Transcript 9 System models

7 Design and Mechatronics
7.1 Stages of the design process
Concept development
Identification of Customer needs
Concept generation & selection (form, function, features)
Concept evaluation
System level design
Brainstorm alternative solutions
Define major subsystems and interfaces
Refine Industrial Design
Detail design, testing and refinement
Exact geometry
Materials
Tolerances
Performance /reliability
7.1.1 Traditional and mechatronics
designs
The basis of the mechatronics approach is
considered to lie in the inclusion of the
disciplines of the electronics, computer
technology and control engineering.
7.2 Loading Analysis
For the determination of the dimensions of
mechanisms elements, selection of motors
and electrical circuits , determine the power
source, etc, loading analysis is necessary ..
7.3 Examples of designs
CS1: Bathroom Scales
weight
weig ht
load cells
elastic member
pointer
bevel
gear
rack attach ed to
deflecting b eam
(a) mechanical solution
strain gauge
bridge
op -amp
display
microprocessor
(b) mechatron ic solu tio n
CS1: Bathroom Scales
mechanical solution: elastic member
deflection can be transformed into the
movement of a pointer mechanical
mechanisms
mechatronic solution:
platform - load cells - electrical strain gauges
gauges strained - changed resistance
small signal input into differential op-amp
amplified signal input into mP via AD
converter
display driven by mP - e.g. weight calculated
& displayed via LEDs
Advantages:
flexibility
durability
simple mechanical construction
functionality transferred to electronics
possibility of adding functionality at low cost
higher accuracy
cost - same as conventional
CS2: Air Spring
Steering an gle
road s peed
brakin g
load h eig ht requ est
microp ro ces s or
res erv oir
air s pring
active damper with
heig ht s ens o r
CS2: Air Spring
advanced adaptive suspension system
sensors measure:
position
velocity
Acceleration
on-board controlling micro-Processor -- data
transfer interval 20ms
Pneumatic valves controlled by micro-Processor -vary pressure in air springs
CS2: Air Spring
modes of operation:
static: adjusting to loading bay height
- stay horizontal
quasi-static : cornering, lane-changing,
prevents from rolling
dynamic: - rough ground - high
frequency vibrations reduced altering
dampers
CS3: Design of 5-Axis Parallel Machine
Tool Family
Reciprocal Screw Theory
Reciprocal
Wrench
Twist
$  $  s  s r  s r  s   0
r
Mobility
•Number
•Properties
R (Rotational DOF)
T (Translational DOF)
(1 0 0;0 0 0)
(0 1 0;0 0 0)
twist
Rxyz
(0 0 1;0 0 0)
(0 0 0;1 0 0)
(0 0 0;0 1 0)
(0 0 0;0 0 1)
Txyz
Twist System and Constraint System
 Structural constraint described by reciprocal screw
Twist
system
Reciprocal
Constraint
system
The unit twists associated with all kinemtic pairs in a limb
form a Limb Twist System
All the linearly independent wrenches reciprocal to the Limb
Twist System form a limb constraint system
Obtaining Five DOFs
5 6-DOF Limbs
Type synthesis
of
5-DOF PM
+
1 5-DOF Limb
=
=
Type synthesis
of
a 5-DOF limb
5-DOF
Procedure of Type Synthesis
Reciprocal
3R+2TXY
5-DOF Limb
N
Check
Structure
Y
Desired Kinematic
Limb Chain
Constraint
system
Limb Twist
system
Kinematic
Limb Chain
Linear
Combination

