JPH06147814A - Rotational angle detector - Google Patents

Abstract

PURPOSE:To obtain a correct output constantly by correcting incommensurate region of combined data based on positional information within single revolution of a rotary body obtained from a resolver, and r.p.m. information of the rotary body obtained from an incremental encoder. CONSTITUTION:A rotary body 3 comprises a resolver 4 for detecting the position thereof within single revolution and an incremental encoder 5 for detecting r.p.m., both of which constitute a mechanical section. The resolver 4 is connected with a resolver count circuit 6 which outputs positional information within single revolution. The encoder 5 is connected with an r.p.m. count circuit 7 which receives r.p.m. information of the rotary body 3. An r.p.m. correcting operation 1C9 subjects positional information within single revolution of the rotary body 3 obtained from the resolver 4 to corrective operation with reference to an original point and adds the corrected positional information to r.p.m. information of the rotary body 3 obtained from the encoder 5 thus correcting incommensurateness even if the original point is shifted between both data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device for detecting a rotation angle position of a rotating body.

[0002]

2. Description of the Related Art Encoders for measuring a rotational angle position of a rotating body, that is, a rotational angle detecting device are roughly classified into an incremental type and an absolute type. In the former case, the rotational position information is obtained by counting the number of pulses output for each unit rotational angle displacement. Therefore, the range of position measurement over multiple revolutions is regulated by the capacity of the counter.

On the other hand, in the absolute type rotation angle detecting device, since the rotating portion itself in the measuring device has the rotational position information by some means, it is not necessary to accumulate data in the counter, and further, a power failure occurs during the rotation. Even if it occurs, the position within one rotation is not lost. However, the advantage of such an absolute type is that it is limited to position information within one rotation, and for displacements over multiple rotations, the rotation speed is discriminated independently, that is, "what rotation". I can't.

Under such circumstances, in order to obtain the absolute position information in multiple rotations, that is, the "address" of the "rotation", the position within one rotation for detecting the position within one rotation of the rotating body. It is necessary to separately provide the information measuring means with a rotation speed counting means for measuring only the rotation speed. A commonly used rotation speed counting means is, for example, 1
There is a low resolution incremental encoder (1P / R) that outputs one pulse per revolution. Then, by combining both data of the rotation number information of the rotating body obtained from the rotation number counting means and the in-one-revolution position information of the rotating body obtained from the in-one-revolution position information measuring means, the multi-revolution absolute position information ( "What number" is "what number"?

In this case, in the encoder using the code plate, the code for the incremental pulse for counting the number of rotations can be placed on the code plate together with the absolute position code within one rotation, so that the rotation can be performed. Only the electric circuit for the number counter needs to be provided separately, but in the case of a resolver, which is a kind of absolute encoder in a broad sense, the rotation detection head and its processing circuit as a whole are separately provided as a rotation number counting subsystem. Must be provided. As the rotation detecting head, as shown in FIG. 2 (a), a disc magnet 1 which is magnetized in two parts into N and S poles is configured to rotate integrally with a rotating body (not shown). In addition, the one in which the rotating magnetic field from the disk-shaped magnet 1 is detected by the two magnetic sensors 2 and 2 including a Hall element, an MR element, a coil, etc. is generally used.

In the case of the rotation speed counting means having such a structure, as shown in FIG. 2B, the combination of the output states of the two magnetic sensors 2 and 2 allows
A region obtained by dividing one rotation into four, that is, a (1,0) region,
Each of the (1,1) area, the (0,1) area, and the (0,0) area is identified. Therefore, as shown in FIG. 3, the polarity of the disk-shaped magnet 1 is divided into each of the above-mentioned four regions for detection. In FIG. 2B, the reference position (origin) is set at the boundary between the (1,0) area and the (1,1) area, but this is merely an example, and Reference position (origin) at the boundary
May be set.

[0007]

However, like the resolver system described above, the rotational speed counting means (for example, the incremental encoder 1P / R) and the one-revolution position information measuring means (for example, the resolver body) are provided. In the case where they are arranged as independent sensors, a "origin" shift may occur between them, as indicated by the hatched area A in FIG. Note that the "origin" in this case is not a "mechanical origin" in a simple sense, but as a result of being affected by various factors such as mechanical, magnetic, electrical, and temperature characteristics, the rotation speed counting is performed. The signal output of the counting circuit in the means and the position information measuring means within one rotation indicates the "virtual origin" that is switched by one rotation.

