Stäubli Robotics Division Manager Peter Pühringer sums up what lies behind this pioneering concept: "We deliberately did not want to develop lightweight robots with limitations in terms of payload and speed for pure HRC applications. Instead, the aim was to make our standard robots fit for interaction with humans while retaining their full performance capabilities. And with the use of the latest safety technology, we have succeeded."

But first things first: At first glance, the three new model series TX2-40, TX2-60 and TX2-90 look like "normal" industrial robots. The six-axis robots, which cover the payload range from two to 15 kilograms with reaches of 515 to 1,450 millimetres, are very compact and are therefore suitable for use in confined spaces. And, of course, the new machines are lighter, stiffer and more powerful, making them even more dynamic and precise and, thanks to a variety of measures, also more energy-efficient.

Safety technology makes all the difference
However, the crucial difference to conventional industrial robots lies in the safety technology. Groundbreaking safety functions have been successfully integrated here. And it is precisely this safety package that enables the manufacturer to open a new chapter in human-machine cooperation with the world's fastest Safe Robots.

The six-axis units have their own digital safety encoder per axis and an integrated safety board. All safety functions are TÜV-certified and meet the strict requirements of the SIL3-/PLe category. To ensure maximum safety, every movement of the robot is monitored by sensors. All of the robot's coordinates, speed and acceleration are recorded in real time. For the TX2 series, Stäubli relies on configurable, safe I/O modules and real-time Ethernet fieldbus systems that guarantee maximum safety and compatibility. These functions enable the highly dynamic robots to work together with humans.

With their overall performance, the TX2 robots are designed to contribute to higher productivity and efficiency in both standard applications and HRC applications. © Stäubli

From robot to cobot with Air-Skin
The automotive industry in particular is increasingly seeing applications in which direct interaction between man and machine without a safety fence is a prerequisite for innovative production concepts. "In order to be able to operate these applications, the robots must comply with the applicable safety regulations for the highest HRC level. To this end, we are modifying the TX2 standard robots. The most obvious change is the new air skin, which turns the six-axis robot into a cobot under the name TX2touch," says Pühringer.

This touch-sensitive skin, which complies with safety category 3 PLe, stops the robot immediately in the event of a collision. The new air skin consists of several pads that can be replaced individually if damaged. The design with air cushions under the skin ensures that the robot does not overheat and can be operated at high speed without limiting its service life.

The reaction time of the skin is just ten milliseconds, which means a speed increase of 40 percent compared to safety sensors with a reaction time of 80 milliseconds. The new skin is also available with a thickness of 20 millimeters, which literally provides a larger safety cushion and therefore allows driving at higher safespeeds.

According to the manufacturer, this skin makes the TX2touch the fastest and safest cobot on the market. "Unlike most lightweight robots, the stop function is PLe-compliant. This makes the robot perfect for all applications with direct human-machine interaction," promises Pühringer.

With all the innovations in the area of safety, Stäubli is relying on the tried and tested on the mechanical side: the new six-axis robots have the typical closed structure with protection class IP65, the wrist is even IP67 and therefore waterproof. The TX2 series is therefore predestined for use in demanding cleanroom conditions as well as for applications in harsh environments such as parts cleaning. All six-axis robots of the TX2 generation have an optional vertical cable feed-through on the robot base and can be mounted on the floor, wall or ceiling. Ralf Högel/as