Type Synthesis of 5-DOF Limb (1)
Desired DOFs，3T2Rxy
3T2Rxy 5-DOF
Limb Constraint System
(1 0 0;0 0 0)
(0 1 0;0 0 0)
(0 0 0;1 0 0)
(0 0 0;0 1 0)
(0 0 0;0 0 1)
Reciprocal
(0 0 1;0 0 0)
Type Synthesis of 5-DOF Limb (2)
Limb twist system
limb contains 5 revolute pairs
(1 0 0;0 0 0)
(0 1 0;0 0 0)
(0 0 0;1 0 0)
Linear
combination
limb contains 4 revolute pairs
and 1 prismatic pair
(0 0 0;0 1 0)
(0 0 0;0 0 1)
limb contains 3 revolute pairs
and 2 prismatic pair
Type Synthesis of 5-DOF Limb (3)
xp
x
zp
x
P R P Uy
(1 0 0;0 0 0)
(0 1 0;0 0 0)
(0 0 0;1 0 0)
Linear
combination
(0 0 0;0 1 0)
(0 0 0;0 0 1)
$1   0 0 0 ; 1 0 0 
$2   1 0 0 ; 0 0 0
$ 3   0 0 0 ; 0 0 1
$ 4   1 0 0 ; 0 b4 c 4 
$5   0 1 0 ; a5 0 c5 
The constraint couple is always
perpendicular to the universal plane
Finite Mobility of 5-DOF PM (1)
In the initial configuration, the
moving platform has three
translational DOFs and two
rotational DOFs about the X axis
and the Y axis, respectively.
Finite Mobility of 5-DOF PM (2)
The moving platform can always
perform a finite rotation about
the fifth revolute axis
$1   0 0 0 ; 1 0 0 
$2   1 0 0 ; 0 0 0
$ 3   0 0 0 ; 0 0 1
$ 4   1 0 0 ; 0 b4 c 4 
Limb twist
system
$5   0 1 0 ; a5 0 c5 
$1   0 0 0 ; 0 0 1 
r
Limb
constraint
system
Finite Mobility of 5-DOF PM (3)
The moving platform is not
parallel to the universal joint
plane.
$ n   ln 0 n n ; a n bn c n 
Normal of the
moving
platform
Reciprocal product of $ n
$ n  $1  n n  0
r
Rotation of the moving
platform about its own
normal is constrained
r
$1
Finite Mobility of 5-DOF PM (4)
The moving platform can always
perform a finite rotation about
the fourth revolute axis
$1 
$2 
$3 
 0 0 0 ; 1 0 0
1 0 0 ; 0 0 0
 0 0 0 ; 0 m 3 n3 
$ 4   1 0 0 ; 0 b4 c 4 
$5 
 0 m5
n 5 ; a 5 b5 c 5 
$   0 0 0 ; 0  n5
r
1
Limb twist
system
Limb
m 5  constraint
system
Finite Mobility of 5-DOF PM (5)
The moving platform is not
parallel to the universal joint
plane.
$ n   l n  n 5 m 5 ; a n bn c n 
Normal of the
moving
platform
Reciprocal product of $ n
$ n  $1  n 4  m 4  0
r
2
2
Rotation of the moving
platform about its own
normal is constrained
r
$1
5-SPS/PRPU Parallel Machine Tool
Universal
Pair
Spherical
Pair
Moving Platform
Motor
Spindle
Control System Architecture
Kinematic Calibration Using the PRPU Limb
Sensor Values of
PRPU Limb
Forward
Kinematics
Of PRPU Limb
Actual
Position
&
Orientation
Of
Moving Platform
Review
 No
one can be expert in all the
mentioned fields
 Team working is a principle
 Mutual understanding necessary
 Interdisciplinary knowledge needed
Mechatronic System Architecture
two main
compone
nts
The Functional Diagram of
Semiotics
Semiotics is
proposed as
a new paradigm
of science in
the 21st Century
The Six-Box Diagram of Behavior
Formation
It Indicates a
Multiresolutional
Hierarchy
The Following Special
Formulation is Offered
Mechatronics studies synergistic fusion of
precise
 mechatronical units,
 electronic,
 electro technical and computer components
for the purpose of designing and manufacturing
qualitatively new
 modules,
 systems,
 machines and complexes of machines
with intellectual control of their functional movements
Comments to the Definition
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Mechatronics studies special conceptual approach to
construction of machines.
The definition emphasizes synergetic character of
components’ integration in mechatronic objects.
Integrated mechatronic components are always chosen
at the designing stage.
Methods of parallel designing serve as methodological
basis for Mechatronic Systems (MS) development.
The main objects that mechatronics studies are
mechatronic modules.
MS are intended to perform a set movement.
In MS methods of advanced intelligent control are used
to secure high quality in performing precise movements.
Principles of
Construction MS
Generalized Scheme
of Machine with
The structure
Control of
of aComputer
traditional
machine
Movement
e.g.: cutting forces for machining processes,
contact forces and moments of forces at assembly,
reactive force of the liquid jet at hydraulic cutting
determ
non-determ
Examples of Mechatronic
Systems
computer disk drive
clothes washer
Computer Control Device Basic
Functions
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Control of mechanical movement process online with current sensor data analysis.
Arrangements to control MS functional
movements.
Interaction with operator via human-machine
interface off-line and on-line interaction at the
moment of MS movement.
Data exchange between peripheral devices,
sensors and other devices of the system.
The Core of Mechatronic
Approach
It consists in integrating of components probably of
different physical nature into a uniform functional module.
in other words
At the stage of designing one interface, as
a separate device, is excluded out of a
traditional structure, but physical essence
of transformation carried out by this
module is kept.
Basic Advantages in Comparison with
Traditional Means of Automation
 rather low cost;
 ability to perform complicated and precise
movements (of high quality);
 high reliability, durability and noise immunity;
 constructive compactness of modules;
 improved overall dimension and dynamic
characteristics of machines;
 opportunity to rebuild functional modules to
sophisticated systems and complexes.
Modern Trends of MS
Development
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Office equipment;
Computer facilities;
Photo and video
equipment;

