[ Computer Engineering Seminar Topic ] |

techalone.com
TECHALON
E
Space Mouse
WWW.TECHALONE.COM
Space Mouse WWW.TECHALONE.COM
1.INTRODUCTION
Every day of your computing life, you reach out for the mouse whenever you want
to move the cursor or activate something. The mouse senses your motion and your
clicks and sends them to the computer so it can respond appropriately. An ordinary
mouse detects motion in the X and Y plane and acts as a two dimensional controller.
It is not well suited for people to use in a 3 graphics environment. !pace "ouse is
a professional 3 controller specifically designed for manipulating o#$ects in a 3
environment. It permits the simultaneous control of all si% degrees of freedom &
translation rotation or a com#ination. . The device serves as an intuitive man&
machine interface
The predecessor of the spacemouse was the '( controller #all.
!pacemouse has its origins in the late seventies when the '( )*erman Aerospace
(esearch Esta#lishment+ started research in its ro#otics and system dynamics
division on devices with si% degrees of freedom ), dof+ for controlling ro#ot
grippers in -artesian space. The #asic principle #ehind its construction is
mechatronics engineering and the multisensory concept. The spacemouse has
different modes of operation in which it can also #e used as a two&dimensional
mouse.

.
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
2.How does computer mouse work?
"ice first #roke onto the pu#lic stage with the introduction of the Apple "acintosh
in /012, and since then they have helped to completely redefine the way we use
computers. Every day of your computing life, you reach out for your mouse
whenever you want to move your cursor or activate something. Your mouse senses
your motion and your clicks and sends them to the computer so it can respond
appropriately
2.1 Inside a Mouse
The main goal of any mouse is to translate the motion of your hand into signals that
the computer can use. Almost all mice today do the translation using five
components3
Fig.1 The guts of a mouse
3
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
/. A #all inside the mouse touches the desktop and rolls when the mouse moves.
Fig 2
The underside of the mouse's logic board: The exposed portion of the ball touches
the desktop.
.. Two rollers inside the mouse touch the #all. 4ne of the rollers is oriented so that
it detects motion in the X direction, and the other is oriented 05 degrees to the
first roller so it detects motion in the Y direction. 6hen the #all rotates, one or
#oth of these rollers rotate as well. The following image shows the two white
rollers on this mouse3
2
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
Fig.3 The rollers that touch the ball and detect X and Y motion
3. The rollers each connect to a shaft, and the shaft spins a disk with holes in it.
6hen roller rolls, its shaft and disk spin. The following image shows the disk3
Fig.4 A typical optical encoding dis! This dis has 3" holes around its outer edge.
7
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
2. 4n either side of the disk there is an infrared 'E and an infrared sensor. The
holes in the disk #reak the #eam of light coming from the 'E so that the
infrared sensor sees pulses of light.
,
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
Fig.# A close$up o% one o% the optical encoders that trac
mouse motion! There is an in%rared &'( )clear* on one
side o% the dis and an in%rared sensor )red* on the other.
The rate of the pulsing is directly related to the speed of the mouse and the
distance it travels.
7. An on&#oard processor chip reads the pulses from the infrared sensors and turns
them into #inary data that the computer can understand. The chip sends the
#inary data to the computer through the mouse8s cord.
9
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
Fig " The logic section o% a mouse is dominated by an encoder
chip+ a small processor that reads the pulses coming %rom the
in%rared sensors and turns them into bytes sent to the
computer. You can also see the t,o buttons that detect clics
)on either side o% the ,ire connector*.
In this optomechanical arrangement, the disk moves mechanically, and
an optical system counts pulses of light. 4n this mouse, the #all is ./ mm in
diameter. The roller is 9 mm in diameter. The encoding disk has 3, holes. !o if the
mouse moves .7.2 mm )/ inch+, the encoder chip detects 2/ pulses of light.
