The use of robots offers the possibility of flexible automation of production by reprogramming the robot used after process or product changes. However, ever greater flexibility is required to ensure competitive production, especially for small series assembly. However, conventional robot programming systems are complex to operate and place high demands on personnel qualifications. With this in mind, a concept for intuitive and simple robot programming was developed. It offers the possibility of reducing the time required to create an executable robot program for complex assembly tasks and the robot knowledge requirements of the programmers.

The concept developed uses an intuitive demonstration approach to simplify the programming of assembly tasks. Instead of conventional approaches, the assembly tasks are entered into the robot program by demonstrating the tasks. In so-called "programming by demonstration", the demonstration is completed without the use of a physical robot system. In order to realize such an approach, the human-machine interaction during programming, including the user's input and feedback, and the operation of the user interface, must be designed to be as intuitive and simple as possible. This is why gestures are used for input. For feedback, the assembly tasks to be programmed are displayed spatially in 3D using augmented reality. This allows programming to be carried out intuitively and flexibly in terms of location. The user interface in the AR environment is customized by the user for virtual assembly planning. This allows assembly tasks to be created or reproduced quickly and easily. The demonstration environment is created with the geometric models of the products and their assembly data.

The information is taken directly from the product development process in the form of CAD data. Standard exchange formats, such as STEP, are used for this purpose. Once the data has been imported, the assembly task is carried out using the digital model. The worker carries out the assembly process in the AR environment. The worker's experience flows directly into the assembly planning. The recorded assembly process is then segmented into sub-steps and an exportable task sequence file is created. The generated task sequence file contains an assembly process that has already been optimized based on the employee's experience, as well as all relevant data for the automatic creation of the robot program. The automatic creation of the robot program is based on a process library and uses predefined templates that are optimized for the robot used. Any inaccuracies in the recognition of the assembly movements are eliminated by a safety comparison with the CAD data. The generated robot program is simulated in the AR environment, validated by an expert and released. Only approved programs are executed by the robot controller. This ensures consistent safety.

The approach developed increases the flexibility of robot use. It also reduces the effort and complexity of robot programming.

The programming concept developed was implemented on a demonstrator that performs the assembly tasks. When operating the demonstrator, the user can independently program a robot for assembly tasks by manually moving and assembling the virtual components of an assembly. This helps the user to generate the robot programs intuitively and quickly and avoids the disadvantages of conventional programming systems.

Wenchao Zou, Marlon Lehmann/as

Chair of Automation Technology at the BTU Cottbus-Senftenberg © BTU Cottbus-Senftenberg

Briefly explained:The Chair of Automation Technology
Since the appointment of Prof. Dr.-Ing. Ulrich Berger in 2001, the Chair of Automation Technology at the BTU Cottbus-Senftenberg has been involved in research and teaching on the planning, programming and experimental validation of automated production systems.
His work focuses on model-based control design, simulation-based design and prototype development of robot-supported machines and systems as well as interdisciplinary research into the interaction between man and machine in an operational environment.

MHI e.V. © MHI e.V.

Briefly explained: The MHI e.V.
The Wissenschaftliche Gesellschaft für Montage, Handhabung und Industrierobotik e.V. (MHI e.V.) is a network of renowned university professors - institute directors and chair holders - from German-speaking countries. The members conduct both fundamental and application-oriented research on a wide range of current topics in the fields of assembly, handling and industrial robotics. Further information on the society, its members and activities: www.wgmhi.de.