DE102018130360A1 - Methods and devices for the transmission of data via an electrical power supply line - Google Patents

Abstract

A transmission unit (310) for transmitting data (314) via an electrical supply line (302) is described. The transmission unit (310) comprises an energy supply module (311), which comprises at least one switching element (331, 332) and which is set up by PWM operation of the switching element (331, 332) electrical energy in the form of an output signal (304) on the supply line (302). Furthermore, the transmission unit (310) comprises a modulation unit (312), which is set up as a function of a target value (315) for the output signal (304), a PWM control signal (313) for the PWM operation of the switching element (331, 332) ), the PWM control signal (313) comprising a sequence of PWM pulses (401, 402) for a sequence of periods (403). In addition, the modulation unit (312) is set up to position the PWM pulses (401, 402) of the individual periods (403) as a function of data (314) to be sent within the respective period (403).

Description

The invention relates to methods and units or devices for transmitting data via an electrical supply line, in particular for transmitting data via a supply line of an electrical vehicle electrical system of a vehicle.

A vehicle comprises an electrical vehicle electrical system, via which a large number of electrical consumers of the vehicle are supplied with electrical energy. Furthermore, a vehicle typically includes communication lines for the transmission of data within the vehicle. The electrical power supply and the data communication typically lead to a significant effort (in particular with regard to installation space, costs and weight) for the wiring in a vehicle, in particular when there are special requirements in terms of redundancy (such as for fully automated or highly automated vehicles) .

To save communication lines, Power Line Communication (PLC) can be used in a vehicle to transmit data via power supply lines. However, the provision of transmitters and receivers for PLC is typically associated with a relatively high outlay, which is not always justifiable, in particular at relatively low data rates.

The present document deals with the technical task of enabling a particularly efficient transmission of data via a power supply line, in particular for an electrical vehicle electrical system.

The task is solved by the independent claims. Advantageous embodiments include described in the dependent claims. It is pointed out that additional features of a claim dependent on an independent claim without the features of the independent claim or only in combination with a subset of the features of the independent claim can form a separate invention that is independent of the combination of all features of the independent claim can be made the subject of an independent claim, a divisional application or a late application. This applies in the same way to the technical teachings described in the description, which can form an invention that is independent of the features of the independent claims.

According to one aspect, a transmission unit for transmitting data via an electrical supply line (e.g. via a supply line of an electrical vehicle electrical system of a vehicle) is described. The transmission unit comprises an energy supply module which comprises at least one switching element and which is set up to provide electrical energy in the form of an output signal on the supply line by PWM operation of the at least one switching element. A switching element can be a semiconductor-based switching element and / or a transistor, e.g. a MOSFET (metal oxide semiconductor, field effect transistor) and / or an IGBT (insulated-gate bipolar transistor).

The power supply module can e.g. comprise a half bridge with a first (e.g. a high side) switching element and a second (e.g. a low side) switching element, which are operated in a complementary and / or alternating manner on the basis of a PWM control signal. Alternatively or in addition, the energy supply module can include a low-pass filter, in particular an LC element, for generating the output signal. In particular, the energy supply module can comprise a voltage converter, for example a DC voltage converter. The at least one switching element of the energy supply module can thus be used to provide electrical energy for the operation of one or more electrical consumers via a supply line. The output signal can be a specific output voltage, in particular a DC output voltage, for the energy supply of the one or more electrical consumers.

In addition, the transmission module comprises a modulation unit which is set up to generate a PWM control signal for the PWM operation of the switching element as a function of a target value for the output signal, the PWM control signal comprising a sequence of PWM pulses for a sequence of periods. The periods with a certain period frequency can follow one another. The period frequency of the sequence of periods can e.g. 100kHz, 500 kHz or more.

The modulation unit can be set up to set the pulse width of a PWM pulse as a function of the target value, e.g. to regulate. In particular, the modulation unit can be set up to acquire sensor data in relation to the output signal. The pulse width of a PWM pulse of the PWM control signal can then be adapted as a function of the sensor data, in particular in order to regulate the output signal to the target value.

The pulse mode of the PWM pulses of the PWM control signal can thus be used to set the output signal (for example a DC output voltage) as a function of a target value. The individual PWM pulses can be used as standard be arranged at a certain standard position within the respective periods (eg in the middle of the individual periods).

The modulation unit can be set up to position the PWM pulses of the individual periods as a function of the data to be sent within the respective period. In particular, the PWM pulses can be positioned or shifted at least partially deviating from the standard position within the respective periods (e.g. shifted towards the beginning of the period or towards the end of the period).

For example, the modulation unit can be set up to position the PWM pulse of a period at the standard position, e.g. middle in relation to the period if no data and / or if a first data value (e.g. the value "0") should be transmitted. Furthermore, the modulation unit can be set up to shift the PWM pulse of the period deviating from the standard position to a period start or to a period end of the period if a second data value (e.g. the value "0") is to be transmitted.

