| 摘要 |
A method is given for finding a reference correction value of an index mark of an angular encoder. The angular encoder includes a first read head, a second read head, and a patterned element having incremental marks and an index mark. In a first instance and in a second instance, the patterned element is rotated relative to the read heads to obtain incremental readings from the first read head and the second read head and an index mark from the first read head. Based on these readings, a processor determines, in the first instance, a first reference position and, in the second instance, a second reference position. The processor determines the reference correction value based at least in part on the first reference position and the second reference position. |
| 主权项 |
1. A method for obtaining a reference correction value for an angular encoder, the method comprising:
providing the angular encoder having a patterned element and a read head assembly, the read head assembly including a first read head and a second read head, the patterned element including a plurality of incremental marks and an index mark; providing a processor; generating, in a first instance, a relative rotation between the patterned element and the read head assembly about a first axis and obtaining, in response, first incremental readings, second incremental readings, and a first index reading, the first incremental readings including a plurality of readings of the incremental marks by the first read head, the second incremental readings including a plurality of readings of the incremental marks by the second read head, and the first index reading including a reading of the index mark by the first read head; determining with the processor a first reference position, the first reference position based at least in part on the first incremental readings, the second incremental readings, and the first index reading; generating, in a second instance, a relative rotation between the patterned element and the read head assembly about the first axis and obtaining, in response, third incremental readings, fourth incremental readings, and a second index reading, the third incremental readings including a plurality of readings of the incremental marks by the first read head, the fourth incremental readings including a plurality of readings of the incremental marks by the second read head, and the second index reading including a reading of the index mark by the first read head; determining with the processor a second reference position, the second reference position based at least in part on the third incremental readings, the fourth incremental readings, and the second index reading; and determining with the processor the reference correction value based at least in part on the first reference position and the second reference position. |
