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Mec
hani
cal b
ody
Front ball bearing
Housing Tool
Back ball bearing
Ele
ctri
cal c
ompo
nent
s Electrical measuring equipment
Drive Power supply
Cou
plin
g
Equ
ipm
ent
Con
trol
har
dwar
e
Sens
ors
Electronic devices
Coupling
Operating system
Programming tools
Control application software
Data manipulation tools
Methods Dynamic modeling Power flow modeling Thermal effects Diagnostics Control Flexibility Balancing Compensation
In order to improve productivity, high-speed spindle systems (HSSS) are used in the production cells. Especially, they are employed for machining, micromachining,
milling, drilling, data reading and recording applications, aerospace, heavy industry, consumer industry, and in many manufacturing sectors.
Spring Feedback
Amp
Force generator
m1
elspindleF _
mispindleF _epspindleF _ wlspindleF _Ideal case
aospindleF _
cvspindleF _
sfspindleF _
Coloumb friction feedback
Viscous friction feedback
c
d/dt aospindleF _
+/-F *sign( )
+/- d
+
+ -
+ +
+
+
spindle with friction
Friction Compensation
Correction of non-linear process statics
A translational motion model of a high-speed spindle system
lspindleespindlespindleallspindle Tdt
dBTT
dt
dJ __2
2
_
a
b
c
d
e f gh i
j
ml
k
n
o
p
q
r
s
Graphical representation of flow of power within the spindle
EMB
ROTOR
Figure-16.4 shows the schematic diagram of this custom-built spindle system with respect to optimized design specifications (Refer Table-16.4.)
0
5000
10000
15000
20000
25000
30000
35000
1 15 29 43 57 71 85 99 113
127
141
155
169
183
197
211
225
2390 25 50 75 100 125 150 175 200 225 250 275
980 N
1876N1444N
Time in Seconds
Speed in Rev. per minute
Developers have studied the operating points i.e., the Quotient Point (Q-point) of the rotary systems since long. The Q-point curves, which are the graphic representation of the dynamic model equations, help the engineer to view the performance of the system instantly. Theoretically, the Q-points are described using state space method. Experimentally, they are plotted from the I/O data.
Loss due to friction in a typical high speed spindle system.
0
100
200
300
400
500
600
700
800
900
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 310 5 10 15 20 25 30
0
5
10
15
2
0
25
30
35
40
45
In W
att
In RPM
Loss due to viscous shear of the air in between the stator and rotor of the high speed spindle systems.
1 = Heat generation at motor at speed 30000 RPM2 = Heat generation at motor at speed 1500 RPM3 = Heat generation at front bearing at speed 30000 RPM4 = Heat generation at front bearing at speed 15000 RPM5 = Heat generation at real bearing at speed 30000 RPM6 = Heat generation at real bearing at speed 15000 RPM
1
2
3
4
5
60 4 8 12 16 20 24 28 32 36 40 45 50 55 60 65
-50
0
50
1
00
150
2
00
250
3
00
350
4
00
450
5
00
Time
Rel
ativ
e he
at g
ener
atio
n
Heat generation with respect to time
-5
0
15
20
0 30 60 90 120 150 180 210
Temperature in degree C
Time in Second
Front bearing
Rear bearing
Temperature with respect to time
0102030405060708090
100
1 10 19 28 37 46 55 64 73 82 91 100
Axial load in Kgf
Dis
pla
cem
ent
in m
icro
met
er
481953726
Relationship between axial load and displacement because of thermal deformation
Curve No. Curve fitting formula Heating/Without heating
1 18.1*L^0.26 No heating
2 8.1*L^0.37 No heating
3 8.1*L^0.36 No heating
4 7.6*L^0.52 Heating
5 6.3*L^0.45 Heating
6 1.3*L^0.68 -
7 10.1*L^0.30 No heating
8 3.5*L^0.67 Heating
9 9.1*L^0.37 No heating
concerned but also of other mechatronic systems. Mass unbalances are the major sources of vibration. A powerful balancing method, called Electro-Magnetic Balancing (EMB) technique has been developed in the micromanufacturing laboratory, K-JIST. The photograph of an EMB for HSSS.
