EP2813040A1

EP2813040A1 - Arrangement and method for generating a substantially sinusoidal synchronisation pulse

Info

Publication number: EP2813040A1
Application number: EP13701241.5A
Authority: EP
Inventors: Gerald Nitsche; Massoud MOMENI
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2012-02-06
Filing date: 2013-01-21
Publication date: 2014-12-17
Also published as: CN104094569B; KR20140122719A; TW201338490A; US9294261B2; JP5986645B2; JP2015509343A; US20150030111A1; DE102012201711A1; CN104094569A; WO2013117415A1; TWI648977B; KR102016775B1

Abstract

The invention relates to a reception arrangement (3) for a control device in a vehicle, comprising a voltage generator (30) for generating a synchronisation pulse, said synchronisation pulse being generated with a predetermined shape and a predetermined time behaviour inside predetermined specification limits, wherein the reception arrangement (3) outputs the synchronisation pulse for synchronising a signal transmission via a data bus (5) to at least one sensor (7). The invention further relates to a method for generating such a synchronisation pulse. According to the invention, the voltage generator (30) comprises a voltage amplifier (36) which, on the basis of a reference voltage (Uref), generates the synchronisation pulse substantially as a sinusoidal oscillation.

Description

Description title

ARRANGEMENT AND METHOD FOR PRODUCING AN ESSENTIALLY SINUS-MADE SYNCHRONIZATION PULSE

State of the art

The invention relates to a receiving arrangement for a control device in a vehicle according to the preamble of independent claim 1 and an associated method for generating a synchronization pulse according to the preamble of independent claim 10.

For transmission of sensor data to a central control unit (ECU) in a vehicle, peripheral sensors for occupant protection systems mostly use power interfaces (e.g., PAS4, PSI5). In the case of the latest generation of current interfaces (PSI5), synchronizing enables bus operation with several sensors on one receiver. For the function of the synchronization, a power clock in the form of a voltage pulse is generated by the central control unit (ECU), which is detected by the sensors on the bus and marks the beginning of a new cycle for data transmission. This voltage pulse is called a synchronization pulse and is generated with the aid of current sources and current sinks, which charge or discharge the bus load. Typically, this voltage pulse is repeated every 500 με.

For a synchronous bus system to function with one or more sensors, it is important that the synchronization pulse has a specific shape and timing for all possible bus configurations and operating conditions. Therefore, in known synchronous bus systems, a trapezoidal synchronization pulse P _T shown in FIG. 3 is generally used with a predetermined edge steepness. Here, the edge steepness is between a slope of a first Characteristic curve representing a lower limit Vu and an edge subunit of a second characteristic representing an upper limit Vo. During synchronous bus operation, the trapezoidal shape of the synchronization pulse P _T leads to increased electromagnetic radiation (EMC) in the frequency spectrum of the signal transmission due to the high harmonic content. This can be counteracted to some extent, for example, by a synchronization _pulse P _Tr shown in FIG. 4, which has a trapezoidal shape with four rounded corners. German Offenlegungsschrift DE 10 2009 001 370 A1 describes a receiving device for receiving current signals, a circuit arrangement having such a receiving device, and a method for transmitting current signals via a bus system. The receiving device described comprises at least two bus connection devices for receiving current signals from a plurality of transmitters, each bus connection device being designed for connection to at least one bus connection in each case, and a control device for outputting synchronization pulses to the bus connection devices for synchronizing the transmitters. The bus connection devices output the synchronization pulses with at least one time offset to the several transmitters, the synchronization pulses each having a trapezoidal shape with rounded corners.

DISCLOSURE OF THE INVENTION The receiving arrangement according to the invention for a control unit in a vehicle having the features of independent patent claim 1 and the method according to the invention for generating a synchronization pulse having the features of independent claim 10 have the advantage that the sinusoidal design of the synchronization pulse within the predetermined limits the lowest possible electromagnetic radiation, in particular in the spectral range of signal transmission (100 kHz to 300 kHz), can be achieved.

The essence and advantage of the invention is not only to round off the corners of the synchronization pulse, but to optimize the whole shape in such a way, that the electromagnetic radiation is limited as possible to the range of the fundamental waves of the synchronization pulse.