By shifting the PWM pulses of a PWM control signal to generate an output signal (e.g. to generate a DC output voltage), data for a communication connection can be transmitted in an efficient manner. The one or more switching elements already used for the energy supply can be used to modulate the data to be transmitted onto the output signal. This enables weight, cost and space-efficient data communication (in particular for a vehicle).

The energy supply module can be designed to generate the output signal in such a way that the positioning of the PWM pulses of the PWM control signal, which is adjusted as a function of the data, is reflected as a (possibly high-frequency) ripple of the output signal. In particular, the adapted positioning of the PWM pulses can lead to a modulation or to a change in the shape of the ripple of the output signal. A receiving unit can then determine the positioning of the PWM pulses from a received signal corresponding to the output signal in order to extract the data to be transmitted. In particular, the ripple of the received signal can be extracted (e.g. by a high-pass filter) and analyzed (e.g. by a time-frequency transformation) to extract the data.

The modulation unit can be set up to shift the PWM pulses of two directly successive periods in a complementary manner relative to the standard position. For example, one of the two PWM pulses can be shifted towards the beginning of the period and the other of the two PWM pulses in a corresponding manner towards the end of the period. By complementarily shifting pairs of PWM pulses, impairments in the data transmission to the output signal used for the energy transmission can be reduced in a particularly efficient manner (since on average no change in the pulse width and / or the period frequency is brought about by the data transmission). Furthermore, the complementary shifting enables a particularly efficient and reliable recovery of the data by means of a time-frequency transformation (e.g. by means of a Fourier transformation).

The modulation unit can thus be set up to transmit one or more bits of data per pair of periods of the PWM control signal by adjusting the position of the PWM pulses of the PWM control signal. In particular, the modulation unit can be set up to position the PWM pulse of a period at K different positions within the period in order to send log ₂ K bits of data, where K = 2.4 or more. The data rate can be increased by using different distances from the standard position of a PWM pulse.

A period with the period T can have a normalized length of 1. The standard position can e.g. be at 0.5. The K different positions can e.g. each be spaced apart by at least 0.1, 0.2 or more. For example, a PWM pulse can be shifted 0.1, 0.2 or more relative to the standard position within a period.

In preparation for the transmission of data, the modulation unit can be set up to position the PWM pulses of several periods at at least partially different positions within the respective period in order to send a synchronization word. The PWM pulses of (directly) subsequent periods of the PWM control signal can then be positioned depending on the data to be sent within the respective period in order to transmit data directly after the synchronization word. The reliability of the data transmission can be further increased by inserting a synchronization word. In particular, a reception unit can be enabled to synchronize itself with the transmission process of the transmission unit by detecting the synchronization word.

The modulation unit can be set up to determine the pulse width of a PWM pulse. The pulse width can typically be a value have between 0 and 1 with respect to the period T. Furthermore, the modulation unit can be set up to only position the PWM pulse for the transmission of data at a position of the respective period that deviates from the standard position if the pulse width is smaller than a maximum width. The maximum width can be, for example, 0.5, 0.6, 0.7, 0.8 or more. The transmission of data by means of the shifting of PWM pulses can thus be limited to PWM pulses with a relatively small pulse width. The quality of the data transmission can be increased in this way.

According to a further aspect, a receiving unit for extracting or receiving data from a received signal received via an electrical supply line is described. The received signal can correspond to the output signal generated by the transmitting unit described in this document. The receiving unit can e.g. Be part of an electrical consumer that is operated with the electrical energy provided by the received signal and / or with the supply line. The received signal can e.g. be a DC supply voltage for the electrical consumer.

The receiving unit comprises an evaluation unit which is set up to transform a processing signal derived from the received signal into the frequency range by means of a time-frequency transformation (for example by means of a DFT or an FFT transformation). By applying a time-frequency transformation, a channel signal can be provided for at least one frequency channel (i.e. for at least one frequency band). The channel signal for a frequency channel indicates the energy of the processing signal in the frequency channel.

mit k = 0, 1, 2, ..., bereitzustellen, wobei $f_{pwm}=\frac{1}{T}$

die Periodenfrequenz des PWM-Steuersignals ist. Es können somit Kanalsignale für ein oder mehrere Frequenzkanäle bereitgestellt werden, die in zuverlässiger Weise eine Daten-abhängige Verschiebung der PWM Pulse des PWM-Steuersignals anzeigen, mit dem das Empfangssignal von einer Sendeeinheit generiert wurde.The frequency channel or the frequency of the frequency channel can depend on the period frequency of the PWM control signal that was used to generate the received signal (or to generate the output signal corresponding to the received signal). In particular, the evaluation unit can be set up to provide a channel signal for one or more frequency channels, each with a frequency of $\left(1+\mathrm{2nd}k\right)\frac{f_{pwm}}{\mathrm{2nd}},$

with k = 0, 1, 2, ..., where $f_{pwm}=\frac{1}{T}$

is the period frequency of the PWM control signal. Channel signals can thus be provided for one or more frequency channels, which reliably indicate a data-dependent shift of the PWM pulses of the PWM control signal with which the received signal was generated by a transmitting unit.

