JP4331461B2 - Rotational angle measuring device or rotational speed measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, the rotation angle or rotational speed to be measured, the sensor signal and the sensor signal is detected based on the incremental markings duration and the time detected by each increment markings preamble of claim 1, wherein The present invention relates to a rotation angle measuring device or a rotation number measuring device. It also relates to a correction method for the actual incremental marking duration according to the superordinate concept of claim 9.
[0002]
[Prior art]
The rotational angle measuring device or the rotational speed measuring device is used, for example, in an automobile to detect the rotational angular position or rotational speed of the crankshaft or camshaft. In this case, the rotational angle measuring device or the rotational speed measuring device typically has a signal generator arranged on the shaft, which has a number of markings, and a sensor cooperating with the signal generator. The markings are incremental markings that are spaced apart from one another.
[0003]
As the sensor, a capacitive sensor, an inductive sensor, an optical sensor, or another general sensor can be used. Correspondingly, the markings provided on the signal generator are electromagnetic elements, protrusions or gear teeth, for example.
[0004]
FIG. 1 shows a known rotational angle measuring device. Here, it is shown how this rotational angle measuring device is used for detecting the rotational angular position of the crankshaft in an automobile, for example. The illustrated rotation angle measuring device has a signal generating wheel 2 arranged on a crankshaft 1. A large number of teeth 3 are arranged on the peripheral surface of the signal generating wheel 2, and these pass through the sensor 4 in the direction of the arrow. The markings or teeth 3 are arranged at regular intervals from one another. The step width of marking 3 is shown as incremental marking (i, i + 1, i + 2).
[0005]
In such a configuration, the rotation angle or speed of the shaft 1 is detected on the basis of the edge signal and the so-called incremental marking duration. The incremental markings duration, the time between two pulses formed by the sensor 4, i.e. one increment markings from the incremental markings i (one rising edge to the next rising edge or one falling edge, ( Incremental marking from one to the next falling edge) is the time required to pass the sensor 4. Therefore, when the incremental marking i is set to 6 °, for example, the actual rotational angle position or the rotational speed of the shaft 1 can be easily calculated.
[0006]
Commonly used signal generators have a relatively small number of markings (teeth). For example, the signal generation wheel 2 that is typically used has only 60 or 120 teeth 3 as shown in FIG. 1, so that it cannot accurately detect the rotation angle or the number of rotations. .
[0007]
For this reason, the rotational angular position between two consecutive markings or tooth edges 3 is usually extrapolated by the incremental marking duration of the preceding incremental marking (i-1). That is, the incremental marking duration in the actual incremental marking (i) is always the “old” incremental marking duration from the previous incremental marking (i−1).
[0008]
This means the following in the embodiment of FIG. That is, after the incremental marking i has passed the sensor 4, the incremental marking duration belonging to this incremental marking (i) is also the basis for the incremental marking i + 1. Therefore, if the acceleration between two incremental markings is large (both positive and negative), there can be considerable measurement errors that are no longer acceptable.
[0009]
Particularly in the case of internal combustion engines, in particular automobile internal combustion engines, relatively large fluctuations in engine speed are caused by cylinder compression or expansion.
[0010]
FIG. 2 shows a typical example of the engine speed profile of a four-cylinder engine of an automobile in one engine cycle (each cylinder is ignited once). Observing the illustrated rotational speed signal of the crankshaft, it can be seen that the sine-shaped rotational speed cycle is repeated in a considerable number of rotational speed regions generated by each cylinder for each injection (or for each ignition). Fuel ignition in the cylinder first causes acceleration to the upper peak of the engine, and ultimately causes deceleration to the start of ignition of subsequent cylinders.
[0011]
However, this relatively high rotational speed dynamics causes an error in the calculated rotational angular position or rotational speed.
[0012]
[Problems to be solved by the invention]
It is therefore an object of the present invention to provide a rotational speed measuring device or rotational angle measuring device that accurately detects measured values and a corresponding method for measuring the rotational angle or rotational speed of a shaft more accurately. It is.
[0013]
[Means for Solving the Problems]
The object is to provide a rotation angle measuring device or rotational speed measuring device according to a superordinate concept with a unit for detecting a corrected incremental marking duration relative to an actual incremental marking in consideration of the incremental marking duration of a reference incremental marking . Solved. The incremental marking duration of the reference incremental marking is already known from the previous evaluation.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
As base increment markings, it is possible to use an incremental markings which can belong to the same cylinder working point and the actual incremental markings. This reference incremental marking can be obtained from the same engine operating cycle as the actual incremental marking , or from a preceding operating cycle.
