Diagnostic method 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) having at least one receiver (9) and a digital interface which is configured as a digital signal generator (5) which generates at least one defined test signal having at least one fundamental, which test signal is conducted to an antenna (2) configured as a transmitting antenna and installed in a vehicle part of the vehicle, which antenna is electromagnetically coupled to the antenna (3) which is 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 that the test signal of the signal generator (5) is received by the receiver (9) via the antenna (3) and the magnitude thereof is measured and used to evaluate 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).

Description

[0001] Diagnostic procedure for a receiving antenna and system

[0002] 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.

[0003] EP 0 816 859 A2 describes a diagnostic method and a diagnostic system for vehicle antenna panes with at least one antenna, in particular with antennas configured for diversity operation, each of which is selected by a diversity processor and connected to the receiver. For diagnostic purposes, the antennas are subjected to a test signal by means of a transmitting antenna, and the resulting antenna signals are evaluated. For fast, reliable, and cost-effective diagnosis of the antennas, the test signal is generated using a transmitting antenna integrated into the antenna pane, and the antenna signals generated in one and / or the other antenna(s) based on this test signal are evaluated.

[0004] DE 200 19677 U1 describes an antenna system with a plurality of antennas which can be connected in predetermined combinations via a combination unit to at least two receivers, with a signal processing unit for evaluating the output signals of the receivers and with a control unit by means of which at least one of the antennas can be switched to transmission mode in order to carry out a self-test, wherein this antenna transmits test signals at 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 in order to carry out the self-test the reception levels of the second receiver are recorded as actual values ​​and compared with predetermined target values.DE 102017 108638 A1 describes a tuner for the mobile reception of high-frequency signals in vehicles, comprising 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 is arranged on the printed circuit board for realizing at least one partial function of the tuner, wherein at least one region of a housing part consists of a heat-conductive material with high thermal conductivity and the at least one heat-critical electronic component is connected to this region in a heat-transferring manner.

[0005] The invention is based on the object of specifying 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.

[0006] 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.

[0007] Advantageous embodiments of the invention are the subject of the subclaims.

[0008] According to the invention, a diagnostic method is proposed for an antenna configured as a receiving antenna and installed in a vehicle part of a vehicle by means of a radio tuner module with at least one receiver and a digital interface which is configured as a digital signal generator which generates at least one defined test signal with at least one fundamental wave.The test signal is routed to an antenna configured as a transmitting antenna and installed in a vehicle part, which is electromagnetically coupled to the antenna configured as a receiving antenna, which is connected to the receiver. The receiver and the digital signal generator are controlled by a microcontroller or microprocessor such that the test signal from the signal generator is received by the receiver via the antenna, its magnitude is measured, and based on this, 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 that serves as a receiving antenna outside of the diagnostic function can also be used as a transmitting antenna. Due to the approximate reciprocity of antennas, it can also be used as a transmitting antenna.

[0009] In one embodiment, the predetermined test signal is further generated by the digital signal generator with at least one harmonic.

[0010] In one embodiment, two receivers are provided, each connected to one of the antennas, wherein initially 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 from the receiver as a reference measurement and stored, wherein the test signal is then 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 as a diagnostic measurement and stored, wherein the test signal is then deactivated and the values ​​of the diagnostic measurements are evaluated and compared with the values ​​of the reference measurements and assessed.

[0011] 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 the receiving antenna, and a radio tuner module with at least one receiver connected to the antenna configured as the receiving antenna, as well as a digital interface configurable as a digital signal generator to generate at least one specified test signal with at least one fundamental wave and to transmit it to the antenna configured as the transmitting antenna, and further comprising a microcontroller or microprocessor. The microcontroller or microprocessor is configured to control the receiver and the digital signal generator and to carry out the method described above.The radio tuner module is arranged on or near at least one of the antennas and can be miniaturized. In one embodiment, a further receiver is arranged in the radio tuner module or in another control unit connected to the radio tuner module via a communications interface. The further receiver can be connected to the antenna configured as a transmitting antenna.

[0012] In one embodiment, the digital signal generator is part of one of the receivers or part of the microprocessor or microcontroller.

[0013] In one embodiment, the vehicle part in which at least one of the antennas is arranged is a window, in particular a windscreen, rear window or side window.

[0014] In one embodiment, both antennas are arranged in the same vehicle part or alternatively in different vehicle parts.

