JP2002357416A - Method and device for detecting angle position of side wall torsion sensor of tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the absolute angle position of a tire. SOLUTION: The absolute angle position of the tire is determined from the measured relative position of the tire and the measured relative position of a rim.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an angular position of a sidewall torsion sensor of a tire, comprising the steps of measuring a phase position of the tire by the sidewall torsion sensor; A method comprising measuring a position. The present invention relates to an apparatus for detecting an angular position of a sidewall torsion sensor of a tire, comprising: means for measuring a phase position of the tire by the sidewall torsion sensor; and means for measuring a phase position of a rim assigned to the tire. Related to the device.

[0002]

2. Description of the Related Art A sidewall torsion sensor is used, in particular, to evaluate the torque transmitted from a wheel or a tire to a road or an instantaneous friction value between the tire and the road. For this purpose, it is known to distribute a number of permanent magnet areas in the sidewall of the tire evenly over the entire circumference of the tire. In particular, the permanent magnet area can be inserted into the tire inner wall or mounted on the tire inner wall. A measurement detector is provided at a predetermined distance from the tire wall, the measurement detector having at least two measuring elements provided at different radial distances from the rotation axis of the wheel. are doing. When the magnetic field changes as a result of the rotation of the tire, a signal indicating the rotation of the tire is output from each output of the measurement detector. When the tire is deformed as a result of the force exerted on the tire or the transmitted driving or braking torque, the phase position between the measuring signals emitted by the measuring elements shifts. Thus, such a phase shift can be evaluated as a measure of the transmitted torque or instantaneous friction value.

A problem in determining the phase position of a tire is that it is extremely difficult to form a sinusoidal magnetization uniformly over the entire circumference of the tire. Therefore, a correction method for compensating for such insufficient magnetization is required. In this correction method, for example, the magnetization of the tire is measured depending on the angular position, and the relationship between these amounts is stored as a characteristic curve. Considering this characteristic curve,
The disadvantage of imperfect magnetization is removed by computer. In any case, in order to take account of this characteristic curve, it is necessary to detect the absolute angular position of the magnetized tire. That is, the apparatus can detect the angular position only by using the position of the characteristic curve to obtain the correction data.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to determine the absolute angular position of a tire.

[0005]

According to the present invention, this object is achieved by determining the absolute angular position of the tire from the measured phase position of the tire and the measured phase position of the rim.

According to the invention, this problem is solved by providing means for determining the absolute angular position of the tire from the measured phase position of the tire and the measured phase position of the rim. You.

The measured phase position of the tire by itself is not sufficient to determine the absolute angular position. However, additionally considering the measured phase position of the rim,
The absolute angular position of the tire can be determined. This angular position can be used for subsequent correction methods.

The basic technical idea of the present invention is that the absolute position of the sidewall torsion sensor can be specified by combining the sidewall torsion sensor and the ABS rotation speed sensor. In particular, the absolute position of the sidewall torsion sensor can be specified by making the number of magnetic phases of the sidewall torsion sensor exactly one different from the number of ABS rotation speed sensors. That is, under such preconditions, the absolute position can be accurately specified using the Vernier principle.

[0009]

According to the invention, it is particularly advantageous that
The rim phase position is measured by N pole pairs or tooth pole wheels, and the sidewall torsion sensor has M magnetic phases, with M ≠ N being further improved. Can be. In this way, the measurement signal of the sidewall torsion sensor changes at a different frequency than the measurement signal of the pole wheel assigned to the rim. Therefore, the absolute angular position of the tire can be estimated by comparing the two measurement signals.

In this connection, it is particularly useful if the pole wheel for measuring the phase position of the rim is assigned to an ABS speed sensor. ABS speed sensors are provided in many vehicles anyway, and as a result, when the signal of this speed sensor is used to determine the absolute angular position of the tire,
Especially economical.