Each encoder disk has two infrared 'Es and two infrared sensors, one on each
side of the disk )so there are four 'E:sensor pairs inside a mouse+. This
arrangement allows the processor to detect the disk8s direction of rotation. There is
a piece of plastic with a small, precisely located hole that sits #etween the encoder
disk and each infrared sensor. This piece of plastic provides a window through
which the infrared sensor can ;see.; The window on one side of the disk is located
1
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
slightly higher than it is on the other && one&half the height of one of the holes in
the encoder disk, to #e e%act. That difference causes the two infrared sensors to see
pulses of light at slightly different times. There are times when one of the sensors
will see a pulse of light when the other does not, and vice versa.
.
3.Three -dimensional user interfaces
<or typical computer displays, three&dimensional is a misnomer=their displays are
two&dimensional. Three&dimensional images are pro$ected on them in two
dimensions. !ince this techni>ue has #een in use for many years, the recent use of the
term three&dimensional must #e considered a declaration #y e>uipment marketers
that the speed of three dimension to two dimension pro$ection is ade>uate to use in
standard graphical user interfaces.
0
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
Three&dimensional graphical user interfaces are common in science fiction
literature and movies, such as in ?urassic @ark, which features !ilicon *raphics8
three&dimensional file manager, ;<ile system navigator;, an actual file manager
that never got much widespread use as the user interface for a Ani% computer.
In science fiction, three&dimensional user interfaces are often immersi#le
environments like 6illiam *i#son8s -y#erspace or Beal !tephenson8s "etaverse.
Three&dimensional graphics are currently mostly used in computer games, art and
computer&aided design )-A+. There have #een several attempts at making three&
dimensional desktop environments like !un8s @ro$ect 'ooking *lass or !phereX@
from !phere Inc. A three&dimensional computing environment could possi#ly #e
used for colla#orative work. <or e%ample, scientists could study three&dimensional
models of molecules in a virtual reality environment, or engineers could work on
assem#ling a three&dimensional model of an airplane. This is a goal of the -ro>uet
pro$ect and @ro$ect 'ooking *lass #y ?ava.
The use of three&dimensional graphics has #ecome increasingly common in
mainstream operating systems, #ut mainly #een confined to creating attractive
interfaces=eye candy=rather than for functional purposes only possi#le using
three dimensions. <or e%ample, user switching is represented #y rotating a cu#e
whose faces are each user8s workspace, and window management is represented in
the form of E%posC on "ac 4! X, or via a (olode%&style flipping mechanism in
/5
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
6indows Dista. In #oth cases, the operating system transforms windows on&the&
fly while continuing to update the content of those windows.
workspace, and window management is represented in the form of E%posC on "ac
4! X, or via a (olode%&style flipping mechanism in 6indows Dista. In #oth cases,
the operating system transforms windows on&the&fly while continuing to update the
content of those windows.
Interfaces for the X 6indow !ystem have also implemented advanced three&
dimensional user interfaces through compositing window managers such as Eeryl
and -ompiF using the AI*'X or X*' architectures, allowing for the usage of
4pen*' to animate the user8s interactions with the desktop.
Another #ranch in the three&dimensional desktop environment is the three&
dimensional graphical user interfaces that take the desktop metaphor a step
further, like the EumpTop, where a user can manipulate documents and windows
as if they were ;real world; documents, with realistic movement and physics. 6ith
the current pace on three&dimensional and related hardware evolution, pro$ects
such these may reach an operational level soon.
4.M'-.AT/01I-2
4.1 3hat is Mechatronics engineering4
"echatronics is concerned with the design automation and operational
performance of electromechanical systems. "echatronics engineering is nothing
newG it is simply the applications of latest techni>ues in precision mechanical
engineering, electronic and computer control, computing systems and sensor and
actuator technology to design improved products and processes.
The #asic idea of "echatronics engineering is to apply innovative controls to
e%tract new level of performance from a mechanical device. It means using modem
cost effective technology to improve product and process performance, adapta#ility
//
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
and fle%i#ility.