Furthermore, the evaluation unit is set up to determine the data on the basis of the at least one channel signal, in particular on the basis of the absolute value or the amount of the at least one channel signal. In particular, the evaluation unit can be set up to compare the channel signal with at least one peak threshold value in order to determine the data. If the peak threshold value is exceeded at a certain point in time, it may indicate that a PWM pulse has shifted at the certain point in time (or in the corresponding period of the PWM control signal) (and thus the second data value, for example “1”) , was transferred). On the other hand, falling below the peak threshold value at the specific point in time may indicate that at the specific point in time (or in the corresponding period of the PWM control signal) there has been no shift of a PWM pulse (and thus no data or the first data value, for example "0" was transferred).

A reception unit is thus described which enables efficient and reliable extraction of data from a reception signal which was generated by PWM operation of at least one switching element.

The receiving unit can comprise a (possibly analog) filter unit for providing a filtered received signal. In this case, the filter unit can be set up to at least partially compensate for a low-pass filtering of the output signal corresponding to the received signal caused by the corresponding transmission unit (e.g. in order to reconstruct the PWM control signal). The evaluation unit can then be set up to derive the processing signal from the filtered received signal (e.g. by sampling the filtered received signal). The quality of the data extraction can be increased by filtering the received signal.

The evaluation unit can be set up to detect a synchronization word by comparing the channel signal with a threshold value. In particular, a synchronization time can be recognized at which a synchronization word is received. The data can then be extracted from the channel signal on the basis of the synchronization time at detection times which are dependent on the period frequency. For example, starting from the synchronization time, data can be extracted at detection times spaced by T or 2T. The recognition of a synchronization word thus enables the receiving unit to reliably synchronize with the corresponding transmitting unit. In this way, the quality of the data transmission can be further improved.

The evaluation unit can be set up to determine a pulse width of a PWM pulse of the PWM control signal in the period on the basis of the processing signal for a period of the PWM control signal (which was used to generate the received signal). Furthermore, the evaluation unit can be set up to extract data from the channel signal only when the pulse rate determined is smaller than the maximum width. The maximum width can be, for example, 0.5, 0.6, 0.7, 0.8 or more. The transmission of data by means of the shifting of PWM pulses can thus be limited to PWM pulses with a relatively small pulse width. The quality of the data transmission can be increased in this way.

According to a further aspect, a communication unit is described which comprises both a transmitting unit and a receiving unit. Two communication units can then carry out bidirectional communication via a supply line, data from the transmission unit of the first communication unit being received by the reception unit of the second communication unit, and data from the transmission unit of the second communication unit being received by the reception unit of the first communication unit. The PWM control signals of the transmission units of the two communication units can have different period frequencies in order to enable reliable differentiation of the data transmitted by the respective transmission unit. The period frequencies are preferably not integral multiples of one another.

Alternatively or additionally, the different transmission units can use different degrees of displacement of the PWM pulses of the respective PWM control signals in order to enable the different reception units to distinguish the data of the different transmission units from one another.

As an alternative or in addition, the different transmission units can use different (disjoint, non-overlapping) time intervals for transmitting data. Time-division multiplexing from different transmitter units can thus take place in order to use a common supply line for data transmission.

For example, DC converters connected in series can perform bidirectional communication. The one or more switching elements of the first DC converter result in a modulated ripple in the output voltage of the first converter (in order to send data to the second DC converter). Furthermore, the one or more switching elements of the second DC-DC converter cause a modulated ripple of the input voltage of the second converter (to send data to the first DC-DC converter).

Alternatively or additionally, DC converters connected in parallel can perform bidirectional communication via a common supply line at the respective outputs of the DC converters.

According to a further aspect, an electrical vehicle electrical system (e.g. for a vehicle) is described, which comprises the transmitting unit and / or receiving unit described in this document.

According to a further aspect, a (road) motor vehicle (in particular a passenger car or a truck or a bus or a motorcycle) is described, which comprises the transmitting unit and / or receiving unit described in this document and / or the electrical system described in this document.

According to a further aspect, a method for sending data via an electrical supply line is described. The method comprises generating a PWM control signal as a function of a target value for an output signal, the PWM control signal comprising a sequence of PWM pulses for a sequence of periods. In addition, the method comprises positioning the PWM pulses of the individual periods within the respective period as a function of data to be transmitted, so that a PWM control signal with at least partially shifted PWM pulses results. Furthermore, the method comprises operating at least one switching element in PWM operation as a function of the PWM control signal (with the at least partially shifted PWM pulses) in order to provide the output signal on a supply line.

According to a further aspect, a method for extracting data from a received signal received via an electrical supply line is described. The method comprises transforming a processing signal derived from the received signal into a frequency range by means of a time-frequency transformation in order to provide a channel signal for at least one frequency channel, the frequency channel being dependent on a period frequency of a PWM control signal that was used to generate the received signal. Furthermore, the method comprises determining the data based on the channel signal.

