Sensor system, radar apparatus, and method for operating a sensor system

Abstract

The invention relates to a sensor apparatus in which a frequency synchronization signal is provided by a primary processing device to a secondary sensor device. According to the invention, the frequency synchronization signal is provided via the same line that is also used for exchanging data between the primary processing device and the secondary sensor device. Data signals and the frequency synchronization signal are combined by means of frequency multiplexing on the common connecting line between the processing device and the sensor device.

Description

[0001] Description

[0002] title

[0003] Sensor system, radar device and method for operating a sensor system

[0004] Technical field

[0005] The present invention relates to a sensor system and a method for operating a sensor system. The present invention further relates to a radar device with such a sensor system.

[0006] background

[0007] Modern radar systems can comprise multiple radar sensors / radar sensor heads. The individual radar sensors can be connected to a central unit via suitable data links. For example, a parallel data stream containing measurement data in the sensor can be serialized and transmitted to the central unit via a data line, such as a serial cable. Depending on the design, bidirectional data transmission is also possible, allowing, for example, control signals to be transmitted from the central unit to the sensors. In such an arrangement, it may be necessary to operate the individual radar sensors coherently. For this purpose, the radar sensors must be synchronized with each other. German patent application DE 10 2018 117 688 A1 describes, for example, a radar system in which a high-frequency signal is transmitted from a first chip to a second chip via a transmission line.

[0008] Disclosure of the invention

[0009] The present invention provides a sensor system, a radar device, and a method for operating a sensor system with the features of the independent claims. Further advantageous embodiments are the subject of the dependent claims.

[0010] Accordingly, the following is planned:

[0011] A sensor system comprising a primary processing unit and at least one secondary sensor unit. The primary processing unit includes at least one first data interface. Each secondary sensor unit includes a second data interface. The second data interfaces are designed to be connected to one of the first data interfaces in the primary processing unit. A suitable cable may be provided for this purpose. Each of the at least one first data interface of the primary processing unit is designed to receive data signals from a corresponding second data interface of a secondary sensor unit. The data signals are received in a first frequency range.Furthermore, each of the at least one first data interface of the primary processing unit is designed to send a frequency synchronization signal to a corresponding second data interface of a secondary sensor unit. The frequency synchronization signal is transmitted in a second frequency range. This second frequency range differs from the first frequency range. The first and second frequency ranges do not overlap. Specifically, the same line is used for the transmission of the data signals and the frequency synchronization signal between each first data interface and its corresponding second data interface.

[0012] Furthermore, the following is planned:

[0013] A radar device with a sensor system according to the invention. The radar system comprises at least one radar unit. Each of the at least one radar unit comprises a secondary sensor unit. Furthermore, the radar system comprises a central unit with a primary processing unit. In this way, the second data interfaces in the secondary sensor units of the radar units can each be coupled with corresponding first data interfaces of the primary processing unit in the central unit.

[0014] Finally, the following is planned:

[0015] A method for operating a sensor system, in particular a radar device. The method comprises a step for transmitting data signals between a first data interface in the primary processing unit and a second data interface in a secondary sensor unit. Furthermore, the method comprises a step for transmitting a frequency synchronization signal from the first data interface in the primary processing unit to the second data interface in the secondary sensor unit. The data signal is transmitted in a first frequency range. The frequency synchronization signal is transmitted in a second frequency range. The first frequency range and the second frequency range are different. In particular, the first frequency range and the second frequency range do not overlap.The same line is used for the transmission of the data signals and the frequency synchronization signal between the first data interface and the second data interface.

[0016] Advantages of the invention

[0017] The present invention is based on the understanding that modern radar systems can comprise several separate radar sensors or radar sensor heads, which are to be synchronized with each other. One aspect of the present invention is to create an efficient concept for such synchronization of the individual radar sensors, which, if possible, builds upon existing or already required wiring paths.

[0018] In particular, the concept according to the invention is based on the finding that synchronization signals based on frequencies significantly different from the usual frequencies for communicative data exchange can be used to synchronize the individual radar sensors in a distributed sensor system. Based on this finding, the invention provides for transmitting signals for data exchange and frequency synchronization via a common line connection using a frequency division multiplexing method. In this way, the effort required for the cabling of such a sensor system, especially a radar system, can be reduced.

