CN101979268A - Automobile steering wheel shimmy control method - Google Patents

Abstract

The invention discloses an automobile steering wheel shimmy control method, which is characterized in that: the running speed V and the complete vehicle mass mw of the automobile are detected by sensors, the optimal caste angle alpha opt of the current automobile steering wheel is calculated and analyzed by a central control unit according to a preset differential equation of motion of a system, and the caster angle alpha of the steering wheel is adjusted by an executive unit in real time to ensure that the steering wheel is positioned in the optimal caster angle state so as to reduce the shimmy of the automobile steering wheel. The method can effectively solve the problem of wheel shimmy in the running process of the automobile, and improves the control stability and safety in the process of driving the automobile.

Description

The shimmy control method of a kind of automobile steering roller

Technical field

The present invention relates to the shimmy control method of a kind of automobile steering roller, be mainly used in the shimmy control of automobile steering roller, the shimmy control of wheel when also can be applicable to aircraft lands such as the control of other power actuated vehicle steering-wheel flutter or aircraft.

Background technology

Steering-wheel flutter is meant automobile on smooth road surface during straight-line travelling, and wheel flutter is with certain amplitude and the frequency phenomenon around the stub sustained vibration.Take place when shimmy, wheel flutter swings with certain frequency and amplitude.After developing into to a certain degree, even can cause the car wander motion, bearing circle is acutely shaken, and may further cause rocking of vehicle body.Steering-wheel flutter can aggravate Tyte Wear, increases the live load of steering hardware, reduces the service life of related components, and vehicle dynamic quality, fuel economy, road-holding property, riding comfort and safety are all had serious negative effect.

Cause that the shimmy principal element of automobile steering roller is very complicated, wherein, the automobile steering roller positional parameter especially influence of kingpin caster angle is comparatively remarkable.The steering-wheel flutter angular transposition was with the variation scheme drawing of kingpin caster angle when Fig. 1 (a) was depicted as under the identical speed of a motor vehicle with the money vehicle fully loaded and underloading, and curve a is that underloading, curve b are for fully loaded among the figure; Along with the increase of kingpin caster angle, the angular transposition of automobile steering roller can increase, promptly shimmy aggravation; Steering reversal moment was with the variation scheme drawing of kingpin caster angle when Fig. 1 (b) was depicted as under the identical speed of a motor vehicle with the money vehicle fully loaded and underloading, and curve a is that underloading, curve b are for fully loaded among the figure; Along with the increase of kingpin caster angle, the motor turning aligning torque can increase, and the stability of promptly travelling is better.Shimmy control occurs contradiction to the requirement of kingpin caster angle and steering reversal moment here to the requirement of kingpin caster angle.For the Control of Automobile steering-wheel flutter, need utilize research technique that deflecting roller location parameter is mated in product development stage usually, its shimmy response is controlled within the acceptable scope.But, mainly be vehicle velocity V and complete vehicle quality m because engineering factor is uncertain in the automobile actual travel process _wBigger variation can take place.When these engineering factor change, can guarantee that the best required deflecting roller location parameter of the shimmy response of automobile steering roller correspondingly changes.And the automobile steering roller positional parameter generally is changeless at present, so just can't make automobile keep best shimmy response.

Summary of the invention

The present invention is for avoiding the above-mentioned existing existing weak point of shimmy control method, provide a kind of automobile steering roller shimmy control method, so that can be, thereby guarantee that automobile obtains good steering-wheel flutter response according to the positional parameter of current condition of the vehicle real-time regulated automobile steering roller.

Technical solution problem of the present invention adopts following technical scheme:

The characteristics of the shimmy control method of automobile steering roller of the present invention are to carry out according to the following procedure:

A, by the clear and definite vehicle velocity V of the following system motion differential equation, complete vehicle quality m _w, the relation between the response of wheel flutter kingpin caster angle α and steering-wheel flutter:

$m_w\stackrel{\&CenterDot;\&CenterDot;}{Y}+4K_{s}Y-2({\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="HSA00000287675200011.png"\; state="\{\{state\}\}">F</figure-callout>}}_1+F_2)=0---\left(5\right)$

In the following formula:

θ ₁: left steering is taken turns around the stub rotational freedom; θ ₂: right steering is taken turns around the stub rotational freedom;

Propons side-sway degree of freedom; ψ: the above mechanism of suspension banking degree of freedom;