According to a further aspect, a software (SW) program is described. The SW program can be set up to run on a Processor (for example on a control unit of a vehicle) to be executed, and thereby to perform one of the methods described in this document.

According to a further aspect, a storage medium is described. The storage medium can comprise a software program which is set up to be executed on a processor and thereby to carry out one of the methods described in this document.

It should be noted that the methods, devices and systems described in this document can be used both alone and in combination with other methods, devices and systems described in this document. Furthermore, any aspect of the methods, devices and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways.

• 1 ein beispielhaftes Fahrzeug mit einem elektrischen Bordnetz;
• 2 ein beispielhaftes elektrisches Bordnetz eines Fahrzeugs;
• 3a ein beispielhaftes Datenübertragungssystem;
• 3b einen beispielhaften Gleichspannungswandler;
• 4 beispielhafte PWM Pulse eines PWM-Steuersignals;
• 5a eine beispielhafte Auswerteeinheit einer Empfangseinheit;
• 5b ein beispielhaftes Kanalsignal;
• 6a ein Ablaufdiagramm eines beispielhaften Verfahrens zum Senden von Daten; und
• 6b ein Ablaufdiagramm eines beispielhaften Verfahrens zum Empfang von Daten.

The invention is described in more detail below with the aid of exemplary embodiments. Show

• 1 an exemplary vehicle with an electrical system;
• 2nd an exemplary electrical system of a vehicle;
• 3a an exemplary data transmission system;
• 3b an exemplary DC-DC converter;
• 4th exemplary PWM pulses of a PWM control signal;
• 5a an exemplary evaluation unit of a receiving unit;
• 5b an exemplary channel signal;
• 6a a flow diagram of an exemplary method for sending data; and
• 6b a flow diagram of an exemplary method for receiving data.

As stated at the beginning, the present document deals with the technical task of enabling efficient data transmission via an electrical supply line. In this context shows 1 an exemplary vehicle 100 with an electrical system 200 , and 2nd shows an exemplary electrical system 200 for a vehicle 100 , in particular for an at least partially electrically powered vehicle 100 . The electrical system 200 includes a charging socket 201 through which the electrical energy storage 102 of the vehicle 100 can be charged (e.g. at a vehicle-external charging station). Furthermore, the vehicle 100 a charger 202 comprise, which is set up an AC charging current in a DC charging current for charging the energy store 102 to convert (for an AC charge). The charger 202 may include an AC / DC converter. For example, the charger 202 be set up a DC charging current for the energy storage 102 to generate on the basis of one or more phases of a three-phase current. On the charging socket 201 the one or more phases of the three-phase current can then be provided.

Furthermore, the electrical system 200 an inverter 204 comprise, which is set up, a (possibly multi-phase) alternating current for operating a drive machine 205 of the vehicle 100 to generate. In addition, one or more electrical consumers 203 directly to the (high-voltage) electrical system 200 be connected (e.g. heating or steering of the vehicle 100 ).

The on-board electrical system also includes 200 a (DC) converter 207 to supply an electrical consumer 212 with a reduced supply voltage (e.g. at 48V or 12V). Operation of the converter 207 and / or the charger 202 and / or the inverter 204 can by a control unit 101 to be controlled.

A vehicle 100 or an electrical system 200 can therefore use one or more converters 202 , 207 , 204 include being a transducer 202 , 207 , 204 typically actively operated switching elements, in particular transistors such as MOSFETs, in order to generate an output signal (eg a DC voltage). The one or more switching elements are typically controlled periodically with a PWM (pulse width modulated) control signal in order to generate an output signal. PWM control of a switching element can be used to efficiently modulate transmission data on the output signal generated by the switching element.

3a shows an exemplary transmission system 300 with a transmitter unit 310 and a receiving unit 320 . The transmitter unit includes 310 a DC-DC converter in the example shown 311 (commonly referred to as a power supply module) that is configured to have an input voltage 303 into an output voltage (ie into an output signal 304 ) on an energy transmission line 302 to walk. The converter 311 becomes dependent on a periodic PWM control signal 313 operated, the PWM control signal 313 from a modulation unit 312 is generated. The PWM control signal 313 depending on a target value 315 for the Output voltage 304 generated (e.g. by means of a regulator that is set up, the output voltage 304 to the target value 315 to regulate). The setting of the output voltage 304 to a target value 315 can by adjusting the pulse width of the PWM pulses of the PWM control signal 313 respectively.

Furthermore, the PWM control signal 313 depending on transmission data 314 are generated, in particular the position or the phase of the PWM pulses of the PWM control signal 313 within one or more periods depending on the transmission data 314 can be changed or modulated.

The one or more switching elements of the transmitter unit 310 , especially the converter 311 , depending on the (modulated) PWM control signal 313 operated to the output signal 304 (in particular an output voltage) to generate that via the power supply line 302 is transmitted. The PWM control signal is modulated 313 to modulate the output signal 304 .

