.In one embodiment, both antennas are arranged in the same vehicle part or alternatively in different vehicle parts.In one embodiment, an amplifier is arranged for amplifying the test signal and / or for impedance matching the signal generator to the antenna. Furthermore, a band pass filter for signal shaping and / or impedance matching and / or limiting the frequency range of the test signal can be arranged. Furthermore, an antenna amplifier can be arranged between the antenna configured as a receiving antenna and the receiver connected thereto.In one embodiment, the microcontroller or microprocessor may be configured to perform the diagnostic method only upon activation of a diagnostic mode.The motor vehicle can be, for example, a passenger car, a commercial vehicle or bus.According to the present invention, the antenna function is tested by using an existing digital interface for generating a defined RF spectrum of a test signal, and conditioning and coupling it to an antenna. Furthermore, a method for measuring and evaluating the coupling of this test signal to another antenna is described.The present invention solves the problem of diagnosing the antenna by using a digital interface of a broadcast receiver IC contained in the receiver for generating a test signal, which is applied to an antenna for transmitting the test signal, and by using a second antenna for receiving the test signal.The solution according to the invention enables the diagnosis of the antenna function without external devices for signal generation or evaluation. A further advantage lies in the use of bursty interfaces for generating an antenna test signal, in particular because the costs of additional components for generating an RF signal, such as frequency synthesizers, comb generators, step recovery diodes or the like, can be saved.In contrast to the prior art described above, it is possible in the solution according to the invention by miniaturization to install the receiver directly on the antenna and thus to dispense with additional components such as the signal generator described in the prior art, which is controlled via the diversity processor.Miniaturization allows the integration of a complete broadcast receiver directly at the antenna structures, in a so-called remote tuner module, so that the functions present in a conventional broadcast receiver IC can be used for antenna diagnosis.Exemplary embodiments of the invention are explained in more detail below with reference to drawings.The following are shown: FIG. 1 is a schematic view of a window of a motor vehicle having two antennas and a radio tuner module connected to the antennas, FIG. 2 shows a schematic diagram of a digital signal in the time domain, FIG. 3 shows a schematic diagram of a digital signal in the frequency domain, and FIG. 4 shows a schematic flow diagram of a diagnostic method.Corresponding parts are provided with the same reference numerals in all figures.FIG. 1 is a schematic view of a window 1, for example a rear window, of a motor vehicle. The pane 1 has two antennas 2, 3 introduced into the pane 1 or applied thereon in the form of conductor tracks. Furthermore, a radio tuner module 4 connected to the antennas 2, 3 is shown, which can also be used for diagnosing the antennas 2, 3.In another embodiment, the pane 1 can have only one antenna 2, 3, while a second antenna 2, 3 is installed in another pane 1 or another component of the same motor vehicle.The radio tuner module 4 has at least one signal generator 5, in particular a digital signal generator 5. For example, two or more signal generators 5 may be provided. The signal generator 5 or one of the signal generators 5 is connected, optionally via an amplifier 6, at least one bandpass filter 7 and / or a switch 8, to one of the antennas 2 in order to apply a test signal to them. The radio tuner module 4 has two receivers 9, 14, in particular radio receivers, which are each connected to one of the antennas 2, 3. The receiver 9 is connected to the antenna 3 which receives the test signal transmitted by the antenna 2 and which can then be evaluated by the receiver 9. In a further embodiment, the radio tuner module 4 can have only one receiver 9, 14, wherein a further receiver 9, 14 is arranged in a control device, not shown, which is connected to the radio tuner module 4 via a communication interface.The signal strength of the test signal received by the receiver 9 provides information about the function of the antenna 3 used as a receiving antenna.According to the invention, the radio tuner module 4 is miniaturized and / or installed directly on the antenna 3. Additional modules can thus be dispensed with. The antenna 3 can be connected to the receiver 9 via plugs 10, 11 and an optional antenna amplifier 12. The antenna 2 used as transmitting antenna can likewise be connected to the signal generator 5 and / or the receiver 14 via a plug 13.Miniaturization enables the integration of a complete broadcast receiver directly at the antennas 2, 3 in a so-called remote tuner module