DE102014202473A1 - Error transmission in the two-level speed sensor - Google Patents

Abstract

The invention relates to a method for transmitting error information in a pulse signal (40) which is set up to receive measured values (12) from a sensor (10) in a frequency modulation manner with pulses (42) having a first height (50) to a receiver (18) transmitting, comprising: - detecting a fault (53) in the sensor (10), and - introducing a pulse (52) having a second height (56) different from the first height (50) into the pulse signal (40) detected error (53) in the pulse signal (40) display.

Description

The invention relates to a method for transmitting error information in a pulse signal, a control device for carrying out the method and a sensor with the control device.

From the DE 10 2011 080 789 A1 a vehicle is known in the wheel speed sensors are installed to detect the wheel speed of the individual wheels. These wheel speed sensors are active wheel speed sensors and transmit their measurement data in the form of wheel speeds via a cable as a transmission path to an evaluation device.

It is an object of the invention to improve the transmission of the measured data.

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 of transmitting error information in a pulse signal configured to transmit measured values from a sensor frequency-modulated having first-magnitude magnitude pulses to a receiver, the steps of detecting an error in the sensor, and introducing a second, different from the first height, having height pulse in the pulse signal to indicate the detected error in the pulse signal.

The specified method is based on the consideration to recognize erroneous measured values for compliance with high safety standards and to take into account accordingly in their processing. The detection of erroneous readings could be done in the facility that processes the readings. Here, however, there is the problem that the recognition partly algorith-intensive algorithms zugrungeliegen, the course of which takes a certain amount of time.

For this reason, it would be desirable to integrate the sensor detecting the measured values into the detection of the erroneous measured values. For this, however, the sensor would have to transmit the information about the error in a measured value in addition to the erroneous measured value itself, so that this information can be taken into account during processing. The more information the sensor provides about the error, the faster it can be reacted to during processing, which can significantly increase safety, especially in applications in a vehicle.

The intention to transmit an indication of the error and as much information as possible about the error is counter to the fact that it is difficult for the receiver to decide from the frequency-modulated signal which pulses information in the sensor sending its measurements in frequency modulation about the measured values and which pulses carry other information.

This is where the specified method begins, in which it is proposed to transmit the information on the measured values and the information about possible errors with pulses of different heights. In this way, it is apparent to the receiver alone from the fact that pulses are received at a height different from the magnitude of the pulses carrying the measurement information, that there is an error, and the receiver can respond accordingly. In this way, the reliability of the measured values and thus their integrity are increased on the receiver side.

In addition to these pulses of the first height and the second height, no further pulses of other heights should be transmitted.

In a development of the specified method, the measured value is entered as a pulse from an active rotational speed sensor into the data transmission signal. In active speed sensors, wheel speed information is known to be frequency modulated with pulses output, the number of which can be derived over a certain period of time the speed. As an example, here is a vehicle dynamics control for a vehicle called, which must respond reliably especially in high speed ranges of the wheels. Here, the method can improve the quality of the error treatment in a particularly favorable manner.

In a further development of the specified method, the pulse with the second height, as seen from the pulses of the first height, is negative. In this way, the distinctness between the pulses with the first height and the pulse with the second height is significantly increased, so that the occurrence of an error in the pulse signal is particularly clearly visible.

In another development of the specified method, the pulse with the second height directly follows a pulse with the first height, so that both pulses have a common edge. In this way, the first altitude pulse immediately prior to the second altitude pulse may be used to indicate an eventual error, either to invalidate all subsequent first height pulses or to initiate the beginning of an error description protocol the closer information on the error occurred are described.

In order to further improve the aforementioned refinement of the specified method, the pulse having the second height can be preceded by a pulse having the first height with a predetermined width, so that it is even clearer that this first-level pulse is used to initiate the error description protocol , It should be noted that in the context of this development, it is not absolutely necessary for the two pulses mentioned to follow one another directly.

In a particular embodiment, the second pulse with the second height and the pulse preceding the second pulse with the first height have the same predetermined width. In this way, the receiver can synchronize to the pulse width of the two pulses and prepare for receiving a possibly downstream error description protocol.

In the context of this error description protocol, at least one further second pulse having a different height from the first height can be introduced into the pulse signal in order to describe the detected error.

Particularly preferably, the error can be coded based on the two pulses with the second height and possibly further subsequent pulses with the second height.

It is possible that between the pulses of the second height carrying the error description protocol further pulses of the first height are introduced into the pulse signal. This is particularly advantageous if the detected error is not safety-critical, so that the recipient must indeed recognize the error, but can continue to use the corresponding measurement data under restrictions. In this case, the error description protocol can be sent almost simultaneously with the measurement data without interrupting the measurement data transmission.

In a particular development of the specified method, the pulses with the second height have an equal width, so that they can be decoded in a simple manner on the receiver side.