In a particularly advantageous embodiment, the sidewall torsion sensor has M magnetic phases, with | MN | = 1. The number of magnetic phases of the sidewall torsion sensor differs from the number of magnetic phases of the ABS rotation speed sensor by exactly one phase. Therefore,
The absolute angular position of the tire can be estimated using the Vernier principle. At this time, as the number of pole pairs increases, the absolute angular position can be specified more accurately. For example, if the pole wheel of the ABS rotation speed sensor has 48 pole pairs and the sidewall torsion sensor has 47 magnetic phases, the angular position is measured with an accuracy of 360 ° / 48. can do.

The method according to the invention advantageously comprises, for a tire fixedly connected to a rim, the phase Ph of the rim being compared with the phase Ph (ImB) of the inner magnetization region and the phase Ph (ImB) of the outer magnetization region. By measuring AmB), Ph (rim) = k · (Ph (AmB) −Ph (ImB)) is obtained, where k can be improved by making each constant of the tire. In the case of a tire fixedly connected to the rim, the phase of the tire corresponds to the phase of the rim. Tire phase position with respect to the rim, and
When the phase position of the rim itself, which is fixedly connected to the rotational speed sensor, is detected, the absolute phase position of the tire can be determined using the Vernier principle.

[0013] It is particularly advantageous if the method according to the invention corrects the measured phase position of the tire in view of the absolute angular position of the tire. Therefore, the measurement of the absolute angular position of the tire can be advantageously used to better determine the phase position of the tire with the sidewall torsion sensor.

It is likewise particularly advantageous if the measured phase position of the tire is corrected by detecting a characteristic curve having a magnetization component of the tire which depends on the angular position of the tire. By detecting the absolute angular position of the tire, it is possible to use a pre-measured characteristic curve which shows the magnetization depending on the angular position.

According to the present invention, there is provided an apparatus for detecting an angular position of a sidewall torsion sensor of a tire,
In a device having a means for measuring a phase position of a tire by a sidewall torsion sensor, and a means for measuring a phase position of a rim assigned to a tire, the tire has a tire phase position and a rim measured phase position. Means for determining the absolute angular position of the camera is provided. In this way, with the device according to the invention, the advantages of the method of the invention can be implemented.

Particularly advantageously, according to the device of the invention, N pole pairs or toothed pole wheels are provided for measuring the phase position of the rim, and the sidewall torsion sensor is provided with M magnetic poles. Phase, where M ≠ N. The absolute angular position of the tire can be estimated by comparison with the measurement signals oscillating at different frequencies.

Within the scope of the device according to the invention, it is advantageous if the pole wheel for measuring the phase position of the rim is assigned to an ABS speed sensor. The ABS speed sensor is a particularly economical solution, since it is provided in any number of vehicles.

In a particularly advantageous embodiment of the device according to the invention, the sidewall torsion sensor has M magnetic phases, where | MN | = 1. Therefore, the number of magnetic phases in each sensor is exactly 1
Since only two phases are different, the absolute angular position can be estimated using the Vernier principle.

Advantageously, in the device according to the invention, in a tire fixedly connected to the rim, the phase of the rim Ph (rim) is the phase of the inner magnetization region Ph (ImB) and the phase of the outer magnetization region By measuring the phase Ph (AmB), Ph (rim) = k · (Ph (AmB) −Ph (ImB)), where k is configured to be a constant of the tire. In the case of a tire fixedly connected to the rim, the phase of the tire corresponds to the phase of the rim. By detecting the phase position of the tire with respect to the rim and the phase position of the rim itself which is fixedly connected with the rotation speed sensor,
Using the vernier principle, the absolute phase position of the tire can be determined.

It is useful for the measured phase position of the tire to be corrected taking into account the absolute angular position of the tire. Therefore, generally, the phase position of the tire can be specified with high accuracy by the sidewall torsion sensor.