Embodiments of the present invention provide a receiver assembly for a controller in a vehicle having a voltage generator for generating a synchronization pulse that generates the synchronization pulse within predetermined specification limits having a predetermined shape and timing. The receiving arrangement outputs the synchronization pulse for synchronization of a signal transmission via a data bus to at least one sensor. According to the invention, the voltage generator comprises a voltage amplifier which generates the synchronization pulse essentially as a sine oscillation based on a reference voltage. In addition, a method for generating a synchronization pulse for synchronizing a subsequent signal transmission between a receiving arrangement and at least one sensor via a data bus in a vehicle is proposed. The synchronization pulse is generated within predetermined specification limits with a predetermined shape and a predetermined temporal behavior and transmitted from the receiving device to the at least one sensor. According to the invention, the synchronization pulse is generated essentially as a sine oscillation based on a reference voltage. The synchronization pulse can preferably be transmitted from the receiving arrangement to the at least one sensor before or at the beginning of the signal transmission between the at least one sensor and the receiver arrangement. The measures and refinements recited in the dependent claims advantageous improvements of the independent claim 1 receiving arrangement for a control unit in a vehicle are possible. It is particularly advantageous that the voltage generator comprises a digital drive circuit and a digital-to-analog converter, which essentially generate sinusoidal reference voltage and output to the voltage amplifier.

In an advantageous embodiment of the receiving arrangement according to the invention, a first voltage supply can provide a supply voltage for the voltage amplifier. In addition, a second voltage supply supply voltages for the digital drive circuit, the digital-to-analog converter and provide for at least one other circuit, which is connectable to the data bus. To output the synchronization pulse, for example, a first switching unit can separate the at least one further circuit from the data bus, and a second switching unit can connect the voltage amplifier to the data bus. The first and second switching units can be implemented, for example, as a changeover switch. This advantageously makes possible a very robust realization of the synchronization pulse and a reduced electromagnetic radiation. In addition, the control of the voltage amplifier can be completely outsourced to the digital part of the circuit, which can lead to an area-efficient solution due to the ever more progressive scaling of semiconductor technology. The at least one further circuit of the receiver arrangement can be disconnected from the data bus during the synchronization pulse, while the voltage generator is activated to generate the synchronization pulse and coupled to the data bus.

In a further advantageous embodiment of the receiving arrangement according to the invention, a common voltage supply can provide a supply voltage for the voltage amplifier, the digital control circuit and the digital-to-analog converter. Furthermore, the voltage amplifier can provide the supply voltage for at least one further circuit, which is connected to the data bus. By combining the two separate power supplies and the elimination of the two switching units, the complexity of the architecture of the receiving arrangement can be advantageously reduced and the bus voltage can be taken over without undue oscillation or discontinuities by the synchronization pulse. The advantages of this embodiment of the invention lie, on the one hand, in a more surface-efficient circuit and, on the other hand, in a continuous or continuous transition between the normal bus voltage and the synchronous voltage. chronization voltage during the period of the synchronization pulse. Above all, the omission of the switching units means a very large savings on layout area or silicon area.

In an advantageous embodiment of the receiving arrangement according to the invention, the supply voltage of the voltage amplifier can be set higher than a maximum amplitude of the synchronization pulse. This means that the voltage amplifier can be operated with a voltage that is greater than the maximum amplitude of the synchronization pulse. The voltage amplifier follows with its output voltage of the form of the reference voltage from the digital-to-analog converter. An important feature of the amplifier is a high drive capability with appropriately sized power amplifiers. This means that the voltage amplifier or power amplifiers are capable of providing a sufficiently high current to enable the desired shape of the synchronization pulse without signal dips and signal distortions.

In a further advantageous embodiment of the receiving arrangement according to the invention, the digital drive circuit can store and / or calculate the predetermined shape and the predetermined temporal behavior of the synchronization pulse, wherein the digital drive circuit can output corresponding digital data words to the digital-to-analog converter. The digital-to-analog converter generates from the N-bit data word a reference voltage, which is supplied to the voltage amplifier. The resolution of the data word can be selected for reasons of radiation so that the synchronization pulse can be imaged without significant jumps.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In the drawings, like reference numerals designate components that perform the same or analog functions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic block diagram of a sensor arrangement with a first exemplary embodiment of a receiver arrangement according to the invention for a control device in a vehicle which generates and outputs an optimized synchronization pulse.

2 shows a schematic block diagram of a sensor arrangement with a second exemplary embodiment of a receiver arrangement according to the invention for a control unit in a vehicle, which generates and outputs an optimized synchronization pulse.

Fig. 3 shows a schematic representation of the shape and the temporal behavior of a conventional trapezoidal synchronization pulse within predetermined limits.

