METHOD AND APPARATUS FOR CONTROLLING A SEMI-ACTIVE SUSPENSION SYSTEM FOR MOTORCYCLES

• US 20110153158A1
• Filed: 08/06/2009
• Published: 06/23/2011
• Est. Priority Date: 08/06/2008
• Status: Active Grant

• Current Assignee: Gerardo Acocella, Spring Off S.r.l.
• Original Assignee: Gerardo Acocella, Spring Off S.r.l.
• Inventors: Acocella, Gerardo
• Granted Patent: US 8,972,108 B2
• Time in Patent Office: Days
• US Class Current: 701/37
• CPC Class Codes: B60G 2300/12 Cycles; Motorcycles
• CPC Class Codes: B60G 2400/0522 Pitch rate
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2600/184 Semi-Active control means
• CPC Class Codes: B62K 25/04 for mounting axles resiliently on cycle frame or fork for sidecars, forecars or the like B62K27/06

Abstract

A method and an apparatus for controlling a semi-active suspension system (1) for motorcycles are described. According to the present invention, the damping forces applied to controllable force generators (2, 3), such as controllable shock absorbers, provided to the front and the rear semi-active suspensions of a motorcycle are jointly controlled. In particular, the pitch velocity (V_p) of the suspended mass (M_s) is taken into account so as to jointly control the front and rear suspension systems of a motorcycle. The present invention allows the optimization of the global adherence of the motorcycle to the road surface and of the driving and the travelling comfort of the vehicle.

Claims

1. Method for controlling a semi-active suspension system for a motorcycle, said method jointly controlling front and rear suspensions, wherein said front suspension comprises a front controllable force generator (2) provided between a suspended mass (M₅) and a front non-suspended mass (m_en) and said rear suspension comprises a rear controllable force generator (3) provided between said suspended mass (M_s) and a rear non-suspended mass (m_ru), said method comprising the following steps:

a. determining a first signal (V_bf) corresponding to the relative velocity between said suspended mass (M_s) and said front non-suspended mass (m_fu);

b. determining a second signal (V_br) corresponding to the relative velocity between said suspended mass (M_s) and said rear non-suspended mass (m_ru);

c. determining a third signal (V_p) corresponding to the pitch angular velocity of the pitch motion of said suspended mass (M_s);

d. determining the front force (F_id) to be generated by said front controllable force generator (2) on the basis of a first function (F_f) of said first signal (V_bf) and said third signal (V_p), wherein said first function (F_f) defines a three-dimensional control surface and wherein said front force (F_id) to be generated is proportional to said first function (F_f);

e. determining the rear force (F_2d) to be generated by said rear controllable force generator (3) on the basis of a second function (F_r) of said second signal (V_br) and said third signal (V_p), wherein said second function (F_r) defines a three-dimensional control surface and wherein said rear force (F_2d) to be generated is proportional to said second function (F_r).

2. Method according to claim 1, further comprising the following steps:

determining a first gain value (G₁);

determining said first function (F_f) of said first signal (V_bf) and said third signal (V_p);

determining said front force (F_id) as the product of said first function (F_f), said first signal (V_bf) and said first gain value (G₁);

determining a second gain value (G₂);

determining said second function (F_r) of said second signal (V_br) and said third signal (V_p); and

determining said rear force (F_2d) as the product of said second function (F_r), said second signal (V_br) and said second gain value (G₂).

3. Method according to claim 1, further comprising the following steps:

f. determining a fourth signal (V_sp) corresponding to the longitudinal velocity of the suspended mass (M_s);

g. determining a fifth signal (V_roll) corresponding to the roll angular velocity of the suspended mass (M_s);

h. determining a sixth signal (A_f) corresponding to the actuation of the braking means acting on said front non-suspended mass (m_fu);

i. determining a seventh signal (A_r) corresponding to the actuation of the braking means acting on said rear non-suspended mass (m_ru);

j. determining the front force (F_id) to be generated by said front controllable force generator (2) further on the basis of said fourth signal (V_sp), said fifth signal (V_roll) and said sixth signal (Ar);

k. determining the rear force (F_2d) to be generated by said rear controllable force generator (3) further on the basis of said fourth signal (V_sp), said fifth signal (V_roll) and said seventh signal (A_r).