Y: car load lateral degrees of freedom; φ: tierod yaw degree of freedom;

I _t: front-wheel is around the rotor inertia (kgm of main pin axis ²);

I _x: front-wheel is around the rotor inertia (kgm of the centroidal principal axis vertical with its S. A. ²)

I: wheel rotates around it the rotor inertia (kgm of axle ²)

I _f: the propons lateral deviation is around the rotor inertia (kgm of its lateral deviation axle ²)

I _u: the above structure inclination of suspension is around its roll axis rotor inertia (kgm ²)

J: intermediate rod is around the rotor inertia (kgm of right tie rod arm and intermediate rod point of connection ²)

J ₁: intermediate rod is around the rotor inertia (kgm of its barycenter ²); m _w: complete vehicle quality (kg);

m _t: wheel mass (kg); m _f: propons quality (kg);

m _u: the above mechanism of suspension quality (kg); M: intermediate rod quality (kg);

K _Tv: tire vertical stiffness (N/m); K _s: tire lateral rigidity (N/m);

K _ρ: tire cornering stiffness (N/rad); K _v: be converted to steering box angular rigidity (Nm/rad) around stub;

K _x: suspension rate (N/m); K: steering trapezium pair clearance place axle sleeve surface rigidity (N/m);

C _t: the damping coefficient (Nms/rad) that wheel rotates around stub;

C _v: around the deflector damping coefficient (Nms/rad) of stub rotation;

C _x: suspension damping coefficient (Ns/m); C: steering trapezium pair clearance place axle sleeve surface damp coefficient (Ns/m);

N: pneumatic trail (m) α: kingpin caster angle (rad);

A: the front suspension spring is apart from (m); B: track front (m);

L: stub extended line and ground intersection point are to the distance (m) of wheel symmetrical plane

R: tire rolling radius (m); R ₁: pivot pin radius (m);

R: steering trapezium pair clearance (m); F ₁: revolver side force (N);

F ₂: right wheel side force (N); V: the speed of a motor vehicle (m/s);

V ₁: intermediate rod barycenter place speed (m/s); φ ₁: left steering trapezoid connection and propons angle (rad);

φ ₂: right steering trapezoid connection and propons angle (rad) l: intermediate rod length;

l ₁: the left steering trapezoid connection length l ₂: right steering trapezoid connection length;

B, by following computing formula, clear and definite vehicle velocity V, complete vehicle quality m _w, wheel flutter kingpin caster angle α and wheel flutter aligning torque M _ZBetween relation:

$M_Z={\mathrm{\&eta;m}}_f[\frac{2}{g}\frac{V^2}{D}R\sin \mathrm{\&alpha;}\cos {\mathrm{\&theta;}}_2+{\mathrm{\&theta;}}_{2}b\sin 2\mathrm{\&beta;}+\frac{1}{2}\mathrm{fc}({\cos \mathrm{\&theta;}}_2-\cos {\mathrm{\&theta;}}_1)]---\left(7\right)$

In the following formula:

η: the adverse efficiency of steering system transmission; G: acceleration due to gravity;

D: turning circle diameter; β: Kingpin inclination angle;

F: tire drag coefficient; C: scrub radius;

C, detect current vehicle velocity V and complete vehicle quality m in real time _w, and use angular-motion transducer and detect the kingpin caster angle α that works as steering front wheel, calculate current vehicle speed V and complete vehicle quality m according to the described system motion differential equation of step a _wThe shimmy response of following automobile is represented with the angular displacement of wheel flutter, with θ and default shimmy controlled target θ _ObjCompare, simultaneously with the steering reversal moment M of this vehicle _ZWith default steering reversal moment controlled target M _ZobjCompare; Can guarantee steering reversal moment M _ZGreater than its goal-selling M _ZobjPrerequisite under, make the angular displacement of wheel flutter less than its goal-selling θ _ObjMaximum kingpin caster angle be best kingpin caster angle α under the current techniques condition _Opt

D, application angular-motion transducer detect the kingpin caster angle α when steering front wheel, and utilize hydraulic actuator or stepping motor as adjusting performance element, and wheel flutter kingpin caster angle α is adjusted to best kingpin caster angle α _Opt

