Page 31 - Welding Robots Technology, System Issues, and Applications

Introduction and Overview

some lack of interest from the robot manufacturing industry. Nevertheless, there
was a considerable evolution that can be summarized as follows. 15

In 1974 the first electrical drive trains were available to use as actuators for robot
joints. In the same year the first microprocessor controlled robots were also
available commercially.

Around 1982, things like Cartesian interpolation for path planning were available
in robot controllers, and many of them were also capable of communicating with
other computer systems using serial and parallel interfaces. In the same year, some
manufacturers introduced joystick control, for easier programming, and teach
pendant menu interface.

In 1984, vision guidance was introduced as a general feature being used for
tracking, parts identification, etc.

In 1986, the first digital control loops were implemented enabling better actuator
control and enabling the use of AC drives.

Networking is a feature of the 1990s with several manufacturers implementing
networking capabilities and protocols.

In 1991 there was the implementation of digital torque control loops which
enabled, for example, the utilization of full dynamical models, which was a feature
available in the first robots around 1994.

During the period 1992-1994 several manufacturers introduced features like
Windows-based graphical interfaces, virtual robot environments for off-line
programming, and fieldbuses.

Robot cooperation is a feature introduced from 1995 to 1996.

Figure 1.7. Several current robot manipulators available on the market

Around 1998 robot manufacturers started introducing collision detection to avoid
damaging robots, and load identification to optimize robot performance. Since then
other features include fast pick and place, weight reduction, optimized