Bin-picking robot is guided by laser profile sensor

Faude Group uses advanced technology and automation expertise to develop innovative products, such as a 'bin picking' system that uses a lightweight six-axis robot from the Danish company Universal Robots and a 2D vision sensor from Leuze electronic.

The robot, which weighs just 18kg, can place components weighing up to 5kg within a working radius of 850mm with a repeatability of +/-0.1mm and with the correct orientation. Faude calls the robot system FIPS, with the initials standing for excellence in Flexibility, Intuitiveness, Price and Safety. And the company says that a FIPS system can be commissioned within a few hours.

To create a 'bin picking' system, Faude gave the robot the ability to detect automatically the components, combining its Flexvision image processing system with Leuze electronic's LPS 36 (Line Profile Sensor). The sensor provides 2D cross-sectional profiles ('slices') across the tray, which the vision system constructs into a 3D image of the tray and its contents. Another way of visualising the LPS36 sensor is that it is equivalent to a chain of 376 optical laser distance measurement sensors working together to scan a 600mm long line, calibrated the moment it is switched on.

3D vision libraries

Faude's Flexvision system is described as an intuitive, high-performance image-detection and processing system that has been developed for industrial use. The modular design uses the HALCON 3D vision libraries, available for the LPS 36 from MVTec Software, to make the image processing system very versatile. This image acquisition interface can easily be operated with the HALCON image processing software to provide simple detection of equidistant 3D data, or profile 'slices' from the sensor. The measurement data from the LPS 36 of complex 3D applications such as object measurement can be read and further processed so that volumes can be calculated and the position of three-dimensional objects determined, thereby saving users the time-consuming tasks of carrying out software developments and programming their own algorithms.

The LPS sensor offers measurement of dimensions or object positions at a price level that is claimed to be well below camera-based vision systems and without the complexity of other multiple-sensor systems that combine sensors with additional evaluation units. The application at Faude shows how the sensor enables the robot to detect automatically which component it can grip best utilising the height information from the sensor to calculate the position in the third dimension. An additional real-world advantage of the LPS sensor over many camera-based vision systems is that its laser line detection system makes it robustly independent of changes in ambient light.

According to Faude, the system benefits from the low weight of the robot and the sensor, its simple installation and configuration and the key competitive advantage of having a low price of about EUR38,000. Dieter Faude, Managing Director of Faude Automatisierungstechnik GmbH (one of the top 100 companies in Germany in 2009), states: "This intelligent automation system satisfies current market requirements with regard to flexibility, simple operation, process reliability and productivity."

The efficient integration of the robot, the image processing and Leuze electronic's sensor provides such reliable pattern detection and position determination that Faude demonstrated the unit at MOTEK, the international trade fair for handling, assembly and automation technology in Stuttgart, and Leuze electronic displayed one of the systems operating on its stand at the SPS exhibition.