Fig. 4 shows a schematic representation of the shape and the temporal behavior of a conventional rounded trapezoidal synchronization pulse within the predetermined limits.

5 shows a schematic representation of the shape and the temporal behavior of an inventively optimized synchronization pulse within the predetermined limits.

6 shows a schematic illustration of a reference voltage during a synchronization pulse optimized according to the invention.

FIG. 7 shows a schematic representation of an output voltage of the voltage generator during a synchronization pulse optimized according to the invention.

8 to 10 each show a schematic representation of the bus voltage during an inventively optimized synchronization pulse.

Embodiments of the invention

As can be seen from FIGS. 1 and 2, the illustrated sensor arrangements 1, 1 'comprise a data bus 5, at least one sensor 7 and in each case an embodiment of a receiving arrangement 3, 3' according to the invention for a control unit in a vehicle. The receiving arrangements 3, 3 'according to the invention each comprise a voltage generator 30, 30 'for generating a synchronization pulse P _S ync. According to the invention, the voltage generator 30, 30 'comprises a voltage amplifier 36, 36' which generates the synchronization pulse P _sy nc essentially as a sine oscillation based on a reference voltage U _re f.

As can be seen from FIG. 5, the voltage generator 30, 30 'generates the synchronization pulse P _sy nc within predetermined specification limits Vo, Vu having a predetermined shape and a predetermined time behavior. The receiving arrangement 3, 3 'outputs the synchronization pulse P _syn c for synchronization of a subsequent signal transmission via a data bus 5 to at least one sensor 7. In order for a synchronous bus system to function with one sensor 7 or more sensors, the illustrated synchronization pulse P _S ync has a specific shape and a specific temporal behavior for all possible bus configurations and under all possible operating conditions. As is further apparent from Fig. 5, the synchronization pulse P _syn c has a slope which is given by the slope of a first characteristic representing the lower limit Vu and the slope of a second characteristic representing the upper limit Vo , Due to the sinusoidal or sinusoidal shape of the synchronization pulse P _syn c in the predetermined limits Vu, Vo optimized so that the lowest possible electromagnetic radiation, especially in the spectral range of the signal transmission (100kHz to 300kHz) can be achieved, which in the range of the fundamental waves of Synchronization pulse P _syn c remains limited.

As can further be seen from FIGS. 1 and 2, the voltage generator 30, 30 'comprises a digital drive circuit 32, 32' and at least one digital-to-analog converter 34, 34 ', which generate and supply a substantially sinusoidal reference voltage U _r ef output the voltage amplifier 36, 36 '. Such a sinusoidal reference voltage U _re f is shown by way of example in FIG. The

Quantization of the reference voltage U _re f due to the finite resolution of the digital-to-analog converter 34, 34 'is shown schematically. The corresponding output voltage U _sy nc of the voltage amplifier 36, 36 'is shown in FIG. 7. The illustrated embodiments allow a very robust realization of the synchronization pulse P _syn c and a reduced electromagnetic

Radiation. In addition, the control of the voltage amplifier 36, 36 ' to generate the synchronization pulse P _syn c completely in the digital part of the receiving device 3, 3 'to be outsourced, which leads to an area-efficient solution due to the more progressive scaling of semiconductor technology.

5

1, the illustrated first exemplary embodiment of the receiving arrangement 3 according to the invention comprises a first voltage generator 30 having a first digital drive circuit 32 and a first digital-to-analog converter 34 which generate the substantially sinusoidal reference voltage U _ref and output to a first voltage amplifier 36. 1, a first power supply 3.1 provides a supply voltage for the first voltage amplifier 36, and a second power supply 3.2 provides supply voltages for the first digital drive circuit 32, the first digital analog converter 34 and at least one further circuit 3.3 is available, which can be connected via a first switching unit 3.4 to the data bus 5. To output the synchronization pulse P _syn c, the first switching unit 3.4 disconnects the at least one further circuit 3.3 from the data bus 5, and a second switching unit 38 connects the voltage amplifier 36 to the data bus 5. The form of the synchronization pulse P _syn c is either in the digital part or is stored in the first digital drive circuit 32 or is calculated in the digital part or in the first digital drive circuit 32 by means of an algorithm. The first digital-to-analog converter 34 generates from the N-bit data word a reference voltage, which is the first voltage amplifier 36

25 is supplied. The resolution of the data word is chosen for reasons of radiation so that the synchronization pulse P _syn c can be mapped without significant jumps. The first voltage amplifier 36 is supplied with a voltage which is greater than the maximum illustrated amplitude of the synchronization pulse P _sync and follows with its output voltage U _sy nc the shape of