Vehicle velocity V, complete vehicle quality m _wAnd kingpin caster angle α is the several key factors that influence steering-wheel flutter.For given automobile, in the parameter that formula (1)～formula (7) is listed except that the speed of a motor vehicle and complete vehicle quality retinue driving skills art condition and manned loading situation change, other parameter immobilizes, perhaps change very I to ignore, therefore, record the current driving engineering factor of given vehicle by sensor, and utilize the predetermined system differential equation of motion to calculate kingpin caster angle α best under the given automobile current line driving skills art condition _Opt, adjust the size of kingpin caster angle α in real time by actuating unit, can obtain comparatively desirable shimmy control effect.Compared with the prior art, beneficial effect of the present invention is embodied in:

1, method provided by the invention can mainly be vehicle velocity V, complete vehicle quality m according to current vehicle condition _w, the positional parameter of real-time regulated automobile steering roller, thus guarantee that automobile remains good steering-wheel flutter response in the process of moving, improve ride safety of automobile, improve vehicle dynamic quality, fuel economy, road-holding property and riding comfort simultaneously.

The shimmy control of wheel when 2, the inventive method also goes for aircraft lands such as the control of other power actuated vehicle steering-wheel flutter or aircraft.

Description of drawings

Fig. 1 (a) be under the identical speed of a motor vehicle with the money vehicle during fully loaded and underloading the steering-wheel flutter angular transposition with the variation of kingpin caster angle;

Fig. 1 (b) be under the identical speed of a motor vehicle with the money vehicle during fully loaded and underloading steering reversal moment with the variation of kingpin caster angle;

Fig. 2 is for realizing the formation scheme drawing of the inventive method.

Number in the figure: 1 bearing circle, 2 stubs, 3 kingpin caster angles detect and adjust performance element, 4 wheel flutters, 5 sensors, 6 Central Processing Unit (CPU)s.

The specific embodiment

Vehicle velocity V, complete vehicle quality m _wAnd kingpin caster angle α is the several key factors that influence steering-wheel flutter.For given automobile, in the parameter that formula (1)～formula (7) is listed except that the speed of a motor vehicle and complete vehicle quality retinue driving skills art condition and manned loading situation change, other parameter immobilize (perhaps change very I to ignore).Therefore, record the current driving engineering factor of given vehicle, and utilize the predetermined system differential equation of motion to calculate kingpin caster angle α best under the given automobile current line driving skills art condition by sensor _Opt, adjust the size of kingpin caster angle α in real time by actuating unit, can obtain comparatively desirable shimmy control effect.

In concrete the enforcement, system shown in Figure 2 relates to bearing circle 1, stub 2 and wheel flutter 4, and system's setting should comprise:

Kingpin caster angle detects and adjusts performance element 3, comprises the angular-motion transducer that is used to test current kingpin caster angle α size, hydraulic actuator or the stepping motor that usefulness adjusts performance element; Casterangle detects and adjust performance element 3 also can be divided into two relatively independent parts: promptly casterangle detecting unit and casterangle are adjusted performance element.

Sensor 5 comprises car speed sensor and load transducer, is used to detect vehicle velocity V and complete vehicle quality m _w

Central Processing Unit (CPU) 6 detects the driving parameter that obtains and sends central controller 6 to, is calculated the kingpin caster angle α of current the best according to pre-set programs by central controller 6 _Opt

The shimmy control method of present embodiment automobile steering roller is carried out according to the following procedure:

A, by the clear and definite vehicle velocity V of the following system motion differential equation, complete vehicle quality m _w, the relation between the response of wheel flutter kingpin caster angle α and steering-wheel flutter:

$m_w\stackrel{\&CenterDot;\&CenterDot;}{Y}+4K_{s}Y-2({\mathrm{<figure-callout\; id="1"\; label="F"\; filenames="HSA00000287675200011.png"\; state="\{\{state\}\}">F</figure-callout>}}_1+F_2)=0---\left(5\right)$

In the following formula:

θ ₁: left steering is taken turns around the stub rotational freedom; θ ₂: right steering is taken turns around the stub rotational freedom;

Propons side-sway degree of freedom; ψ: the above mechanism of suspension banking degree of freedom;

Y: car load lateral degrees of freedom; φ: tierod yaw degree of freedom;

I _t: front-wheel is around the rotor inertia (kgm of main pin axis ²);

I _x: front-wheel is around the rotor inertia (kgm of the centroidal principal axis vertical with its S. A. ²)

I: wheel rotates around it the rotor inertia (kgm of axle ²)

I _f: the propons lateral deviation is around the rotor inertia (kgm of its lateral deviation axle ²)