That is, the origins of both data of the rotational speed information of the rotating body obtained from the rotational speed counting means and the in-one-revolution position information of the rotating body obtained from the in-one-revolution position information measuring means,
If they match as shown in FIG. 4A, absolute position information of multiple rotations can be continuously obtained as shown in FIG. 4B. However, as shown in FIG. If there is a deviation, a mismatch area B as shown in FIG. 5B is generated in the composite data, and discontinuous position information that is misread by one rotation in places is erroneously output. Become.

Therefore, the present invention corrects a mismatched region in the combined data of the rotational speed information and the position information within one rotation so that the multi-rotation absolute position information can always be accurately output even when there is a deviation in the origin. An object of the present invention is to provide a rotation angle detection device that can be used.

[0010]

A rotational speed detecting device according to the present invention detects a rotational angular position of a rotating body, and position information within one rotation for detecting a position of the rotating body within one rotation. In a rotation angle detecting device comprising a measuring means and a rotation speed counting means for detecting the rotation speed of the rotating body, one of the rotating bodies obtained by the in-one-revolution position information measuring means is provided.
Receiving the in-rotation position information and the rotation speed information of the rotating body obtained by the rotation speed counting means, the correction operation means for correcting the rotation speed information on the basis of both of the information.

[0011]

In the means having such a structure, the correction calculation processing is performed by the correction calculation means based on the origin of the position information within one rotation of the rotating body obtained by the position information within one rotation measurement means. In addition to the rotational speed information of the rotating body obtained by the means, even if there is a deviation of the origins of both data, the mismatch is properly corrected.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, the rotating body 3 includes a resolver 4 as one-rotation position information measuring means for detecting the position of the rotating body 3 within one rotation, and the rotating body 3.
An incremental encoder (1P / R) 5 as a rotation speed counting means for detecting the rotation speed of the above is provided so as to constitute a mechanical section. Further, the resolver 4 has
The resolver counting circuit 6 is connected, and the resolver counting circuit 6 outputs position information within one rotation of the rotating body 3. Further, a rotation speed counting circuit 7 is connected to the incremental encoder 5, and the rotation speed counting circuit 7 outputs the rotation speed information of the rotating body 3.

As described above, the incremental encoder 5 serving as the rotation speed counting means has the two magnetic sensors 2 including the Hall elements shown in FIG. 2 (a).
According to the combination of the two output states, as shown in FIG. 2B, one rotation is divided into four, (1,0) area, (1,1) area, (0,1) area, and (0,0) area. It identifies each area, and a 2-bit detection signal corresponding thereto is applied from the rotation speed counting circuit 7 to the logic gate 8.

Similarly, regarding the resolver 4 as the position information measuring means within one rotation, one rotation can be divided into four areas for the sake of convenience. The measurement resolution of the resolver 4 in this embodiment is 13 bits (8192 divisions).
Therefore, four areas of "1 to 2048", "2049 to 4096", "4097 to 6144", and "6145 to 8192" are considered, and the corresponding MSB signal from the resolver counting circuit 6 It is applied to the logic gate 8.

The logic gate 8 has the above-mentioned incremental
It has a function of converting a total of 3 bit detection signals input from the encoder 5 and the resolver 4 into a 4 bit select signal as described later, and sends it to a rotation speed correction calculation IC 9 as a correction calculation means. . The rotation speed correction calculation IC 9 has a function of correcting the rotation speed information obtained by the incremental encoder 5. For example, the 74HC181 is used as a calculation IC for executing this correction calculation operation. This rotation speed correction calculation IC 9
In the case, the 4-bit select signal is set as shown in Table 1 below, so that the addition / subtraction and through output operation modes are selected.

[Table 1]

Correspondingly, the above-mentioned logic gate 8 is
3-bit information determined from the positional relationship between the resolver 4 and the incremental encoder 5, that is, the output state of the two magnetic sensors of the incremental encoder 5 and the MSB signal of the position data within one rotation from the resolver 4 are used as a 4-bit select signal. Table 2 below for conversion
The above relationship is set as the input / output characteristic of the logic gate 8.

[Table 2]

With such a configuration means, the rotation speed correction calculation IC 9 adds the following correction operation to the rotation speed information. First, as described above,
There are 4 × 4 = 16 combinations of the current position areas independently shown by the encoder 5 and the resolver 4.
The origin deviation correction value is set for each of the six cases. That is, the above-mentioned origin deviation (see symbol A in FIG. 3)
Assuming that the origins of the two can be adjusted to the extent that does not exceed ± 90 degrees,
The origin deviation correction value in each of the above 16 cases is set as shown in Table 3 below.