or radio tuner module 4, so that the functions present in a conventional broadcast receiver IC can be used for antenna diagnosis.The radio tuner module 4, which is designed, for example, as an integrated circuit, is controlled, for example, by a microprocessor 15 or microcontroller 15, which implements both diagnostic and control functions. This microprocessor 15 can be integrated within the radio tuner module 4 or can be designed as a separate component.Radio tuner modules 4 and microprocessors 15 may have digital interfaces that can output digital clock and data signals. Such interfaces are included in the radio tuner module 4, for example, for transmitting digital audio signals in the I 2 S, SPDIF or TDM format. Interfaces for transmitting digital baseband signals may likewise be included.Furthermore, digital general purpose interfaces (GPIO) suitable for the purpose may also be included in the radio tuner module 4. In particular in the latter, the signal shapes can often also be improved by further functions which can be contained in the components, such as PLL modules, FLL modules, timer / counter modules, PWM modules and the like.Not all of these digital interfaces included in the radio tuner modules 4 are used for the main application proper and therefore can be used for other purposes. The present invention therefore proposes using at least one of the unused digital interfaces of the radio tuner module 4 to generate an RF signal which can be used for checking the operation of the at least one antenna 3 connected to the receiver 9. The antenna 2 used for transmitting the RF signal should be connected as directly as possible to the radio tuner module 4, for example the receiver 14. The antenna 3 used for reception can be connected either directly or indirectly (e.g. via an antenna amplifier 12) to the receiver 9.FIG. 2 is a schematic diagram of a digital signal in the time domain, wherein a magnitude U(t) is depicted over time t.The waveforms of digital signals in the time domain can be converted into a corresponding frequency spectrum by Fourier transformation, as is known.FIG. 3 is a schematic diagram of the digital signal in the frequency domain, with magnitude U(f) plotted against frequency.Digital signals approximately correspond to a trapezoidal signal shape which has a spectrum in the frequency range consisting of fundamental wave and multiple harmonics.The frequency spectrum is defined in particular by a period duration T, a rise time τ Rise( shown in FIG. 2 ) of a signal edge, a fall time τ Fall( shown in FIG. 2 ) of the signal edge, and a pulse ratio or pause ratio τ / T.The period duration T and the pulse ratio or pause ratio τ / T of a digital signal are variable at the time of flight within the defined limits of the interface.The rise time τ Rise and the fall time τ Fall of the signal edge may be adjusted by switching and / or adjusting the driving strength of the interface or amplifier 6 (shown in FIG. 1 ).In addition, the interface can have further possibilities for changing the signal shape, depending on the possibilities of the interfaces and their modules used.By selecting such parameters, it is possible to generate, within the limits of the selected interface, a signal having a spectrum consisting of fundamental and harmonic waves which corresponds to the reception range of the antenna 3 to be diagnosed (illustrated in FIG. 1 ) and is therefore suitable for diagnosing the antenna 3.This interface with the above-mentioned parameters is referred to in the context of the present invention as a digital signal generator 5 (shown in FIG. 1 ) (DSG). The digital signal generator 5 may be part of one of two or more reception paths of the radio tuner module 4 (shown in FIG. 1 ), each reception path including one of the receivers 9, 14 (shown in FIG. 1 ). The digital signal generator 5 can likewise be part of the microcontroller 15 or microprocessor 15.By means of control by the microcontroller 15 or microprocessor 15, the fundamental frequency of the digital signal generator 5 can be varied in order to be able to cover and diagnose uncovered frequency ranges in a plurality of iterations.To diagnose the antenna function, the received signal strength at preselected frequencies is compared to a reference value. If the reference values are within predefined limit values, the antenna function can be considered to be given. Otherwise, an error message is generated. Subsequently, measures for fault diagnosis and repair can be initiated.The reference values used for the comparison can be determined in a number of ways, for example by simulation and calculation of the signal spectrum and inclusion of the expected coupling attenuation between the antennas 2, 3 or they can be determined by measuring a reference vehicle. These reference values can be stored as a table in a control software of the receiver 9.Since the signal used for checking the antenna function can also be received within a specific radius around the vehicle to be checked, and thus represents an interference