"echatronics covers a wide range of application areas including consumer
product design, instrumentation, manufacturing methods, computer integration and
process and device control. A typical "echatronic system picks up signals processes
them and generates forces and motion as an output. In effect mechanical systems
are e%tended and integrated with sensors )to know where things are+,
microprocessors )to work out what to do+, and controllers )to perform the re>uired
actions+.
The word "echatronics came up descri#ing this fact of having technical
systems operating mechanically with respect to some kernel functions #ut with
more or less electronics supporting the mechanical parts decisively. Thus we can
say that "echatronics is a #lending of "echanical engineering,Electronics
engineering and -omputing. These three disciplines are linked together with
knowledge of management, manufacturing and marketing.
4.2 3hat do Mechatronics engineers do4
"echatronics design covers a wide variety of applications from the physical
integration and miniaturiFation of electronic controllers with mechanical systems to
the control of hydraulically powered ro#ots in manufacturing and assem#ling
factories.
-omputer disk drives are one e%ample of the successful application of
"echatronics engineering as they are re>uired to provide very fast access precise
positioning and ro#ustness against various distur#ances.
/.
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
An intelligent window shade that opens and closes according to the amount
of sun e%posure is another e%ample of a "echatronics application.
"echatronics engineering may #e involved in the design of e>uipments and
ro#ots for under water or mining e%ploration as an alternative to using human
#eings where this may #e dangerous. In fact "echatronics engineers can #e found
working in a range of industries and pro$ect areas including
esign of data collection, instrumentation and computeriFed machine
tools.
Intelligent product design for e%ample smart cars and automation for
household transportation and industrial application.
esign of self&diagnostic machines, which fi% pro#lems on their own.
"edical devices such as life supporting systems, scanners and BA
se>uencing automation.
(o#otics and space e%ploration e>uipments.
!mart domestic consumer goods
-omputer peripherals.
!ecurity systems.
/3
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
4.3 Mechatronic goals
4.3.1 The multisensory concept
The aim was to design a new generation of multi sensory lightweight ro#ots.
The new sensor and actuator generation does not only show up a high degree of
electronic and processor integration #ut also fully modular hardware and software
structures. Analog conditioning, power supply and digital pre&processing are typical
su#systems modules of this kind. The .5khF lines connecting all sensor and actuator
systems in a galvanically decoupled way and high speed optical serial data #us
)!E(-4!+ are the typical e%amples of multi sensory and multi actuator concept for
the new generation ro#ot envisioned.
The main sensory developments finished with these criteria have #een in the
last years3 optically measuring force&tor>ue&sensor for assem#ly operations. In a
more compact form these sensory systems were integrated inside plastic hollow
#alls, thus generating ,&degree of freedom hand controllers )the '( control #alls+.
The !@A-E&"4A!E is the most recent product #ased on these ideas.
stiff strain&gauge #ased , component force&tor>ue&sensor systems.
miniaturiFed triangulation #ased laser range finders.
integrated inductive $oint&tor>ue&sensor for light&weight&ro#ot.
In order to demonstrate the multi sensory design concept, these types of
sensors have #een integrated into the multi sensory '(&gripper, which contains /7
sensory components and to our knowledge it is the most comple% ro#ot gripper #uilt
so far )more than /555 miniaturiFed electronic and a#out 255 mechanical
components+. It has #ecome a central element of the (4TEX space ro#ot
e%periment.
/2
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
#.25A-'M062'
!pacemouse is developed #y the '( institute of ro#otics and mechatronics.
'(& eutsches Henturum far 'uft&und (aumfahrt
#.1 3hy 3( motion4
In every area of technology, one can find automata and systems controlla#le
up to si% degrees of freedom& three translational and three rotational. Industrial
ro#ots made up the most prominent category needing si% degrees of freedom #y
maneuvering si% $oints to reach any point in their working space with a desired
orientation. Even #roader there have #een a dramatic e%plosion in the growth of 3
computer graphics.
