METHOD OF SENSOR MISALIGNMENT LEARNING FOR MOTOR SPEED ESTIMATION

• US 20180248450A1
• Filed: 02/28/2017
• Published: 08/30/2018
• Est. Priority Date: 02/29/2016
• Status: Active Grant

• Current Assignee: Dana Automotive Systems Group, LLC (Dana, Inc.)
• Original Assignee: Dana Automotive Systems Group, LLC (Dana, Inc.)
• Inventors: van Ginkel, Johannes
• Granted Patent: US 10,298,099 B2
• Time in Patent Office: Days
• CPC Class Codes: G01D 3/036 on measuring arrangements themselves
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00
• CPC Class Codes: G01R 1/00 Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00 constructional details particular to electromechanical arrangements for measuring the electric consumption G01R11/02
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position
• CPC Class Codes: H02P 6/17 and for generating speed information

Abstract

A method of estimating electric motor speed. The method determines whether a sequential cycle of the electric motor has occurred. The method calculates a correction factor for each of the Hall states. Where a sequential cycle of the electric motor has occurred, the method also calculates an update quality factor for the correction factors of the sequential cycle. The method updates the correction factors utilizing the update quality factor. Utilizing the updated correction factors, the method updates the electric motor speed signal.

Claims

1. A method for estimating electric motor speed, comprising:

providing an electric motor including;

a stator having at least one Hall-effect sensor coupled therewith; and

a rotor having at least one magnetic pole pair;

calculating a correction factor for each Hall state of said electric motor via comparing time periods of said Hall states to a time period of a sequential cycle;

determining whether a sequential cycle of said electric motor has occurred;

calculating an update quality factor where said electric motor has experienced said sequential cycle;

updating said correction factors utilizing said update quality factor and a previously calculated correction vector, where said sequential cycle has occurred; and

calculating said electric motor speed signal utilizing said correction factors.

2. The method for estimating electric motor speed according to claim 1, further comprising:

calculating said electric motor speed utilizing a correction vector from a previous sequential cycle where a second sequential cycle has not occurred.

3. The method for estimating electric motor speed according to claim 1, wherein:

said sequential cycle is one electrical revolution.

4. The method for estimating electric motor speed according to claim 1, wherein calculating a correction factor for one of said Hall states comprises:

determining a number of Hall states in said sequential cycle;

determining a duration of each said Hall state;

determining a duration of said sequential cycle;

multiplying said number of Hall states in said sequential cycle by said duration of one of said Hall states to produce a first product; and

dividing said first product by said duration of said sequential cycle.

5. The method for estimating electric motor speed according to claim 1, wherein calculating an update quality factor comprises:

comparing said correction factors of said sequential cycle to a physical constraint of said at least one Hall-effect sensor to determine an accuracy of said correction factors; and

determining a value from said accuracy.

6. The method for estimating electric motor speed according to claim 1, wherein calculating an update quality factor comprises:

determining a speed of said electric motor from a duty ratio for said electric motor;

determining an acceleration of said electric motor from said duty ratio; and

determining a value from said electric motor acceleration.

7. The method for estimating electric motor speed according to claim 1, wherein calculating an update quality factor comprises:

comparing each said correction factor of said sequential cycle to determine an acceleration of said electric motor; and

determining a value from said electric motor acceleration.

8. The method for estimating electric motor speed according to claim 1, wherein updating said correction factors utilizing said update quality factor comprises:

multiplying a new correction vector by a new update quality factor to produce a first product;

multiplying a previously calculated correction vector by a sum of said update quality factors to produce a second product;

adding said first product to said second product to produce a first sum;

adding said new update quality factor to said sum of said update quality factors to produce a second sum; and

dividing said first sum by said second sum.

9. The method for estimating electric motor speed according to claim 1, wherein calculating said electric motor speed signal utilizing said updated correction factors comprises:

multiplying one of said correction factors by a number of mechanical degrees traveled by said rotor during said Hall state related to said correction factor to produce a first product; and

dividing said first product by a duration of a Hall state previous to said Hall state.

10. The method for estimating electric motor speed according to claim 1, wherein:

said sequential cycle is one mechanical revolution.

11. The method for estimating electric motor speed according to claim 1, wherein:

said electric motor is controlled by a cascaded closed-loop controller.

12. The method for estimating electric motor speed according to claim 1, wherein updating said correction factors comprises:

incorporating a forgetting factor.

13. The method for estimating electric motor speed according to claim 1, further comprising:

mapping the characteristics of said electric motor during end-of-line testing.

14. The method for estimating electric motor speed according to claim 1, wherein:

said electric motor is coupled with an automobile all-wheel drive disconnect apparatus.