© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
VHDL-AMS Modeling of an Electric
Power Steering System in a Multi-
Physics Simulation Environment.
SEKISUE, Takayuki
Ansoft Japan K.K.
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Presentation Goals
• Mechanical modeling in SIMPLORER
– About the mechanical system model’s description and the
usage.
– About the description of the motor drive part
• VHDL-AMS model
• System simulation with power unit
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Introduction
•
In the design of the electric equipment component, the
optimization of the equipment unit has been advanced.
•
On the other hand, modeling a complex phenomenon
and detailed operation is requested by making to high
performance in the design of the system that controls
them.
•
Cannot a new solution point be found by sharing the
simulation model as both cooperating?
– This presentation introduces the example of
simulating the subsystem as an example of EPS
control model and driving system.
– The example of simulating a necessary element
technology is referred to make it to high accuracy.
– And this introduces everything from each
simulation result to the power management as an
example of designing the total system.
Accept total
system
Subsystem
verification
Built-in
verification
Demand
definition
Optimize of
elements
Subsystem
design
Topology
layout
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
• SIMPLORER can be applied not only for electrical circuits
but also Multi-domain system & circuit.
SIMPLORER OverView
OMEGA
M
3 ~
B
A
C
I1C
I1B
I1A
N
H
Θ
EQU
RTH_Chip
K := 1.5
CTH_J
C_TH := 1m
H1
CTH_Chip
C_TH := 10m
RTH_Case
K := 0.2
CTH_Case
C_TH := 0.1
RTH_Sink_Conv
K := 1.02
THM1
THM2
THM3
RTH_Sink_Rad
K := 4.2
Tambient
VALUE := 300
Celsius
PEL
TR1
ROT2
TSF
tra
Wheel_dynamics
Thermal model design
Design of magnetic
components
Mechanical model design
Common mode- noise
SIMPLORER
ePhysics
Maxwell
Q3D
VHDL-AMS
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Steering assist system.
1. Steering
2. Torsion bar
&
Column shaft
3. Intermediate shaft
6.Assist motor
4.Rack & Pinion gear
Deceleration
gear
自動車工学入門 :野崎博路 著:山海堂 ISBN 4-381-08855-7
Steering
Torque sensor
+
+
Assist motor
Vehicle speed
Rack & Pinion
Slip angle
Side force
•
Change of the assistant gain by vehicle speed
• The moment of self aligning
=> These have not been considered yet
Diagram
Composition
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
TR1
ROT2
TSF
ROT1 ROT2
TSF
ROT
ROT_V
ROT
ROT_V
T
Φ
+
TBar
Motion model of steering system.
Steer Angle
Torque detection
1. Steering
1.
2. Torsion bar
2.
3. Intermid shaft
3.
4.Rack & Pinion gear
4.
6.Assist motor
6.
0.025[kgm2]
0.04[Nm s/rad]
130[Nm/rad]
130[Nm/rad]
12[kg]
6500[Ns/m]
210k [N/m]
Gear ratio 4
0.5m[kgm2]
• Reaction force imitates the set end with a high
rigidity spring.
• The detected torque of torsion bar refers from
assit motor.
Steer
inertia
Friction
Twist rigidity
Translation <> rotation
Rotor intertia
5. Reaction
5.
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Steering angle and Steering torque
TR1
ROT2
TSF
ROT1 ROT2
TSF
ROT
ROT_V
ROT
ROT_V
T
Φ
+
TBar
-11.40
11.35
0
0
1.00
500.00m
トーションバー・トルク
TBar.TORQUE [Nm]
-10.00
10.00
0
0
1.00
500.00m
操舵量
S_ROTB1.PHI [deg]
Steering Angle
10[deg] 1Hz
Torsion bar
torque
• Input : steering angle 10[deg], 1[Hz]
• Confirm steering torque with out assist system
Steering angle [deg]
Torsion bar torque [deg]
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Modeling of motion system
ω
+
ω
+
W
+
DAMPING := .05 Nm*s/rad
C := 10 Nm/rad
VALUE := 10 rad/s
T
Angular speed source
Twist
Rigidity C
DAMPING
Inertia J
Inertia J
Rigidity
Viscous coeff.