signal for other systems, the checking must take place within a defined diagnostic mode, which is to be activated as far as possible only in a controlled environment.It is also possible for the environment of the vehicle to interfere with the measurement if external signal sources can be received on the frequencies to be checked.Therefore, a zero measurement with inactive signal generator 5 is to take place first. The results of the measurement at the reference points are stored in a memory of the microprocessor 15.The test signal can be adapted to a target impedance of the antenna system by an amplifier 6, in particular a buffer amplifier or a transimpedance amplifier.This amplifier 6 should have as high a return path attenuation as possible and should also be designed to be switchable, for example by means of the switch 8 (illustrated in FIG. 1 ), in order to avoid influencing the reception quality outside the abovementioned diagnostic mode.Signal shaping of the test signal by means of the at least one bandpass filter 7 (illustrated in FIG. 1 ) may be advantageous in order to avoid undesired influencing of other, unaffected systems.The measurement of the antenna 3 used as a receiving antenna can be carried out by a method with the following sequence:First, a so-called zero measurement of the environment is carried out in order to detect the environment signals in the reception path. For this purpose, a reception field strength of the antenna 3 is detected and stored by the receiver 9 at each defined test frequency in a measured area.In the next step, the signal generator 5, in particular a test signal output of the receiver 14 connected to the antenna 2 used as transmitting antenna, is activated under the selected signal parameters and the amplifier 6, which may be present, is activated.Then, the antenna 2 is connected to the signal generator 5, in particular the test signal output of the receiver 14. This can be done via a suitable switch 8, for example an RF changeover switch or switch-on. This is necessary since the test signal itself, as well as interference from the digital interface, should as far as possible not be coupled to the antenna 2 during normal operation in order to avoid interference between the receivers 9, 14.For the measurement, the receiver 9 connected to the antenna 3 used as receiving antennas 3 is set to a first frequency of the test signal spectrum and a measurement of the signal strength is carried out.This measurement is repeated for a defined number of measurements at previously determined further test frequencies. If necessary, the fundamental frequency of the test signal is also adjusted in order to achieve uncovered frequency ranges.If a predetermined number of the measured values on each test frequency minus the values of the zero measurement are above certain predetermined threshold values, then the antenna 3 can be evaluated as functional.FIG. 4 is a schematic flow diagram of an example diagnostic method:In a step S 1, both receivers 9, 14 (shown in FIG. 1 ) are muted.In a step S2, phase diversity is deactivated if it is active.In a loop L 1, for each test frequency from a plurality of defined test frequencies, the receiver 9 is set to the current test frequency in a step S 3, a field strength value is read out from the receiver 9 as a reference measurement in a step S 4, and the field strength value of the reference measurement is stored in an associated memory cell at the current test frequency in a step S 5.After termination of the loop L 1, a test signal is activated in a step S 6, for example by activating the signal generator 5 (shown in FIG. 1 ).In a step S 7, the amplifier 6 is activated, if present. In a step S 8, the switch 8 (illustrated in FIG. 1 ) is closed, if present.In a loop L 2, a fundamental frequency of the test signal is adjusted for each test frequency from a plurality of defined test frequencies in a step S 9, if necessary. In a step S 10, the receiver 9 is set to the test frequency. In a step S 11, a field strength value is read out from the receiver 9 as a diagnostic measurement and in a step S 12 the field strength value of the diagnostic measurement is stored in an associated memory cell at the current test frequency.After termination of the loop L2, the test signal is deactivated in a step S13. In a step S 14, the switch 8 is opened, if present. In a step S 15, the amplifier 6 (shown in FIG. 1 ) is deactivated, if present and previously activated.In a step S 16, the values of the diagnostic measurements are evaluated and a comparison with the values of the reference measurements is made. Messages are generated which indicate whether the respective values are in order or not in order.In a step S17, the original reception frequencies of the receiver 9 or the receivers 9, 14 are recovered.In a step S18, the phase diversity is reactivated.In a step S19, the muting of the receivers 9, 14 is canceled.List of reference characters1 Slice 2 Antenna 3 Antenna 4 Radio tuner module 5 Signal generator 6 Amplifier 7 Bandpass filter 8 Switch 9 Receiver 10 Plug 11 Plug 12 Antenna amplifier 13 Plug 14 Receiver 15 Microprocessor, microcontroller L 1, L 2 Loop S 1 to S 19 Step t Time T Period duration U(f), U(t) Magnitude τ Fall Fall time τ Rise Rise time

