Robot innovation automates short production runs

VTT has developed a control system for the industrial robots used for manufacturing of single-item products that substantially cuts the setting and programming time for the robot. Thanks to the new innovations, the time required for programming a robot can now be counted in minutes at best, when earlier, using traditional programming methods, it could take an hour or more.

"The new solution significantly enhances the efficiency of productive operations and opens up new opportunities for utilising robots," says Tapio Heikkilä, Principal Scientist at VTT.

The unique features of the new control system include, for instance, the use of two force/torque sensors, when traditionally robotic systems have one or none at all. The purpose of a force/torque sensor is to recognise the pressure on the tool. In the VTT solution, one sensor is attached to a wireless control stick by which the robot can be steered through the operation step by step.

The control stick and the control system operating in real time make it possible for a human controller to work in the same working space with the robot and control the robot's movements directly using a control stick attached to the robot or the load.

When the human steers the robot from a short distance, the interaction between the human and the robot becomes easier.

"The interactive solution makes it possible to take advantage of the human observation capacity for carrying out the required task," Heikkilä says.

Thanks to the interactive system, both the teaching of new tasks and continuous paths to the robot and direct control of the robot become much faster than before. This is particularly useful in the manufacturing of test pieces and single-item products, because heavy objects and even the entire assembly process can be moved in a flexible manner.

In the traditional solution, the robot's work path is programmed slowly one point at a time, and the robot unvaryingly repeats the predefined task. Reprogramming and even minor variations in such factors as the locations of the items being handled cause immediate errors.

A solution for the internet era

Quick programming of robots and human-robot interaction will become even more important features in the industrial internet era, when flexible production and short runs are essential competitive assets for companies. Traditional hard automation meets such requirements quite poorly.

"When the customer has a versatile range of single-item products to process, efficient partial automation may be a competitive solution," Heikkilä points out.

The robot solution developed by VTT for its part boosts Finland's chances of succeeding as a manufacturing economy. The solution is suited to tasks requiring a high level of expertise, where the robot does the hard work and the people do the brainwork.

The new solution also enables service models to become more common in the industrial internet era. The data measured from the sensors of the robot can be stored in a cloud service, which makes it possible to run different analyses as a remote service. The robot's performance can also be monitored in real time through the internet.

The control solution developed can be applied to any robots with an open control interface. In practice, this means several major robot manufacturers. The solution was developed in the HEPHESTOS project within the 7th EU Framework Programme, and, in addition to robot manufacturers, VTT expects it also to interest the industry using robots and system suppliers.

The three-year HEPHESTOS project that ended in October involved nine research organisations and companies from six countries: Fraunhofer IPK, Easy-Robot and ME Messsysteme from Germany; Universidad Politechnica de Madrid from Spain; G-Robots from Hungary; Universiteit I Agder from Norway; Comau Robotics from Italy; and Jot Automation and VTT from Finland.