Rover of Windsor －流浪者: Robotics

Parallel Robots Websites

Fri, 04 Nov 2005 13:59:47 GMT

Laboratories Working On Parallel Mechanisms

Canada (8)

USA (20)

Germany (9)

Switzerland (6)

Italy (8)

France (7)

South Korea (8)

Japan (11)

Others (16)

Companies Manufacturing Industrial Parallel Robots

Fanuc Robotics Company Profile: N/A Other Related Links: F-200i (1, 2)	Ross-Hime Designs Company Profile: N/A Other Related Links: Omni-Wrist III
Demaurex Company Profile: N/A Other Related Links: N/A	ABB Automation Company Profile: N/A Other Related Links: IRB 340 (FlexPicker)
GROB-Werke Company Profile: Other Related Links: N/A	SIG Robotics Company Profile: N/A Other Related Links: N/A
MICOS Company Profile: N/A Other Related Links: PAROS	Physik Instrumente Company Profile: N/A Other Related Links: Advanced MicroPositioners
LIDAX Company Profile: N/A Other Related Links: Hexapod	Dr. Mader Machinenbau Company Profile: N/A Other Related Links: Hexapod for handling operations TU-Dresden Transferbrief
ALIO Industries Company Profile: N/A Other Related Links: Hexapod & Tripod	Adept Technology Company Profile: N/A Other Related Links: NanoStage Six

R&D Centers Working On Parallel Mechanisms

Canada (2)

USA (7)

France (1)

Netherlands (2)

UK (1)

Germany (1)

Gallery of Existing Parallel Mechanisms

Parallel Kinematic Machines

Organization	Existing PKMs	Specifications
Giddings & Lewis	Variax	5-axis vertical machining center
Ingersoll	Octahedral Hexapod HOH-600 Oct. Hexapod VOH-1000	5-axis horizontal machining center 5-axis vertical machining center
Hexel	Tornado	5-axis vertical machining center
Toyoda	HexaM	5-axis vertical milling machine
CMW	HEXAPODE CMW 300	5-axis milling machine
Fatronik	Ulyses	3-axis high speed cutting machine
Krause & Mauser	Quickstep	3-axis horizontal machining center
Tekniker	SEYANKA	5-axis milling machine
Daeyoung Machinery	Eclipse-RP	5-axis rapid prototyping system
Okuma	Cosmo Center PM-600	5-axis milling machine
INDEX-Werke	VerticalLine V100	3-axis vertical turning center
METROM	P 800	5-side milling machine

Legend: Click on to go to the web site of the company or on to see the detailed specifications.

Companies Manufacturing Parallel Mechanisms or Components for Them

Motion Simulators

Parallel Kinematic Machines

Industrial APP- PR

Wed, 02 Nov 2005 13:59:35 GMT

Industrial applications

F200: Fanuc F-200iB robot Specification 6DOF UTR PICS

PA: Measuring machine (Perry Automation, USA)

LA: Machine-toll and Measuring Machine (Lapic)

FCS: Test rig and simulators (FCS) E-Cue 624-1800 -2800 636-4500 660-8000 -12000 6DOF UTR

PO: Data M Engineering (porcelain decoration) PDF 6DOF UTR

GC: Lens hexapod (Gerber Coburn) PDF 6DOF unknown

PD: Packaging with Delta (Phoenix Packaging Systems)

BS: Biological screening with Delta (RTS)

ELG: Elevator for landing gear (Hydro-Ger\"atbau)

OM: Forcedimension (Omega haptic device) 3-DOF OMEGA 3-DOF DELTA 6-DOF DELTA PICS

AI: Simulator motion base (AI Group) PDF

FA: Simulator motion base (Flight-Avionics)

MO: Motion base (Moog) 4DOF9000E 6DOF2000E

REX: Motion base (Rexroth Hydraudine)