[0019] The concept according to the invention can, in principle, be applied to any sensor arrangement that requires the synchronization of several spatially separated sensor components by means of a synchronization signal, in particular a high-frequency synchronization signal. For example, the concept can be applied to radar systems in which several spatially separated transmitting and receiving components are to be synchronized with one another. For example, such radar systems can be used in motor vehicles for environmental detection.

[0020] According to one embodiment, the first frequency range for transmitting the data signals is lower than the second frequency range for transmitting the frequency synchronization signal. For example, the first frequency range can extend up to a frequency of several tens of megahertz, such as 100 MHz, 200 MHz, 500 MHz, or optionally 1 GHz. The second frequency range is higher and has a lower cutoff frequency that is significantly greater than the maximum frequency of the first frequency range. For example, the second frequency range can be between 1 and 10 GHz, particularly between 3 and 6 GHz. Depending on the application, any other suitable frequency ranges are, of course, also possible.

[0021] According to one embodiment, the at least one first data interface of the primary processing unit is designed to send further data signals to a corresponding second data interface of a secondary sensor unit. The first frequency range, which is also used for the reverse transmission of data signals from the second data interface to the first data interface, can be used for this transmission of further data signals from the first to the second data interface. In this way, bidirectional data transmission between the first and the corresponding second data interface can be realized. However, such bidirectional data transmission does not necessarily have to be symmetrical.In other words, the data rate from the first data interface to the second data interface can differ from the data rate in the reverse direction, from the second data interface to the first data interface. Such a configuration allows, for example, the transmission of measurement data from the sensor device to the processing device and, simultaneously, the transmission of control signals from the processing device to the sensor devices. According to one embodiment, the at least one first data interface and the corresponding second data interface each comprise a diplexing device. The diplexing devices can be designed to combine or separate the data signals in the first frequency range and the frequency synchronization signals in the second frequency range. In principle, for such a combination or separation, a diplexing device can be used.Any suitable hardware structure can be used to separate the signals in the different frequency ranges.

[0022] According to one embodiment, the at least one first data interface can further be configured to provide a DC voltage signal. In particular, the DC voltage signal can be a DC voltage signal for supplying power to a secondary sensor device. This DC voltage signal can also be output to the same line used for transmitting the data signals and the frequency synchronization signal. In this way, no additional line is required for supplying power to the sensor devices.

[0023] According to one embodiment, the second data interface can include a frequency divider designed to divide or reduce the frequency of the received frequency synchronization signal according to a predetermined ratio. Additionally or alternatively, the second data interface can include a frequency multiplier designed to multiply, i.e., increase, the received frequency synchronization signal according to a predetermined factor. In this way, synchronization signals can also be obtained in the secondary sensor devices that differ in frequency from the transmitted frequency synchronization signal. Thus, the frequency synchronization signal between the first and second data interfaces can be selected according to the transmission characteristics of the lines used between the first and second data interfaces. By subsequent increase or...By reducing the received frequency synchronization signal, a synchronization signal suitable for operation in the secondary sensor devices can be generated. Optionally, it is also possible to first generate a reference signal in the primary processing unit and then adapt it, using a frequency multiplier and / or frequency divider, to a frequency or frequency range that is particularly suitable according to the transmission characteristics of the lines between the first and second data interfaces.

[0024] According to one embodiment, the second data interface or another component of the corresponding secondary sensor device is designed to determine, and in particular extract, a clock signal from the data signal in the first frequency range. This clock signal can be provided in the secondary sensor device. For example, such a clock signal can be used as the basis for components such as analog-to-digital converters or similar devices.

[0025] According to one embodiment, the at least one first data interface and the corresponding second data interfaces are each connected to each other by means of a coaxial cable. However, any other suitable cable or wire connections are also possible in principle.

[0026] According to one embodiment, the frequency synchronization signal comprises a frequency signal with a predetermined frequency. According to an alternative embodiment, the frequency synchronization signal can be a variable synchronization signal. In particular, the frequency synchronization signal can, for example, be varied within a predetermined frequency range. For example, the frequency synchronization signal can also be a modulated signal, such as for FMCW or a chirp.