Already in the early eighties, the first wire frame models of volume o#$ects
could move smoothly and interactively using so called kno#&#o%es on the fastest
graphics machines availa#le. A separate #utton controlled each of the si% degrees of
freedom. Be%t, graphics systems on the market allowed manipulation of shaded
volume models smoothly, i.e. rotate, Foom and shift them and thus look at them
from any viewing angle and position. The scenes #ecome more and more comple%G
e.g. with a ;reality engine; the mirror effects on volume car #odies are updated
several times per second & a task that needed hours on main frame computers a
couple of years ago.
@arallel to the rapid graphics development, we o#served a clear trend in the
field of mechanical design towards constructing and modeling new parts in a 3
environment and transferring the resulting programs to B- machines. The machines
are a#le to work in 7 or , degrees of freedom )dof+. Thus, it is no surprise that in the
last few years, there are increasing demands for comforta#le 3 control and
manipulation devices for these kinds of systems. espite #reathtaking
/7
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
advancements in digital technology it turned out that digital man& machine
interfaces like key#oards are not well suited for people to use as our sensomotory
reactions and #ehaviors are and will remain analogous forever.
#.2 (&/ control ball+ Magellan7s predecessor
At the end of the seventies, the '( )*erman Aerospace (esearch
Esta#lishment+ institute for ro#otics and system dynamics started research on
devices for the ,&dof control of ro#ot grippers .in -artesian space. After lengthy
e%periments it turned out around /01/ that integrating a si% a%is force tor>ue sensor
)3 force, 3 tor>ue components+ into a plastic hollow #all was the optimal solution.
!uch a #all registered the linear and rotational displacements as generated #y the
forces: tor>ues of a human hand, which were then computationally transformed into
translational : rotational motion speeds.
The first force tor>ue sensor used was #ased upon strain gauge technology,
integrated into a plastic hollow #all. '( had the #asic concept centre of a hollow
#all handle appro%imately coinciding with the measuring centre of an integrated ,
dof force : tor>ue sensor patented in Europe and A!.
<rom /01.&/017, the first prototype applications showed that '(8s control
#all was not only e%cellently suited as a control device for ro#ots, #ut also for the
first 3&graphics system that came onto the market at that time. 6ide commercial
distri#ution was prevented #y the high sales price of a#out I1,555 per unit. It took
until /017 for the '(8s developer group to succeed in designing a much cheaper
optical measuring system.
/,
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
#.2.1 8asic principle
The new system used , one&dimensional position detectors. This system
received a worldwide patent. The #asic principle is as follows. The measuring
system consists of an inner and an outer part. The measuring arrangement in the
inner ring is composed of the 'E, a slit and perpendicular to the slit on the
opposite side of the ring a linear position sensitive detector )@!+. The slit : 'E
com#ination is mo#ile against the remaining system. !i% such systems )rotated #y
,5 degrees each+ are mounted in a plane, where#y the slits alternatively are vertical
and parallel to the plane. The ring with @!8s is fi%ed inside the outer part and
connected via springs with the 'E&slit&#asis. The springs #ring the inner part #ack
to a neutral position when no forces : tor>ue are e%erted3 There is a particularly
simple and uni>ue. This measuring system is drift&free and not su#$ect to aging
effects.
The whole electronics including computational processing on a one&chip&
processor was already integra#le into the #all #y means of two small dou#le sided
surface mount device )!"+ #oards, the manufacturing costs were reduced to
#elow I/,555, #ut the sales price still hovered in the area of I3,555.
The original hopes of the developers group that the license companies might
#e a#le to redevelop devices towards much lower manufacturing costs did not
materialiFe. 4n the other hand, with passing of time, other technologically
compara#le #all systems appeared on the market especially in A!A. They differed
only in the type of measuring system. Around /005, terms like cy#erspace and
virtual reality #ecame popular. Jowever, the effort re>uired to steer oneself around
in a virtual world using helmet and glove tires one out >uickly. "ovements were
measured #y electromagnetic or ultrasonic means, with the human head having
/9
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
pro#lems in controlling translational speeds. In addition, moving the hand around in
free space leads to fairly fast fatigue. Thus a redesign of the #all idea seemed
urgent.