VMP: Virtogo motion platform

SMB: Simulator motion base (Servos Simulation) 2-AXIS 3-AXIS 5-AXIS 6-AXIS

DEX: Deltalab EX800 & 830 (educational robot) EX800 PIC EX830 PIC

Machine-tools

G500: 2 d.o.f. machine tool Genius 500 (Cross H\"uller)

900H: 2 d.o.f. machine tool Trijoint 900H (Kovosvit Mas)

Z3: 3 d.o.f. machine tool Sprint Z3 (DS Technologie)

SKM: 3 d.o.f. machine-tool SKM 400 (Starrag-Heckert)

HS: 3 d.o.f. machine-tool HS500 (Krauseco/Mauser)

V100: 3 d.o.f. machine-tool V100 (Index)

FHB: Machine tool DiGiHex (FH Bielefeld)

M560: MultiCraft 560 (machine-tool, Greif)

HS1: Machine tool Hexamech-1 (Savelovo)

PR: Machine tool Pegasus (Reichenbacher)

CMW: Machine-tool (CMW)

OK: Machine-tool (Okuma)

DR: Machine-tool (DR Mader)

MK: 6X machine tool (Mikromat)

DY: German machine-tool project Dynamil

RT: European project ROBOTOOL

M21: European project MACH21

LME: Milling machine (LME, England)

Positioning devices

PI: Positioning hexapods (Physik Instrumente, Germany)

MI: Micos (Paros positioning robot)

AL: Alio Industries (positioning robot HR4)

MA: Piezo hexapod (Marco)

ESRF: European Synchrotron Radiation Facility

ILL: ILL Salsa project

Miscellaneous applications

NZ: Antenna pointing system (Canterbury University, New-Zealand)

IS: IN-SNEC antenna support

TH: VISTA (telescope hexapod)

ADS: ADS International (hexapods)

CSN: CSEM NAOS 3-d.o.f. mechanism

VA: Vertex Antennen (telescope hexapods)

MD: Active damping Micromega Dynamics

CSA: CSA Vibration isolator

HXA: CSA HXA isolator

VISS: Vibration isolation (VISS, USA)

EN: Vibration isolation (Energen)

OHE: OHE Hagenbuch (Hexamove)

ISIS: ISIS SurgiScope

MAZ: MARS/Spine Assist robot (Mazor Surgical Technologies)

CMU: Mini Bone-Attached Robotic System (CMU)

MI: HexaPOD patient positioner (Medical Intelligence)

BU: Endoscope (Berkeley University, USA)

MO: Rehabilitation platform Caren (Motek)

CAE: Motion simulator (CAE, Canada)

TH: Motion simulator (Thales,France)

FRA: Motion simulator (FRASCA, USA)

INRT: www.inrets.fr/ur/sara/Pg_simus_e.html

NADS: NADS Driving simulator (U. Iowa)

TMB: Turret Motion Based Simulator(TACOM)

PHS: Persival horse simulator

-------------------------------------------

Architectures

Goo: Planar redundant robot (Googol)

HS: Planar parallel robot NAF3 (Hephaist Seiko)

DD: Demaurex Delta robot

ABB: ABB IRB 340 Delta robot (FlexPicker)

CS: CSEM Microdelta

AE: Agile Eye(University Laval, Québec)

OW: 2 d.o.f Omni-Wrist (Ross-Hime Designs)

DP: Dockwelder project

VL: 3 d.of. motion base (Visible Light)

IM: 3 d.o.f. motion base (InMotion Simulation)

LIRMM: Hexa Robot (LIRMM, Montpellier, France)

RH: Rotobot (Hexel Corp., USA)

PMR: Parallel modular robots (Nanyang Technological University)

WC: Wire crane (August Design Inc., USA)

SC: Skycam wire camera

Research to date

Tue, 01 Nov 2005 13:59:38 GMT

April 12, 2006 Presentation on Lab meeting. RPK OF GSP

The True Origins of Parallel Robots

Mon, 29 Aug 2005 13:00:57 GMT

The True Origins of Parallel Robots

By Ilian Bonev
Special thanks to Willard L.G. Pollard,
Klaus Cappel, Mike Beeson (Dunlop Tyres), and
Sam Evans (British National Museum of Science and Industry)

Recently, I had the rare opportunity to talk with two of the pioneers in the field of parallel robots, Mr. Willard L.G. Pollard Jr. and Mr. Klaus Cappel, and to learn remarkable facts about a third one, Dr. Eric Gough, and his still existent tire-testing machine. This feature article makes a number of key revelations that will rewrite the history of parallel robots. Through this new look at the past, a major lesson should be learned concerning the lack of communication between industry and academia.

