Task space control of ram poses of multipoint Servo Presses

Robotic manipulators are known for their numerous degrees of freedom with which they can manipulate objects in task space. With the help of model-based control concepts, it is possible to precisely closed-loop control their pose, thus meeting high positioning accuracy requirements. As a result, they are ideally suited for carrying out flexible activities in manufacturing processes in which freely programmable tool paths are required, such as pick and place, welding or assembly tasks. If high forces have to be applied in manufacturing processes, as is the case in bulk forming processes, robots can no longer be used due to low stiffness and moderate force provision. The development of flexible forming machines with several degrees of freedom overcomes this problem. Machine tools such as the 3D Servo Press have three ram degrees of freedom and can provide forces of up to 1600 kN, but require highly accurate position control in task space. For this reason, this paper shows how control concepts from robotics can be applied to machine tools with high stiffness, high provided forces and multiple degrees of freedom. The functionality of the control is validated using the example of upsetting tests in which off-center forces are applied to the ram and the control counteracts tilting of the ram.