1.44n
18.90
10.00
0
20.00
10.00
VM_ROT1.OMEGA [rad/s]
Velocity differential
Speed source
C: Rigidity over an angle difference of twist
Damping: Viscosity over a velocity differential
Tm
Td
Tk
0
=
−
−
Td
Tm
Tk
(
)
dt
D
C
J
∫
=
−
−
=
0
0
0
ω
θ
θ
θ
θ
θ
&
&&
Disturbance
Te =0
・Conservation law of torque.
0
ω
θ
θ
&
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
ω
+
10 rad/s
C := 10 Nm/rad
DAMPING := .05 Nm*s/rad
J := 1 kg m %
C := 10 Nm/rad
DAMPING := .05 Nm*s/rad
J := 2 kg m %
2 DOF system
Angle
Rigidity C
Inertia
Velocity differential
Speed source
0
18.00
10.00
0
20.00
10.00
MASS_ROT2.OMEGA [rad/s]
• Series connection of elasticity
• Easy expansion to the multi body system.
(
)
(
)
(
)
∫
=
−
−
=
−
−
−
−
=
dt
D
C
J
D
C
C
J
0
0
2
2
2
1
2
2
2
1
1
2
1
2
1
0
1
1
1
ω
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
θ
&
&&
&
&&
1
θ
2
θ
0
ω
Damping
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Connecting in parallel
ω
+
10 rad/s
C := 10 Nm/rad
DAMPING := .05 Nm*s/rad
J := 1 kg m %
Velocity differential
S
+
S
VALUE := 10 m/s
DAMPING := .05 N*s/m
C := .1 N/m
M := 1 kg
Velocity differential
• Consider damping to the speed difference in which section.
• Easy understanding where is the reference of a position and an angle
Rotational motion
Translational motion
x
ω
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
GAIN
GAIN
GAIN
N EG
NPG
NPG
NPG
NPG
NPG
NPG
TSP1
TSP4
TSP2
TSP5
TSP3
TSP6
COMP1
COMP2
COMP3
TRIANG1
Vref_u
Vref_v
Vref_w
PWM Generator
Vector control of IPM : Basic model
FREQ := 20k
AMPL := 1
SET: := ST4:=0
SET: := ST1:=1
TSP4.VAL=1
SET: := ST4:=0
SET: := ST1:=0
U1
SET: := ST4:=0
SET: := ST1:=0
TSP1.VAL=1
SET: := ST1:=0
SET: := ST4:=1
U2
Dead Time Control
ICA:
deadtime:=5u
Friction:=8e-3
A
A
A
+
V
MS
MS
3 ~
B
A
C
ST1
ST2
ST3
ST4
ST5
ST6
Vdc
DC_bus
AM1
AM2
AM3
Motor
theta
d
q
dq_abc
GAIN
GAIN
GAIN
GAIN
GAIN
GAIN
Vref_u
Vref_v
Vref_w
EQU
Dw:=Friction*Motor.N*2*pi/60
a
b
c
theta
abc_dq
Input
PI_1
CONST
Omega
N
Omega
N
id
id
iq
CONST
Idref
GAIN
Input
PI_2
Input
PI_3
GAIN
GAIN
iq
id
GAIN
CONST
Psi
Omega
GAIN
+
V
VMA
+
V
VMB
+
V
VMC
DC_bus:=12
Motor.KE
Motor.L1D
Motor.P
GAIN
Motor.P
2 * PI/60.0
Motor.L1Q
P_Gain 0.5
I_Gain 2
0.6
20m
P_Gain 13
I_Gain 3
1/(DC_bus/2)
200
PWM carrier = 20kHz
q-axis voltage
compensation
Speed
control
q-axis
current control
d-axis
current control
12[V]
d-axis voltage
compensation
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Basic Component :
PM 3Phase synchronous motor(SYMP1)
MS
3 ~
B
A
C
N:
Rotor Speed [rpm]
OMEGA: Rotor Angular Velocity [rad/s]
MI:
Inner Torque [Nm]
PHI
Electrical Angle [rad]
PHIDEG
Electrical Angle [deg]
PHIM
Mechanical Angle [rad]
PHIMDEG Mechanical Angle [deg]
PHI := PolePairs * PHIM
LOAD:
Load torque [Nm]
R1:
Stator Resistance [Ohm]
L1D
d-axis Inductance [H]
L1Q
q-axis Inductance [H]
KE
Rotor Flux [Wb]
P
Pole pairs
J
Rotor Moment of Inertia [kgm