30 reference voltage U _ref from the first digital-to-analog converter 34. An important

Characteristic of the first voltage amplifier 36 is a high drive capability with correspondingly dimensioned output stages. This means that the voltage amplifier 36 or the output stages are able to provide a sufficiently high current to enable the desired shape of the synchronization pulse P _syn c without signal collapses and signal deformations. 2, the illustrated second exemplary embodiment of the receiving arrangement 3 'according to the invention comprises a second voltage generator 30' having a second digital drive circuit 32 'and a second digital-to-analog converter 34', which converts the substantially sinusoidal reference voltage U _ref generate and output to a second voltage amplifier 36 '. As is further apparent from FIG. 2, in contrast to the first exemplary embodiment, a common voltage supply 3.1 'supplies supply voltages for the second digital drive circuit 32', the second digital-to-analog converter 34 'and for the second voltage amplifier 36'

Available. In addition, the second voltage amplifier 36 'provides the supply voltage for at least one further circuit 3.3', which is connected to the data bus 5. Thus, the output voltage U _sy nc of the second voltage amplifier 36 'as a power supply for at least one nen further circuit 3.3' of the receiving device 3 'used, whereby one of the two power supplies 3.1, 3.2 omitted from the first embodiment of FIG. The at least one further circuit 3.3 'of the receiving arrangement 3' is therefore not disconnected from the data bus 5 during the synchronization _pulse P _sy , whereby the two switching units 3.4, 38 from FIG. 1 can be dispensed with. By eliminating the switching units

3.4, 38 arise by taking over the bus voltage U _Bu s from the second voltage generator 30 'in an advantageous manner, no voltage jumps at the transfer points UP, which will be described below with reference to FIGS. 8 and 9.

8 and 9 show, by way of example, the effects which can arise due to an incorrect assumption of the _bus voltage U _Bus if switching operations are carried out. In the first exemplary embodiment according to FIG. 1, the current _bus voltage U _Bus is provided by the second voltage supply 3.2 of the receiving arrangement 3 up to the start time ti. During the synchronization period t _sy nc, the first voltage amplifier 36 provides the data bus 5 with the output voltage U _syn c.

In the illustration in FIG. 8, the first voltage generator 30 'initially assumes too great an initial voltage when generating the synchronization pulse P _syn c, so that at the transfer point UP at the time t 1 a voltage nungssprung from the normal bus voltage U _Bu s up to the value provided by the first voltage amplifier 36 value of the synchronization voltage Usync can arise. At the end of the synchronization pulse P _syn c at the time t ₂ , the voltage at the transfer point UP jumps back down to the normal _bus voltage U _Bus -

In the illustration in FIG. 9, the first voltage generator 30 'at the beginning starts from too low an initial voltage when generating the synchronization pulse P _syn c, so that at the transfer point UP at the instant ti a voltage jump from the normal _bus voltage U _Bus downwards can arise on the provided by the first voltage amplifier 36 value of the synchronization voltage Usync. At the end of the synchronization pulse P _syn c at time t ₂ , the voltage at the transfer point UP jumps back up to the normal _bus voltage U _Bus -

FIG. 10 shows the synchronization _pulse Ρ _5γηο generated by the second _exemplary embodiment of the receiving _arrangement 3 ' _{according to} the invention from FIG. 2. By combining the two separate power supplies to a common power supply 3.1 'and the elimination of the two switching units 3.4, 38, the normal _bus voltage U _bus without undershooting or discontinuities on the output voltage U _syn c of the second voltage amplifier 36' transition and vice versa. As can be seen from FIG. 10, at the transfer point UP at the time t 1, the normal _bus voltage U _Bus continuously changes to the value of the synchronization voltage U _syn c provided by the second voltage amplifier 36. At the end of the synchronization pulse

P _sy nc at time t ₂ , the voltage at the transfer point UP is also continuously from the provided by the second voltage amplifier 36 value of the synchronization voltage U _syn c on the normal _bus voltage U _bus over.