[0015] In one embodiment, an amplifier is arranged for amplifying the test signal and / or for impedance matching of the signal generator to the antenna. Furthermore, a bandpass filter can be arranged for signal shaping and / or impedance matching and / or limiting the frequency range of the test signal. Furthermore, an antenna amplifier can be arranged between the antenna configured as a receiving antenna and the receiver connected to it.

[0016] In one embodiment, the microcontroller or microprocessor may be configured to execute the diagnostic method only when a diagnostic mode is activated.

[0017] The motor vehicle can be, for example, a passenger car, a commercial vehicle or a bus.

[0018] According to the present invention, the antenna function is tested by using an existing digital interface to generate a defined RF spectrum of a test signal, as well as processing 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 antenna diagnosis by using a digital interface of a radio receiver IC contained in the receiver to generate a test signal, which is applied to an antenna for transmitting the test signal, and by using a second antenna to receive the test signal.

[0019] The inventive solution enables the diagnosis of antenna function without external devices for signal generation or evaluation. A further advantage lies in the use of unused interfaces for generating an antenna test signal, particularly because the costs of additional components for generating an RF signal, such as frequency synthesizers, comb generators, step-recovery diodes, or similar, can be saved.

[0020] In contrast to the prior art described above, the solution according to the invention makes it possible, through 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.

[0021] The miniaturization enables the integration of a complete radio receiver directly on the antenna structures, in a so-called remote tuner module, so that the functions present in a conventional radio receiver IC can be used for antenna diagnostics.

[0022] Embodiments of the invention are explained in more detail below with reference to drawings.

[0023] Showing:

[0024] Fig. 1 is a schematic view of a windscreen of a motor vehicle with two antennas and a radio tuner module connected to the antennas, Fig. 2 is a schematic diagram of a digital signal in the time domain,

[0025] Fig. 3 is a schematic diagram of a digital signal in the frequency domain, and Fig. 4 is a schematic program flow chart of a diagnostic method.

[0026] Corresponding parts are provided with the same reference numerals in all figures.

[0027] Figure 1 is a schematic view of a pane 1, for example, a rear window, of a motor vehicle. The pane 1 has two antennas 2, 3, which are incorporated into the pane 1 or mounted thereon in the form of conductor tracks. Also shown is a radio tuner module 4 connected to the antennas 2, 3, which can also be used to diagnose the antennas 2, 3.

[0028] In another embodiment, the window 1 may have only one antenna 2, 3, while a second antenna 2, 3 is installed in another window 1 or another component of the same motor vehicle.

[0029] 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 can 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 it. The radio tuner module 4 has two receivers 9, 14, in particular radio receivers, 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, which can then be evaluated by the receiver 9.In a further embodiment, the radio tuner module 4 may have only one receiver 9, 14, wherein a further receiver 9, 14 is arranged in a control unit (not shown) which is connected to the radio tuner module 4 via a communication interface.

[0030] The signal strength of the test signal received by receiver 9 provides information about the function of antenna 3 used as the receiving antenna.

[0031] According to the invention, the radio tuner module 4 is miniaturized and / or installed directly on the antenna 3. This eliminates the need for additional components. The antenna 3 can be connected to the receiver 9 via connectors 10, 11 and an optional antenna amplifier 12. The antenna 2 used as the transmitting antenna can also be connected to the signal generator 5 and / or the receiver 14 via a connector 13.

[0032] The miniaturization enables the integration of a complete radio 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 radio receiver IC can be used for antenna diagnostics.

[0033] The radio tuner module 4, which is designed 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 designed as a standalone component.

[0034] Radio tuner modules 4 and microprocessors 15 may have digital interfaces that can output digital clock and data signals. Such interfaces are used, for example, for transmitting digital audio signals in the 2S, SPDIF, or TDM format are included in the radio tuner module 4. Interfaces for transmitting digital baseband signals can also be included.

[0035] Furthermore, digital multi-purpose interfaces (GPIO) suitable for this purpose can also be included in the radio tuner module 4. Especially with the latter, the signal waveforms can often be enhanced by additional functions that may be included in the components, such as PLL modules, FLL modules, timer / counter modules, PWM modules, and the like.