[0027] The above embodiments and further developments can be combined with one another as appropriate. Further embodiments, further developments, and implementations of the invention also include combinations of features of the invention described previously or subsequently with regard to the exemplary embodiments, even if not explicitly mentioned. In particular, those skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the invention.

[0028] Brief description of the drawings

[0029] Further features and advantages of the invention are explained below with reference to the figures. These show:

[0030] Fig. 1 : a schematic representation of a principle diagram of a sensor system according to one embodiment;

[0031] Fig. 2: a schematic representation to illustrate frequency ranges as they underlie a sensor system according to one embodiment;

[0032] Fig. 3: a schematic representation of a principle diagram of a sensor system according to a further embodiment;

[0033] Fig. 4: a schematic representation of a principle diagram of a

[0034] Sensor system according to yet another embodiment; and Fig. 5: a flowchart as it may underlie a method for operating a sensor system according to an embodiment.

[0035] Description of embodiments

[0036] Figure 1 shows a schematic representation of a principle diagram of a sensor system according to one embodiment. The sensor system comprises a primary processing unit 1 and at least one secondary sensor unit 2. Although only a single secondary sensor unit 2 is shown in Figure 1 and the following figures, the present invention is not limited to this. In principle, it is also possible to couple more than one secondary sensor unit 2 with the primary processing unit 1. Furthermore, it is also possible in principle to integrate a sensor unit into the primary processing unit 1.

[0037] The primary processing unit 1 comprises a processor unit 12 and a first data interface 11. If more than one secondary sensor unit 2 is to be coupled with the primary processing unit 1, a separate first data interface 11 can be provided for each secondary sensor unit 2.

[0038] Each secondary sensor device 2 comprises a second data interface 21 and a sensor unit 22. For example, the sensor unit 22 can be an integrated circuit, in particular an MMIC (Monolithic Microwave Integrated Circuit). Such a component can be used, for example, to implement a radar sensor or radar sensor head. However, other suitable sensor units 22 are also possible. The sensor data acquired by the sensor unit 22 can be provided to the second data interface 21. The second data interface 21 can serialize the received data and transmit it via a communication line 3 to the first data interface 11 of the primary processing device 1. The first data interface 11 can then parallelize the received signals and pass them to the processing unit 12.

[0039] Data transmission in the reverse direction is also possible, if necessary. For example, the processing unit 12 can output control data, which is serialized by the first data interface 11 and then transmitted via data line 3 to the second data interface 21. The second data interface 21 can parallelize the received data and then pass it to the sensor unit 22. With such bidirectional data transmission, the same data rate can be selected in both directions. However, it is also fundamentally possible to implement asymmetric data transmission, in which the data rate from the first data interface 11 to the second data interface 21 differs from the data rate in the opposite direction.

[0040] For serial data transmission between the first data interface 11 and the second data interface 21, a suitable clock rate can be selected, which may conform to predefined specifications and which can meet the requirements for the data rate to be transmitted. As a rule, a clock rate of a few kilohertz, possibly a few tens of kilohertz up to 100 MHz, possibly 200 MHz or 500 MHz is sufficient for the data stream to be transmitted. Accordingly, the data transmission between the first data interface and the second data interface will take place in a first frequency range corresponding to this clock rate.

[0041] Furthermore, a frequency generator can be installed in the primary processing unit 1.

[0042] 13, for example, a local oscillator may be provided. This frequency generator 13 can generate a frequency synchronization signal suitable for synchronizing the secondary sensor devices 2. In this way, for example, synchronization of the transmitted and / or received radar signals can be achieved in radar applications. This frequency synchronization signal typically has a frequency significantly higher than the frequency range in which data exchange takes place between the first data interface 11 and the second data interface 21. For example, the frequency synchronization signal can be in the range between 1 and 10 GHz, particularly between 3 and 6 GHz. Depending on the application, other frequencies or frequency ranges are of course also possible.In any case, the frequency synchronization signal lies in a second frequency range, which differs from the first frequency range for data transmission between the first data interface 11 and the second data interface 21.

[0043] A diplexer 11a can be provided in the first data interface 11 for combining the frequency synchronization signal and the data signals. Similarly, a diplexer 21a can also be provided in the second data interface 21, which separates the frequency synchronization signal from the data signals or feeds the corresponding data signals into the primary processing unit 1 for the transmission of the sensor data.