#.3 Magellan )the 'uropean 2pacemouse*!
the result o% a long de9elopment chain
6ith the developments e%plained in the previous sections, '(8s
development group started a transfer company, !@A-E -4BT(4' and addressed a
clear goal3 To redesign the control #all idea with its unsurpassed opto electronic
measuring system and optimiFe it thus that to reduce manufacturing costs to a
fraction of its previous amount and thus allow it to approach the pricing level of
high >uality @- mouse at least long&term.

Fig :.2pacemouse system
/1
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
The new manipulation device would also #e a#le to function as a
conventional mouse and appear like one, yet maintain its versatility in a real
workstation design environment. The result of an intense one&year8s work was the
European !pace"ouse, in the A!A it is especially in the European market place.
Eut end of 03, '( and !@A-E
-4BT(4' $ointly approached '4*ITE-J #ecause of their wide e%pertise with
pointing
devices for computers to market and sell "agellan in A!A and Asia. The wear
resistant and drift free opto electronic, , component measuring system was
optimiFed to place all the electronics, including the analogous signal processing, AT
conversion, computational evaluation and power supply on only one side of a tiny
!"& #oard inside "agellan8s handling cap. It only needs a few milliamperes of
current supplied through the serial port of any @- or standard mouse interface. It
does not need a dedicated power supply. The electronic circuitry using a lot of time
multiple% technology was simplified #y a factor of five, compared to the former
control #alls mentioned #efore. The un#elieva#ly tedious mechanical optimiFation,
where the simple ad$ustment of the @!8s with respect to the slits played a central
role in its construction, finally led to 3 simple in$ection moulding parts, namely the
#asic housing, a cap handle with the measuring system inside and the small nine
#utton key#oard system. The housing, a punched steel plate provides "agellan with
the necessary weight for sta#ilityG any kind of metal cutting was avoided. The small
#oard inside the cap )including a #eeper+ takes diverse mechanical functions as
well. <or e%ample, it contains the automatically mounta#le springs as well as
overload protection. The springs were optimiFed in the measuring system so that
they no longer show hysteresisG nevertheless different stiffness of the cap are
realiFa#le #y selection of appropriate springs.
Ergonomically, "agellan was constructed as flat as can #e so that the human hand
may rest on it without fatigue. !light pressures of the fingers on the cap of "agellan
is sufficient for generating deflections in X, Y, and H planes, thus shifting a cursor
/0
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
or flying a 3 graphics o#$ect translationally through space. !light twists of the cap
cause rotational motions of a 3 graphics o#$ect around the corresponding a%es.
@ulling the cap in the H direction corresponds to Fooming function. "oving the cap
in X or Y direction drags the horiFontally and vertically respectively on the screen.
Twisting the cap over one of the main a%es or any com#ination of them rotates the
o#$ect over the corresponding a%is on the screen. The user can handle the o#$ect on
the screen a he were holding it in his own left hand and helping the right hand to
undertake the constructive actions on specific points lines or surfaces or simply #y
unconsciously #ringing to the front of
appropriate perspective view of any necessary detail of the o#$ect. 6ith the
integration of nine additional key #uttons any macro functions can #e mapped onto
one of the keys thus allowing the user most fre>uent function to #e called #y a slight
finger touch from the left hand. The device has special features like dominant mode.
It uses those degrees of freedom in which the greatest magnitude is generated. !o
defined movements can #e created. -onnection to the computer is through a 3m
ca#le )E0 female+ and platform adapter if necessary. Ase of handshake signals
)(T!!-T!+ are recommended for the safe operation of the spacemouse. 6ithout
these handshake signals loss of data may occur. Additional signal lines are provided
to power the "agellan )T!K(T!+. Thus, no additional power supply is needed.
<lying an o#$ect in , dof is done intuitively without any strain. In a similar way,
flying oneself through a virtual world is $ust fun. Touching the keys results in either
the usual menu selection, mode selection or the pickup of 3 o#$ects.