[0036] Not all of these digital interfaces contained in the radio tuner modules 4 are used for the actual main application and can therefore 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 to test the functionality of the at least one antenna 3 connected to the receiver 9. The antenna 2 used to transmit the RF signal should, if possible, be connected directly to the radio tuner module 4, for example the receiver 14. The antenna 3 used for reception can be connected to the receiver 9 either directly or indirectly (e.g., via an antenna amplifier 12).

[0037] Figure 2 is a schematic diagram of a digital signal in the time domain, showing a magnitude ll(t) versus time t.

[0038] The waveforms of digital signals in the time domain can be converted into a corresponding frequency spectrum using Fourier transformation.

[0039] Figure 3 is a schematic diagram of the digital signal in the frequency domain, with the magnitude ll(f) plotted against frequency.

[0040] Digital signals approximately correspond to a trapezoidal signal shape, which has a spectrum in the frequency range consisting of a fundamental wave and several harmonics.

[0041] The frequency spectrum is characterized in particular by a period T, a rise time TRise (shown in Figure 2) of a signal edge, a fall time T Fa ii (shown in Figure 2) of the signal edge, as well as a pulse ratio or pause ratio T / T.

[0042] The period T as well as the pulse ratio or pause ratio T / T of a digital signal can be changed at runtime within the defined limits of the interface.

[0043] The rise time TRj Se and the fall time T Fa ii of the signal edge can be adjusted by wiring and / or adjusting the driver strength of the interface or amplifier 6 (shown in Figure 1).

[0044] In addition, the interface can have further options for changing the signal shape, depending on the capabilities of the interfaces used and their modules.

[0045] By selecting such parameters, a signal with a spectrum consisting of fundamental and harmonic waves can be generated within the limits of the selected interface. This signal corresponds to the reception range of the antenna 3 to be diagnosed (shown in Figure 1) and is thus 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 Figure 1) (DSG). The digital signal generator 5 can be part of one of two or more reception paths of the radio tuner module 4 (shown in Figure 1), wherein each reception path includes one of the receivers 9, 14 (shown in Figure 1). The digital signal generator 5 can also be part of the microcontroller 15 or microprocessor 15.

[0046] By means of control by the microcontroller 15 or microprocessor 15, the fundamental frequency of the digital signal generator 5 can be changed in order to cover and diagnose uncovered frequency ranges in several iterations.

[0047] To diagnose antenna function, the received signal strength at preselected frequencies is compared with a reference value. If the reference values ​​are within predefined limits, the antenna is considered to be functioning properly. Otherwise, an error message is generated. Following this, measures for fault diagnosis and repair can be initiated.

[0048] The reference values ​​used for comparison can be determined in several ways, for example, by simulating and calculating the signal spectrum and incorporating the expected coupling loss between antennas 2 and 3, or they can be determined by measuring a reference vehicle. These reference values ​​can be stored as a table in the control software of receiver 9.

[0049] Since the signal used to check the antenna function can also be received within a certain radius of the vehicle being tested and thus represents an interference signal for other systems, the test must be carried out within a defined diagnostic mode, which should ideally only be activated in a controlled environment.

[0050] It is also possible that the vehicle's surroundings may interfere with the measurement if external signal sources can be received on the frequencies to be checked.

[0051] Therefore, a zero measurement should first be performed with the signal generator 5 inactive. The measurement results at the reference points are stored in a memory of the microprocessor 15. The test signal can be adjusted to a target impedance of the antenna system by an amplifier 6, in particular a buffer amplifier or a transimpedance amplifier.

[0052] This amplifier 6 should have the highest possible return path attenuation and should also be switchable, for example by means of the switch 8 (shown in Figure 1), in order to avoid influencing the reception quality outside the above-mentioned diagnostic mode.

[0053] Signal shaping of the test signal by means of the at least one bandpass filter 7 (shown in Figure 1) can be advantageous in order to avoid undesired influences on other, unaffected systems.

[0054] The measurement of antenna 3 used as a receiving antenna can be carried out using a procedure with the following sequence:

[0055] First, a so-called zero measurement of the environment is performed to detect the ambient signals in the reception path. For this purpose, the receiver 9 measures and stores the received field strength of antenna 3 at each defined test frequency within a measured area.

[0056] 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 the transmitting antenna, is activated under the selected signal parameters and the amplifier 6, if present, is activated.

