Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
  • G01D5/245—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using a variable number of pulses in a train
  • G01D5/2454—Encoders incorporating incremental and absolute signals
  • G01D5/2455—Encoders incorporating incremental and absolute signals with incremental and absolute tracks on the same encoder
  • G01D5/2457—Incremental encoders having reference marks
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P13/00—Indicating or recording presence, absence, or direction, of movement
  • G01P13/02—Indicating direction only, e.g. by weather vane
  • G01P13/04—Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement
  • G01P13/045—Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement with speed indication
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P21/00—Testing or calibrating of apparatus or devices covered by the preceding groups
  • G01P21/02—Testing or calibrating of apparatus or devices covered by the preceding groups of speedometers
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/46—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring amplitude of generated current or voltage
  • G01P3/465—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring amplitude of generated current or voltage by using dynamo-electro tachometers or electric generator
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/42—Devices characterised by the use of electric or magnetic means
  • G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
  • G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
  • G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals

Definitions

• the invention is based on a method and a device for detecting polarity reversal in a signal transmitter, in particular in an inductive transmitter according to the type of the main claim
• inductive signal transmitters are used for speed or angular position detection on rotating shafts.
• Signal transmitters are used, in particular, to determine the angular position of the crankshaft or another shaft in a motor vehicle, in which a fixed transducer scans the rotating shaft or an encoder disk connected to the rotating shaft.
• the encoder disc has a large number of angular marks on its surface
• an AC voltage is induced with positive and negative half-vibrations.
• This AC voltage reflects the surface of the encoder disc.
• the voltage is usually converted into a square-wave voltage changed.
• it is compared in an evaluation circuit with predeterminable threshold values, and each time a threshold value is reached, the level of the rectangular output signal changes.
• the evaluation of this signal for example, in one
• Engine control unit or a microprocessor is essential, whether the high level is caused by a rising or falling edge of an angle mark, must be monitored whether the encoder is reverse polarity or not. This is necessary because an inductive sensor usually has two connection options.
• a method and a device for detecting the correct or incorrect polarity of signal transmitters is known from DE-OS 197 23 866.
• the encoder disk to be scanned has a plurality of similar angle marks, the configuration of the angle marks being such that the signal generated in the sensor after conversion into a square wave signal is one of the
• Signal transmitter with the features of claim 1 has the advantage that it works very reliably and that it can be used with any encoder disks with a number of similar angle marks and a reference mark, the shape of the angle marks or the length of the Angle marks are not subject to any special requirements in relation to the distances between the angle marks.
• the method according to the invention and the device according to the invention can be used particularly advantageously in connection with an encoder disk, as is common today in internal combustion engines.
• Such an encoder disk has 60-2 regularly distributed angular marks over its surface, the reference mark is formed by the two missing angular marks.
• Such an incremental disk is used to determine the angular position of the crankshaft of the internal combustion engine. The evaluation of the angle determination runs from the control unit of the internal combustion engine.
• the polarity reversal of the encoder can be recognized according to the invention.
• this polarity reversal detection runs independently of the rest of the signal evaluation.
• the conditions under which the polarity reversal detection should be carried out can be applied in an advantageous manner.
• One of these conditions can be a predefinable one, for example
• Speed range or the polarity reversal detection is only carried out in overrun mode of the internal combustion engine or only at constant speeds or only if the speed fluctuations remain within predefined limits.
• time measurements are carried out between predeterminable angle marks for polarity reversal detection, for example certain time windows being set within which the expected signal edge must appear if there is no polarity reversal.
• FIG. 1 shows the components of a system for controlling an internal combustion engine that are essential for understanding the invention, in which the device according to the invention or the method according to the invention can preferably be used.
• FIG. 2 shows various signal curves which are obtained with a sensor that is not reverse polarity or with reverse polarity.
• the associated angular marks of the encoder disc are plotted.
• FIG. 1 shows the components of a system for controlling an internal combustion engine that are essential for understanding the present invention, for which the invention can preferably be used.
• 10 denotes an encoder disk which is rigidly connected to the crankshaft 11 of the internal combustion engine and has a multiplicity of similar angular marks 12 on its circumference, each of which has the same distance from one another.
• similar angle marks 12 is one
• Reference mark 13 is provided, which is formed, for example, by two missing angle marks, which creates a larger distance between the two adjacent identical angle marks.
• the encoder disk 10 is scanned by the pickup 20, which delivers an output signal with positive and negative half-oscillations as the angular marks pass, which are each generated by the flanks of the angular marks.
• the encoder disk 10, which is also known as a Incremental disk is designated and the sensor 20 assigned to it together form the encoder 20 A, the output signal U 20 of which is to be evaluated. Since the output signal U 20 is to be converted into a square-wave signal before further processing, it becomes one
• Analog / digital converter 21 is supplied, which ultimately feeds the digitized signal to the processor 23, which carries out the signal evaluation.
