Granted Patent B1

US 12,732,122 · App. 18/187,392 · Granted Sep 8, 2026

Inventors: John Giarratana (Whitman, MA); William G. Near (Boston, MA); Colin Patrick O'Shea (Cambridge, MA); Tyson David Sawyer (Mason, NH); Johannes Schneider (Cambridge, MA); Clive Tucker (Charlestown, MA); Richard Anthony Zuckerman (Somerville, MA); Zackary Martin Anderson (Cambridge, MA); Marco Giovanardi (Melrose, MA); Jack A. Ekchian (Belmont, MA)

Assignee: ClearMotion, Inc.

H02P6/00

Abstract

Claims (15)

1 . A method for determining an absolute angular position with a detection system of an electric motor, the method comprising:

detecting an index signal produced by the electric motor;

determining that the detected index signal is a first detected index signal since the detection system was initialized;

initializing a histogram centered at an incremental motor position where the detected index signal was detected;

determining that the histogram is a valid histogram;

based on the histogram, determining an incremental motor position value with a highest count;

setting a motor index position equal to the incremental motor position with the highest count; and

operating the electric motor based on the motor index position.

2 . The method of claim 1 , wherein determining that the histogram is a valid histogram comprises determining that the incremental motor position is not located in an edge bin.

3 . The method of claim 1 , wherein determining that the histogram is a valid histogram comprises detecting whether the histogram approximates a bell-shaped distribution.

4 . The method of claim 1 , wherein detecting the index signal produced by the electric motor is performed at a rate of approximately 5 kHz.

5 . The method of claim 4 , wherein the absolute angular position determination is performed at a lower rate than detecting the index signal.

6 . The method of claim 1 , wherein operating the electric motor comprises controlling torque based on the motor index position.

7 . The method of claim 1 , wherein operating the electric motor comprises reducing pressure ripple using an absolute motor position.

8 . The method of claim 1 , wherein the absolute angular position determination is performed independently of motor speed or acceleration.

Assignments (4)

Continuity (9)

References Cited (55)