8/12/2019 Lec02 Manipulators
1/7
Lecture 02
Industrial Robot Manipulators
Prof. Rohan MunasingheDepartment of Electronic and Telecommunication EngineeringUniversity of Moratuwa 10400
Industrial Applications of Robots
Paletizing / Unitizing in warehouses
Laser cutting
Palletizing.dat
rc we ng po e ng
Assembly lines
List goes on ..Laser Cutting.dat
Arc Welding.dat
Spot Welding.datAssemblyt.dat
.
Industrial Robot Manipulators IFR Def: An automatically
controlled, reprogrammable,multipurpose manipulatorprogrammable in three or moreaxes, w c may e e t er xe n
place or mobile for use in industrialautomation applications
Robot manipulators consists of rigidlinks, which are connected throughoint actuators that create relative
In robotics, constant
motion of neighboring links. Joints
are attached with sensors that readjoin position and speed
mon or ng o pos onsand orientations ofmanipulator links, tools,objects it handles, andother objects in thevicinity is essential
Joint Primitives Describes how adjacent links are connected to each other
Two primitive joint types
Prismatic (sliding) joint : Pair of links makes a.
slides on the other along a straight line Revolute (rotary) joint : Two links rotate about a fixed
axis. This type of joint is often referred to as a hinge,articulated, or rotationaljoint
Man useful mechanisms for robot mani ulation andlocomotion can be designed by combining these primitive
joints.
8/12/2019 Lec02 Manipulators
2/7
Serial Link Manipulators
Most of the industrial robots are serial combinations ofrevolute and prismatic joints.
The most fundamental functional requirements for a robotic
sys em s o e a e o oca e s en -e ec er an , oo , orend-device), in 3D space, with respect to the world co-ordinate frame
Following types of robot mechanisms are available:
Cartesian co-ordinate robot
-
Spherical co-ordinate robot
SCARA robot
Articulated robot
Cartesian Co-ordinate Robot PPP: three prismatic
joints indpendentlyadjust the three co-ordinates (x,y,z) of theend-effector osition
Applicationspick and place applications (where eitherthere are no orientation requirements orthe parts can be pre-oriented before therobot picks them up such as surfacemounted circuit board assembly), position
CrocRobot.dat
a w e var e y o en -e ec ors suc as:
automatic screwdrivers, automatic drills,dispensing heads, welding heads, waterjetcutting heads and grippers, materialhandling applications such as pick andplace, machine loading and unloading,stacking, unitizing, palletizing, and co-ordinate measuring devices
Cylindrical Co-ordinate Robot RPP
R(spans a cylindricalworkspace)
P(adjusts the height)
Sands Technology, R19
CrocRobot.dat
Spherical Co-ordinate Robot RRP: called as polar co-ordinate
robot
R (horizontal swing)
R vertical swin
P (radius).
.
8/12/2019 Lec02 Manipulators
3/7
SCARA Robot SCARA: Selective Compliant
Assembly Robot Arm
No analogy with commoncoordinate systems, however, it
CrocRobot.dat
s use u n ocat ng t e en -effecter in space, and it hassalient features desirable forspecific tasks.
Assembly automation in manufacturingsystems, having a wide workspace in thehorizontal direction and an independentvertical axis appropriate for insertion of parts
Articulated Robot RRR (all rotary) known as Elbow Robot
Great amount of flexibility, manipulatability, and versatality
.
Precision
Robot Type HorizontalPrecision
VerticalPrecision
Cartesian Uniform Uniform
y n r ca ecreaseradially
n orm
Spherical Decreaseradially
Decreaseradially
SCARA Varies Uniform
Articulated Varies Varies
Parallel Linkages Joints are constrained with each other
Possesses active joints as well as passive joints
Complex, mechanisms, yet provide some useful behaviors
be passive joints, which are
free to rotate. Only two jointsshould be active joints, drivenby independent actuators
Closed kinematic chain is formedby five links and, thereby, the twoserial link arms must conform to
a certain geometric constraint.End-effecter position isdetermined if two of the five jointangles are given.
The robot arm can be made lighter by placing both actuators at the base. A largerload at the end-effector can be born with the two serial linkage arms sharing the load
8/12/2019 Lec02 Manipulators
4/7
Stewart Mechanism Consists of a moving platform, a fixed base, six prismatic
joints connecting moving platform to the base
The position and orientation of the moving platform aredetermined by the six independent actuators
The load acting on themoving platform isborn by the six "arms".Therefore, the loadcapacity is generally
CrocRobot.dat
arge, an ynam c
response is fast
Degrees of Freedom
Degrees of Freedom: is the number of independent positionvariables that would have to be specified in order to locateall parts of the mechanism
In open kinematic chains, where each joint contributes a
End-Effector
single joint variable (joint angle or link offset), number ofdegrees of freedom is equal to the number of joints
At the end of the manipulator is the end-e ec or. cou e a gr pper, a we ng
torch, electromagnet, or any othertool/device that is required to perform theintended task
Manipulator Control System
Controller calculates at each loop, the torque commands for joint actuators.loop time is usually 2~10ms
Calculated torque commands are sent to the individual joint servo controllers
Manipulator Control System
JointTrajectory(pos, vel)
Robot ControlRobot Arm
u(k)
ABBI
RB6
640
CTM, PID, etc
Robot Armmotion
(pos, vel)
TrackingPerformanceEvaluation
ynam cModel
ref
ref (k-1)
8/12/2019 Lec02 Manipulators
5/7
8/12/2019 Lec02 Manipulators
6/7
Usage of Industrial Mnipulators
Altogether 1million
industrial robots
are in the world
Japan records highest
density (10 times the
average)
Asian
Europe is the regional epicenter of industrial robots
Data: International Federation of Robotics and Intl Labor Organization
21
Industrial Robots: Recent Statistics
Data: International Federation of Robotics and Intl Labor Organization
22
Growth of Market Worldwide stock of operational industrial robots
at the end of 2011 was in the range of 1,153,000and 1,400,000 units. Value of the market ofrobotsystems (HW/SW+) was up to US$25.5 billion
166,02838%
Distribution Among Industries Usage of industrial robots
8/12/2019 Lec02 Manipulators
7/7
Usage Trend in Regions Factory Roboticization is Demanding
The major reasons for the increasing demand for factoryroboticization are:
Declining cost of robots and increasing cost of humanlabor
Robots continue to getting speed, accuracy, capability,and reprogrammability for a variety of jobs (welding,painting etc.)
Deployability of robots for tasks that might be dangerous,or impossible for human workers to perform (space,undersea, radioactive sites)
Robots and Automatic Machines
Small volumes use human labor volume [v1,v2] use robots volume > v2 hard automation
The distinction between a robot and a factory machine (such
as NC machines) lies in the programmability of the device.Robots can be re-programmable to perform a wide variety oftasks, whereas factory machines, which are generallylimited to one class of tasks (fixed automation)
Recommended