Note: Use the ParalleMIC Forum for comments or general questions regarding this review.

The Chicken or the Egg?

Theoretical works related to parallel mechanisms, and particularly to six-strut platforms, date back to centuries ago, when English and French geometricians were obsessed with polyhedra. But except for the inquisitive Prof. Manfred Husty, the first to find an analytic method for calculating the 40 solutions to the direct kinematics problem of a hexapod, and the curious Dr. Jean-Pierre Merlet, the author of the first book on parallel robots, there might be very few other designers of parallel kinematic systems that have even glanced upon these ancient texts... Where, then, did parallel robots originate from?

When I first got acquainted with parallel robots, I was left with the impression that this was a new technology. Indeed, even today many scientific papers and a couple of textbooks refer to the introduction of parallel manipulators as a "remedy" to the drawbacks of serial ones and something that has stimulated "considerable attention" in "the past few decades." And it all comes back to the late 1950s when Gough built the "first hexapod" that many paradoxically refer to as the "Stewart platform." So were parallel robots an upgrade of serial ones?

In what follows, one can clearly witness the gap between industry and academia. Until now, what researchers used to know about the origins of parallel robots was very much based on a chain of papers spurred by a single publication—that of Mr. Stewart. As we will see, history is not quite as most have believed...

Ahead of Time

Whoever thought first of building a motion platform (commonly known under the oxymoron "motion base") for the entertainment industry was a great visionary. One of the first such amusement devices was designed by James E. Gwinnett who applied for a patent in 1928. What a surprise then that this device was based on ... a spherical parallel mechanism! Imagine, just a couple of years after the first motion picture in color and the first with sound, and some were already thinking parallel...

Possibly the first spatial parallel mechanism, patented in 1931 (US Patent No. 1,789,680).

It is not known whether this was the first design of a multi-degree-of-freedom (DOF) parallel kinematic system, nor whether the simulator was ever built. But one thing is for sure: James Gwinnett was too much ahead of his time and the industry was not ready for the complexity of his invention.

Was the First Industrial Robot a Parallel Robot?

A decade later and only seventeen years after the term "robot" was coined, a new parallel robot was invented for automated spray painting by Willard L.V. Pollard. Was this the commonly claimed first industrial robot (see for example BusinessWeek's Robot Milestones)?

In the parallel kinematics community, Pollard's parallel robot is well known as the first industrial parallel robot design. This ingenious invention represents a five-DOF three-branched parallel robot. In this parallel robot, three proximal arms are pivoted by rotary motors fixed to the base, and three distal arms are connected to the three proximal arms via universal joints. Two of the distal arms are connected to the third via ball joints, while a tool head is connected to the third distal arm via a universal joint. Thus, the three motors determine the position of the tool head, while its orientation is controlled by two other motors fixed at the base and transmitting the motion to the tool head via flexible rotary cables. Pollard's parallel robot was intended for spray painting but, unfortunately, was never built.

The first spatial industrial parallel robot, patented in 1942 (US Patent No. 2,286,571).

The first industrial robot to be built was not the above one and cannot be credited to the same Willard Pollard... The engineer who co-designed the first industrial robot was Willard L.V. Pollard's son, Willard L.G. Pollard Jr.