2
]
PWRELEC:
Input Power [W]
PWRMECH:
Output Power [W]
PWRLOSS:
Losses [W]
Input parameters
Output parameters
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Basic Component :
PM 3Phase synchronous motor(SYMP1)
d
q
q
q
q
d
d
d
p
dt
d
R
i
v
p
dt
d
R
i
v
ωψ
ψ
ωψ
ψ
+
+
⋅
=
−
+
⋅
=
q
q
q
e
d
d
d
L
i
k
L
i
⋅
=
+
⋅
=
ψ
ψ
(
)
{
}
q
d
q
d
q
e
i
i
L
L
i
k
p
mi
⋅
−
+
⋅
=
2
3
dt
d
J
Load
mi
ω
=
−
R
L
q
v
q
e
k
p
ω
〜
dq-Axis Voltage Equation
dq-Axis Flux Linkage
Motor Torque
Equation of Motion
R
L
d
v
d
q
q
i
L
p
ω
d
d
i
L
p
ω
d
i
q
i
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Input parameters
MS
3 ~
B
A
C
Temporary Load model
Friction := 10.0 e-3
Torque
ω
⋅
= Friction
Dw
EQU
Dw:=Friction*Motor.n*2*pi/6
Dw := Friction * Motor.N * 2 * PI/60
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
MS
3 ~
B
A
C
Mo to r
theta
d
q
d q_ab
GAIN
GAIN
GAIN
GAIN
GAIN
GAIN
Vref_u
Vref_v
Vref_w
a
b
c
theta
ab c_d q
Input
PI_1
Omega
N
Omega
id
iq
id
iq
CONST
Id re
GAIN
Input
PI_3
iq
id
GAIN
CONST
Ps
Omega
GAIN
Motor.KE
Motor.L1D
GAIN
Motor.P
Motor.L1Q
P_Gain 0.5
I_Gain 2
P_Gain 13
I_Gain 3
1/(DC_bus /2)
CONST
TR ef
1
GAIN
1/(1.5 * Motor.KE * Motor.P)
Check : Motor torque control
-50.00u
935.00m
500.00m
0
60.00m
20.00m
40.00m
モータトルク [Nm]
Motor.MI [(kg m)/s]
• Convert the reference torque into iq
• Check the following capability and steady-state error at reference torque = 1[Nm]
(
)
{
}
q
d
q
d
q
e
i
i
L
L
i
k
p
mi
⋅
−
+
⋅
=
2
3
Motor torque
Motor Torque [Nm]
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Parametric : searching gains for torque control
-10.00m
1.84
1.00
0
60.00m
20.00m
40.00m
モータート ルク [Nm] /KP
-5.00m
940.00m
500.00m
0
60.00m
20.00m
40.00m
モータトルク [Nm] / KI
KP valid
KI fixed=3
KP fixed=13
KI valid
KP = 0.1
0.2
0.8
1
2
8
10
20
KP = 20
KP=0.1
KI = 0.1
0.2
0.8
1
2
8
10
20
KI = 20
KI = 0.1
KP = 2
Check : KP
following capability
Check : KI
Steady state error
• Gain KP influences the following capability.
• In this case, KP >= 2 is required.
Motor Torque [Nm] / KP
Motor Torque [Nm] / KI
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
TR1
ROT2
TSF
ROT1 ROT2
TSF
ROT
ROT_V
ROT
ROT_V
T
Φ
+
TBar
The load model system and motor torque
MS
3 ~
B
A
C
Torque Source
• The load torque in standard SML motor model is defined as a simple signal.
• How much torque should we refer as load ?
The parameter display of a SML motor model.
Motor torque
Where can we get the load torque ??
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Intricate case : Described as individual system.
MS
3 ~
B
A
C
MS
3 ~
B
A
C
Motor
Omega
N
GAIN
Motor.P
ROT1
ROT2
TSF
ROT
ROT_V
T
ROTB_ROT3
+
ω
+
Motor.J
OMEGA
LOAD
• Load torque from axis.
• Add rotor inertia.
• Motor speed is compelled to axis
OR
• Motor torque is compelled to axis
• Note that the direction of the torque meter.
• Don’t forget that the addition of rotor inertia at the terminal.