4. Method according to claim 3, further comprising the following steps:

determining a third function (C_f,roll) of said first signal (V_bf) and said fifth signal (V_roll);

determining a third gain function (G_Af) of said sixth signal (A_f);

determining a fourth gain function (G_f) of said fourth signal (V_sp);

determining the front force (F_1d) as the product of said first function (F_f), said first signal (V_bf), said first gain value (G₁), said third function (C_f,roll), said third gain function (G_Af) and said fourth gain function (G_f);

determining a fourth function (C_r,roll) of said second signal (V_br) and said fifth signal (V_roll);

determining a fifth gain function (G_Ar) of said seventh signal (A_r);

determining a sixth gain function (Gr) of said fourth signal (V_sp); and

determining the rear force (F_2d) as the product of said second function (F_r), said second signal (V_br), said second gain value (G₂), said fourth function (C_r,roll), said fifth gain function (G_Ar) and said sixth gain function (G_r).

5. Apparatus for controlling a semi-active suspension system for a motorcycle, said apparatus jointly controlling front and rear suspensions, wherein said front suspension comprises a front controllable force generator (2) provided between a suspended mass (M_s) and a front non-suspended mass (m_fu) and said rear suspension comprises a rear controllable force generator (3) provided between said suspended mass (M_s) and a rear non-suspended mass (m_ru), said apparatus comprising:

means for determining a first signal (V_bf) corresponding to the relative velocity between said suspended mass (M_s) and said front non-suspended mass (m_fu);

means for determining a second signal (V_br) corresponding to the relative velocity between said suspended mass (M_s) and said rear non-suspended mass (m_ru);

means for determining a third signal (V_p) corresponding to the pitch angular velocity of the pitch motion of said suspended mass (M_s);

means for determining the front force (F_id) to be generated by said front controllable force generator (2) on the basis of a first function (F_f) of said first signal (V_bf) and said third signal (V_p), wherein said first function (F_f) defines a three-dimensional control surface and wherein said front force (F_id) to be generated is proportional to said first function (F_f);

means for determining the rear force (F_2d) to be generated by said rear controllable force generator (3) on the basis of a second function (F_r) of said second signal (V_br) and said third signal (V_p), wherein said second function (F_r) defines a three-dimensional control surface and wherein said rear force (F_2d) to be generated is proportional to said second function (F_r).

6. Apparatus according to claim 5, further comprising:

means for determining a fourth signal (V_sp) corresponding to the longitudinal velocity of the suspended mass (M_s);

means for determining a fifth signal (V_roll) corresponding to the roll angular velocity of the suspended mass (M_s);

means for determining a sixth signal (A_t) corresponding to the actuation of the braking means acting on said front non-suspended mass (m_fu);

means for determining a seventh signal (A_r) corresponding to the actuation of the braking means acting on said rear non-suspended mass (m_ru);

means for determining the front force (F_id) to be generated by said front controllable force generator (2) further on the basis of said fourth signal (V_sp), said fifth signal (V_roll) and said sixth signal (A_f);

means for determining the rear force (F_2d) to be generated by said rear controllable force generator (3) further on the basis of said fourth signal (V_sp), said fifth signal (V_roll) and said seventh signal (A_r).

7. Apparatus according to claim 5 wherein said front and rear controllable force generators (2 and 3) comprise controllable shock absorbers.

8. A semi-active suspension system for a motorcycle having a suspended mass including the motorcycle body and a non-suspended mass including the front and rear wheels comprising:

front relative velocity means, coupled between the suspended mass of the motorcycle body and the non-suspended mass of the front wheel, for providing a front relative velocity signal representative of the relative velocity between the suspended mass of the motorcycle body and the non suspended mass of the front wheel;

rear relative velocity means, coupled between the suspended mass of the motorcycle body and the non-suspended mass of the rear wheel, for providing a rear relative velocity signal representative of the relative velocity between the suspended mass of the motorcycle body and the non suspended mass of the rear wheel;

pitch velocity means, coupled to the suspended mass of the motorcycle body, for providing a pitch velocity signal representative of a pitch velocity of the suspended mass of the motorcycle body;

a front controllable force generator placed between the suspended mass of the motorcycle body and the non-suspended mass of the front wheel;

a rear controllable force generator placed between the suspended mass of the motorcycle body and the non-suspended mass of the rear wheel;

a controller coupled to said front relative velocity means, rear relative velocity means, pitch velocity means, front controllable force generator, and rear controllable force generator; and

wherein said controller provides control signals for regulation of said front and rear controllable force generators based on a predetermined control policy for optimizing global adherence of the motorcycle to a road surface,

whereby driving and traveling comfort of the motorcycle is improved.

9. A semi-active suspension system for a motorcycle having a suspended mass including the motorcycle body and a non-suspended mass including the front and rear wheels as in claim 8 wherein:

the predetermined control policy comprises a three dimensional control surface defined by a function of the front relative velocity signal, the rear relative velocity signal, and the pitch velocity signal.