VisSim and dimensional robot
brook502
RoboticsVisSim1.ppt
Fundamental Source Blocks
File Import
Constant
Unit Step
Unit Ramp
Unit Pulse
Random Signal
Fundamental Sink Blocks
Digital Display
Plot
File Export
Comparison Blocks
Less Than
Greater Than
Equal
Less Than or Equal
Greater Than or Equal
Not Equal
And
Logical Blocks
Not
Or
Xor
Math Operator Blocks
Multiply
Divide
Add, Subtract
Modulus
Cantilever Beam Force Measurement
�����������������������
WheatStone Bridge Resistors
h
F
w
L
time
F
Construct a block diagram in VISSIM, for the following equation for Cantilever Beam Force Measurement.
Where, L is the beam length,
W is the beam width,
H is the height of the beam,
Y is the modulus of elasticity,
A is the amplifier gain, and
G is the gage factor
F
1
1000
6
2
12
0.1
30000000
W
A
VS
G
L
H
Y
W
H
Y
*
*
/
Force
Voltage
A
VS
G
L
6
Configuring VisSim for Real Time Operation
Analog Input Range: Available analog input ranges.
Analog Output Range: Available analog output ranges.
Base Address: The I/0 port register address through which the driver commands the card, typically set to 0x300 (hexadecimal 300) and configurable between 0x220 and 0x3FF.
Board Number: The I/O card being configured, ranges from 0 to 15.
Board Type: The different board types available
Mux Settling Time (ms): The time needed for the voltages to settle when using the multiplexer cards. The default is 4 ms.
Superposition of Multiple Inputs:
Steps:
1. Set all inputs except one equal to zero
2. Canonical form
3. Calculate response due to chosen input alone
4. Repeat steps 1,2,3 for other inputs
5. Add all the response values.
G1
G2
+
+
R
C
U
Put U = 0,
CR
Put R = 0,
U
G1G2
R
+
-
-1
G1
G2
+
+
Cu
G2
-1
G1
U
+
+
G1
G2
U
+
-
Cu
Suppose the system is modeled by the following equations,
Where R=System Input
C=System Output
X 1, X 2, X 3 = Intermediate Variables
C
3
1/S
4
1/S
8
6
1/S
R
+
+
-
+
+
-
SYSTEM MODELING
System modeling is used to predict the performance of a mechanical system without actually observing the system in operation. Mechanical system consists of interconnected masses, springs, dampers and energy sources. The performance of ideal lumped masses is predicted by Newton's second law F(t)=m.a(t)
m
mass
spring
dashpot
k
b
F(t) x(t)
F(t) x1(t)
F(t) x1(t)
X2(t)
X2(t)
Mass-Spring -Damper:
Assume, mass M suspended from a ceiling by a spring -damper arm having a spring constant of K. The mass is connected to the ground by a damper having a damping force B. let F be the force acting on the mass and X be the displacement of the mass.According to Newton's second law ,
X
K
F
B
M
ANALOGY
ELECTRICAL
THERMAL
FLUID
MECH.
TRANSLATIONAL
MECH.
ROTATIONAL
e,i I/o variables
T,
V=2r.
T=F.r
F=P.A
P T
Q=heat flow
= mass flow rate of fluid
= sp. Heat of fluid
= T1-T2
P=pressure F=force
A=area V=velocity
W = flow rate
W=AV
P =Pressure
T = temperature
R = radius T = torque
= rotational angle
Kt =Torque constant
In terms of q
e
L
R
C
i
K
F
B
M
Block Reduction
Block Diagram Reduction
y
if
x
and
x
else
=
=
=
ì
í
î
1
1
1
0
1
2
y
if
x
if
x
=
=
=
ì
í
î
1
0
0
1
y
if
x
or
x
if
x
and
x
=
=
=
¹
¹
ì
í
î
1
1
1
0
1
1
1
2
1
2
y
if
x
and
x
if
x
and
x
else
=
=
¹
¹
=
ì
í
ï
î
ï
1
1
1
1
1
1
0
1
2
1
2
2
1
x
x
y
×
=
y
x
x
=
1
2
y
x
x
=
±
1
2
y
x
x
=
Remainder
of
(
)
1
2
F
w
L
time
F
h
WheatStone
Bridge Resistors
Y
WH
GLF
AV
V
S
2
0
6
=
F
w
h
Y
A
V
G
L
V
s
o
=
×
×
×
×
×
×
×
2
6
w
h
L
Y
A
V
G
s
=
=
=
=
=
=
=
1
10
12
2
inch
0.1 inche
s
12 inches
30x10
psi,
Youngs Mo
dulus of E
lasticity
6
2
1
2
1
1
G
G
G
G
R
C
R
+
=
2
1
2
1
G
G
G
U
C
U
+
=
[
]
U
R
G
G
G
G
T
+
ú
û
ù
ê
ë
é
+
=
1
2
1
2
1
1
3
3
1
2
2
1
1
3
4
8
6
X
C
R
X
R
X
X
X
R
X
X
X
=
=
+
+
-
=
+
+
-
=
&
&
&
å
å
3
X
&
2
X
&
1
X
&
3
X
1
X
2
X
2
2
)
(
)
(
dt
t
x
d
m
t
f
=
[
]
)
(
)
(
)
(
2
1
t
x
t
x
k
t
f
-
=
ú
û
ù
ê
ë
é
-
=
dt
t
dx
dt
t
dx
b
t
f
)
(
)
(
)
(
2
1
F
KX
dt
dX
B
dt
X
d
M
=
+
+
2
2
x
kv
e
&
.
=
i
k
F
t
=
T
C
m
Q
p
D
=
&
T
D
m
&
p
C
ò
=
+
+
e
idt
C
Ri
dt
di
L
1
e
q
C
dt
dq
R
dt
q
d
L
=
+
+
1
2
2
