ROBOTICS

DEMYSTIFYING ROBOT

PROGRAMMING

Software suppliers are disproving preconceptions about robot offline programming

(OLP) being too complicated or not cost-effective. Ta n y a M. A n a n d a n reports.

20 March 2019 http://www.controlengeurope.com Control Engineering Europe

E

ven though offline

programming (OLP) has come

a long way, misconceptions

about it still linger. A lot

of robot programming in

the welding industry still is done

manually, point by tedious point,

with a teach pendant. Many still

remember the old days of robotics

that overpromised and under

delivered. Dreamers and doers

have been working to exceed

expectations.

Simulation and OLP software

has evolved and become smarter,

faster, more flexible, and reliable.

This is a new era in ease of use and

OLP software suppliers are here to

demystify the softer side of robotics.

Most simulation and OLP solution

providers will tell you it’s not one

or the other. Simulation and OLP go

hand in hand. Though the terms are

often used interchangeably, but you

can have simulation without

OLP but you cannot have

OLP without simulation.

Robot simulation is the 3D

representation of a robotic

cell or production line. It

visually demonstrates how

a robot moves along a path

or trajectory from one XYZ

coordinate to another XYZ

coordinate. It can include

multiple robots mounted

on external axes working

with multi-axis workpiece

positioners, or coordinating

on an assembly line.

All this movement and

planning, however, can get

complicated.

“A lot of customers

purchase a robot thinking it

will behave like a computer numerical

control (CNC). This is not the case,”

said Albert Nubiola, CEO of RoboDK

Inc. “CNCs are easy to program. The

workspace is properly defined. It’s

like a cube.” However, robots have

a spherical workspace, and because

of joint limits and robot singularities

(points at which a robot movement

is not mathematically predictable),

there are certain types of movements

you cannot do. OLP helps avoid errors

when programming a robot.

In robotic machining, there could

be hundreds to thousands of points,”

Nubiola continued. “Nobody would

ever be able to program that point

by point using a teach pendant. You

definitely need software to be able to

do that offline.”

Simulation can be used for a

proof of concept such as a robot

integrator’s sales tool to demonstrate

how a robotic system will perform.

With simulation, users can detect

possible collisions between the robot,

tooling, fixtures and any safety fences.

Simulation can analyse joint limits,

singularities, and reach issues. Plus,

it can reveal a host of eye-opening

issues that save time and money in

the long term. OLP uses simulation to

output robot-specific code that can

be loaded onto the physical robot

controller and run the program.

Post processors turn programming

code into a language the robot can

understand. Robot manufacturers

have their own proprietary

programming languages, which

means third-party software must be

multilingual.

When OLP makes sense

The main impetus for OLP is robot

downtime, which is the time required

to manually program a robot point by

point with a teach pendant. There also

Offline programming (OLP) software accurately simulates a robotic welding process using calibrated data for

robot kinematics, external axes, and workpiece positioners.

Courtesy: CENIT North America Inc./Robotic Industries Association (RIA)