[0015]
According to one advantageous embodiment of the invention, the actual incremental reference and the reference incremental marking are separated from each other by exactly one or more engine cycles (corresponding to the shaft rotation m). In this case, therefore, the incremental marking duration in the same cylinder is detected.
[0016]
The corrected incremental marking duration can also be detected, optionally taking into account the reference incremental marking in another cylinder. In this case, the actual incremental marking and the reference incremental marking correspond to a 1 / k (k = number of cylinders) engine cycle (2 * n / k marking for a normal automobile crankshaft. N = marking in one revolution Number), or multiples of this.
[0017]
According to one advantageous embodiment of the invention, the unit for detecting the corrected incremental marking duration also takes into account any additionally generated engine acceleration (caused by gas supply or braking). . For this, the difference or the difference in rotational speed corresponding to that of the incremental markings duration and incremental markings duration of base increment markings first increment markings are calculated.
[0018]
Advantageously, the incremental marking duration of the first incremental marking is derived from the actual engine cycle, and the incremental marking duration of the reference incremental marking is derived from the preceding engine cycle.
[0019]
Also advantageously, the first increment markings, incremental marking and base increment markings actually passes the sensor is belongs incremental markings from the preceding engine cycle.
[0020]
According to one advantageous embodiment of the invention, the signal generator is configured as a signal generating wheel with teeth arranged on the peripheral surface.
[0021]
The measured incremental marking duration or speed is preferably stored in a memory (RAM). From this memory, the unit reads the incremental marking duration or the rotational speed of the reference incremental marking to which it belongs.
[0022]
【Example】
In the following, the invention will be described in more detail by way of example with reference to the accompanying drawings.
[0023]
FIG. 1 shows a signal generator 2 arranged on a shaft 1. This signal generator 2 has teeth (marking) 3 arranged in a row on the peripheral surface, and these teeth pass through the sensor 4 in the direction of the arrow.
[0024]
The configuration of the signal generator 2 and sensor 4 is provided with a unit 5 for detecting the corrected incremental marking duration. This unit 5 calculates the incremental marking duration for the actual incremental marking (i) taking into account the incremental marking duration of the reference incremental marking . The incremental marking duration of this reference incremental marking is known.
[0025]
In the simplest case, the corrected incremental marking duration P _korr (i) or the rotational speed N _korr (i) of the incremental marking i that actually passes through the sensor 4 is detected as follows:
P _korr (i) = P (i ′ + 1)
N _korr (i) = N (i ′ + 1)
In this case, the incremental markings i and i ′ are separated by 1 / k times the engine cycle (k = number of cylinders) or a multiple thereof. This also corresponds to a predetermined number of markings 3 defined by the step width of the markings 3.
[0026]
FIG. 2 shows a typical speed profile during the engine operating cycle. Here, a sine-shaped rotation speed cycle that repeats for each injection or for each ignition is clearly shown. This process is caused by cylinder expansion and compression.
[0027]
Points i1 to i3 each show an incremental marking corresponding to the same working point of the cylinder. Accordingly, these incremental markings can be used as reference incremental markings for incremental marking i4.
[0028]
FIG. 3 shows two parts of the rotational speed profile for the first cylinder of the internal combustion engine. The sign-like progress is the actual rotational speed of the first cylinder, and the stepwise progress is the rotational speed detected by the measuring device.
[0029]
As can be seen from this, there is a phase shift between the actual number of revolutions and the detected number of revolutions. As already explained, this is caused by the rotational speed detection format.
[0030]
Observing the embodiment of FIG. 1, the incremental marking duration to which the incremental marking i passes after passing through the sensor 4 is detected, and based on this, the rotation angle or the rotational speed of the shaft 1 at the incremental marking i + 1 is calculated. . However, this incremental marking duration is already in the past at this point.
[0031]
In Figure 3, although the incremental markings i 'rotational speed N for incremental markings i' can be finally used in + 1, it can be seen much lower than the rotational speed actually present in the incremental markings i '+ 1.
[0032]
Here, in order to correct the increment markings duration for the actual incremental markings i, is known from the preceding operation cycle, the corresponding base increment markings i 'incremental markings duration of P (i' + 1) or the rotational speed N (I ′ + 1) is used.