On October 29, 1934, Willard Pollard Jr. filed a patent for a spray painting machine. The patent consists of two parts: (1) an electrical control system and (2) a mechanical manipulator. The control system consists basically of perforated films, the hole density of which is directly proportional to the speed of each motor. The mechanical manipulator, on the other hand, is a parallel robot based on a pantograph actuated by two rotary motors at the base. Pollard Jr.'s patent was eventually issued on June 16, 1942, but, in the meantime, a license was granted to the DeVilbiss company in 1937. In 1941, DeVilbiss, later to become the first industrial robot supplier, completed the first prototype under the direction of Harold Roselund. Roselund's spray painting robot, later patented in 1944, was not a parallel robot and used only the control system proposed by Pollard Jr.

Willard L.G. Pollard Jr. is now ninety-one year old. His latest patent was issued in 1995 and represents a tripod parallel robot with parallel driving screw actuators.

Gough's Tire-Testing Machine Is Still In Shape

A couple of years later, in 1947, on the other side of the Atlantic, a new parallel mechanism was invented,—the one that became the most popular, the one that changed an industry, and the one that has been replicated over a thousand times—the variable-length-strut octahedral hexapod.

The first octahedral hexapod or the original Gough platform at birth in 1954 (Proc. IMechE, 1965-66) and shortly before retirement in 2000 (courtesy of Mike Beeson, Dunlop Tyres).

Dr. Eric Gough, the person who built this first octahedral hexapod, was a distinguished automotive engineer at Dunlop Rubber Co., Birmingham, England. Contrary to what has been claimed in literature, he was of English descent, born in Smethwick, Staffordshire, England, on October 16, 1906. He joined Dunlop at the early age of twenty and obtained his D.Sc. (Eng.) in 1967 from the University of London. His doctoral degree was awarded for research carried out during the normal course of employment.

The universal tire-testing machine, or the universal rig, as Dr. Gough called his brainchild, was invented in order to respond to problems of aero-landing loads. A universal machine was needed to determine the properties of tires under combined loads. But the octahedral hexapod was not invented from scratch. At that time, as Dr. Gough mentions in his key paper, systems with six jacks (hexapods) were already known! Indeed, as confirmed by others (see the next section), hexapods with three vertical jacks and three horizontal ones have been so common that their origins were long forgotten. These systems have been very popular because, for small variations, "the jack adjustments would be simple and interpretable." Systems of this type (or slightly modified) are known under the acronym MAST, which stands for Multi-Axis Simulation (or Shake) Table, and are still manufactured by numerous companies.

A typical MAST system (courtesy of Prof. Hubert Hahn, RTS, University of Kassel).
Hexapods of this type have existed long before the Gough platform.

The new thing about the Gough platform was the arrangement of the six struts. Since Eric Gough needed relatively large ranges of motion, he naturally selected the symmetrical arrangement forming an octahedron. The machine was built in the early 1950s and was fully operational in 1954. Although the original design implied the use of common universal joints at the base and mobile platform, the jacks were finally attached separately. In the early days, the extensible struts were manually adjustable screw jacks. A second hexapod structure mounted below the mobile platform incorporated the load cells. Tables with pre-calculated data were used for carrying the intricate force conversions and the pose adjustment. A decade later, the machine was upgraded with digitally controlled motor drives and electronic recording of the load cells.

According to Mr. Mike Beeson from Dunlop Tyres who occasionally had a lift to work from his neighbor and colleague, Dr. Gough, the universal rig played an important role in the birth of rubber science. Unfortunately, Dr. Eric Gough passed away in December 1973, just when octahedral hexapods were getting increasingly popular.

Gough's universal rig continued to be in operation in the Dunlop factory until the break of the new millennium. Following the merger of Dunlop Tyres with Goodyear in 1998/1999, the factory was eventually closed and flattened. In an attempt to save his favorite test machinery from the torch, Mike Beeson contacted Sam Evans from the British National Museum of Science and Industry and arranged for the machine to be taken, two days before the demolition team moved in. After serving faithfully for nearly half a century, the first octahedral hexapod left Fort Dunlop on August 9, 2001, on a big truck for its new home at the Science Museum Wroughton near Swindon, some 120 km west of London. But is the Gough machine the forerunner of today's motion platforms?

