US 12,278,575 B2
System and method of increasing resolution of position feedback for motor control
John A. Backman, Cedarburg, WI (US); and Bryan Radke, West Allis, WI (US)
Assigned to Magnetek, Inc., Menomonee Falls, WI (US)
Filed by Magnetek, Inc., Menomonee Falls, WI (US)
Filed on Nov. 17, 2022, as Appl. No. 18/056,528.
Prior Publication US 2024/0171101 A1, May 23, 2024
Int. Cl. H02P 23/28 (2016.01); H02P 8/14 (2006.01); H02P 21/18 (2016.01)
CPC H02P 21/18 (2016.02) 20 Claims
OG exemplary drawing
 
1. A method for increasing resolution of a position feedback signal to a motor drive, the method comprising the steps of:
receiving the position feedback signal at an input to the motor drive;
executing at least two position determination modules within the motor drive, wherein each of the at least two position determination modules further executes the steps of:
sampling the position feedback signal,
incrementing a pulse counter when a new pulse from the position feedback signal is detected,
reading a high resolution pulse count register from a high resolution pulse counter,
adding the pulse counter to the high-resolution pulse count register to obtain a new value for the high resolution pulse count register,
storing the new value in the high resolution pulse count register, and
calculating an approximate position as a function of the high-resolution pulse count register;
calculating an average approximate position by averaging the approximate position calculated by each of the at least two position determination modules; and
executing a speed regulator in the motor drive, wherein:
the speed regulator periodically executes at a slower rate than each of the at least two position determination modules, and
the speed regulator uses the average approximate position.