a |
distance front axle to c.g.; half of contact length |
ax |
longitudinal acceleration |
ay |
lateral acceleration |
aμ |
slip velocity dependency coefficient for friction |
Ar |
rolling resistance coefficient |
b |
distance rear axle to c.g.; half contact width |
B |
stiffness factor in ‘Magic Formula’ |
B1 |
brake force of rolling wheel |
c |
stiffness; factor |
cc |
lateral carcass stiffness per unit length |
cgyr |
non-dimensional gyroscopic coefficient |
cpx,y |
tread element stiffness per unit length of circumference |
|
tread element longitudinal stiffness per unit area |
C |
cornering stiffness ; sum front and rear |
Ci |
cornering stiffness, sum left and right |
C |
contact centre (point of intersection) |
C |
shape factor in ‘Magic Formula’ |
CdA |
air drag coefficient |
CFx |
longitudinal stiffness of standing tyre |
CFy |
lateral stiffness of standing tyre |
CFz |
stiffness of tyre normal to the road |
CFα |
cornering stiffness |
CFκ |
longitudinal slip stiffness |
CFγ |
camber stiffness for side force |
CFφ |
spin stiffness for side force |
Cgyr |
tyre gyroscopic coefficient |
CMα |
aligning torque stiffness |
CMγ |
camber stiffness for aligning torque |
CMφ |
spin stiffness for aligning torque |
CMψ |
torsional yaw stiffness of standing tyre |
CMxγ |
overturning couple stiffness against camber |
Ccx,y |
carcass horizontal stiffness of standing tyre |
Cgyr |
gyroscopic coefficient |
dfz |
normalised change in normal load, Eq.(4.E2a) |
dpi |
normalised change in inflation pressure, Eq.(4.E2b) |
dt |
tread depth |
D |
peak factor in ‘Magic Formula’; dissipation function |
E |
curvature factor in ‘Magic Formula’ |
e |
caster length; tread element deflection |
f |
trail of c.g.; frequency [Hz] |
fr |
rolling resistance coefficient |
Fax |
force for forward acceleration |
Fd |
air drag force |
Fx,tot |
sum of longitudinal tyre forces |
Fx |
longitudinal tyre force |
Fy |
lateral tyre force |
Fz |
vertical (normal) tyre force (load) (>0), in Chap.9, 10: Fz <0 |
Fr |
rolling resistance force (>0) |
FN |
tyre normal force (>0) |
FNo |
reference vertical load, nominal load (= |Fzo|) |
FV |
tyre vertical force |
FH |
tyre longitudinal horizontal force |
g |
acceleration due to gravity; feedback rider control gain |
G |
weighting factor |
h |
height |
H |
height; sharpness factor in ‘Magic Formula’ |
H |
transform; Hurwitz determinant |
i |
|
iz |
radius of inertia |
I |
moment of inertia |
Iw |
wheel polar moment of inertia |
Ip |
wheel polar moment of inertia |
j |
|
k |
radius of inertia; viscous damping coefficient |
K |
centrifugal force; force acting on belt, wheel centre |
l |
wheel base |
ls |
shift; two-point follower length |
lb |
length of basic curve |
lf |
offset |
l |
unit vector along line of intersection |
m |
mass; fraction of contact length 2a where adhesion occurs |
mc |
contact patch mass |
mt |
tyre mass |
mm |
mass of mainframe (including lower part of rider) |
mmr |
mass of mainframe plus rider |
mr |
mass of upper torso |
MB,D |
brake, drive torque |
Mx |
overturning couple |
My |
rolling resistance moment |
Mz |
(self) aligning torque |
|
(self) aligning torque due to lateral deflections |
|
aligning torque due to longitudinal deflections |
Mz,gyr |
gyroscopic couple |
Mδ |
steer torque |
n |
number of elements; frequency [Hz] |
n |
unit vector normal to the road =(0,0,‒1)T |
nst |
steer system ratio |
p |
Laplace variable [1/m] |
pi |
inflation pressure |
q |
average vehicle yaw resistance arm; generalised coordinate |
q |
contact force per unit length of circumference, vector |
Q |
generalised force |
r |
yaw rate; tyre (loaded) radius |
rc |
radius of carcass (belt), unloaded; cross section crown radius |
ryo |
free tyre radius varying along cross section contour, ryo = ryo(yco) |
re |
effective rolling radius of freely rolling wheel |
rf |
free unloaded tyre radius |
rl |
loaded radius |
ro |