The receiving unit 320 of the transmission system 300 comprises a processing unit 322 , which is set up, the transmission data (as reception data 324 ) from the output signal 304 on the supply line 302 to extract. The receiving unit further comprises 320 in the in 3a example shown another DC-DC converter 321 .

3b shows an exemplary converter 311 with a half bridge made of a hide side switching element 331 and a low side switching element 332 . The switching elements 331 , 332 are complementary to the PWM control signal 313 driven to on the basis of an input voltage or an input signal 303 at the entrance 333 an output voltage or an output signal 304 at the exit 334 to provide.

As already explained above, the sending unit 310 , especially the modulation unit 312 , be set up, the position or the phase of one or more PWM pulses of a PWM control signal 313 depending on the transmission data 314 to postpone. This is exemplified in 4th shown. In particular shows 4th a sequence of pulses 401 , 402 a PWM control signal 313 for a corresponding sequence of periods 403 . Here are the PWM pulses 401 by default arranged in a standard position (for example, in the middle of a period 403 ). The PWM pulses arranged at the standard position 401 are in 4th shown in dashed lines. The pulse width of the individual PWM pulses 401 can depend on the target value 315 for the output signal 304 can be set.

For the transmission of data 314 can single pulses 401 relative to the default position. In particular, a PWM pulse 401 at the end of a period 403 or at the beginning of a period 403 be moved there. The pulses can be used in a particularly advantageous manner 401 of two consecutive periods 403 in a complementary manner to each other to move data 314 transferred to. In the in 4th The example shown is the first pulse 401 one pulse pair towards the end of the period and the second pulse 401 of the pulse pair shifted towards the beginning of the period. By pairwise, complementary shifting of pulses 402 can be caused in an efficient and reliable manner that the mean pulse width of the pulses 402 of the PWM control signal 313 (for setting the target value 315 for the output signal 304 ) remains unchanged.

For the transmission of data 314 can therefore use the pulses 401 of a pulse pair can be shifted (eg to transmit the binary value "1") or not shifted (eg to transmit the binary value "0"). As a result, at least one bit can be transmitted with each pair of pulses.

Possibly. can the "amplitude" or the extent or degree of shift of pulses 401 , 402 can be used to increase the amount of data to be encoded. For example, per pulse 401 , 402 or four different shift values per pulse pair, each with 2 bits of data 314 transferred to.

In the lower part of 4th becomes a difference signal 404 shown the difference between a PWM control signal 313 with pulses not shifted 401 and a PWM control signal 313 with shifted pulses 402 displays. How out 4th can be seen, the difference signal 404 a period that is the duration of two periods 403 of the PWM control signal 313 corresponds. The frequency spectrum of the difference signal 404 thus has a significant component at half the pulse or period frequency. For the detection of the shift of PWM pulses 402 and thus for demodulation of the transmission data 314 can thus be the frequency spectrum of the output signal 304 corresponding received signal at the receiving unit 320 are analyzed (especially at half the pulse or period frequency).

The evaluation unit 322 the receiving unit 320 can be set up the output signal 304 the sending unit 310 corresponding reception signal at the reception unit 320 with a high pass filter to filter a DC component of the Eliminate received signal, and possibly a low-pass function of the transmitter unit 310 to compensate at least partially. Furthermore, the (filtered) received signal can be sampled at a specific sampling frequency in order to provide a digital (filtered) received signal (which is also referred to in this document as a processing signal). A section of the processing signal which corresponds to a pair of pulses can then be transformed by means of a time-frequency transformation (for example by means of an FFT or a DFT) in order to provide a frequency spectrum with a multiplicity of frequency bands or frequency channels. A section of the received or processing signal can thus be extracted by means of a window function and transformed into the frequency range. Overlapping window functions are preferably used. In other words, the (sliding) windows for the selection of sections of the received or processing signal are preferably chosen to overlap.

betrachtet werden, mit k = 0,1, 2, ..., wobei $f_{pwm}=\frac{1}{T},$

und wobei T die Periodendauer einer Periode 403 des PWM Steuersignals 313 ist.One or more frequency bands or frequency channels can then be analyzed for the presence or absence of a shift and / or for the degree of shift of the pulses 401 , 402 of the PWM control signal 313 to detect. In particular, the frequency bands or frequency channels for the frequencies $\left(1+\mathrm{2nd}k\right)\frac{f_{pwm}}{\mathrm{2nd}},$

are considered, with k = 0.1, 2, ..., where $f_{pwm}=\frac{1}{T},$

and where T is the period of a period 403 of the PWM control signal 313 is.

5a shows an exemplary evaluation unit 322 a receiving unit 320 . The (filtered) receive signal 501 is in a (sliding) register 502 saved. Using a window function 503 (overlapping) sections of the received signal 501 extracted and by means of a time-frequency transformation 504 transformed into the frequency domain. It will then at least be a suitable channel 505 for the detection of the modulation of the PWM control signal 313 selected.

