WO2014027094A1

WO2014027094A1 - Method for generating a clock signal for a vehicle electrical system

Info

Publication number: WO2014027094A1
Application number: PCT/EP2013/067166
Authority: WO
Inventors: Wolfgang Jöckel; Klaus Rink
Original assignee: Continental Teves Ag & Co. Ohg
Priority date: 2012-08-17
Filing date: 2013-08-16
Publication date: 2014-02-20
Also published as: DE102012214705A1

Abstract

The invention relates to a method for generating a clock signal (4) for a vehicle electrical system (34), comprising: - the reception of a wireless signal (10) that includes time data; and - the generation of the clock signal (4) having a clock period (8) that depends on the time data.

Description

The invention relates to a method for generating a clock signal for a vehicle electrical system

Clock signal for a vehicle electrical system, method for using the clock signal and control devices for

Carrying out the specified procedures. As known from DE 32 164 12 C2, to measure the state of charge of an electrical energy source of the

electrical power source supplied or dissipated power are integrated in time. To carry out measurements of the electric

Power source to an electrical consumer electrical power emitted in a motor vehicle, a current sensor can be connected in series between the electrical energy source and the electrical load. Such a current sensor is known for example from DE 10 2011 078 548 AI.

It is an object of the present invention to improve the charge measurement.

The object is solved by the features of the independent claims. Preferred developments are the subject of the dependent claims. According to one aspect of the invention, a method for the

Generating a clock signal for a vehicle electrical system the steps:

Receiving a wirelessly transmitted signal with a time information, and

Generating the clock signal with a dependent of the time information clock period.

The specified method is based on the consideration that the could be formed over a numerical integration of the detected electric current over time. Based on this consideration, the invention recognizes, however, that for the numerical integration of the time interval of the individual nodes within the numerical integration must be precisely defined in order to keep the integration error as low as possible and to calculate the charge level accurately. Although the time interval of the support points via a clock generator, such as an oscillator could be specified, a clock generator can the time interval between the

However, do not generate support points with an accuracy that would be necessary to perform the numerical integration of the electric current over a comparatively long period of time with the required accuracy and output the battery level with a small error.

With the specified method, it is therefore proposed that the numerical integration based on a temporal

Reference source, which also has a

comparatively long period of time has sufficient accuracy. Such a reference source is wireless

transmitted signals carrying corresponding time information. The time information may for example be the frequency, ie the carrier frequency, of the wireless signal itself. For example, if a wirelessly transmitted signal of a

Receive radio station, this wireless signal can be assigned to the corresponding radio station and then determined based on the known radio station, the carrier frequency of the radio station. If the carrier frequency is known, the clock signal may be based on the carrier frequency

sufficient accuracy can be generated. However, the wirelessly transmitted signal is particularly preferably a radio-transmitted time signal into which the time information is modulated. Such signals may include, for example, a global positioning system signal, GPS signal, or a short Timer signal, which is known in Europe, for example, under the name DCF77 signal. The advantage of these signals is that they can carry the modulated time information with any accuracy. In the case of the two examples mentioned above, the information is accurate to the atomic clock and therefore represents a reliable reference source for numerical integration even over the years.

In a further development, the specified method comprises the step of generating the clock signal with an oscillator controlled based on the time information. Such a controlled oscillator will be understood below to mean a tunable oscillator circuit or a tunable frequency generator. These can be arbitrarily, for example as a digitally controlled oscillator, called DCO for short, as a numerically controlled oscillator, called NCO for short, or as a voltage-controlled oscillator, called VCO for short. Suitable circuits for the controlled oscillators are, for example, phase-locked loops or also Wien-Robinson bridges.

In an additional development, the specified method comprises the step of generating the clock signal with a local oscillator when the wirelessly transmitted signal is not available. In this way, for example, driving with a vehicle can be bridged by a tunnel without the clock signal would fail.

In accordance with another aspect of the invention, a method of using a clock signal that includes a specified one of

A method for generating a clock signal for a vehicle electrical system of a vehicle has been produced the steps:

Measuring a physical quantity, and

numerically integrating the measured physical quantity over time based on time intervals between the clocks of the clock signal.