• Though thinking the motor to be a torque source…
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Improvement motor model : using VHDL-AMS
shaft
c
b
a
Motor
LIBRARY
IEEE;
USE
IEEE.ELECTRICAL_SYSTEMS.ALL;
USE
IEEE.MECHANICAL_SYSTEMS.ALL ;
USE
IEEE.MATH_REAL.ALL;
ENTITY
SYMP
IS
GENERIC
(
L1d : INDUCTANCE :=
0.042
;
L1q : INDUCTANCE :=
0.042
;
…..
MS
3 ~
B
A
C
・ Equal 3PH synchronous motor model included in AMS library.
• Improve the AMS model to create the shaft output to connect mechanical model.
Copy the definition and create subsheet.
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
• Addition of a rotation system terminal
• Quantity definition
• Equation of motion
Improvement of VHDL-AMS motor model.
PORT
(
TERMINAL
a, b, c : ELECTRICAL;
TERMINAL
shaft : ROTATIONAL_V ;
shaft
c
b
a
Motor
QUANTITY
omega
across
load
through
shaft
to
ROTATIONAL_V_REF ;
mi ==
3.0
/
2.0
* P * (psi1d * i1q - psi1q * i1d);
j * omega‘dot == mi + load ;
mi : motor torque
P : pole pairs
psi1d, psi1q : d,q axis flux
load
omega
+
• “shaft
to
ROTATIONAL_V_REF” expresses the direction which
load torque flows.
Note that the direction is opposite with “load” of a standard model.
⇒ With equation of motion, “load” should be added.
T
shaft
ω
+
omega
load
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Integrate Steering model and electrical system.
ICA:
deadtime:=5u
Friction:=8e-3
A
A
A
+
V
ST1
ST2
ST3
ST4
ST5
ST6
Vdc
DC_bus
AM1
AM2
AM3
theta
d
q
dq_abc
GAIN
GAIN
GAIN
GAIN
GAIN
GAIN
Vref_u
Vref_v
Vref_w
EQU
Dw:=Friction*Motor.n*2*pi/60
a
b
c
theta
abc_dq
Input
PI_1
Omega
N
Omega
id
iq
id
iq
C ON ST
Idref
GAIN
Input
PI_3
iq
id
GAIN
C ONST
Psi
Omega
GAIN
+
V
VMA
+
V
VMB
+
V
VMC
DC bus:=12
Motor.ke
Motor.l1d
GAIN
Motor.p
Motor.l1q
P_Gain 0.5
I_Gain 2
P Gain 13/*20*/
I Gain 3 /*0.2*/
1/(DC_bus/2)
C ON ST
TRef
TBar.TORQUE
GAIN
1/(1.5 * Motor.ke * Motor.p)
TR1
ROT2
TSF
ROT1
ROT2
TSF
ROT
ROT_V
ROT
ROT_V
Φ
+
TBar
shaft
c
b
a
Motor
T
FM_ROT1
Reference
Torque
CONST
CONST
TRef
TBar.TORQUE
1) Connect motor shaft terminal to steering model.
2) Add torque reference value into a control block.
• Refer to torsion bar torque.
(1)
(2)
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Integrated model : Simulation result.
0
10.00
5.00
0
500.00m
200.00m
400.00m
操舵量 [d...
S _ROT B 1.PHI [deg
-36.00
38.50
0
0
500.00m
200.00m
モータトルク [Nm]
Motor.mi
-5.00m
9.45
5.00
0
200.00m
100.00m
モータトルク [Nm]
Motor.mi
ICA:
deadtime:=5u
Friction:=8e-3
A
A
A
+
V
ST1
ST2
ST3
ST4
ST5
ST6
Vdc
DC_bus
AM1
AM2
AM3
theta
d
q
dq_abc
GAIN
GAIN
GAIN
GAIN
GAIN
GAIN
Vref_u
Vref_v
Vref_w
EQU
Dw:=Friction*Motor.n*2*pi/60
a
b
c
theta
abc_dq
Input
PI_1
Omega
N
Omega
id
iq
id
iq
CONST
Idref
GAIN
Input
PI_3
iq
id
GAIN
CONST
Psi
Omega
GAIN
+
V
VMA
+
V
VMB
+
V
VMC
DC_bus:=12
Motor.ke
Motor.l1d
GAIN
Motor.p
Motor.l1q
P_Gain 0.5
I_Gain 2
P Gai n 13/*20*/
I Gain 3 /*0.2*/
1/(DC_bus/2)
CONST
TRef
TBar.TORQUE
GAIN
1/(1.5 * Motor.ke * Motor.p)
TR1
ROT2
TSF
ROT1
ROT2
TSF
ROT
ROT_V
ROT
ROT_V
Φ
+
TBar
shaft
c
b
a
Motor
T
FM_ROT1
Steering Angle [deg]
Time < 200ms
Whole time
Motor Torque [Nm]
•
Oscillation !!