Claims

Diagnostic method for an antenna (3) configured as a receiving antenna and installed in a vehicle part of a vehicle by means of a radio tuner module (4) having at least one receiver (9) and a digital interface configured as a digital signal generator (5) which generates at least one fixed test signal having at least one fundamental wave which is conducted to an antenna (2) configured as a transmitting antenna and installed in a vehicle part of the vehicle which is electromagnetically coupled to the antenna (3) configured as a receiving antenna and is connected to the receiver (9), wherein the receiver (9) and the digital signal generator (5) are controlled by a microcontroller (15) or microprocessor (15) in such a way, the test signal of the signal generator (5) is received by the receiver (9) via the antenna (3) and its magnitude is measured and the function of the antenna (3) configured as a receiving antenna and optionally the function of the antenna (2) configured as a transmitting antenna and / or the electromagnetic coupling of the antennas (2, 3) is evaluated on the basis of said function.Diagnostic method according to Claim 1, characterized in that the defined test signal is also generated by the digital signal generator (5) using at least one harmonic.Diagnostic method according to Claim 1 or 2, characterized in that two receivers (9, 14) are provided, each connected to one of the antennas (2, 3), wherein first both receivers (9, 14) are muted, wherein in a loop (L1) for each test frequency from a plurality of defined test frequencies the receiver (9) is set to a current test frequency, a field strength value is read out from the receiver (9) as a reference measurement and stored, wherein subsequently the test signal is activated, optionally amplified and fed to the antenna (2), wherein in a loop (L2) for each test frequency from a plurality of defined test frequencies the receiver (9) is set to the test frequency, a field strength value is read out from the receiver (9) as a diagnostic measurement and stored, wherein subsequently the test signal is deactivated and the values of the diagnostic measurements are evaluated and compared and evaluated with the values of the reference measurements.A system comprising an antenna (3) configurable as a receiving antenna and installed in a vehicle part of a vehicle, an antenna (2) configurable as a transmitting antenna and installed in a vehicle part of the vehicle, which antenna is electromagnetically coupled to the antenna (3) configured as a receiving antenna, and a radio tuner module (4) having at least one receiver (9) connected to the antenna (3) configured as a receiving antenna, and a digital interface configurable as a digital signal generator (5) in order to generate at least one fixed test signal having at least one fundamental wave and to conduct it to the antenna (2) configured as a transmitting antenna, and furthermore a microcontroller (15) or microprocessor (15), characterized in that the microcontroller (15) or microprocessor (15) is configured to control the receiver (9) and the digital signal generator (5) and to carry out the method according to one of the preceding claims, wherein the radio tuner module (4) is arranged at or near at least one of the antennas (2, 3).System according to Claim 4, characterized in that a further receiver (14) is arranged in the radio tuner module (4) or in another control device which is connected to the radio tuner module (4) via a communication interface.System according to claim 4 or 5, characterised in that the digital signal generator (5) is part of one of the receivers (9, 14) or part of the microprocessor (15) or microcontroller (15).System according to one of Claims 4 to 6, characterized in that the vehicle part in which at least one of the antennas (2, 3) is arranged is a window (1), in particular a front window, rear window or side window.System according to one of Claims 4 to 7, characterized in that both antennas (2, 3) are arranged in the same vehicle part or in different vehicle parts.System according to one of Claims 4 to 8, characterized in that an amplifier (6) for amplifying the test signal and / or for impedance matching the signal generator (5) to the antenna (2) is arranged, and / or in that a bandpass filter (7) for signal shaping and / or impedance matching and / or limiting the frequency range of the test signal is arranged, and / or in that an antenna amplifier (12) is arranged between the antenna (3) configured as a receiving antenna and the receiver (9) connected thereto.The system according to any one of claims 4 to 9, characterized in that the microcontroller (15) or microprocessor (15) is configured to execute the diagnostic method only upon activation of a diagnostic mode.

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