In this case, it is particularly advantageous if the measured phase position of the tire is corrected by detecting a characteristic curve having a magnetization component of the tire which depends on the angular position of the tire. By means of the characteristic curves measured in advance, it is possible to send out the magnetization which is specific to the tire and which depends on the angular position of the tire. Therefore, as described above, by detecting the magnetization depending on the angular position of the tire and by detecting the absolute angular position, the characteristic accuracy of the phase position of the tire can be improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a part of a wheel for explaining a tire phase position identification. The rim 12 is provided with a tire 10. The tire 10 has regions 14, 16, 18 of differently magnetized permanent magnets, the poles of each region being provided alternately. For example, region 14 is the north pole of the magnet, region 16 is the south pole, region 18 is the north pole, and so on. Tire 10, Figure 1
Here, the tire 10 is shown in a distorted state, that is, the tire area in this figure is shifted substantially in the circumferential direction of the tire 10. At that time, the region located on the radially outer side of the tire 10 is shifted more strongly than the region located on the inner side, that is, the region located near the rim 12. Due to the forces acting on the tire 10, if different measuring positions are mounted in the radial direction, i.e. at lines a and b, for example, due to the force acting on the tire 10, or the transmitted driving or braking torque When the tire 10 is deformed due to this, it is detected that the phase position between the measuring element provided at the line a and the measuring element provided at the line b is shifted. In the tire fixedly connected to the rim, the phase of the rim Ph (rim) (line c) is Ph (rim) = k (Ph (AemB)-Ph (ImB)), where Ph (AemB ): Phase of the outer magnetization region at line a in FIG. 1; Ph (ImB): phase of the inner magnetization region at line b in FIG. 1; Ph (rim): rim phase at line c in FIG. 1; k : Each constant of the tire.

Phase position and ABS of tire 10 with respect to rim 12
When the phase position of the rim 12 itself fixedly connected to the rotation speed sensor is detected, the absolute phase position of the tire 10 can be estimated.

FIG. 2 shows how the absolute phase position of the tire is specified from the above-mentioned respective amounts. FIG. 2 shows a plurality of views for explaining the principle of the vernier used for this purpose. In the diagram shown in FIG. 2, the various quantities are each described as a function of the wheel rotation angle φ. Figure
2a shows a sine or cosine function corresponding to the detection of each measurement value using N pole pairs. In this embodiment, N = 2. FIG. 2b shows a corresponding sine or cosine-like curve which is corrected using N + 1 = 3 pole pairs. By forming the inverse tangent function (Arctan), the functions shown in FIGS. 2c to 2d are obtained, where c is the sine or cosine shape shown in FIG. 2a. FIG. 2d is derived from the sine-to-cosine-like profile of FIG. 2b. From Figure 2e,
It can be seen that the absolute phase position can be specified by subtraction of the functions shown in 2c and 2d. Figure 2a
And c correspond to, for example, a pole wheel of an ABS rotation speed sensor, and b and d in FIG. 2 correspond to a sidewall torsion sensor, and use e in FIG. It can be seen that after rotation of the wheels by 0 °, the difference between the function of c in FIG. 2 and the function of d in FIG. 2 is 0 ° mod 360 °. This situation corresponds to the predetermined angular position of the sidewall torsion sensor. When such an absolute angular position changes, a difference of 0 ° mod 360 ° occurs at other wheel angular positions, and the absolute angular position of the sidewall torsion sensor is derived from this difference.

FIG. 3 is a block diagram for explaining the apparatus of the present invention. First, the symbols used in Fig. 3 are explained: 101: Measurement of phase position with sidewall torsion sensor 102: Measurement of phase position with ABS pole wheel 103: Determination of absolute phase position by vernier method 104: Correction of phase position measured by sidewall torsion sensor 105: Result of determination of absolute phase position in functional element 103 106: Output of improved phase position of sidewall torsion sensor 106: Side wall in functional element 101 The phase position is measured by the torsion sensor. In this way, the phase position measured by the sidewall torsion sensor is corrected in the functional element 104, for example, via a characteristic curve containing information on the magnetic field depending on the angular position. In order to perform such a correction in the functional element 104 with high reliability, it is necessary to detect an absolute phase position.
To this end, the phase position of the ABS pole wheel is measured at the function element 102. The phase positions measured at functional element 101 and functional element 102 are combined at functional element 103 using the Vernier method. This provides the result 105, the absolute phase position. In the function element 104,
From the measured phase position and the absolute phase position, it is corrected, for example, via a characteristic curve, so that the functional element 106
An improved phase position is output.