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Frequency response of mechanics
Φ
+
TBar
D2D
D2D1
T
Steering Inertia
BodePlotSel3
TBar.TORQUE
Gain
Phase
1
1
2
2
3
3
4
4
5
5
6
6
10
10
20
20
30
30
50
50
100
100
200
200
400
400
1k
1k
1
1
2
2
3
3
4
4
5
5
6
6
10
10
20
20
30
30
50
50
100
100
200
200
400
400
1k
1k
-75.00
-50.00
-25.00
0.00
25.00
-75.00
-50.00
-25.00
0.00
25.00
0.00
45.00
90.00
135.00
180.00
0.00
45.00
90.00
135.00
180.00
f [Hz]
f [Hz]
[dB]
[deg]
Inertia of Motor
• The resonance point by the inertia
of motor is seen in 100Hz.
• other point 8Hz caused by the
steering inertia.
Transfer ratio : Steering Torque/Motor Torque
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Oscillation control / phase compensation
Input
PI_3
iq
id
GA IN
C ON ST
Ps
Omeg a
Motor.ke
Motor.l1d
P Gain 13 /*20*/
I Gain 3 /*10 */
C ON ST
TR ef
TBar.TORQUE
GA IN
1/(1.5 * Motor.ke * Motor.p)
G(s)
GS1
-10.00
10.00
0
0
1.00
500.00m
操舵 量
S _ROT B 1.P HI [deg
-7.60
7.55
0
0
1.00
500.00m
モータトルク [Nm]
Motor.mi
-1.00m
1.03
500.00m
0
30.00m
10.00m
20.00m
モータトルク [Nm]
Motor.mi
Motor Torque
(Zoom )
( )
s
s
G
c
c
s
⎟
⎠
⎞
⎜
⎝
⎛
+
⎟
⎠
⎞
⎜
⎝
⎛
+
=
ω
ω
1
.
0
1
1
1
Primary progress compensation
• The oscillation frequency of the mechanical system was avoided and
the torque assistance was attained.
Steering Angle 10[deg]
Motor Torque [Nm]
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
VHDL-AMS model can use AC simulation.
System stability : mechanics + controls
shaft
c
b
a
Motor
E1
E2
E3
Φ
+
D2D
ROT
ROT_V
TBar
D2D1
theta
d
q
GAIN
GAIN
GAIN
GAIN
GAIN
GAIN
a
b
c
theta
Input
CONST
GAIN
Input
GAIN
CONST
GAIN
GAIN
CONST
GAIN
G(s)
dq_abc
1/(DC_bus/2)
Vref_u
Vref_v
Vref_w
abc_dq
PI_1
P_Gain 0.5
I_Gain 2
Omega
N
Omega
id
id
iq
Idref
Motor.l1q
PI_3
P_Gain 13/*13*/
I_Gain 3 /*3*/
iq
id
Motor.l1d
Psi
Motor.ke
Omega
Motor.p
TRef
TBar.TORQUE
1/(1.5 * Motor.ke * Motor.p)
GS1
ICA:
Friction:=8e-3
deadtime:=5u
DC_bus:=12
iq
Vref_u
Vref_v
Vref_w
BodePlotSel9
dq_abc.d
dq_abc.q
Gain
Phase
1
1
10
10
100
100
1k
1k
10k
10k
100k
100k
1
1
10
10
100
100
1k
1k
10k
10k
100k
100k
136.82
0.00
50.00
100.00
136.82
0.00
50.00
100.00
44.85
-180.00
-135.00
-90.00
-45.00
0.00
44.85
-180.00
-135.00
-90.00
-45.00
0.00
f [Hz]
f [Hz]
[dB]
[deg]
Transfer characteristic of control system
10.00u
1.00
200.00u
2.00m
20.00m
1.00
100.00k
20.00 200.00 2.00k
2DGraphSel5
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
-3.14
3.14
0
1.00
100.00k
10.00 100.00 1.00k
2DGraphSel5
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
dq_ab...