[0044] The frequency synchronization signal extracted by the diplexer 21a in the second data interface 21 can then be provided to the sensor unit 22. Thus, the sensor unit 22 can be synchronized according to the frequency synchronization signal from the frequency generator 13 in the primary processing unit 1.

[0045] The frequency synchronization signal can, for example, be a synchronization signal with a fixed, constant frequency. However, it is also possible to generate a frequency signal with a variable frequency as the frequency synchronization signal and transmit it to the secondary sensor devices 2 according to the previously described concept. For example, the frequency synchronization signal can be modulated for a frequency-modulated continuous wave (FMCW) radar or a chirp. Depending on the application, other modulations of the frequency synchronization signal are also possible.

[0046] Figure 2 illustrates the relationship between the first frequency range I for data transmission and the second frequency range II, in which the frequency synchronization signal is transmitted. As shown in this diagram, data transmission typically takes place in a first frequency range I within a frequency band that lies below the frequency band in which the frequency synchronization signal is provided. Thus, the data signals and the frequency synchronization signal can be easily combined and separated using the aforementioned diplexers 11a and 21a without the signals significantly influencing each other. Reference numeral 101 denotes the data signal and 102 the frequency synchronization signal.

[0047] For the transmission between the first data interface 11 in the primary processing unit 1 and the second data interface 21 in the secondary sensor unit 2, the first data interface 11 and the second data interface 21 can be connected, for example, by means of a coaxial cable. The frequency characteristics and / or attenuation characteristics of the line 3 used and between the first data interface 11 and the second data interface 21 can be taken into account, if necessary.

[0048] For example, is a [missing information] required for the operation of the secondary sensor devices 2?

[0049] If a frequency synchronization signal is required that lies outside the specifications of the line 3 used, a frequency synchronization signal that lies within the specifications of the line 3 used can first be transmitted via line 3. Subsequently, another synchronization signal suitable for the operation of the sensor unit 22 can be generated based on the transmitted frequency synchronization signal.

[0050] As shown, for example, in Figure 3, a frequency multiplier 24a or a frequency divider 24b can be provided in the secondary sensor device 2 for this purpose. This allows the frequency of the received frequency synchronization signal to be increased or decreased as appropriate. If necessary, several, possibly different, signals can also be generated from the received frequency synchronization signal and provided to the sensor unit 22.

[0051] Optionally, it is also possible to first generate an initial frequency signal in the primary processing unit 1 using the local frequency generator 13 and to adapt this signal for transmission via the connecting line 3 by multiplying or dividing the frequency. For this purpose, a frequency multiplier or frequency divider 14 can be provided, for example.

[0052] As further shown in Figure 3, the clock rate used can optionally be extracted from the transmitted data signals and provided as the clock signal CLK to the sensor unit 22. For example, this clock signal CLK can be used as the basis for an analog-to-digital converter or other components in the sensor unit 22.

[0053] Figure 4 shows a schematic representation of a block diagram of a

[0054] Sensor device according to a further embodiment.

[0055] The sensor device according to Figure 4 differs from the sensor devices described previously, in particular, in that a DC voltage source 15 is provided in the primary processing unit 1. This DC voltage source 15 can provide a DC voltage suitable for powering the secondary sensor device 2. For this purpose, the DC voltage provided by the DC voltage source 15 can also be transmitted to the secondary sensor device 2 via the connecting line 3. Since this DC voltage is a signal with a frequency of zero, it can be easily extracted by means of a low-pass filter in the second data interface 21.In this way, a single connecting line 3, in particular a coaxial line, is sufficient to supply the sensor device 2 with energy, to realize the data exchange between the primary processing device 1 and the secondary sensor device 2 and, in addition, to provide a high-frequency frequency synchronization signal.

[0056] It is understood that all previously described embodiments can be combined with one another in any suitable manner and that the description in the individual figures does not constitute a limitation of the present invention.