I _u: the above structure inclination of suspension is around its roll axis rotor inertia (kgm ²)

J: intermediate rod is around the rotor inertia (kgm of right tie rod arm and intermediate rod point of connection ²)

J ₁: intermediate rod is around the rotor inertia (kgm of its barycenter ²); m _w: complete vehicle quality (kg);

m _t: wheel mass (kg); m _f: propons quality (kg);

m _u: the above mechanism of suspension quality (kg); M: intermediate rod quality (kg);

K _Tv: tire vertical stiffness (N/m); K _s: tire lateral rigidity (N/m);

K _ρ: tire cornering stiffness (N/rad); K _v: be converted to steering box angular rigidity (Nm/rad) around stub;

K _x: suspension rate (N/m); K: steering trapezium pair clearance place axle sleeve surface rigidity (N/m);

C _t: the damping coefficient (Nms/rad) that wheel rotates around stub;

C _v: around the deflector damping coefficient (Nms/rad) of stub rotation;

C _x: suspension damping coefficient (Ns/m); C: steering trapezium pair clearance place axle sleeve surface damp coefficient (Ns/m);

N: pneumatic trail (m) α: kingpin caster angle (rad);

A: the front suspension spring is apart from (m); B: track front (m);

L: stub extended line and ground intersection point are to the distance (m) of wheel symmetrical plane

R: tire rolling radius (m); R ₁: pivot pin radius (m);

R: steering trapezium pair clearance (m); F ₁: revolver side force (N);

F ₂: right wheel side force (N); V: the speed of a motor vehicle (m/s);

V ₁: intermediate rod barycenter place speed (m/s); φ ₁: left steering trapezoid connection and propons angle (rad);

φ ₂: right steering trapezoid connection and propons angle (rad); L: intermediate rod length;

l ₁: left steering trapezoid connection length; l ₂: right steering trapezoid connection length;

B, by following computing formula, clear and definite vehicle velocity V, complete vehicle quality m _w, the relation between wheel flutter kingpin caster angle α and the wheel flutter aligning torque MZ:

$M_Z={\mathrm{\&eta;m}}_f[\frac{2}{g}\frac{V^2}{D}R\sin \mathrm{\&alpha;}\cos {\mathrm{\&theta;}}_2+{\mathrm{\&theta;}}_2\mathrm{<figure-callout\; id="2"\; label="b\; sin"\; filenames="HSA00000287675200011.png,HSA00000287675200021.png"\; state="\{\{state\}\}">b</figure-callout>}\sin 2\mathrm{\&beta;}+\frac{1}{2}\mathrm{fc}({\cos \mathrm{\&theta;}}_2-\cos {\mathrm{\&theta;}}_1)]---\left(7\right)$

In the following formula:

η: the adverse efficiency of steering system transmission; G: acceleration due to gravity;

D: turning circle diameter; β: Kingpin inclination angle;

F: tire drag coefficient; C: scrub radius;

C, detect current vehicle velocity V and complete vehicle quality m in real time _w, and use angular-motion transducer and detect the kingpin caster angle α that works as steering front wheel, calculate current vehicle speed V and complete vehicle quality m according to the described system motion differential equation of step a _wThe shimmy response of following automobile is represented with the angular displacement of wheel flutter, with θ and default shimmy controlled target θ _ObjCompare, simultaneously with the steering reversal moment M of this vehicle _ZWith default steering reversal moment controlled target M _ZobjCompare; Can guarantee steering reversal moment M _ZGreater than its goal-selling M _ZobjPrerequisite under, make the angular displacement of wheel flutter less than its goal-selling θ _ObjMaximum kingpin caster angle be best kingpin caster angle α under the current techniques condition _Opt

D, application angular-motion transducer detect the kingpin caster angle α when steering front wheel, and utilize hydraulic actuator or stepping motor as adjusting performance element, and wheel flutter kingpin caster angle α is adjusted to best kingpin caster angle α _Opt

Claims (1)

1. shimmy control method of automobile steering roller is characterized in that carrying out according to the following procedure:

A, by the clear and definite vehicle velocity V of the following system motion differential equation, complete vehicle quality m _w, the relation between the response of wheel flutter kingpin caster angle α and steering-wheel flutter:

$m_w\stackrel{\&CenterDot;\&CenterDot;}{Y}+4K_{s}Y-2(F_1+F_2)=0---\left(5\right)$

In the following formula:

θ ₁: left steering is taken turns around the stub rotational freedom; θ ₂: right steering is taken turns around the stub rotational freedom;

Propons side-sway degree of freedom; ψ: the above mechanism of suspension banking degree of freedom;

Y: car load lateral degrees of freedom; φ: tierod yaw degree of freedom;

I _t: front-wheel is around the rotor inertia (kgm of main pin axis ²);

I _x: front-wheel is around the rotor inertia (kgm of the centroidal principal axis vertical with its S. A. ²)

I: wheel rotates around it the rotor inertia (kgm of axle ²)

I _f: the propons lateral deviation is around the rotor inertia (kgm of its lateral deviation axle ²)

I _u: the above structure inclination of suspension is around its roll axis rotor inertia (kgm ²)

J: intermediate rod is around the rotor inertia (kgm of right tie rod arm and intermediate rod point of connection ²)

J ₁: intermediate rod is around the rotor inertia (kgm of its barycenter ²); m _w: complete vehicle quality (kg);

m _t: wheel mass (kg); m _f: propons quality (kg);

m _u: the above mechanism of suspension quality (kg); M: intermediate rod quality (kg);

K _Tv: tire vertical stiffness (N/m); K _s: tire lateral rigidity (N/m);

K _ρ: tire cornering stiffness (N/rad); K _v: be converted to steering box angular rigidity (Nm/rad) around stub;

K _x: suspension rate (N/m); K: steering trapezium pair clearance place axle sleeve surface rigidity (N/m);

C _t: the damping coefficient (Nms/rad) that wheel rotates around stub;

C _v: around the deflector damping coefficient (Nms/rad) of stub rotation;

C _x: suspension damping coefficient (Ns/m); C: steering trapezium pair clearance place axle sleeve surface damp coefficient (Ns/m);

N: pneumatic trail (m) α: kingpin caster angle (rad);

A: the front suspension spring is apart from (m); B: track front (m);

L: stub extended line and ground intersection point are to the distance (m) of wheel symmetrical plane

R: tire rolling radius (m) R ₁: pivot pin radius (m);

R: steering trapezium pair clearance (m); F ₁: revolver side force (N);

F ₂: right wheel side force (N); V: the speed of a motor vehicle (m/s);

V ₁: intermediate rod barycenter place speed (m/s); φ ₁: left steering trapezoid connection and propons angle (rad);

φ ₂: right steering trapezoid connection and propons angle (rad); L: intermediate rod length;

l ₁: left steering trapezoid connection length; l ₂: right steering trapezoid connection length;

B, by following computing formula, clear and definite vehicle velocity V, complete vehicle quality m _w, wheel flutter kingpin caster angle α and wheel flutter aligning torque M _ZBetween relation:

$M_Z={\mathrm{\&eta;m}}_f[\frac{2}{g}\frac{V^2}{D}R\sin \mathrm{\&alpha;}\cos {\mathrm{\&theta;}}_2+{\mathrm{\&theta;}}_{2}b\sin 2\mathrm{\&beta;}+\frac{1}{2}\mathrm{fc}({\cos \mathrm{\&theta;}}_2-\cos {\mathrm{\&theta;}}_1)]---\left(7\right)$

In the following formula:

η: the adverse efficiency g of steering system transmission: acceleration due to gravity;

D: turning circle diameter; β: Kingpin inclination angle;

F: tire drag coefficient; C: scrub radius;

C, detect current vehicle velocity V and complete vehicle quality m in real time _w, and use angular-motion transducer and detect the kingpin caster angle α that works as steering front wheel, calculate current vehicle speed V and complete vehicle quality m according to the described system motion differential equation of step a _wThe shimmy response of following automobile is represented with the angular displacement of wheel flutter, with θ and default shimmy controlled target θ _ObjCompare, simultaneously with the steering reversal moment M of this vehicle _ZWith default steering reversal moment controlled target M _ZobjCompare; Can guarantee steering reversal moment M _ZGreater than its goal-selling M _Zobj'sUnder the prerequisite, make the angular displacement of wheel flutter less than its goal-selling θ _ObjMaximum kingpin caster angle be best kingpin caster angle α under the current techniques condition _Opt

D, application angular-motion transducer detect the kingpin caster angle α when steering front wheel, and utilize hydraulic actuator or stepping motor as adjusting performance element, and wheel flutter kingpin caster angle α is adjusted to best kingpin caster angle α _Opt

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