The evaluation unit 322 can thus be set up the input signal 501 with a window function 503 and subsequent Fourier transformation 504 to edit so different frequency channels 505 are available. The right frequency channel 505 can be chosen and the amount can be calculated (in units 507 ). Through a matched filter unit 508 a start sequence or a synchronization word can be detected (for example using a threshold value comparison 509 ). A control logic 510 can then (starting from the start sequence) control the sampling process of the channel signal (for example by means of a threshold value comparison 511 ), and the data received 324 in a register 506 provide.

) des Empfangssignals 501. Das Kanalsignal 521 umfasst Peaks bzw. Spitzen, wenn eine Verschiebung der Pulse 402 von Pulspaaren vorliegt. Diese Peaks bzw. Spitzen können über einen Vergleich mit einem Peak-Schwellenwert 522 detektiert werden. 5b shows an exemplary channel signal 521 of a frequency channel 505 (e.g. the basic channel for the frequency $\frac{f_{pwm}}{\mathrm{2nd}}$

) of the received signal 501 . The channel signal 521 includes peaks when there is a shift in the pulses 402 of pulse pairs is present. These peaks or peaks can be compared to a peak threshold 522 can be detected.

To transmit data, one or more synchronization bits can first be transmitted to the receiving unit 320 to enable yourself with the transmitter unit 310 to synchronize and / or to recognize the beginning of a message. In the example shown, four synchronization bits with the values " 1010 "Used. The evaluation unit can be used for synchronization 322 a first exceeding of the threshold 522 at the time 531 and then falling below the threshold value 522 at the time 532 detect. The middle between the two times 531 , 532 lying time 533 can then be viewed as the time of synchronization. It can then start from the synchronization time 533 at intervals of 2T signal values 534 , in particular bits, of the received data 324 in the received signal 501 can be detected. The received signal values 534 can in a register 506 to be written.

A communication method is thus described which, for example, communication between two DCDC converters 311 , 321 enables. Here, symmetries and asymmetries in the switching behavior of one or more switching elements 331 , 332 of a converter 311 used to data 314 transferred to. The switching behavior of the one or more switching elements 331 , 332 is at the ripple voltage of the output signal 304 of the converter 311 measurable. Recipient 302 can be set up to amplify this signal, ie the ripple voltage, with an amplifier circuit. Furthermore, the data sent 314 be recovered using digital signal processing. The actual operation of the converter 311 is, in particular due to a suitable choice of modulation of the PWM control of the switching elements 331 , 332 , not significantly influenced.

The communication method described in this document can be applied in an analogous manner to modules in which electrical loads and / or capacitors are based on one or more switching elements 331 , 332 switched will. This means that, in particular, various modules of an electrical system can 200 of a vehicle 100 be used by means of existing hardware data 314 over the power transmission lines 302 an electrical system 200 transferred to. The transmission lines 302 be designed for high-voltage voltages (e.g. 200V, 300V or more) or for low-voltage voltages (e.g. 60V or less, about 48V or 12V).

It should be pointed out that the described transmission method alternatively or additionally enables frequency modulation and / or phase modulation. Furthermore, (alternatively or in addition to a DCDC converter 311 ) every digital activation of a consumer 203 , 212 be used for message transmission. In addition, bidirectional communication connections can also be established with the described method.

6a shows a flow diagram of an exemplary method 600 for sending data 314 via an electrical supply line 302 . The procedure 600 can, for example, by a transmitter unit 310 be carried out. The supply line 302 can be designed electrical energy for the operation of one or more electrical consumers 203 , 212 transferred to. In particular, the supply line 302 be provided for a direct current to supply energy to one or more electrical consumers 203 , 212 transferred to.

The procedure 600 includes generating 601 a PWM control signal 313 depending on a target value 315 for an output signal 304 . The output signal 304 in particular be a DC output voltage, which is used to operate one or more electrical consumers 203 , 212 to the supply line 302 is placed. The target value 315 can display a setpoint of the desired output voltage. The PWM control signal 313 can be generated to bring the DC output voltage to the target value 315 discontinue (especially regulate).

aufeinander folgen. Die Pulsweite der PWM Pulse 401, 402 kann in Abhängigkeit von dem Zielwert 315 eingestellt und/oder angepasst werden, insbesondere um eine DC-Ausgangsspannung (d.h. das Ausgangssignal 304) auf den Zielwert 315 einzustellen.The PWM control signal 313 comprises a sequence of PWM pulses 401 , 402 for a corresponding sequence of periods 403 . The periods 403 each have a (constant) period T or the periods 403 can with a period frequency $f_{pwm}=\frac{1}{T}$

follow each other. The pulse width of the PWM pulses 401 , 402 can depend on the target value 315 can be set and / or adjusted, in particular around a DC output voltage (ie the output signal 304 ) to the target value 315 adjust.