[0057] Figure 5 shows a schematic representation of a flowchart underlying a method for operating a sensor device according to one embodiment. In particular, the method according to the invention can be used, for example, to operate a radar device with one or more external radar sensor heads. In step S1, data signals can be transmitted between a first data interface 11 of a primary processing unit 1 and a second data interface 21 of a secondary sensor unit 2. The transmission of these data signals can take place in a first frequency range. In parallel, in step S2, a frequency synchronization signal can be transmitted from the first data interface 11 of the primary processing unit 1 to the second data interface 21 of the secondary sensor unit 2.The frequency synchronization signal is located in a second frequency range, which differs significantly from the first frequency range used for data transmission. Specifically, the frequency synchronization signal can be transmitted in a higher frequency range than the first frequency range used for data transmission between the first and second data interfaces.

[0058] As previously explained in connection with the sensor device, the data signals and the frequency synchronization signal are transmitted via the same line 3. Optionally, this line 3 can also be used to supply power to the secondary sensor device 2 by means of a DC voltage.

[0059] In summary, the present invention relates to a sensor device in which a frequency synchronization signal is provided to a secondary sensor device by a primary processing device. It is provided that the frequency synchronization signal is supplied via the same line that is also used for data exchange between the primary processing device and the secondary sensor device. Data signals and the frequency synchronization signal are combined onto the common connection line between the processing device and the sensor device by means of frequency division multiplexing.

Claims

Claims 1. Sensor system comprising: a primary processing unit (1) with at least one first data interface (11); and at least one secondary sensor unit (2) with each a second data interface (21);wherein a second data interface (21) of a secondary sensor device (2) is coupled to a corresponding first data interface (11) of the primary processing device (1), wherein the at least one first data interface (11) of the primary processing device (1) is configured to receive data signals from the corresponding second data interface (21) of a secondary sensor device (2) in a first frequency range, and wherein the at least one first data interface (11) of the primary processing device (1) is configured to send a frequency synchronization signal to the corresponding second data interface (21) of a secondary sensor device (2) in a second frequency range, wherein the second frequency range is different from the first frequency range, and wherein for the transmission of the data signals and the frequency synchronization signal between the at least one first; The same lines (3) are used for the data interface (11) and a corresponding second data interface (21).

2. Sensor system according to claim 1, wherein the first frequency range is lower than the second frequency range and the two frequency ranges do not overlap.

3. Sensor system according to claim 1 or 2, wherein the at least one first data interface (11) of the primary processing device (1) is designed to send further data signals to the corresponding second data interface (21) of a secondary sensor device (2) in a first frequency range.

4. Sensor system according to one of claims 1 to 3, wherein the at least one first data interface (11) and the corresponding second data interface (21) each comprise a diplex device (11a, 21a) designed to combine and / or separate the data signals in the first frequency range and frequency synchronization signals in the second frequency range.

5. Sensor system according to one of claims 1 to 4, wherein the at least one first data interface (11) is further designed to provide a DC voltage signal, in particular a DC voltage signal for powering a secondary sensor device (2), and to output it on the same lines (3) which are used for transmitting the data signals and the frequency synchronization signal.

6. Sensor system according to one of claims 1 to 5, wherein the second data interface (21) comprises a frequency divider (24b) and / or a frequency multiplier (24a) designed to produce a frequency of the to decrease or increase the received frequency synchronization signal in a predetermined ratio.

7. Sensor system according to one of claims 1 to 6, wherein the second data interface (21) is further designed to determine a clock signal (CLK) using a clock rate for the transmission of the data signals.

8. Sensor system according to one of claims 1 to 7, wherein the at least one first data interface (11) of the primary processing unit (1) and the corresponding second data interface (21) of the at least one secondary sensor unit (2) are each connected to each other via a coaxial cable (3).

9. Radar device with a sensor system according to one of claims 1 to 8, wherein the radar system comprises at least one radar device with a secondary sensor device (2) and a central unit with a primary processing device (1).

10. Method for operating a sensor system, in particular a radar device, comprising the steps: Transmission (S1) of data signals between a first data interface (11) in a primary processing unit (1) and a second data interface (21) in a secondary sensor unit (2); and Transmission (S2) of a frequency synchronization signal from the first data interface (11) in the primary processing unit (1) to the second data interface (21) in the secondary sensor unit (2), wherein the data signal is transmitted in a first frequency range and the frequency synchronization signal is transmitted in a second frequency range that is different from the first frequency range, and wherein for the transmission of the data signals and the The same lines (3) are used for the frequency synchronization signal between the first data interface (11) and the second data interface (21).

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