Gough or Stewart platform? Or ... Cappel platform?

In 1965, Stewart's famous paper appeared in the proceedings of the (British) IMechE. In that paper, Mr. Stewart describes a 6-DOF motion platform for use as a flight simulator. The proposed parallel mechanism, however, is different from the octahedral hexapod that is, paradoxically, often referred to as the "Stewart platform." In the same proceedings, Stewart's paper is followed by ardent discussions from scientists and engineers, one of which was Dr. Gough who reminded of the existence of his tire-testing machine.

Schematic of the one and only "Stewart platform" (Proc. IMechE, 1965-66).

There is no doubt that Stewart's excellent paper had a great impact on the subsequent development in the field of parallel kinematics. Various suggestions for the use of the hexapod were made, many of which were accurate predictions of the future. Unfortunately, nothing further is known about D. Stewart. But was he the real harbinger of today's flight simulators?

Back in America, US engineer Klaus Cappel was faced with a serious problem. It was 1962, and Mr. Cappel's employer, the Franklin Institute Research Laboratories in Philadelphia, requested him to improve an existing conventional 6-DOF vibration system based on a hexapod. The MAST accommodated not three horizontal actuators but four in a cyclic pattern, in an attempt to reduce the required horizontal reaction masses. However, the redundancy of the seven-strut configuration was too complex to control and the resulting antagonistic forces eventually fractured the table. It is by observing this that Mr. Cappel came up with the same octahedral arrangement as the one proposed by Dr. Gough...

Excerpt from the first patent on an octahedral hexapod issued in 1967 (US patent No. 3,295,224).

It may be difficult to believe this revelation which comes out of the blue. But in 1971, the US Patent and Trademark Office granted a patent to Klaus Cappel for his invention and its use as ... a motion simulator. The patent was filed on December 7, 1964, at which time Mr. Cappel was unaware of Gough's invention (or of Stewart's paper which was not yet published). In fact, the patent application and the motion simulator idea resulted from a request by the corporate office of the Sikorsky Aircraft Division of United Technologies for the design and construction of a 6-DOF helicopter flight simulator. And thus was made the first ever flight simulator based on the octahedral hexapod.

The first flight simulator based on an octahedral hexapod as in the mid 1960s (courtesy of Klaus Cappel).

The first license was granted in the late 1960s to Link, then the prime manufacturer of flight simulators. The first infringement occurred in the early 1970s by CAE, the present leader in flight simulators. The lawsuit was successful for the Franklin Institute resulting in a penalty and a license. Later, other companies entered the market and had to comply with Cappel's patent. Meanwhile, two other motion simulators were directly built by the Franklin Institute. The first one was a helicopter simulator for the Rock Island Arsenal, built in an upside-down configuration and attached to a 2-DOF gimbal system. The second one was a driving simulator sold to the former Daimler-Benz and later mounted on rails.

Klaus Cappel has devised various other parallel kinematic systems for vibration testing. He has been working as a technical advisor for Team Corporation, a manufacturer of vibration equipment, and co-invented their parallel kinematic CUBE. The designer with the longest experience on hexapods is still active in the field, but few are those who take advantage of his valuable expertise.

Klaus Cappel explaining the octahedral hexapod to managers of the Franklin Institute in the mid 1960s (courtesy of Klaus Cappel).

According to Mr. Cappel, the initial response to the new hexapod concept was unexpectedly negative for many years before wide acceptance finally arrived. And then, Klaus Cappel's name was quickly forgotten. More than three decades later, thousands of nearly identical octahedral hexapods are still manufactured, mostly for motion simulators. Yet, there are still companies that mechanically copy this design without having any notion of workspace, singularities, or direct kinematics. There is even an anecdote about a company that built such a motion simulator and when it finally made it move ... it smashed down the hangar walls.