HSSS are vulnerable to vibration. Balancing is an important area as far as design and developme-nt of not only HSSS are
2
1 = Roundness of the Shaft after compensation (EMB)2= Roundness of the Shaft before compensation
Y-a
xis
disp
lace
men
t in
mic
rom
eter
X-axis displacement in micrometer
-5 -4 -3 -2 -1 0 1 2 3 4 5
-5
-4
-
3
-2
-1
0
1
2
3
4
5
Vibration compensation by the use of Electromagnetic Balancer (EMB). A new technique for compensation of induced mass unbalances.
Residual Generator
Fault size, type, location, time, cause
Controller Actuator ProcessDynamics
Sensor
Decision making
UR Y
Model-based DAP, on the other hand rely on quantitative mathematical relation between the I/O (hence model of the plant) and depends only on the availability of a mathematical model of the plant. This involves two tasks, generation of residuals and design of decision rules based on these residuals.
Normal
Faulty
F-1 = Fault due to thermal deformationA measure of radial pressure in exerted
Time
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Preload applied deliberately
0 300 600 900 1200 1500
F-1 = Fault due to thermal deformation ; Change of Coulomb Friction Coefficient
1
0.8
0.6
0.4
0.2
0
-0.2 Time
0 300 600 900
F-1
F-1
F-2 = Bearing jam F-2 = Bearing jam
0 600 1200 1800 2100 2400 2700
Preload applied deliberately
F-2 F-2Time Time
0 600 1200 1800 2100 2400 2700
Insufficient cooling Insufficient cooling
12
10
8
6
4
2
0
0.05
0.04
0.03
0.02
0.01
0.00
-0.01
allspindleJ _ Power; (VI)
Some FDI results based on spectral analysis and stricture estimation using model equations. Figure illustrates how the strictures are changed with respect to additive faults.
(a) Fault due to shaft wear. (b) & (c) Fault due to thermal deformation (d) & (e) Fault due to spindle jam
Formulation Stage
Inventory Stage
Tracking Stage
Validation
1. Scope(i) component classification(ii) characterization
2. Model construction(i) Identification of variables(ii) Determination of Life Span Value
1. Algorithm generation2. Design (Hw & Sw)3. Data acquisition
1. Decision maker ( Watchdog)
Data Acquisition Display
GUI, Seven segment
Disk files
File handling
Miscellaneous
Configuration
1. Components-based2. Distributed Control
Machine control requirements
SEA development knowledge base and workbench
A SEA variable must have a life span value (LSV). Life Span Value (LSV) is defined as a predictable value i.e., LSVs are the measure of active life of the variables defined for a specific component/device.
Central Controller
Interfacing
Sensors Actuators
Valves Switches
Drives Controllers
Etc..
Parallel connection
A schematic diagram of Centralised Control
C
C
C
C
Sensors
Actuators
Drives
Etc.
P L A N T
C O N T R O L L E R S
A schematic diagram of DCS
N E T W O R K E D
Plant
In resent years industrial automation and control systems preferred to implement Distributed Control System (DCS) instead of centralized, because of its advantage of great flexibility over the whole operating range.
Process/System level
Network level
Component level
Management level
Sensors, Actuators, PLCs, PCs (hardware)
Protocol, System image (firmware)
SC to OC, Config., Registration (Compiler, COM, DDE, OLE )
Installation, Binding, Monitor & Control
Distributed control can be leveled into four layers of automation services. Component level is the physical layer that connects devices, PC, industrial PC, PLC, microprocessor, micro-controller etc. Network interface layer is similar to MAC sub-layer of the link layer protocol. Process layer includes application layer features. Application layer defines the variables, which are responsible to transfer data from one place to other when they are connected logically.
Converter
Bearing
Displacement & Vibration sensors
Current sensors
Driver
FIELDBUS (LON)
Balancer
Schematic diagram of the spindle system in the context of control interfacing
N1 N2 N3
Interfacings Interfacings Interfacings
Drive (actuator)
Position sensors(Encoders)Temperature And vibration sensors
DisplayAlarm,Switch,Buttons
TransceiverTransceiverTransceiver
Fieldbus based DCS network
NT, LNS, VB6, OS for DCS, Simulation tool
Graphical User InterfaceClient ServerObject OrientedVirtual design
Code-N2Code-N1 Code-N3
System Image
HIGH SPPED SPINDLE MACHINE(co-ordination, synchronization, acknowledgement, timing )
Sp
ind
le c
ontr
ol r
eali
zati
on u
sin
g D
CS
sch
eme
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