[0033]
The engine acceleration from the previous engine cycle to the actual engine cycle occurs when the incremental marking duration decreases (in this case when the speed increases by the value a). To account for engine acceleration is ultimately base increment markings i the 'incremental markings duration of P (i' + 1) or the rotational speed N (i '+ 1), incremental markings duration immediately before the incremental markings i-1 The difference between the time P (i) and the incremental marking duration to which the previous operating cycle P (i ′) belongs is added.
[0034]
The corrected incremental marking duration P _korr is calculated as follows:
P _korr (i) = P (i ′ + 1) + P (i) −P (i ′)
For the corrected rotation speed N _korr (i), the following formula applies:
N _korr (i) = N (i ′ + 1) + N (i) − (N (i ′))
The phase corrected incremental marking duration P _korr (i) or the rotational speed N _korr (i) determined in this way is finally used for extrapolation of the rotational angle.
[Brief description of the drawings]
FIG. 1 is a rotation angle measuring device according to an embodiment of the present invention.
FIG. 2 is the number of revolutions during the engine operation cycle of the automobile.
FIG. 3 is the measured actual rotational speed curve of individual cylinders.
[Explanation of symbols]
1 Shaft 2 signal generator 3 teeth 4 sensor 5 correction unit 6 memory i actual incremental markings i 'already elapsed incremental marking N rotational speed N _korr corrected direction shifted on the rotational speed by the rotational speed a engine acceleration was

Claims (10)

A rotational angle measuring device or a rotational speed measuring device having a signal generator (2) arranged on a shaft of an internal combustion engine,
The signal generator (2) has a large number of markings arranged in a ring and a sensor (4) that cooperates with the signal generator (2),
The markings are incremental markings spaced apart from each other;
Rotation angle or rotational speed to be measured, a sensor signal, the sensor signal is detected on the basis of the incremental markings duration and detected by each increment markings,
The actual incremental markings (i) corrected incremental markings duration P _korr for (i), the reference increment markings (i ') unit for detecting with incremental markings duration P (i' of + 1) ( In the rotation angle measuring device or the rotation number measuring device of the type provided with 5),
The incremental reference marking (i ') and the actual incremental markings (i) and are offset from each other by one or more engine cycle, the incremented reference marking (i') is evaluated before the actual point A rotation angle measuring device or a rotation number measuring device characterized in that it is detected and known . Spacing between the incremental reference marking (i ') the actual incremental markings (i) and is, 1 / k times (k = number of cylinders) of the engine cycle or a multiple, rotation angle measurement according to claim 1, wherein Or rotation speed measuring instrument. The unit for detecting the corrected incremental markings duration P _korr (i) (5) uses agencies acceleration additionally,
The difference between the incremental reference marking (i'-1) increment markings duration (Pi ') corresponding to the first increment markings (i-1) increment markings duration of P (i) is calculated, claims 3. A rotation angle measuring device or a rotation number measuring device according to 1 or 2. 4. The rotational angle measuring device or the rotational speed measuring device according to claim 3, wherein the incremental reference marking (i'-1) is an incremental marking detected in a preceding engine cycle. The rotation angle according to claim 3 or 4, wherein the corrected incremental marking duration P _korr (i) for the incremental marking (i) passing through the sensor (4) at that time is calculated according to the following formula: Measuring instrument or revolution measuring instrument:
P _korr (i) = P (i ′ + 1) + P (i) −P (i ′) The rotation angle measuring device or the rotation number measuring device according to any one of claims 1 to 5, wherein the signal generator is a signal generating wheel (2) having teeth (3) arranged on a peripheral surface thereof. The rotational angle measuring device or the rotational speed measuring device has a memory (6),
The rotation angle measuring device or the rotation speed measuring device according to any one of claims 1 to 6, wherein an incremental marking duration P (i) or a rotation speed N (i) is stored in the memory (6). A method for detecting the rotational angle or the rotational speed of a shaft (1) of an internal combustion engine,
The rotation angle or rotational speed to be measured, and the sensor signal, in what format the sensor signal is detected based on the incremental markings duration and detected by each increment markings,
Corrected incremental markings duration P _korr (i ') and detected using an incremental markings duration P _korr of a corresponding incremental reference marks i' (i '+ 1) ,
The incremental reference marking (i ') and the actual incremental markings (i) and are offset from each other by one or more engine cycle, the incremented reference marking (i') is evaluated before the actual point A method characterized in that it is known from The method according to claim 8, wherein the incremental marking duration P (i '+ 1) of the incremental reference marking (i') is read from the memory (6). 10. A method according to claim 8 or 9, wherein the engine acceleration generated in the case of detection of the corrected incremental marking duration _Pkorr (i) is used .

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