According to another aspect of the invention, a control device is arranged to perform one of the specified methods.

In a development of the specified control device, the specified device has a memory and a processor. In this case, one of the specified methods is stored in the form of a computer program in the memory and the processor is provided for carrying out the method when the computer program is loaded from the memory into the processor.

According to a further aspect of the invention, a computer program comprises program code means for performing all the steps of one of the specified methods when the computer program is executed on a computer or one of the specified devices.

According to another aspect of the invention, a computer program product includes program code stored on a computer-readable medium and, when executed on a data processing device, performs one of the specified methods.

According to another aspect of the invention, a sensor comprises one of the specified control devices.

In a particular embodiment, the specified sensor is a wheel speed sensor.

According to another aspect of the invention, a vehicle includes one of the indicated wheel speed sensors.

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 in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings, in which:

1 a schematic view of a vehicle with a vehicle dynamics control,

2 a schematic view of a wheel speed sensor in the vehicle of 1 .

3 a diagram with an output signal from the wheel speed sensor of 2 , and

4 another diagram with an output signal from the wheel speed sensor of 2 demonstrate.

In the figures, the same technical elements are provided with the same reference numerals and described only once.

It will open 1 Reference is made to a schematic view of a vehicle 2 with a known vehicle dynamics control shows. Details of this driving dynamics control, for example, the DE 10 2011 080 789 A1 be removed.

The vehicle 2 includes a chassis 4 and four wheels 6 , Every bike 6 Can be fixed on the chassis 4 fixed brake 8th opposite the chassis 4 slowed down to a movement of the vehicle 2 to slow down on a road, not shown.

It can happen in a manner known to those skilled in the way that the wheels 6 of the vehicle 2 lose their grip and get the vehicle 2 even by a, for example, via a not further shown steering wheel predetermined trajectory by understeer or oversteer away. This is avoided by known control circuits such as ABS (antilock braking system) and ESP (electronic stability program).

In the present embodiment, the vehicle 2 for speed sensors 10 at the wheels 6 on that one speed 12 the wheels 6 to capture. Further, the vehicle points 2 an inertial sensor 14 on, the vehicle dynamics data 16 of the vehicle 2 may include, for example, a pitch rate, a roll rate, a yaw rate, a lateral acceleration, a longitudinal acceleration, and / or a vertical acceleration in a manner known per se to those skilled in the art.

Based on the recorded speeds 12 and vehicle dynamics data 16 can be an evaluation device in the form of a regulator 18 in a manner known to those skilled determine whether the vehicle 2 slips on the road or even deviates from the above-mentioned predetermined trajectory and accordingly with a known regulator output signal 20 to react to that. The regulator output signal 20 can then be from a control device 22 to be used by means of actuating signals 24 Actuators, like the brakes 8th to drive, which respond to the slippage and the deviation from the given trajectory in a conventional manner.

Look for one of the in 1 shown speed sensors 10 the present invention should be further clarified, even if the present invention on any sensors, such as the inertial sensor 14 is feasible.

It will open 2 Reference is made, which is a schematic view of one of the speed sensors 10 in the vehicle dynamics control of 1 shows.

The speed sensor 10 is in the present embodiment designed as an active speed sensor, which rotatably on the wheel 6 attached encoder disk 26 and a stationary to the chassis 4 attach reading head 28 includes.

The encoder disk 26 consists in the present embodiment of juxtaposed magnetic north poles 30 and magnetic south poles 32 , which together excite a donor magnetic field not shown. Turns on the wheel 6 attached encoder disk 26 with this in one direction 34 , the encoder magnetic field rotates accordingly synchronously.

The reading head 28 is in the present embodiment, a magnetostrictive element, which depends on the angular position of the encoder wheel 26 energized transmitter magnetic field changes its electrical resistance.

For detecting the speed 12 is the change of the angular position of the encoder wheel 26 and thus the change in the electrical resistance of the reading head 28 detected. This can be the read head 28 in a conventional manner to a resistance measuring circuit, not shown, such as a known bridge circuit can be connected. Depending on the electrical resistance of the reading head 28 becomes in the resistance measuring circuit a periodic output signal, hereinafter the speed sensor signal 36 called, generated. Based on the speed sensor signal 36 can in a conventional manner in a read head 28 downstream signal conditioning circuit 38 one from the speed 12 dependent and in 3 shown pulse signal 40 generated and sent to the regulator 18 be issued. For this purpose and for further background information on active wheel speed sensors, the relevant prior art, such as the DE 101 46 949 A1 directed.

The pulse signal 40 carries the speed 12 frequency modulated in below measuring pulses 42 said first pulses, in 3 in a signal 44 - Time 46 - Diagram are plotted. The frequency modulation itself is already by the measurement method in the above-mentioned speed sensor 10 given, with the measuring pulses 42 in the signal conditioning circuit 38 can be generated.

