Real-time machine simulation using cutting force calculation based on a voxel material removal model

Machining processes must be adjusted regarding tolerances in dimension and shape to fulfill product requirements. For this purpose, machine simulations are used to allow a preliminary characterization of the given process, thus minimizing the number of physical prototypes and scrap parts. However, these simulations are either extremely specialized for single problems, e.g., dynamic machine behavior, or they are simplified to a kinematic simulation of the machine without considering the machine behavior at all. This article presents a new approach for a real-time machine simulation by combining four types of simulations to close this gap. This proposed approach uses a voxel-based material removal inside a kinematic machine simulation as input parameters for a cutting force calculation. Afterwards, the forces are applied to a multi-body simulation of the static machine behavior. Starting point of the simulation is a hardware-in-the-loop coupling of a real CNC and a real-time visualization of a virtual machine tool. The simulation is experimental verified by comparing the simulated cutting forces and displacements with the measured forces during the process and the resulting shape of the manufactured work piece. The presented conclusions show the general applicability of the proposed method for the simulation of milling processes.