P A R A M E T E R O P T IM IZ A T IO N O F
E L E C T R IC P O W E R ST E E R IN G IN T E G R A T E D W IT H
Foundation item s
:
Supported by the National Natural Science Foundation of China
(51005115);
the Risiting Schola
Foundation of the State Key Lab of M echanical T ransmission in Chongqing U niversity
(
SKL M T
-
KFKT
-201105);
th
Science Fund of State Key Laboratory of Automotive Satefy and Energy in T singhua U niversity
(
KF
11202).
R eceived date
: 2011-01-15;
revision received date
: 2011-10-12
E
-
m ail
:
2000@126.
A C T IV E F R O N T ST E E R IN G F U N C T IO N
W ang C hunyan
1,2
,
Z hao W anzhong
1,2
,
L iu Shun
1
,
Sun P eikun
1
(1.
College of Energy and Pow er Engineering
,
Nanjing U niversity of A eronautics and Astronautics
,
Nanjing
, 210016,
P
.
R
.
China
;
2.
Stat e Key Laboratory of M echanical T ransmission
,
Chongqing U niversity
,
Chongqing
, 400044,
P
.
R
.
China
)
A bstract
:
T he dynanaic model of a novel electric pow er steering
(
EPS
)
system integrated w ith active front steer-
ing function and the three
-
freedom steering model are built
.
Based on these models
,
the concepts and the quanti-
tative expressions of road feel
,
sensitivity
,
and operation stability of the steering are introduced
.
T hen
,
according
to constrained optimization features of multi
-
variable function
,
a genetic algorithm is designed
.
M aking the road
feel of the steering as optimization objective
,
and operation stability and sensitivity of the steering as constraints
,
the system parameters are optimized by the genetic and the coordinate rotation algorithms
.
Simulation results
show that the optimization of the novel EPS system by the genetic algorithm can effectively improve the road feel
,
thus providing a theoretical basis for the design and optimization of the novel EPS system
.
K ey w ords
:
vehicle engineering
;
electric pow er steering
;
active front steering
;
road feel
;
genetic algorithm
C L C num ber
:
U
461.4
D ocum ent code
:
A
A rticle ID
:1005-1120(2012)01-0096-07
N om enclature
g
/(
m
·
s
)
Aacceleration due to gravity
u
/(
m
·
s
)
Velocity
ω
/(
rad
·
s
)
Yaw rate
/
rad
Roll angle of vehicle
β
/
rad
Sideslip angle of vehicle centre of mass
δ
/
rad
Steer angle of front w heels
α
/
rad
Sideslip angle of front wheels
α
/
rad
Sideslip angle of front wheels
k
/(
N
·
rad
)
Cornering stiffness coefficient of rear
w heels
k
/(
N
·
rad
)
Cornering stiffness coefficient of rear
w heels
a
/
m
Distance betw een vehicle centre of mass and front
axle
b
/
m
Distance betw een vehicle centre of mass and rear
axle
m
/
kg
M ass of vehicle
m
/
kg
M ass of sprung
I
/(
kg
·
m
)
Inertia moment of sprung mass abou
x
-
axis
I
/(
kg
·
m
)
Inertia moment of sprung mass about
z
-
ax
I
/(
kg
·
m
)
Inertia product of sprung mass about
x
,
z
axis
E
Front roll steer coefficient
E
Rear roll steer coefficient
C
/(
N
·
m
·
rad
)
Stiffness coefficient of roll angle
front suspension
C
/(
N
·
m
·
rad
)
Stiffness coefficient of roll angle
rear suspension
D
/(
N
·
m
·
s
·
rad
)
Damping of roll angle of fron
suspension
D
/(
N
·
m
·
s
·
rad
)
Damping of roll angle of rear su
pension
J
/(
kg
·
m
)
Inertia moment of input shaft
θ
/
rad
Rotation angle of input shaft
B
/(
N
·
m
·
s
·
rad
)
Damping coefficient of input sha
T
/(
N
·
m
)
Anti
-
torque of input shaft
T
/(
N
·
m
)
T orque of input shaft
M ar
.2012
T ransactions of Nanjing U niversity of A eronautics & Astronautics Vol
.29
No
.1