The measuring pulses 42 possess starting from a certain reference signal value 48 a predetermined first height 50 , In the context of frequency modulation, the number of measuring pulses is determined 42 over time 46 according to the measured value for the speed to be transmitted 12 , which means that the number of measuring pulses 42 with increasing speed 12 increases. In 3 is therefore the pulse signal 40 shown in a state where the speed 12 over time 44 decreases and the number of measuring pulses 42 decrease over a period of time.

The transmission of measuring pulses 42 in active speed sensors, like the one before described speed sensor 10 is well known and should therefore not be further explored.

In the present embodiment, the pulse signal 40 next to the speed 12 descriptive measuring pulses 42 also below error pulses 52 entered second pulses from which the occurrence of a fault 53 from a time of error 54 evident. The mistake 53 can the signal conditioning circuit 38 be provided for example via a monitoring circuit not shown. The error pulses 52 have a second height in the present embodiment 56 up, seen from the measurement pulses 42 from the reference signal value 48 to run in the negative direction.

For the recipient 18 is thus alone due to the occurrence of the error pulses 52 immediately apparent that the error 53 is present, whereby the error time 54 itself can be estimated.

To the receiver 18 In addition, to allow the assessment of the error, moreover, error information can be transmitted, which is described below with reference to 4 should be described.

In 4 will appear after the occurrence of the error 53 at the time of the error 54 a synchronization pulse 58 sent the same height 50 has, as the measuring pulses 42 , A time width 60 of the synchronization pulse 58 is just as big as the time width 60 the error pulses 52 , That way, the recipient can 18 on the error pulses 52 synchronize so that he can decode them accordingly.

The information about the error 53 at the time of the error 54 and more information can be provided with the error pulses 52 coded to be transmitted. Every fault pulse 52 carries a bit. If, for example, eight bits # 0 to # 8 are transmitted, then correspondingly eight error pulses will result 52 needed. Every fault pulse 52 that with the second height 56 is transmitted, carries for its corresponding bit # 0 to # 8 the information 1. Each error pulse 52 that with the reference value 48 is transmitted carries the information 0 for its corresponding bit # 0 to # 8.

Is in the speed sensor 10 at the time of the error 54 the mistake 53 detected, the bit # 0 = "1" can be set and thus the first error pulse 52 with the second height 56 be transmitted. The bit sequence from the remaining definable bits # 1, # 2, # 5, # 6 and # 7, ie the remaining error pulses 52 can then be used for a clear breakdown of a general error information in 2 ⁵ = 32 error causes.

The technical objects of 3 and the 4 can be combined with each other in a suitable manner.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011080789 A1 [0002, 0033]
• DE 10146949 A1 [0043]

Claims (10)

Method for transmitting error information in a pulse signal ( 40 ), which is set up, measured values ( 12 ) from a sensor ( 10 ) frequency modulated with a first height ( 50 ) having height pulses ( 42 ) to a receiver ( 18 ), comprising: - detecting an error ( 53 ) in the sensor ( 10 ), and - introducing a second, from the first height ( 50 ) different height ( 56 ) having pulse ( 52 ) into the pulse signal ( 40 ), the detected error ( 53 ) in the pulse signal ( 40 ). The method of claim 1, wherein the pulse ( 52 ) with the second height ( 56 ), seen from the pulses ( 42 ) with the first height ( 50 ) is negative. Method according to claim 1 or 2, wherein the pulse ( 52 ) with the second height ( 56 ) directly on a pulse ( 42 ) with the first height ( 50 ), so that both pulses ( 42 . 52 ) have a common edge. Method according to one of the preceding claims, wherein the pulse ( 52 ) with the second height ( 56 ) a first height ( 50 ) pulse ( 58 ) having a predetermined width ( 60 ). Method according to claim 4, wherein the second pulse ( 52 ) with the second height ( 56 ) and the second pulse ( 52 ) preceding pulse ( 58 ) with the first height ( 50 ) the same predetermined width ( 60 ) exhibit. Method according to one of the preceding claims, comprising introducing at least one further a second, from the first height ( 50 ) different height ( 56 ) having pulse ( 52 ) into the pulse signal ( 40 ), the detected error ( 53 ) to describe. Method according to one of the preceding claims, comprising coding the error ( 53 ) based on the pulses ( 52 ) with the second height ( 56 ). Method according to claim 6 or 7, wherein the pulses ( 52 ) with the second height ( 52 ) an equal width ( 60 ) exhibit. Control device ( 38 ) arranged to perform a method according to any one of the preceding claims. Sensor ( 13 ), in particular wheel speed sensor, comprising a control device ( 38 ) according to claim 9.

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