Cooperate and Stop Reinventing the Wheel

The purpose of this review is not to crown the "real" inventor of today's most popular parallel robot. Dr. Gough was the first to invent and build the popular octahedral hexapod. However, it was Klaus Cappel who later designed independently the very same hexapod, had it patented, licensed it to the first flight simulator companies, and made the first commercial octahedral hexapod motion simulators. Yet, it was Stewart who, unintentionally, made Gough's concept popular and proposed, once again, the idea for flight simulators, this time to academia. But then, non-octahedral hexapods have existed long before the octahedral one... And most "octahedral" ones are not really octahedral but only fairly close to being such. To be politically correct, the variable-length-strut (nearly) octahedral hexapod should be called neither a Gough nor a Cappel nor a Stewart platform. The contributions, though, of all three engineers should be adequately recognized.

The real lesson from this story is different. It is about the shameful gap between industry and academia, the individualism, the superficiality of prior art research. Willard Pollard was in the yellow pages, a phone call away, but no one ever thought of calling him. Tons of publications were written on the hexapod but no one ever cared to contact Dunlop where the first ever octahedral hexapod functioned anonymously for decades. Klaus Cappel licensed and built most motion simulators prior to the early 1980s but no one even knew about him. In the meantime, expensive motion simulators demolish hangar walls...

There is a tremendous body of information and expertise related to parallel robots but few in industry are taking advantage of it. On the other hand, researchers keep inventing new mechanisms that industry does not necessarily need now. While Gough, Stewart, and Cappel made their inventions unaware of each other in the age of snail mail but in direct response to industry needs, now that we are just a click away, isn't it time that we stop reinventing the wheel and put our efforts together?

Bibliography

	Gwinnett, J.E., "Amusement devices," US Patent No. 1,789,680, January 20, 1931.
	Pollard, W.L.G., "Spray painting machine," US Patent No. 2,213,108, August 26, 1940.
	Pollard, W.L.V., "Position controlling apparatus," US Patent No. 2,286,571, June 16, 1942.
	Roselund, H.A., "Means for moving spray guns or other devices through predetermined paths," US Patent No. 2,344,108, March 14, 1944.
	Cappel, K.L., "Motion simulator," US Patent No. 3,295,224, January 3, 1967.
	Pollard, W.L., "Robotic tool manipulating apparatus," US Patent No. 5,378,282, January 3, 1995.
	Gough, V.E. and Whitehall, S.G., "Universal tyre test machine," Proceedings of the FISITA Ninth International Technical Congress, pp. 117-137, May, 1962.
	Stewart, D., "A platform with six degrees of freedom," Proceedings of the IMechE, Vol. 180, Pt. 1, No. 15, pp. 371-385, 1965-66.

Published on: January 24, 2003

6-DOF Hybrid Parallel Manipulators With 3 Kinematic Chains

Sun, 28 Aug 2005 13:00:56 GMT

6-DOF Hybrid Parallel Manipulators With 3 Kinematic Chains

Statically-Balanced Hybrid Parallel Manipulator

Recent investigations at the Laval University Robotics Laboratory allowed the development of a 6-DOF spatial parallel platform mechanism of a new type that can be statically balanced. The mechanism consists of a base and a mobile platform which are connected by three legs using five-bar-linkages. For each leg, the two proximal links of the parallelogram are mounted using revolute joints, thus providing two degrees of freedom. In addition, the whole leg can rotate about a vertical axis, which provides a third degree of freedom for the leg. This rotation includes the mounting points of the springs at the base, so that the springs always remain in the plane of the parallelogram. The upper end of the leg is attached to the mobile platform through a spherical joint. In practice, a universal joint combined with an additional revolute joint have been used in the design of the prototype. If six of the joints are actuated, the mechanism has six degrees of freedom.

Static balancing of the mechanism was achieved by introducing additional springs in the system. For each leg, two springs are attached to the extremities of the proximal links of the parallelogram structure. The springs were designed so that the total potential energy of the system is constant for all possible configurations of the mobile platform when the manipulator is in its equilibrium state, i.e., zero actuator torques (or force) are required whenever the manipulator is at rest in any configuration. As such an architecture could find great potential as a motion simulator, and in particular as a motion base for flight simulators, thus involving large accelerations of the platform, the use of springs was preferred to the use of counterweights. Therefore, the static balancing related constraints can be fulfilled without a substantial increase of the overall inertia of the mechanism.