By using the clock signal described above in the numerical integrations, measurement values to be determined by numerical integration over time can be accurately and reliably determined over a longer period of time. In a preferred refinement, the physical variable is an electrical current flowing from or to an electrical energy source in the electrical system of the vehicle, so that the numerical integration of the electric current results in the charge state of the electrical energy source. In this way, the state of charge of the electrical energy source can be determined with high accuracy. Another advantage of

given method gives the opportunity for a given tolerance for the charge this exploit the technical quality of the current sensor. So can these

Tolerances are now played with a lower-cost current sensor, whereby the charge measurement can be carried out more economically even with the same quality. In other words, by the specified method, the accuracy requirements can be relaxed to the current sensor and thus costs can be significantly reduced without the accuracy of the charge detection of the electrical energy source

is restricted.

In a further development, the specified method comprises the steps

Generating an absolute time based on the clock signal, and

Combining the measured and numerically integrated physical quantity and / or the measured physical quantity with the absolute time specification.

Since the absolute time is calculated based on a wirelessly transmitted signal, it is the same in different locations, such as in different vehicles. In this way, the measured and numerically integrated ones associated with the absolute time indication can be used

physical quantities and / or the measured physical quantities that have been recorded at different locations be correlated with each other, which increases the Auswertemöglichkeiten these sizes.

According to a further aspect of the invention, a method for using a clock signal, which has been generated with a specified method for generating a clock signal for an on-board network of a vehicle, comprises the step:

Synchronizing a first electrical device in the electrical system with a second electrical device based on the clock signal.

Since the clock signal itself is used for synchronization in the vehicle electrical system of the vehicle, fall more

Synchronization expenses away.

The two electrical devices can be arranged in two different vehicles, so that electrical devices in two different vehicles can be operated synchronously with each other. However, the second electrical device is preferably arranged in the electrical system of the vehicle.

According to another aspect of the invention is a

Control device configured to perform a method according to any one of the preceding claims.

In a development of the specified control device, the specified device has a memory and a processor. The specified method is in the form of a

Computer program stored in the memory and provided the processor for carrying out the method, if the

Computer program is loaded from memory into the processor.

According to a further aspect of the invention, a

Computer program program code means to perform all steps of one of the specified methods when the computer program is run on a computer or one of the specified devices. According to another aspect of the invention includes a

Computer program product, a program code which is stored on a computer-readable medium and which, when executed on a data processing device, performs one of the specified methods.

The above-described characteristics, features and advantages of this invention as well as the manner in which they are achieved will become clearer and more clearly understood

Related to the following description of

Embodiments, which are explained in more detail in connection with the drawings, wherein: Fig. 1 is a schematic diagram of a circuit for carrying out a method for generating a clock signal, and

Fig. 2 shows a schematic diagram of another circuit for carrying out a method for generating a clock signal.

In the figures, the same technical elements are provided with the same reference numerals and described only once. Reference is made to FIG. 1 which shows a schematic diagram of a circuit 2 for carrying out a method for generating a clock signal 4.

The clock signal 4 is generated in the present embodiment in a tunable oscillator 6, which may be, for example, as a known to those skilled fed-back phase loop, called phase locked loop executed. The tunable oscillator 6 receives a reference frequency 8 for tuning, which is obtained in the present embodiment from a wirelessly transmitted signal 10 via a receiver 12.

The wirelessly transmitted signal 10 may be any signal from which a periodicity may be derived that is related to the Setting the clock signal 4 is suitable. In the present embodiment, this wirelessly transmitted signal 10 is radiated by a satellite 14 for transmitting GPS signals or by an antenna 16 for transmitting time synchronization signals.

In a manner known to those skilled in the GPS signals contain time information on the basis of which the position of a receiver of the GPS signals can be determined. Details can be found in the

relevant prior art be looked up. In addition, in the present embodiment, the timing information of the GPS signals may be used to generate the clock signal 4 by equalizing one period of the clock signal 4 with the timing of this time information. For this purpose, the GPS signal is first received by an antenna 18 in the receiver 12 and demodulated from the time profile of the time information, the reference frequency 8 in a demodulator 20.