Machine-tool
construction and
equipment for
automation of
technological
processes;
Robotics;
Modern Trends of MS
Development
Aviation, space
and military
techniques;
 Motor car
consrtuctior;
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Modern Trends of MS
Development
Micro machines;
 Control and measuring devices and
machines;
 Simulators for training of pilots and
operators;
 Show-industry;
 Non-conventional vehicles.

Requirements of the World Market
in the Considered Area
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Standard ISO 9000;
Necessity for active introduction of forms and methods of
international engineering and putting new technologies into
practice;
Increasing role of small and average industrial enterprises
in economy owing to their ability to quick and flexible
reaction to changing requirements of the market;
Intellectualization of mechanical movement control
systems and technological functions of modern machines.
Fundamental Problems
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Structural integration of mechanical, electronic and
information departments into a uniform creative staff;
Education and training of engineers specialized in
mechatronics and managers able to organize integration
and supervise work of strictly specialized experts with
different qualifications;
Integration of information technologies from various
scientific and technical fields into a uniform toolkit to
provide computer support of mechatronic problems;
Standardization and unification of all used elements and
processes at designing and manufacturing MS.
Levels of Mechatronic Systems’
The First Level
Integration
conveyors,
 rotary tables,
 auxiliary
manipulators

Levels of Mechatronic Systems’
The Second Level
Integration


operated power machines (turbines
and generators),
machine tools and industrial robots
with numerical program management
Levels of Mechatronic Systems’
Integration
The Third Level
Synthesis of new precise, information and
measuring high technologies gives a basis
for designing and producing intellectual
mechatronic modules and systems.
Career Paths in Mechatronics
mechatronics is seen as a prime career
path for mechanical engineers of the
future;
 mechanical engineers with a
mechatronics background will have a
better chance of becoming managers;
 classically trained mechanical engineers
will run the risk of being left out of the
interesting work.

A Mechatronics systems engineer must be able to
design and select analog and digital circuits,
microprocessor based components, mechanical
devices, sensors and actuators, and controls so
that the final product achieves a desired goal”.
A Mechatronics engineer should be a generalist,
willing to seek and apply knowledge from a
broad range of sources
(Introduction to Mechatronics and Measurement Systems by Michael
Histand and David Alciatore
Homework, page 325, problem 2(b)
Thank you