.5
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
%ig ; 2pacemouse
#.4 Table$1
Technical speci%ications o% spacemouse
./
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM


".MA<'&&A1! F'AT6/'2 A1( 8'1'FIT2
".1 Features
Ease of use of manipulating o#$ects in 3 applications.
-ali#ration free sensor technology for high precision and uni>ue relia#ility.
Bine programma#le #uttons to customiFe users preference for motion control
<ingertip operation for ma%imum precision and performance.
!ettings to ad$ust sensitivity and motion control to the users preference.
!mall form factor frees up the desk space.
..
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
ou#le productivity of o#$ect manipulation in 3 applications.
Batural hand position )resting on ta#le+ eliminates fatigue.
".2 8ene%its
As the user positions the 3 o#$ects with the "agellan device the necessity
of going #ack and forth to the menu is eliminated. rawing times is reduced #y
.5L&35L increasing overall productivity. 6ith the "agellan device improved
design comprehension is possi#le and earlier detection of design errors contri#uting
faster time to market and cost savings in the design process. Any computer whose
graphics power allows to update at least 7 frames per second of the designed
scenery, and which has a standard (!.3. interface, can make use of the full
potential of "agellan spacemouse. In 3 applications "agellan is used in
con$unction with a . mouse. The user positions an o#$ect with spacemouse while
working on the o#$ect using a mouse. 6e can consider it as a workman holding an
o#$ect in his left hand and working on it with a tool in his right hand. Bow "agellan
spacemouse is #ecoming something for standard input device for interactive motion
control of 3 graphics o#$ects in its working environment and for many other
applications.

:.F6T6/' 2-05' A1( -01-&62I01
:.1 F6T6/' 2-05'
"agellan8s predecessor, '(8s control #all, was a key element of the first
.3
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
real ro#ot inspace, (4TEX& )3+, which was launched in April 03 with space shuttle
-4'A"EIA inside a rack of the spacela#&.. The ro#ot was directly teleoperated
#y the astronauts using the control #all, the same way remotely controlled from
ground )on&line and off line+ implying ;predictive; stereographics. As an e%ample,
the ground operator with one of the two #alls or "agellans steered the ro#ot8s
gripper in the graphics presimulation, while with the second device he was a#le to
move the whole scenery around smoothly in , dot @redictive graphics simulation
together with the a#ove mentioned man machine interaction allowed for the
compensation of overall signal delays up to seven seconds, the most spectacular
accomplishment #eing the grasping of a floating o#$ect in space from the ground.
!ince then, (4TEX has often #een declared as the first real ;virtual reality;
application.
:.1.1 =I26A& 25A-'M062'
A most intuitive controlling device would #e a system that can #e instructed
#y watching and imitating the human user, using the hand as the ma$or controlling
element. This would #e a very comforta#le interface that allows the user to move a
ro#ot system in the most natural way. This is called the visual space mouse. The
system of the visual space mouse can #e divided into two main parts3 image
processing and ro#ot control. The role of image processing is to perform operations
on a video signal, received #y a video camera, to e%tract desired information out of
the video signal. The role of ro#ot control is to transform electronic commands into
movements of the manipulator.

:.2 -01-&62I01
The graphics simulation and manipulation of 3 volume o#$ects and virtual
.2
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
worlds and their com#ination e.g. with real information as contained in TD images
)multi&media+ is not only meaningful for space technology, #ut will strongly change
the whole world of manufacturing and construction technology, including other
areas like ur#an development, chemistry, #iology, and entertainment. <or all these
applications we #elieve there is no other man& machine interface technology
compara#le to "agellan in its simplicity and yet high precision. It is used for 3
manipulations in , dof, #ut at the same time may function as a conventional .
mouse.
.7
Computer Engg
Seminar
Space Mouse WWW.TECHALONE.COM
/'F'/'1-'2
)/+ www.howstuffworks.com
).+ www.wikipedia.com
)3+www.altavista.com

.,
Computer Engg
Seminar