One of the interesting topics of research related to mechanisms of this new type is the analysis of their singularities. In this context, an analysis based on the Grassmann line geometry has proved to be very efficient, allowing simultaneously (i) the geometric characterization of all singularities of type II, and (ii) the determination of the inherent closed-form equations of the singularity loci in a very compact form. It was shown that most of the singular configurations of the 3-leg 6-DOF parallel manipulator can be reduced to the generation of a general linear complex (case 5a). Moreover, for a given orientation of the mobile platform, the singularity locus corresponding to the general linear complex is a quadratic surface, i.e., either a hyperbolic, a parabolic, or an elliptic cylinder, oriented along the vertical axis.

Finally, let us mention that the design of the prototype was optimized such that the volume of the constant-orientation workspace located inside the above mentioned critical surfaces of singularities be maximum. This guarantees no loss of controlabillity of the architecture during any trajectory tracking.

Ultra-Fast Hybrid Parallel Manipulator

The principal goal of this work was to design a 6-DOF ultra-fast spatial parallel mechanism (accelerations of at least 2g). The goal was accomplished through the use of an architecture composed of a base connected to a mobile platform by three symmetrically arranged legs. Each of the legs constitutes a 5-bar mechanism with two revolute joints at the base (the actuated joints). The above figure illustrates the architecture of this manipulator.

After an optimal design, the manipulator resulted with a workspace of approximately 30 mm × 30 mm × 30 mm, rotational capabilities of ±25 degrees in any direction, and an excellent dexterity. The manipulator was then constructed through the use of rapid prototyping.

Video Clips

The following video clips (in MPEG format) illustrate the prototype of the ultra-fast hybrid manipulator:

Demonstration of range of motion through simple manipulation (seq. 1).
	best quality `(1.6 Mb)`	medium quality `(849 Kb)`	low quality `(377 Kb)`
Demonstration of range of motion through simple manipulation (seq. 2).
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Normal operation using motors (seq. 1).
	best quality `(1.5 Mb)`	medium quality `(772 Kb)`	low quality `(319 Kb)`
Normal operation using motors (seq. 2).
	best quality `(1.2 Mb)`	medium quality `(634 Kb)`	low quality `(268 Kb)`

Parallel References - Merlet

Sat, 27 Aug 2005 13:00:51 GMT

1846 references by author

Last update:10-18-05

This small text explains the various References chapters that follow:

A parallel robot has a mechanical structure that is determined through the structural synthesis, an approach that relies on design theory and mobility analysis. See the chapters Architectures, patent and ... DOF Robot. You may also check if the considered structure has not been aleready studied (use the above link to the robots drawings).

After having chosen the structure one has to move to the design phase and to optimisation which allow one to determine the dimensioning of the robot, based on analysis that relies on criterion such as isotropy (which involves the inverse jacobian and the jacobian), workspace (authors A-L, authors M-Z) (for which we need the kinematics modeling (authors A-L, authors M-Z)), singularities (authors A-L, authors M-Z), accuracy, stiffness, static, velocity analysis, dynamics (authors A-L, authors M-Z) (may be with vibrations analysis or a l'balancing analysis of the robot), or, in other words, to perform a performance analysis

We must also take into account the hardware, such as the actuators and the passive joints.

For control (authors A-L, authors M-Z) we will need the Forward Kinematics (authors A-L, authors M-Z) to study trajectories and to plan them (motion planning) We may need also to perform a calibration of the robot.

Some parallel robots are special due to their actuation mode (binary robot or wires-driven robot) or because of their special mechanical architecture: decoupled robot with translation and orientation that can be independently controled, flexible robot, hybrid robot, mixing serial and parallel architecture, modular robot whose geometry can be changed to adapt the robot to the task at hand, redundant robot with more actuators or sensors than necessary or singular robot that are always in a singular configuration.