• the processor 23 is, for example, part of the control unit of a motor vehicle.
• the analog / digitally converted output signal U 20 of the encoder 20 A is also referred to as an increment signal INK.
• a second encoder disk 14 is connected to the camshaft 15 of the internal combustion engine and has on its circumference a number of angular marks, so-called segments, the number of which corresponds, for example, to the number of cylinders of the internal combustion engine.
• One of these angle marks is designed as a double mark and is used to assign the crankshaft angle to the cylinder 1.
• This angle mark which comprises the individual marks 19a, 19b, is designated by 19, the other angle marks are designated by 16, 17 and 18.
• the distances between the back flanks of the angle marks are the same.
• the encoder disk 14 is scanned with the aid of a pickup 21, which supplies an output signal U 21 which has positive and negative half-oscillations, which are each generated when the angle marks pass.
• square-wave signals are produced, which are also referred to as segment signals SEG. They are also fed to the processor 23.
• the segment disk 14 and the transducer 21 are also referred to as segment sensors 21 A.
• the microprocessor processes the increment and segment signals to generate control pulses 25, for example for the injection of fuel. These pulses are labeled 25.
• further information 26 is required, which is fed to the processor 23 via further inputs E. None is to be said here regarding the acquisition of this information, for example by means of suitable sensors.
• Processor 23 from. If the processor 23 is a component of the control unit of an internal combustion engine, the method according to the invention runs in addition to the control method previously used, for example for injection. If the processor is only used to evaluate the output signals of an encoder, the processor can only be used for signal evaluation and polarity reversal detection.
• FIG. 2A shows the surface of the encoder disk 10 with the angle marks 12 and the reference mark 13, which is formed by two missing angle marks.
• the output signal U 20 of the encoder 20 A is plotted in FIG. 2 B, provided that the encoder has not been connected with the wrong polarity and that the encoder disc 10 rotates at a constant speed. In this case, signal maxima occur at the transition from the angle mark to the gap and signal minima at the transition from the gap to the angle mark. If the signal U 20 2B converted into a digital signal or into a square-wave signal in an analog / digital converter, the signal shown in FIG.
• FIG. 3 shows further signal profiles, by means of which a second evaluation method is explained.
• 3A again shows the signal curve with the sensor not reversed in polarity.
• the time between two zero crossings is t if it is a regular angle mark and 3 t if it is a reference mark.
• So-called dynamic plausibility windows are formed in order to detect whether the encoder is polarized correctly, in which the zero crossing of the signal is expected. If the encoder is poled incorrectly, it delivers an output signal as shown in FIG. 2B. It should be taken into account that the signal curve in the case of an incorrectly polarized encoder is shifted by half an angular mark spacing compared to the illustration according to FIG. If the signal according to FIG. 3 A or 3 B is converted into a square-wave signal (FIG.
• a plausibility window P can be specified in a so-called gate array and it can be monitored whether a zero crossing occurs within a plausibility window P. If this is not the case, there is a signal curve according to FIG. 3C and a zero crossing lies outside the plausibility window P, while no zero crossing is detected within the plausibility window. The wrong polarity can be identified by checking this.
• the conversion into a square-wave signal takes place, for example, in such a way that changes in level of the square-wave signal occur each time the analog signal crosses zero (switching threshold SO) and when a switching threshold S1 (FIG. 2) or S2 (FIG. 3) is reached.
• the signal tests are carried out at high speed, the signal curves are system-dependent to be evaluated particularly precisely. Very narrow plausibility windows can then be set, within which a zero crossing is to be expected.
• the reverse polarity detection can in principle be carried out in a simple system in which only the signal evaluation of a speed sensor is carried out. If the invention is used in connection with the signal evaluation in a vehicle control unit, the polarity reversal detection can run in addition to the usual signal evaluation and take advantage of the already existing hardware configuration. For example, the dynamic plausibility of a gate array in the area of the reference mark gap can be used for polarity reversal detection.
• the polarity reversal detection described above for an incremental disk can also be carried out for a segment disk in which, as shown in FIG. 1, a segment mark is formed, for example, by a double mark. In this case, too, there is a significantly different signal curve in the area of the double mark with polarity reversal compared to the signal curve with correct encoder connection.
• a polarity reversal detection can be carried out, with the help of which both sensors can be examined for polarity reversal. The check should not run at the same time, but one after the other in a predefinable manner.
• the polarity reversal detected can be displayed and / or electronically compensated.
• Speed sensors were specifically mentioned as an exemplary embodiment of the invention.
• the invention can also be carried out in other signal analyzes in which a singularity is dependent on the direction of movement Signal curve occurs or in which a signal curve dependent on the direction of rotation is generally recognizable.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Maintenance And Management Of Digital Transmission (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=7934502

Family Applications (1)

Country Status (7)

Families Citing this family (15)

Family Cites Families (12)

• 1999
  • 1999-12-24 DE DE19963007A patent/DE19963007A1/de not_active Withdrawn
• 2000
  • 2000-12-15 US US10/168,915 patent/US6727686B2/en not_active Expired - Lifetime
  • 2000-12-15 CN CNB008177058A patent/CN1293385C/zh not_active Expired - Fee Related
  • 2000-12-15 EP EP00993644A patent/EP1244919A2/de not_active Withdrawn
  • 2000-12-15 KR KR1020027008139A patent/KR100852816B1/ko not_active IP Right Cessation
  • 2000-12-15 JP JP2001549084A patent/JP4662674B2/ja not_active Expired - Fee Related
  • 2000-12-15 WO PCT/DE2000/004476 patent/WO2001048488A2/de active Application Filing

Non-Patent Citations (1)

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