GAIN
PHASE
Transfer characteristic of control system ( KP dependency)
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
The modeling of side-force by a tire.
Slip rate
Side angle
Traction force, Side fo
rce [kgf]
Perpendicular load 380[kgf]
Side force
Slip rate
Slip
Vehicle speed
Slip angle
Rotational
Speed of tire
Load
Force of Rack F
Diagram of side force of Tire
Gap of a rack and rotational center : R
Sidewall equivalent radius : Rc
Ref. ISBN 4-381-08855-7
β
Fs
v
ω
v
V
mg
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
VHDL-AMS code
R
V
F
R
T
×
=
×
=
ω
)
,
(
/
)
(
β
µ
ω
β
ω
Slip
F
dt
V
V
Slip
lookup
v
v
v
=
=
−
=
∫
)
(
Fs
R
T
J
mg
Fs
×
−
=
⋅
=
ω
µ
&
begin
T == R * F ;
V == omg * R ;
if
(vv'dot <
0.0
)
use
slip_rate == (vv-ww)/vv ;
else
slip_rate == (ww-vv)/ww ;
end use
;
beta == omg'integ ;
mur == lookup_SideFC(slip_rate,
abs
(beta)) ;
Fs == mur * mass *
9.8
* sign(beta);
J * omg'dot == (T- Fs*R) ;
end architecture
beh ;
Slip rate
• VHDL-AMS model expresses definitional equations directly.
Friction Coeff.
Equations
Translation <> Rotation
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Nonlinear side force model
-4.20
4.00
0
0
1.00
500.00m
TBar.TORQUE [Nm]
SPRING_ROTB2.TORQUE [Nm]
-4.20
4.00
0
0
1.00
500.00m
トーションバー・トルク
TBar.TORQUE [Nm]
SPRING_ROTB2.TORQUE [Nm]
Motor.mi
-4.20
4.00
0
0
1.00
500.00m
トーションバー・トルク
TBar.TORQUE [Nm]
SPRING_ROTB2.TORQUE [Nm]
Motor.mi
TR1
ROT2
TSF
tra
Wheel_dynamics
-35.00
34.80
-20.00
0
20.00
0
1.00
500.00m
タイヤ横力 [kgf]
Steering torque = side force torque
Steering torque reduces as 1/2
• Nonlinear side force mapping.
• Confirm reducing steering force by assist motor.
w/o Power Assist
with Assist
Side force of Tire [N]
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
System Simulation
CONST
TRef
TBarAMS.m
TR1
ROT2
TSF
ROT1
ROT2
TSF
ROT
ROT_V
ROT
ROT_V
T
FM_ROT1
G(s)
ハンドル
操舵量
トーションバー
インタミ
ラック・ピニオン
反力
ピニオン
Φ
Φ
+
GAIN
1/2
AssistGain
W
+
WM_T
W
W
+
WM1
shaft
dcn
dcp
M
INV
Ave
~
Motor
tra
Tire
Y
t
GAIN
DATAPAIRS1
Battery
-
+
fp
fm
np
nm
SYM
PI
100 %
1
1
2
MRV
ω
ω
+
Pulley_ratio
Engine
VM_Eng
ECU
DCp
Fuel_Calc
Name
Value
Fuel_Calc.fc
9.7746m
DCp
Energy Balanced Model
Mechanics
Power supply
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Components
•
Motor + Inverter
– Energy balanced model written by VHDL-AMS.