The procedure also includes 600 positioning 602 the PWM Pulse 401 , 402 of the individual periods 403 within the respective period 403 depending on the data to be sent 314 . In other words, the PWM pulse 401 , 402 of the PWM control signal 313 can depend on data to be sent 314 relative to a standard position within the respective period 403 be moved (e.g. towards the beginning or end of the period). The shift of the individual PWM pulses 401 , 402 then shows the data to be sent 314 (eg one or more bits of the data to be sent 314 ) at.

The procedure 600 also includes operating 603 at least one switching element 331 , 332 in a PWM operation depending on the PWM control signal 313 to the output signal 304 on a supply line 302 to provide. For example, a half bridge with two switching elements 331 , 332 depending on the PWM control signal 313 operated to a DC output voltage as an output signal 304 to provide. The PWM operation of the one or more switching elements 331 , 332 a modulation of the output signal 304 that the shift of each PWM pulse 401 , 402 of the PWM control signal 313 displays. Thus, data can be stored in a reliable and efficient manner 314 via an electrical power supply line 302 be transmitted.

6b shows a flow diagram of an exemplary method 610 to extract data 324 from one via an electrical supply line 302 received signal 501 . The procedure 610 can, for example, by a receiving unit 310 be carried out. The receive signal 501 can do this according to the procedure 600 generated output signal 304 correspond.

The procedure 610 involves transforming 611 one of the received signal 501 derived processing signal by means of a time-frequency transformation 504 in the frequency range to for at least one frequency channel 505 a channel signal 521 to provide. For example, the received signal 501 filtered and sampled to provide the processing signal. Furthermore, the processing signal can be transformed into the frequency range, for example by means of a DFT (Discrete Fourier Transform) and / or an FFT (Fast Fourier Transform). Sequentially overlapping window sections of the processing signal can be transformed. The at least one frequency channel 505 can correspond to a frequency band in the frequency domain.

The frequency channel 505 , especially the frequency of the frequency channel 505 depends on the period frequency of the PWM control signal 313 from that for the generation of the received signal 501 (or to generate the received signal 501 corresponding output signal 304 a transmission unit 310 ) has been used. In particular, at least one frequency channel 505 be considered in which a data dependent shift of PWM pulses 401 , 402 of the PWM control signal 313 can be detected.

The procedure also includes 610 investigating 612 of the data 324 based on the channel signal 521 . In particular, it can be checked for this purpose (eg by means of a threshold value comparison) whether the channel signal 521 Has energy (and thus a shift of PWM pulses 401 , 402 for data transmission) or not (and therefore no displacement of PWM pulses 401 , 402 is done).

The measures described in this document allow data to be stored efficiently 314 via an electrical supply line 302 transferred to. Hardware for coupling the data can be used for the electrical supply 314 be used. This enables cost-efficient, space-saving and weight-efficient data transmission, in particular in an electrical system 200 of a vehicle 100 .

The present invention is not restricted to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are only intended to illustrate the principle of the proposed methods, devices and systems.

Claims (20)

