Machine Vision Drives Smart Robot Assistant

Due to the industry standard 4.0, digitalization, automation and networking of systems and facilities are becoming the predominant topics in production and thus also in logistics. Industry 4.0 pursues the increasing optimization of processes and workflows in favor of productivity and flexibility and thus the saving of time and costs. Robotic systems have become the driving force for automating processes. Through the Internet of Things (IoT), robots are becoming increasingly sensitive, autonomous, mobile and easier to operate. More and more they are becoming an everyday helper in factories and warehouses. Intelligent imaging techniques are playing an increasingly important role
in this.

To meet the growing demands in scaling and changing production environments towards fully automated and intelligently networked production, ONTEC Automation GmbH from Germany has developed an autonomously driving robotic assistance system. The ‘Smart Robot Assistant’ uses the synergies of mobility and automation: it consists of a powerful and efficient intralogistics platform, a flexible robot arm and a robust 3D stereo camera system from the Ensenso N series by IDS Imaging Development Systems.

The solution is versatile and takes over monotonous, weighty set-up and placement tasks, for example. The autonomous transport system is suitable for floor-level lifting of Euro pallets up to container or industrial format as well as mesh pallets in various sizes with a maximum load of up to 1,200 kilograms. For a customer in the textile industry, the AGV (Automated Guided Vehicle) is used for the automated loading of coil creels. For this purpose, it picks up pallets with yarn spools, transports them to the designated creel and loads it for further processing. Using a specially developed gripper system, up to 1000 yarn packages per 8- hour shift are picked up and pushed onto a mandrel of the creel. The sizing scheme and the position of the coils are captured by an Ensenso 3D camera (N45 series) installed on the gripper arm.

For this task, the mobile use for 3D acquisition of moving and static objects on the robot arm, the Ensenso 3D camera is suitable due to its compact design. The Ensenso N 45’s 3D stereo electronics are completely decoupled from the housing, allowing the use of a lightweight plastic composite as the housing material. The low weight facilitates the use on robot arms such as the Smart Robotic Assistant. The camera can also cope with demanding environmental conditions. “Challenges with this application can be found primarily in the different lighting conditions that are evident in different rooms of the hall and at different times of the day,” explains Tim Böckel, software developer at ONTEC. Even in difficult lighting conditions, the integrated projector projects a high-contrast texture onto the object to be imaged by means of a pattern mask with a random dot pattern, thus supplementing the structures on featureless homogenous surfaces.

The matching process empowers the Ensenso 3D camera to recognize a very high number of pixels, including their position change, by means of the auxiliary structures projected onto the surface and to create complete, homogeneous depth information of the scene from this. This in turn ensures the necessary precision with which the Smart Robot Assistant proceeds. Other selection criteria for the camera were, among others, the standard vision interface Gigabit Ethernet and the global shutter 1.3 MP sensor. “The camera only takes one image pair of the entire pallet in favor of a faster throughput time, but it has to provide the coordinates from a relatively large distance with an accuracy in the millimeter range to enable the robot arm to grip precisely,” explains Matthias Hofmann, IT specialist for application development at ONTEC. “We therefore need the high resolution of the camera to be able to safely record the edges of the coils with the 3D camera.” The localization of the edges is important in order to be able to pass on as accurate as possible the position from the center of the spool to the gripper.

For more information: www.ids-imaging.de