[0057] The antenna 2 is then connected to the signal generator 5, specifically the test signal output of the receiver 14. This can be done via a suitable switch 8, for example, an RF selector switch or a power switch. This is necessary because the test signal itself, as well as interference from the digital interface, should not be coupled to the antenna 2 during normal operation, in order to avoid interference between the receivers 9, 14.

[0058] For the measurement, the receiver 9 connected to the antenna 3 used as the receiving antenna is tuned to a first frequency of the test signal spectrum, and a signal strength measurement is performed. This measurement is repeated for a defined number of measurements at previously determined additional test frequencies. If necessary, the fundamental frequency of the test signal is also adjusted to reach uncovered frequency ranges.

[0059] If a predetermined number of the measured values ​​on each test frequency less the values ​​of the zero measurement are above certain predetermined thresholds, then antenna 3 can be assessed as functional.

[0060] Figure 4 is a schematic program flow chart of an exemplary diagnostic procedure:

[0061] In a step S1, both receivers 9, 14 (shown in Figure 1) are muted.

[0062] In step S2, a phase diversity is deactivated if it is active.

[0063] In a loop L1, for each test frequency from several defined test frequencies, the receiver 9 is set to the current test frequency in a step S3, a field strength value is read out from the receiver 9 as a reference measurement in a step S4 and the field strength value of the reference measurement is stored in a memory cell assigned to the current test frequency in a step S5.

[0064] After the loop L1 has ended, a test signal is activated in a step S6, for example by activating the signal generator 5 (shown in Figure 1).

[0065] In step S7, amplifier 6 is activated, if present. In step S8, switch 8 (shown in Figure 1) is closed, if present.

[0066] In a loop L2, a fundamental frequency of the test signal is adjusted for each test frequency from several specified test frequencies in a step S9, if necessary. In a step S10, the receiver 9 is set to the test frequency. In a step S11, a field strength value is read out from the receiver 9 as a diagnostic measurement, and in a step S12, the field strength value of the diagnostic measurement is stored in a memory cell assigned to the current test frequency. After the end of the loop L2, the test signal is deactivated in a step S13. In a step S14, the switch 8 is opened, if present. In a step S15, the amplifier 6 (shown in Figure 1) is deactivated, if present and previously activated.

[0067] In step S16, the values ​​of the diagnostic measurements are evaluated and compared with the values ​​of the reference measurements. Messages are generated indicating whether the respective values ​​are OK or not.

[0068] In a step S17, the original reception frequencies of the receiver 9 or the receivers 9, 14 are restored.

[0069] In a step S18, the phase diversity is reactivated.

[0070] In a step S19, the muting of the receivers 9, 14 is canceled.

Claims

Mercedes-Benz Group AG Patent claims 1. 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 configured as a digital signal generator (5) that generates at least one defined test signal with at least one fundamental wave, which is passed 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) in such a way,that 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., 2. Diagnostic method according to claim 1, characterized in that the defined test signal is further generated by the digital signal generator (5) with at least one harmonic.

3. 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 initially 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) and stored as a reference measurement, 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 as Diagnostic measurement is read out from the receiver (9) and stored, whereby the test signal is then deactivated and the values ​​of the diagnostic measurements are evaluated and compared and assessed with the values ​​of the reference measurements.

4. System comprising an antenna (3) that is configurable as a receiving antenna and installed in a vehicle part of a vehicle, an antenna (2) that is 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) with at least one receiver (9) connected to the antenna (3) configured as a receiving antenna, as well as a digital interface that is configurable as a digital signal generator (5) to generate at least one specified test signal with at least one fundamental wave and to transmit it to the antenna (2) configured as a transmitting antenna, further comprising a microcontroller (15) or microprocessor (15), characterized in thatthat 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 on or near at least one of the antennas (2, 3).

5. 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.

6. System according to claim 4 or 5, characterized 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).

7. 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 windscreen, rear window or side window.

8. 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.

9. System according to one of claims 4 to 8, characterized in that an amplifier (6) is arranged for amplifying the test signal and / or for impedance matching of the signal generator (5) to the antenna (2) and / or that a bandpass filter (7) is arranged for signal shaping and / or impedance matching and / or limiting the frequency range of the test signal and / or that an antenna amplifier (12) is arranged between the antenna (3) configured as a receiving antenna and the receiver (9) connected thereto.

10. System according to one of claims 4 to 9, characterized in that the microcontroller (15) or microprocessor (15) is configured to execute the diagnostic method only when a diagnostic mode is activated.

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