•
Power sources
– Battery : Automotive Library (Lead Acid battery)
– Alternator : Automotive Library (Averaged Model)
– Engine : Torque source (Throttle controlled torque source with
Torque-RPM lookup table)
– ECU : Analog PI control ( to keep RPM as idle )
MRV
T
X Y
Trq_per_ro
+
ω
+
AxWM
10
ThrPct
DAMP_ROT1
INPUT
Power
Motor Power OUT
Motor Losses
Inverter Losses
Engine model
RPM vs. Torque
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
High Accuracy Estimation of Efficiency
for Inverter Losses
for Motor Losses
• Device Level IGBT and Diodes
• Easy estimation by
RMxprt
Ic
Vce
Loss:ON
Loss:Off
200
RA
LA
Lcoil
Rcoil
RC
Rcoil
RB
Rcoil
A
IA
A
IB
A
IC
ICA:
Rcoil := 178m
LB
Lcoil
LC
Lcoil
Lcoil :=2.46m
Pp := 4
Turns := 9
Pars := 2
500u
200
E
G
E
G
E G
E
G
E
G
E G
A
A
AMuIfw
AMuIC
WiHE
WdHA
WiHC
WdHC
ViHC
VdHC
UiHC
UdHC
ViHE
VdHA
UiHE
UdHA
w
VccP
V
u
VccN
WiLC
WdLC
ViLC
VdLC
UiLC
UdLC
WiLE
WdLA
ViLE
VdLA
UiLE
UdLA
Sheet7
• Parasitic LCR with
Q3D
• Core Loss from
Maxwell 2D/3D
Speed
Efficiency
FEA
sourceA1
sourceA2
sourceB1
sourceB2
sourceC1
sourceC2
Magnet01
Magnet02
Q1
Q2
Q3
Q5
Q4
Q6
400 V
RA Ohm
LL H
LDUM H
Core Loss vs. time
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Energy Balanced model verification.
Motor Rotation Speed [RPM]
Motor Torque [Nm]
shaft
dcn
dcp
shaft
dcn
dcp
M
INV
Ave
~
Input :
Reference Torque
Equation
ω
η
η
⋅
=
⋅
⋅
T
I
V
inv
motor
T
T
J
ref
+
=
ω
&
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Simulation result : Battery Voltage
wEPS
woEPS
0
0
180.0
180.0
25.0
25.0
50.0
50.0
75.0
75.0
100.0
100.0
125.0
125.0
150.0
150.0
2.500
12.500
3.100
2.600
12.600
2.700
12.700
2.800
12.800
2.900
12.900
3.000
13.000
(1)
(2)
(1) : t= 30 : start EPS control
(2) : t=150 : end EPS control
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Simulation result : Engine Speed
wEPS
woEPS
0
0
180.0
180.0
25.0
25.0
50.0
50.0
75.0
75.0
100.0
100.0
125.0
125.0
150.0
150.0
0
0
700.0
100.0
100.0
200.0
200.0
300.0
300.0
400.0
400.0
500.0
500.0
600.0
wEPS
wo...
60.00
60.00
70.00
70.00
62.50
62.50
65.00
65.00
67.50
67.50
625.0
625.0
650.0
630.0
630.0
635.0
635.0
640.0
640.0
645.0
(1)
(2)
(1) : t= 30 : start EPS control
(2) : t=150 : end EPS control
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Fuel Consumption
wEPS
woEPS
0
0
180.0
180.0
25.0
25.0
50.0
50.0
75.0
75.0
100.0
100.0
125.0
125.0
150.0
150.0
0
0
700.0
100.0
100.0
200.0
200.0
300.0
300.0
400.0
400.0
500.0
500.0
600.0
MRV
ω
+
Engine
VM Eng
ECU
Fuel Calc
• 4 cycle engine
• Displacement : 1800[cc]
• ideal Air-Fuel ratio : 14.7
• Specific gravity : C
7.5
H
13.5
Engine rotational speed
Total Fuel consumption @2.5[min]
]
[
l
m
With EPS
26.8
WO EPS
26.1
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Summary
• The construction method of the mechanical load model by
using SIMPLORER.
• By using VHDL-AMS, modeling with high degree of
freedom or more was able to be made easily.
• In addition, it introduced the continuousness to the system
simulation of power consumption and components
simulation.
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
Conclusions
•
SIMPLORER can be as a communications tool that the designer of an
electric equipment and the designer of the regulating system guess the
function from the viewpoint of power consumption.
•
The equipment designer can optimize it by sharing the model under a more
concrete environment.
•
For a system designer, over-specked apparatus is presumed and the whole
cost can be reduced.
•
The model construction in standard language VHDL-AMS has a high ability
for such a demand, and the importance increases.
自動車工学入門 :野崎博路 著:山海堂 ISBN 4-381-08855-7
自動車工学 –基礎- :: (社)自動車技術会 ISBN 4-915219-30-5
車両システムのダイナミクスと制御:(社)日本機会学会:養賢堂: ISBN 4-8425-9901-4
電動機制御工学 〜可変速ドライブの基礎〜:松瀬貢規 著:電気学会/オーム社 ISBN 978-4-88686-255-6
© 2008 Ansoft, LLC All rights reserved.
Ansoft, LLC Proprietary
• Thank you