Method for Detecting the Angular Position of a Knob for the Gas of a Motorcycle

• US 20080295801A1
• Filed: 01/23/2008
• Published: 12/04/2008
• Est. Priority Date: 06/04/2007
• Status: Active Grant

• Current Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Original Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Inventors: Zanotti, Massimo, Lambertini, Loris, Grossi, Claudio
• Granted Patent: US 7,729,849 B2
• Time in Patent Office: Days
• US Class Current: 123/361
• CPC Class Codes: B62K 11/14 Handlebar constructions, or arrangements of controls thereon, specially adapted thereto hand controls per se B62K23/02

Abstract

A method for detecting the angular position of a gas knob of a motorcycle; the method presents the steps of: detecting simultaneously four mutually redundant measurements of the angular position of the gas knob by means of two mutually independent angular-position sensors forming part of an acquisition system; making a cross comparison two by two between the four measurements for diagnosing any possible malfunctioning of the angular-position sensors; and determining the angular position of the gas knob, using at least one measurement supplied by an angular-position sensor operating properly.

Claims

1. ) A method for detecting the angular position (α

) of a gas knob (2) of a motorcycle;

the method comprises the steps of;

detecting simultaneously four mutually redundant measurements (V_A, V_B, V_C, V_D) of the angular position (α

) of the gas knob (2) by means of two mutually independent angular-position sensors (10, 11) forming part of an acquisition system (1);

making a cross comparison two by two between the four measurements (V_A, V_B, V_C, V_D) for diagnosing any possible malfunctioning of the angular-position sensors (10, 11); and

determining the angular position (α

) of the gas knob (2), using at least one measurement (V_A, V_B, V_C, V_D) supplied by an angular-position sensor (10, 11) operating properly.

2. ) The method according to claim 1, wherein the angular position (α

) of the gas knob (2) is assumed as being equal to a single measurement supplied by an angular-position sensor (10, 11) operating properly.

3. ) The method according to claim 1, wherein the angular position (α

) of the gas knob (2) is assumed as being equal to an average of at least two measurements supplied by at least one angular-position sensor (10, 11) operating properly.

4. ) The method according to claim 1, and comprising the further step of limiting the performance of an engine of the motorcycle in the case of failure in at least one angular-position sensor (10, 11).

5. ) The method according to claim 4, wherein the performance of the engine is limited in a way increasing as a function of the increase in the number of wrong measurements (V_A, V_B, V_C, V_D).

6. ) The method according to claim 4, wherein:

in the event of just one wrong measurement (V_A, V_B, V_C, V_D), the performance of the engine is slightly limited, enabling travel at a lower speed with respect to the nominal performance;

in the event of two wrong measurements (V_A, V_B, V_C, V_D), the performance of the engine is limited, enabling travel at a much lower speed with respect to the nominal performance,

in the event of three wrong measurements (V_A, V_B, V_C, V_D), the performance of the engine is markedly limited, only enabling operation at constant r.p.m.

7. ) The method according to claim 1, wherein the cross comparison two by two between the four wrong measurements (V_A, V_B, V_C, V_D) supplied by the angular-position sensor (10, 11) envisages verification of the following equations:

V_A=2*V_B±

Tolerance₁ 

 

[1]

V_C=2*V_D±

Tolerance₁ 

 

[2]

V_A+V_C=K₁±

Tolerance₂ 

 

[3]

V_B+V_D=K₂±

Tolerance₂ 

 

[4]

2*V_B+V_C=K₃±

Tolerance₂ 

 

[5]

2*V_D+V_A=K₄±

Tolerance₂ 

 

[6]

V_A, V_B, V_C, V_D are the four measurements supplied by the angular-position sensor (10, 11);

K₁, K₂, K₃, K₄ are four constants of verification;

Tolerance₁ is a first predefined threshold value that takes into account the errors of measurement committed by the angular-position sensors (10, 11);

Tolerance₂ is a second predefined threshold value that takes into account the errors of measurement committed by the angular-position sensors (10, 11).

8. ) The method according to claim 7 and comprising the further step of learning the effective value of the verification constants (K₁, K₂, K₃, K₄) during a initial calibration step of the acquisition system (1).

9. ) The method according to claim 8, wherein the first time that the acquisition system (1) is set in operation, the acquisition system (1) goes automatically into a calibration condition, in which a tester must get the gas knob (2), with the engine turned off, to make some rotations to determine the effective values of the verification constants (K₁, K₂, K₃, K₄).