Subsequently, the clock signal 4 with the tunable

Oscillator 6 generated based on this reference frequency 8.

Alternatively, a time synchronization signal known to the person skilled in the art can be used to generate the clock signal 4. Such a time synchronization signal is sent, for example, in Western Europe by the long-wave transmitter DCF77 in the district Mainflingen in Mainhausen and provides most radio controlled clocks with the exact legal time applicable in Germany. This time synchronization signal therefore contains, in the same turnout as the GPS signals, one or more time information, whose timing can be used to derive the clock signal 4 analogously to the manner described above.

Alternatively, however, the carrier frequency of the wirelessly transmitted signal 10 itself could be used to generate the clock signal 4, which will not be discussed further below for the sake of brevity.

The generated clock signal 4 can then via a clock input 22 of a circuit 24 for calculating a charge 26 of a be supplied not shown vehicle battery. In this circuit 24, measured values for a current 28 received from the circuit 24 from or to the vehicle battery, measured with a current sensor 30, are integrated in time with the charge level 26 based on the clock signal 4. The integration could, for example, run numerically.

The calculated charge level 26 can then via a

Communication interface 32 are fed into a vehicle electrical system 34 of a vehicle, in which also the vehicle battery, not shown, is arranged.

Reference is made to FIG. 2 which shows a schematic diagram of a further circuit 2 for carrying out a method for generating a clock signal 4.

The circuit 2 of FIG. 2 functions analogously to the circuit of FIG. 1 until the clock signal 4 is generated. If, however, the clock signal 4 fails because, for example, no wirelessly transmitted signal 10 is available, then the time of unavailability of the wirelessly transmitted signal 10 may be bridged by an internal oscillator 36, but does not need to meet the high tolerance requirements in the generation of the clock signal 4, as the tunable

Oscillator 6. For a comparatively short period of time, this is acceptable, for example, when calculating the charge level. The bridging can be realized by switching on the clock signal 4 from the internal oscillator 36, for example via a changeover switch 38.

Subsequently, the clock signal 4 is distributed to a plurality of electronic devices that require a clock for their functionality. The advantage is that this

electronic devices are all synchronized by the clock signal 4 so that there is no further

Synchronization measures required. In addition to the already described circuit 24 for calculating a charge level 26 of a not shown

Vehicle battery may include the current sensor 30 or a voltage sensor 40 to these electronic devices.

Claims

claims

A method of generating a clock signal (4) for a

Vehicle electrical system (34) of a vehicle, comprising:

Receiving a wirelessly transmitted signal (10) with time information, and

Generating the clock signal (4) with one of the

Time information dependent clock period (8).

2. The method of claim 1, wherein the wirelessly transmitted signal (10) is a radio-transmitted time signal in which the time information is modulated.

3. The method according to claim 1 or 2, comprising generating the clock signal (4) with an oscillator (6) controlled based on the time information.

A method according to any one of the preceding claims, comprising generating the clock signal (4) with a local oscillator (36) when the wirelessly transmitted signal (10) is unavailable.

A method of using a clock signal (4) generated by a method according to any one of the preceding claims, comprising:

Measuring a physical quantity (28), and

numerically integrating the measured physical quantity (28) over time based on time intervals between the clocks of the clock signal (4).

6. The method of claim 5, wherein the physical quantity (28) is an electric current flowing from or to an electrical energy source in the electrical system of the vehicle, so that the numerical integration of the electric current

Charge level (26) of the electrical energy source results.

7. The method according to claim 5 or 6 comprising:

Generating an absolute time based on the Clock signal, and

A method of using a clock signal generated by a method according to any one of claims 1 to 4, comprising:

Synchronizing a first electrical device (24) in the electrical system with a second electrical device (30, 40) based on the clock signal.

9. The method of claim 8, wherein the second electrical device (30, 40) is arranged in the electrical system.

A control device configured to perform a method according to any one of the preceding claims.