The foregoing description of the embodiments of the present invention is illustrative only and not limiting. Within the scope of the present invention, various modifications and embodiments are possible as long as the scope of the present invention is not impaired and the invention is equalized.

[0027]

The absolute angular position of the tire can be estimated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a part of a wheel for explanation of tire phase position identification.

FIG. 2 is a plurality of diagrams for explaining the principle of vernier;

FIG. 3 is a block diagram for explaining the apparatus of the present invention.

[Explanation of symbols]

 10 Tire 12 Rim 14,16,18 Permanent magnet area 101,102,103,104,106 Functional element 105 Result

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Henrik Siegler Leonberg Anne-Frank-Strasse 8 Germany (72) Inventor Dietmar Arnto Germany Klein-Saxonyheim Bezigheimer Strasse 103 F-term (reference) 2F069 AA71 BB28 GG06 HH30

Claims (14)

[Claims] 1. A method for detecting an angular position of a sidewall torsion sensor of a tire (10), comprising: measuring a phase position of the tire (10) by a sidewall torsion sensor; Measuring the phase position of the rim (12) assigned to the tire (10), the absolute phase of the tire (10) from the measured phase position of the tire (10) and the measured phase position of the rim (12). A method characterized in that a complicated angular position is obtained. 2. The phase position of the rim (12) is measured by means of N pole pairs or toothed pole wheels so that the sidewall torsion sensor has M magnetic phases, where M ≠ N. The method of claim 1, wherein 3. The method according to claim 1, wherein a pole wheel for measuring the phase position of the rim is assigned to the ABS speed sensor. 4. The method according to claim 1, wherein the sidewall torsion sensor has M magnetic phases, wherein | MN | = 1. 5. A tire (1) fixedly connected to a rim (12).
0), the phase Ph (rim) of the rim (12) is determined by measuring the phase Ph (ImB) of the inner magnetized region and the phase Ph (AmB) of the outer magnetized region. 5. The method according to claim 1, wherein (Ph (AmB) -Ph (ImB)) is obtained, where k is a constant of a tire. 6. The method as claimed in claim 1, wherein the measured phase position of the tire is corrected taking into account the absolute angular position of the tire. 7. The measured phase position of the tire (10) is corrected by detecting a characteristic curve having a magnetization component of the tire (10) depending on the angular position of the tire (10).
6. The method according to any one of 6 to 6. 8. An apparatus for detecting an angular position of a sidewall torsion sensor of a tire (10), comprising: means for measuring a phase position of the tire (10) by a sidewall torsion sensor; A means for measuring the phase position of the rim (12) assigned to the
(10) The apparatus according to (10), further comprising means for determining an absolute angular position. 9. For measuring the phase position of the rim (12), N pole pairs or tooth pole wheels are provided, the sidewall torsion sensor has M magnetic phases, 2. The device according to claim 1, wherein M ≠ N. 10. The device according to claim 1, wherein a pole wheel for measuring the phase position of the rim is assigned to an ABS speed sensor. 11. When the sidewall torsion sensor is M
11. The device according to claim 8, comprising | MN | = 1, wherein | MN | = 1. 12. A tire fixedly connected to a rim (12).
In (10), the phase Ph (rim) of the rim (12) is changed to the phase of the inner magnetized region.
By measuring Ph (ImB) and the phase Ph (AmB) of the outer magnetized region, Ph (rim) = k · (Ph (AmB)-Ph (ImB)), where k is the tire The device according to any one of claims 8 to 11, wherein each constant is a constant. 13. The device according to claim 8, wherein the measured phase position of the tire is corrected taking into account the absolute angular position of the tire. 14. The measured phase position of the tire (10) is corrected by detecting a characteristic curve having a magnetization component of the tire (10) depending on the angular position of the tire (10).
14. The apparatus according to any one of items 1 to 13.