Hand Wheel Position Detection System

• US 20130166141A1
• Filed: 07/20/2012
• Published: 06/27/2013
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Inventors: Sebastian, Tomy, Fisher, Paul M., Ross, Christian E., Ryne, Zaki, Kidder, Keith A., Tarum, Carl D., Blehm, Scott T.
• Granted Patent: US 9,254,869 B2
• Time in Patent Office: Days
• US Class Current: 701/34.4
• CPC Class Codes: B62D 15/0215 by measuring on the steering column
• CPC Class Codes: B62D 15/0245 Means or methods for determination of the central position of the steering system, e.g. straight ahead position
• CPC Class Codes: G01D 3/0365 the undesired influence being measured using a separate sensor, which produces an influence related signal
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06

Abstract

A steering system for detecting a hand wheel position is provided and includes an input shaft connected to a hand wheel, a main gear disposed around the input shaft, a puck gear meshingly engaged with the main gear, and a control module. The control module receives an angular main position of the main gear and an angular puck position of the puck gear. The control module includes a rotational calculation module for calculating the hand wheel position based on at least the angular main position and the angular puck position.

Claims

1. A steering system for detecting a hand wheel position, comprising:

an input shaft connected to a hand wheel;

a main gear disposed around the input shaft;

a puck gear meshingly engaged with the main gear; and

a control module that receives an angular main position of the main gear and an angular puck position of the puck gear, the control module including;

a rotational calculation module for calculating the hand wheel position based on at least the angular main position and the angular puck position.

2. The steering system as recited in claim 1, wherein the hand wheel position is calculated by:

c₁=α

−

360 n₁, c₂=Gα

−

360 n₂, and α

=c₁+360 n₁, wherein c₁ is the angular main position, c₂ is the angular puck position, α

is the hand wheel position, n₁ is a number of rotations of the input shaft, n₂ is a number of rotations of the puck gear, and G is a gear ratio.

3. The steering system as recited in claim 2, wherein a term [c₁−

1/G c₂] is an empirical value used to determine a number of rotations of the input shaft and is compared to a value in a lookup table saved in a memory of the control module.

4. The steering system as recited in claim 3, wherein the term [c₁−

1/G c₂] differs by at least thirty degrees depending on the angular main position c₁, the angular puck position c₁, the hand wheel position α

, the number of rotations of the input shaft n₁, and the number of rotations of the puck gear n₂.

5. The steering system as recited in claim 1, wherein a position of the main gear and a position of the puck gear are aligned generally at zero degrees.

6. The steering system as recited in claim 1, wherein a position of the main gear and a position of the puck gear are offset from zero degrees.

7. The steering system as recited in claim 6, wherein the control module includes an offset module, and wherein the offset module executes an alignment algorithm for adjusting the position of the main gear and the position of the puck gear.

8. The steering system as recited in claim 1, wherein the control module includes a diagnostic module that receives the angular main position, the angular puck position, a number of rotations of the input shaft, and a number of rotations of the puck gear.

9. The steering system as recited in claim 8, wherein the diagnostic module calculates the hand wheel position and a second hand wheel position.

10. The steering system as recited in claim 9, wherein the second hand wheel position is calculated by:

α

′

=(c₂+360 n₂)/G

wherein α

′

is the second hand wheel position, c₂ is the angular puck position of the puck gear, n₂ is a number of rotations of the puck gear, and G is a gear ratio.

11. The steering system as recited in claim 9, wherein the diagnostic module determines an error of the hand wheel position by comparing the hand wheel position with the second hand wheel position.

12. The steering system as recited in claim 11, wherein the diagnostic module determines if the error is above a threshold value.

20. The steering system as recited in claim 1, wherein the diagnostic module receives the angular main position, the angular puck position, a number of rotations of the input shaft, and a number of rotations of the puck gear, and wherein the second hand wheel position is calculated by:

α

′

=(c₂+360 n₂)/G

wherein α

′

is the second hand wheel position, c₂ is the angular puck position of the puck gear, n₂ is a number of rotations of the puck gear, and G is a gear ratio.

13. A steering system for detecting a hand wheel position, comprising:

an input shaft connected to a hand wheel;

a main gear disposed around the input shaft;

a puck gear meshingly engaged with the main gear; and

a control module that receives an angular main position of the main gear and an angular puck position of the puck gear, the control module including;

a rotational calculation module for calculating the hand wheel position based on at least the angular main position and the angular puck position; and

a diagnostic module for determining an error of the hand wheel position by comparing the hand wheel position with a second hand wheel position.

14. The steering system as recited in claim 13, wherein the hand wheel position is calculated by:

c₁=α

−

360 n₁, c₂=Gα

−

360 n₂, and α

=c₁+360 n₁, wherein c₁ is the angular main position, c₂ is the angular puck position, α

is the hand wheel position, n₁ is a number of rotations of the input shaft, n₂ is a number of rotations of the puck gear, and G is a gear ratio.

15. The steering system as recited in claim 14, wherein a term [c₁−

1/G c₂] is an empirical value used to determine a number of rotations of the input shaft and is compared to a value in a lookup table saved in a memory of the control module.

16. The steering system as recited in claim 15, wherein the term [c₁−

1/G c₂] differs by at least thirty degrees depending on the angular main position c₁, the angular puck position c₁, the hand wheel position α

, the number of rotations of the input shaft n₁, and the number of rotations of the puck gear n₂.

17. The steering system as recited in claim 13, wherein a position of the main gear and a position of the puck gear are aligned generally at zero degrees.

18. The steering system as recited in claim 13, wherein a position of the main gear and a position of the puck gear are offset from zero degrees.

19. The steering system as recited in claim 18, wherein the control module includes an offset module, and wherein the offset module executes an alignment algorithm for adjusting the position of the main gear and the position of the puck gear.