Improved path guidance of feed drive axes by means of an inertia-based momentum actuator at the machine table (IMPULS)

• Applicant: Professor Dr.-Ing. Alexander Verl
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 391879683

Feed drives in machine tools create relative paths between tool and workpiece by executing a programmed motion sequence. Typical requirements are to keep the given geometry within a given tolerance limit at constant path velocity. However, limited motor power and structural compliance of the machines require a limitation of accelerationand jerk. Profiles that include velocity steps therefore cannot be planned with constant path velocity.Within the first funding period of the research project a hybrid approach to overcome such limitations was investigated. An inertia-based actuator is attached to a machine table and transmits a defined impulse to the table by mechanical impacts. This allows abrupt changes of the feed rate with negligible reaction force on the structural components. In the first step, the implementation was initially carried out on one axis of a cross table with linear direct drives.Within the course of the second funding period, the concept is to be transferred to the second axis, which will allow new questions to be posed in addition to the previous investigations, such as the effects on the other axis in operation with impulse actuators or an application with significantly larger masses. For ongoing research, the mechanical structure in the second, heavier axis is therefore to be extended by an impulse actuator, the existing setpoint generation and control are to be adapted and the simulation model is to be adjusted with the real test rig. In addition to the validation of the concept on the new, heavier axis, the focus will be on multi-axis operation, in which the actual corner profile will be realized. Furthermore, in addition to the tracking error of the individual axis, the actual path deviation from the target profile can be analyzed and optimized.

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Armin Lechler