Research work and workshops on the delta robot
Within the framework of a long-term cooperation with the Institute for Mechanism Theory, Machine Dynamics and Robotics, research and development work on the topic of further development of the delta robot of the industrial partner with associated advanced training and workshops was carried out. This work concerned both the side of the control system and the mechanics of the delta robot in terms of performance and cost. Through training and workshops, methods, software tools as well as algorithms and calculation bases have been established with the industrial partner on a sustainable basis.
In order to create a common knowledge base, an intensive exchange of knowledge regarding the theoretical kinematics, useful calculation tools and applied robot operation was carried out at the beginning of the research cooperation. In order to carry out research work, a test bench for a delta structure was developed, set up and put into operation at the IGMR. The first step was to show the physical limits of the system by means of optimized movements that were preset by the controller.
The specification of an optimized movement could visibly improve the robot's motion behavior. For this purpose, the control unit has been adapted so that it can independently generate the new and improved movement. A new software module has been developed for this purpose, which contains the kinematic transformations as well as the optimization algorithms. Fast calculations and time-optimized data processing are key targets.
Metrological path comparison
In order to increase accuracy and reduce vibrations during movement, structure-specific properties can be taken into account in motion planning. For this purpose, kinematic and dynamic analyses have been carried out. In this context, a position control system with speed and torque feedforward control and error compensation for elasticity and backlash have been tested on the IGMR test bench and implemented on the existing overall system.
The optimization of the mechanics has the goal of adapting the kinematics and component dimensioning or component tolerance in such a way that the dynamics and accuracy are increased and the manufacturing costs are reduced. By means of analysis and synthesis steps, the influences of the individual components of the robot were investigated and optimized in a targeted manner. A kinematic calibration of the robot enables manufacturing and assembly inaccuracies in the assembled state to be mathematically and metrologically identified and taken into account in the control system. In this way, the accuracy of the entire system can be improved and costs saved in spite of greater component tolerance.
In addition, in the course of peripheral optimization, it is advisable to consider adjacent components influencing the handling process in order to further optimize the overall performance of the system. These include, for example, investigations on the grippers used, which influence the non-productive times of the gripping process, or further improvements to the frame and robot suspension. If necessary, packaging logistics planning can also be adapted to the modified robot's motion planning in order to achieve a higher overall performance.
Potential in path design