free unloaded tyre radius (= Ro) |
R |
radius of curvature |
Ro |
free unloaded tyre radius (= ro) |
s |
forward position of neutral steer point; half track width |
s |
Laplace variable; travelled distance |
ssx |
κ (practical longitudinal slip component) |
ssy |
tanα (practical lateral slip component) |
s |
unit vector along wheel spin axis |
S |
wheel slip point; impulse; string tension force |
SV,H |
vertical, horizontal shift |
t |
pneumatic trail; time |
tc |
caster length |
tr |
rise time |
t |
unit vector in road plane perpendicular to line of intersection l |
T |
kinetic energy; moment acting on belt, wheel centre |
u |
forward velocity of c.g.; longitudinal deflection |
U |
potential energy |
v |
lateral velocity of c.g.; lateral deflection |
V |
speed of travel of c.g. (with x, y components) |
V |
speed of travel of wheel centre (with x, y components) |
Vc |
speed of contact centre C (with x, y components) |
Vg |
speed of sliding (with x, y components) |
Vo |
reference velocity =√(gRo) |
Vr |
wheel linear speed of rolling (= Vcx ‒Vsx) |
Vs |
wheel slip velocity of slip point S (with x, y components) |
Vx |
longitudinal speed component of wheel centre |
|
velocity of contact patch mass (with x, y components) |
w |
vertical road (effective) profile (positive downwards) |
W |
work |
x,y,z |
longitudinal, lateral, vertical displacement |
x,y,z |
coordinates with respect to moving axes system, z axis vertical |
xo,yo,zo |
global coordinates |
|
global coordinates |
X |
longitudinal horizontal tyre force |
X,Y,Z |
global coordinates |
yco |
distance from wheel centre plane |
ymr |
lateral offset of mmr c.g. |
| |
α |
wheel (side) slip angle; axle (side) slip angle |
α |
road transverse slope angle |
|
transient tyre slip angle |
αa |
virtual axle slip angle |
β |
vehicle side slip angle; tyre yaw torsion angle |
βx,y |
road transverse, forward (effective) slope angle |
βgyr |
gyroscopic wheel coupling coefficient, Eq.(6.35) |
γ |
camber (wheel inclination) angle |
|
transient tyre camber angle |
Γ |
unit step response function |
δ |
steer angle of front wheels |
δo |
≈l/R, steer angle at V→0 |
Δ |
increment |
ε |
roll steer coefficient; rake angle of steering axis |
ε |
string length ratio, Eq.(5.153); eff. roll. radius gradient ‒∂re/∂dt |
ε |
small quantity to avoid singularity |
εγ |
camber stiffness reduction factor |
εNL |
non-lagging part |
ζ |
damping ratio; spin factor (=1 if spin influence is disregarded) |
ζh |
height ratio, Eq.(6.36) |
ζα |
cornering stiffness load transfer coefficient |
ζγ |
camber stiffness load transfer coefficient |
η |
understeer coefficient; effective rolling radius gradient ‒∂re/∂ρz |
ηy |
c.g. offset steer coefficient |
θ |
tyre model parameter, Eqs.(3.6, 3.24, 3.46) |
θ |
angular displacement about η axis; pitch angle |
θc |
string model composite parameter, Eq.(5.160) |
κ |
longitudinal wheel slip |
|
transient longitudinal tyre slip |
κ∗ |
damping coefficient due to tread width |
λ |
wavelength; root characteristic equation |
λ |
fraction of 2a where adhesion occurs; user scaling factor |
μ |
coefficient of friction |
ρ |
tyre radial (vertical) deflection |
ρx,y,z |
tyre longitudinal, lateral, normal deflection |
σ |
relaxation length; load transfer coefficient |
σ |
theoretical slip, vector, Eq.(3.34) |
σ∗ |
intersection length in string model with tread elements |
σc |
string model length parameter, Eq.(5.153) |
σc |
contact patch relaxation length |
τ |
roll camber coefficient |
φ |
body roll angle; spin slip |
|
transient spin slip |
φt |
turn slip |
ϕ |
phase angle |
ψ |
yaw angle; steer angle |
ψc1 |
compliance steer angle |
ψio |
toe angle |
ω |
frequency [rad/s] |
ωo |
undamped natural frequency |
ω1,2 |
natural frequencies |
ωn |
damped natural frequency |
ωs |
path frequency [rad/m] |
Ω |
wheel speed of revolution |
ξ;,η,ζ |
moving axes system, η axis along spin axis, ξ; horizontal |