Also in the second embodiment of the receiving device 3 'is the form of the synchronization pulse P _syn c deposited either in the digital part or in the first digital drive circuit 32 or is calculated in the digital part or in the first digital drive circuit 32 by means of an algorithm. The second digital-to-analog converter 34 'generates from the N-bit data word a reference voltage U _r ef which is supplied to the second voltage amplifier 36'. The Resolution of the data word is chosen for reasons of radiation so that the synchronization _pulse P _sy nc can be mapped without significant jumps. The second voltage amplifier 36 'is also supplied with a voltage which is greater than the maximum illustrated amplitude of the synchronization pulse P _sy nc and follows with its output voltage U _sy nc the shape of the reference voltage U _r ef from the second digital-to-analog converter 34th An important feature of the second voltage amplifier 36 'is a high drive capability with correspondingly dimensioned output stages. This means that the second voltage amplifier 36 'or the corresponding output stages are also able to provide a sufficiently high current to enable the desired shape of the synchronization pulse P _syn c without signal collapses and signal deformations.

Embodiments of the inventive method for generating a synchronization pulse P _syn c for synchronizing a subsequent signal transmission between the receiving device 3, 3 'and at least one sensor 7 via a data bus 5 in a vehicle generate the synchronization _pulse P _sy nc within predetermined specification limits Vo, Vu with a predetermined form and a given temporal behavior. At the beginning of the signal transmission between the at least one sensor 7 and the

Receiver assembly 3, 3 ', the synchronization pulse P _syn c from the receiver assembly 3, 3' to the at least one sensor 7 is transmitted. According to the invention, the synchronization pulse P _syn c is generated essentially as a sinusoidal oscillation based on a reference voltage U _r ef.

Claims

claims

Reception arrangement for a control unit in a vehicle with a voltage generator (30, 30 ') for generating a synchronization pulse (Psync), which the synchronization pulse (P _syn c) within predetermined specification limits (Vo, Vu) with a predetermined shape and a predetermined temporal behavior generated, wherein the receiving arrangement (3, 3 ') outputs the synchronization pulse (P _syn c) for synchronizing a signal transmission via a data bus (5) to at least one sensor (7), characterized in that the voltage generator (30, 30') a Voltage amplifier (36, 36 ') which generates the synchronization pulse (Psync) based on a reference voltage (U _re f) substantially as a sine wave.

Receiving arrangement according to Claim 1, characterized in that the voltage generator (30, 30 ') comprises a digital drive circuit (32, 32') and a digital-to-analog converter (34, 34 ') which converts the substantially sinusoidal reference voltage (U _re f) and output to the voltage amplifier (36, 36 ').

Receiving arrangement according to Claim 1 or 2, characterized in that a first voltage supply (3. 1) provides a supply voltage for the voltage amplifier (36). 4. receiving arrangement according to claim 2 or 3, characterized in that a second voltage supply (3.2) provides supply voltages for the digital drive circuit (32), the digital-to-analog converter (34) and for at least one further circuit (3.3), which is connectable to the data bus (5).

5. receiving arrangement according to one of claims 1 to 4, characterized in that for outputting the synchronization pulse (P _syn c) a first switching unit (3.4) separates the at least one further circuit (3.3) from the data bus (5) and a second switching unit (38 ) connects the voltage amplifier (36) to the data bus (5).

6. receiving arrangement according to claim 1 or 2, characterized in that a common voltage supply (3.1 ') is a supply voltage for the voltage amplifier (36'), the digital drive circuit (32 ') and the digital-to-analog converter (34') available provides.

7. receiving arrangement according to claim 1, 2 or 6, characterized in that the voltage amplifier (36 '), the supply voltage for at least one further circuit (3.3') is available, which is connected to the data bus (5).

8. receiving arrangement according to claim 3 or 6, characterized in that the supply voltage of the voltage amplifier (36, 36 ') is higher than a maximum amplitude of the synchronization pulse (P _syn c).

9. receiving arrangement according to one of claims 2 to 8, characterized in that the digital drive circuit (32, 32 ') stores the predetermined shape and the predetermined temporal behavior of the synchronization pulse (Psync) and / or calculated, wherein the digital drive circuit (32, 32 ') outputs corresponding digital data words to the digital-to-analog converter (34, 34').

10. A method for generating a synchronization pulse for synchronizing a subsequent signal transmission between a receiving arrangement (3, 3 ') and at least one sensor (7) via a data bus (5) in a vehicle, wherein the synchronization pulse (P _syn c) within predetermined specification limits (Vo, Vu) is generated with a predetermined shape and a given temporal behavior and is transmitted from the receiving arrangement (3, 3 ') to the at least one sensor (7), characterized in that the synchronization pulse (P _syn c) based is generated on a reference voltage (U _ref ) substantially as a sine wave.