Transmitting unit (310) for transmitting data (314) via an electrical supply line (302); the transmitter unit (310) comprising - A power supply module (311) which comprises at least one switching element (331, 332) and which is set up to provide electrical energy in the form of an output signal (304) on the supply line (302) by PWM operation of the switching element (331, 332); and - a modulation unit (312) which is set up - Depending on a target value (315) for the output signal (304) to generate a PWM control signal (313) for the PWM operation of the switching element (331, 332); wherein the PWM control signal (313) comprises a sequence of PWM pulses (401, 402) for a sequence of periods (403); and - To position the PWM pulses (401, 402) of the individual periods (403) depending on the data to be sent (314) within the respective period (403). Transmitter unit (310) according to Claim 1 , wherein the modulation unit (312) is set up - to position the PWM pulse (401) of a period (403) at a standard position, in particular in the center with respect to the period (403), if no data (314) and / or a first one Data value to be transferred; and - to shift the PWM pulse (402) of the period (403) deviating from the standard position to a period start or to a period end of the period (403) when a second data value is to be transmitted. Transmitting unit (310) according to one of the preceding claims, wherein the modulation unit (312) is set up to shift the PWM pulses (402) from two directly successive periods (403) in a complementary manner relative to a standard position. Transmitting unit (310) according to one of the preceding claims, wherein the modulation unit (312) is set up by adjusting the position of the PWM pulses (402) of the PWM control signal (313) one or more bits of data (314) per pair of periods ( 403) of the PWM control signal (313). Transmitting unit (310) according to one of the preceding claims, wherein the modulation unit (312) is set up to position the PWM pulse (401, 402) of a period (403) at K different positions within the period (403) in order to log ₂ K bits to send to data (314). Transmitting unit (310) according to one of the preceding claims, wherein the modulation unit (312) is set up, - in preparation for sending data (314) to position the PWM pulses (401, 402) from several periods (403) at at least partially different positions within the respective period (403) in order to send a synchronization word; and - To position the PWM pulses (401, 402) of subsequent periods (403) of the PWM control signal (313) depending on the data to be sent (314) within the respective period (403). Transmitting unit (310) according to one of the preceding claims, wherein the energy supply module (311) is designed to generate the output signal (304) in such a way that the PWM pulses (401, 402) of the PWM are adjusted as a function of the data (314) Control signal (313) in a ripple of the output signal (304). Transmitting unit (310) according to one of the preceding claims, wherein the energy supply module (311) is a half-bridge with a comprises a first switching element (331) and a second switching element (332), which are operated in a complementary and / or alternating manner on the basis of the PWM control signal (313). Transmitting unit (310) according to one of the preceding claims, wherein the energy supply module (311) comprises a low-pass filter, in particular an LC element, for generating the output signal (304). Transmitting unit (310) according to one of the preceding claims, wherein the energy supply module (311) comprises a voltage converter, in particular a DC voltage converter. Transmitting unit (310) according to one of the preceding claims, wherein - A period frequency of the sequence of periods (403) is 100 kHz, 500 kHz or more, and / or - The modulation unit (312) is set up to set, in particular to regulate, a pulse width of a PWM pulse (401, 402) as a function of the target value (315); and or - The modulation unit (312) is set up, - acquire sensor data in relation to the output signal (304); and - Adapting the pulse width of a PWM pulse (401, 402) as a function of the sensor data, in particular in order to regulate the output signal (304) to the target value (315). Transmitting unit (310) according to one of the preceding claims, wherein the modulation unit (312) is set up, - to determine a pulse width of a PWM pulse (401, 402); and - To position the PWM pulse (401, 402) for the transmission of data (314) at a position deviating from a standard position only if the pulse width is smaller than a maximum width. Receiving unit (320) for extracting data (324) from a received signal (501) received via an electrical supply line (302); the receiving unit (320) comprising an evaluation unit (322) which is set up - transforming a processing signal derived from the received signal (501) into a frequency range by means of a time-frequency transformation (504) in order to provide a channel signal (521) for at least one frequency channel (505); wherein the frequency channel (505) depends on a period frequency of a PWM control signal (313) which was used to generate the received signal (501); and - To determine the data (324) based on the channel signal (521). Receiving unit (320) according to Claim 13 , wherein - the receiving unit (320) comprises a filter unit for providing a filtered received signal (501); - The filter unit is in particular set up to at least partially compensate for a low-pass filtering of an output signal (304) corresponding to the received signal (501), which is effected by a corresponding transmitting unit (310); and - the evaluation unit (322) is set up to derive the processing signal from the filtered reception signal (501). Receiving unit (320) according to one of the Claims 13 to 14 , wherein the evaluation unit (322) is set up to compare the channel signal (521) with at least one peak threshold value (522) in order to determine the data (324). Receiving unit (320) according to one of the Claims 13 to 15 , wherein - the evaluation unit (322) is set up a channel signal (521) for one or more frequency channels (505) with a frequency of $\left(1+\mathrm{2nd}k\right)\frac{f_{pwm}}{\mathrm{2nd}},$

with k = 0, 1, 2, ... to provide; and - $f_{pwm}=\frac{1}{T}$

is the period frequency. Receiving unit (320) according to one of the Claims 13 to 16 , wherein the evaluation unit (322) is set up to - detect a synchronization word by comparing the channel signal (521) with a threshold value (522) at a synchronization time (533); and - extracting the data (324) from the channel signal (521) starting from the synchronization time (533) at detection times which are dependent on the period frequency. Receiving unit (320) according to one of the Claims 13 to 16 , wherein the evaluation unit (322) is set up, on the basis of the processing signal for a period (403) of the PWM control signal (313), a pulse width of a PWM pulse (402) of the PWM control signal (313) in the period (403) determine; and - only to extract data (324) from the channel signal (521) if the determined pulse mode is smaller than a maximum width. Method (600) for sending data (314) over an electrical supply line (302); the method (600) comprising - generating (601) a PWM control signal (313) as a function of a target value (315) for an output signal (304); where the PWM control signal (313) comprises a sequence of PWM pulses (401, 402) for a sequence of periods (403); - positioning (602) the PWM pulses (401, 402) of the individual periods (403) within the respective period (403) as a function of data (314) to be sent; and - operating (603) at least one switching element (331, 332) in a PWM mode in dependence on the PWM control signal (313) in order to provide the output signal (304) on a supply line (302). Method (610) for extracting data (324) from a received signal (501) received via an electrical supply line (302); the method comprising (610) Transforming (611) a processing signal derived from the received signal (501) into a frequency range by means of a time-frequency transformation (504) in order to provide a channel signal (521) for at least one frequency channel (505); wherein the frequency channel (505) depends on a period frequency of a PWM control signal (313) which was used to generate the received signal (501); and - Determining (612) the data (324) based on the channel signal (521).

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