[Table 3]

More specifically, considering the case where the resolver 4 is in the region of R1 in Table 1, if the incremental encoder 5 is located at [1]: C1, the regions indicated by both are shown. (Which of the four divided areas) are the same and correct. Therefore, the correction value is 0. [2]: If it is located at C2, the correction value is set to 0 because the origin is displaced but the rotation speed itself is not wrong. [3]: Positioning at C3 is a state in which the deviation of the origin corresponds to ± 90 degrees or more, which is impossible and should not occur. Therefore, it is regarded as an error (E). [4]: If it is located at C4, the count value of the rotation speed counting means (incremental encoder 5) is lower by one rotation. Therefore, a correction of +1 rotation is added. Correction values based on the same consideration (thinking experiment) are also set for the other columns.

The correction operation based on Table 1 is performed in the apparatus of this embodiment. That is, under the condition that the origin misalignment of both is less than ± 90 degrees, the MSB signal of the position information within one rotation obtained from the resolver 4 becomes high level and the position information within one rotation becomes 1/2 of the latter half. Incremental encoder 5 shown to be in rotation
When the rotation speed information of the rotating body obtained from the above is in the C1 region, the rotation speed information is corrected by -1.
Also, the MSB of the position information within one rotation obtained from the resolver 4.
The signal becomes low level and the position information within one revolution is 1 in the first half.
/ 2 rotations and incremental
When the rotation speed information of the rotating body obtained from the encoder 5 is in the C4 region, the rotation speed information is corrected by +1.

Further, every time the data of both the resolver 4 and the incremental encoder 5 are updated, the correction calculation process (+1, ±
A calculation operation of 0, -1) is added to the rotation speed information according to the output relationship between the two. As a result of performing such a correction, even if there is a deviation of the origins of both data as shown in FIG. 5A, the mismatch is appropriately corrected and the system output of FIG. Such ideal multi-rotation absolute position information can be obtained.

In the above embodiment, the Hall element is used as the magnetic sensor, but any other magnetic sensor can be adopted. Further, a means other than the resolver can be used as the one-revolution position information measuring means, and similarly, a means other than the incremental encoder can be used as the rotation speed counting means.

[0022]

As described above, the turning angle detecting device according to the present invention uses the origin of the position information within one rotation as a reference according to the output relationship of the position information within one rotation measuring means and the rotation speed counting means. Since the correction calculation process is added to the rotational speed information to obtain the ideal multi-rotation absolute position information, the inconsistent area in both the rotational speed information and the position information within one rotation is corrected, Even if there is a deviation in the origin, the multi-rotation absolute position information can always be accurately output, and the reliability of the rotation angle detection device can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a rotation angle detection device according to an embodiment of the present invention.

2A and 2B show a rotation number counting means, FIG. 2A is a plan view of a main part of the apparatus, and FIG. 2B is a diagram showing a magnetic sensor output state.

FIG. 3 is an explanatory plan view showing the origin deviation between the in-one-revolution position information measuring means and the rotation speed counting means.

FIG. 4 is a diagram showing a case of obtaining ideal multi-rotation absolute position information, in which (a) is a diagram showing an information signal obtained by a position information measurement means within one rotation and a rotation speed counting means; (B) is a diagram showing an ideal multi-rotation absolute position information signal obtained by combining.

FIG. 5 is a diagram showing a case where multi-rotation absolute position information is obtained while causing a deviation of the origin, and (a) shows an information signal obtained by the in-one-revolution position information measuring means and the rotation speed counting means. Diagram (b) is a diagram showing an ideal multi-rotation absolute position information signal obtained by combining.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 disk magnet 2a, 2b magnetic sensor 3 rotating body 4 resolver (position information measuring means within one rotation) 5 incremental encoder (rotation speed counting means) 8 logic gate 9 rotation speed correction calculation IC

Claims (1)

[Claims] 1. An in-one-revolution position information measuring means for detecting a rotational angular position of a rotating body, for detecting a position of the rotating body within one rotation, and a rotation for detecting a rotational speed of the rotating body. In the rotation angle detecting device including the number counting means, the within-one-revolution position information of the rotating body obtained by the within-one-revolution position information measuring means, and the rotation number information of the rotating body obtained by the rotation number counting means. In response to the above information, the rotation angle detecting device further comprises a correction calculating unit that corrects the rotation speed information.