10. ) The method according to claim 7, wherein:

if all six equations [1]-[6] are verified within the predefined tolerance margins, then both of the angular-position sensors (10, 11) function properly and all four measurements (V_A, V_B, V_C, V_D) supplied by the angular-position sensor (10, 11) are correct;

if only three of the six equations [1]-[6] are verified within the predefined tolerance margins, then an angular-position sensor (10, 11) is partially failed and one of the four measurements (V_A, V_B, V_C, V_D) supplied by the angular-position sensors (10, 11) is wrong;

if only one of the six equations [1]-[6] is verified within the predefined tolerance margins, then at least one angular-position sensor (10, 11) is partially failed and two of the four measurements (V_A, V_B, V_C, V_D) supplied by the angular-position sensors (10, 11) are wrong;

if none of the six equations [1]-[6] is verified within the predefined tolerance margins, then both of the angular-position sensors (10, 11) are at least partially failed and at least three of the four measurements (V_A, V_B, V_C, V_D) supplied by the angular-position sensors (10, 11) are wrong.

11. ) The method according to claim 1, wherein the first time that the acquisition system (1) is set in operation, the acquisition system (1) goes automatically into a calibration condition, in which the effective angular position (α

) of the gas knob (2) is measured corresponding to the resting position.

12. ) The method according to claim 1, wherein whenever the acquisition system (1) is set in operation, the acquisition system (1) goes automatically into a calibration condition, in which the effective angular position (α

) of the gas knob (2) is measured corresponding to the resting position.

13. ) The method according to claim 11, wherein turning-on of the engine of the motorcycle is inhibited if the effective angular position (α

) of the gas knob (2) corresponding to the resting position does not correspond to an expected value.

14. ) The method according to claim 1, wherein the acquisition system (1) comprises:

a fixed supporting body (3);

a rotating shaft (4), rotatably mounted in the supporting body (3) and mechanically coupled to the two angular-position sensors (10, 11); and

a transmission device (6), mechanically connected to the gas knob (2) and to the rotating shaft (4) for transmitting the motion from the gas knob (2) to the rotating shaft (4) itself.

15. ) The method according to claim 14, wherein the transmission device (6) is of the cable type and comprises a sheave (7) of a push-pull type, fixed with respect to the rotating shaft (4) and a pair of cables of a Bowden type, each of which has one end constrained to the gas knob (2) and one opposite end, fixed with respect to the sheave (7).

16. ) The method according to claim 14, wherein the transmission device (6) is of the cable type and comprises a sheave (7), fixed with respect to the rotating shaft (4), and a cable of a Bowden type, which has one end constrained to the gas knob (2) and one opposite end, fixed with respect to the sheave (7).

17. ) The method according to claim 14, wherein the transmission device (6) comprises a direct mechanical connection for rendering the rotating shaft (4) coaxial and angularly fixed with respect to the knob (2).

18. ) The method according to claim 1, wherein a return spring is provided, set around the rotating shaft (4) for pushing the rotating shaft (4) itself with a given force towards a resting position corresponding to a zero torque.

19. ) The method according to claim 14, wherein the two angular-position sensors (10, 11) are set at the opposite ends of the rotating shaft (4).

20. ) The method according to claim 19, wherein the fixed supporting body (3) is C-shaped, and is traversed by the rotating shaft (4) that exits from the fixed supporting body (3) at two opposite ends of the rotating shaft (4) itself.

21. ) The method according to claim 20, wherein the transmission device (6) is of the cable type and comprises a sheave (7), fixed with respect to the rotating shaft (4) and set in a position of centre of the rotating shaft (4) itself, and at least one cable of a Bowden type, which has one end constrained to the gas knob (2) and one opposite end, fixed with respect to the sheave (7).

22. ) The method according to claim 1, wherein each main angular-position sensor (10, 11) is a double potentiometer.

23. ) The method according to claim 22, wherein for each angular-position sensor (10, 11) a measurement of the angular position (α

) of the rotating shaft (4) is equal to half of the other measurement of the angular position (α

) of the rotating shaft (4).

24. ) The method according to claim 23, wherein the two measurements of the angular position (α

) of the rotating shaft (4) of a first angular-position sensor (10) follow a law different with respect to the two measurements of the angular position (α

) of the rotating shaft (4) of a second angular-position sensor (11).

25. ) The method according to claim 24, wherein the measurements (V_A, V_B) of the angular position (α

) of the gas knob (2) supplied by a first angular-position sensor (10) increase as the angular position (α

) of the gas knob (2) increases, whilst the measurements (V_C, V_D) of angular position (α

) of the gas knob (2) of a second angular-position sensor (11) decrease as the angular position (α

) of the gas knob (2) increases, with a rate of variation equal and opposite to the rate of variation of the measurements (V_A, V_B) of the angular position (α

) of the gas knob (2) supplied by the first angular-position sensor (10).

26. ) The method according to claim 1, wherein each sensor (10;

11) of position is connected to a processing unit (14) of the acquisition system (1) by means of a wiring (15) of its own, independent of the other angular-position sensor (11;

10).

27. ) The method according to claim 26, wherein connectors of the wiring (15) of a first angular-position sensor (10) are physically different from the connectors of the wiring (15) of a second angular-position sensor (11).