STATE SPACE MODELING OF DIMENSIONAL MACHINING ERRORS OF SERIAL-PARALLEL HYBRID MULTI-STAGE MACHINING SYSTEM

The final product quality is determined by cumulation,coupling and propagation of prod- uct quality variations from all stations in multi-stage manufacturing systems(MMSs).Modeling and control of variation propagation is essential to improve product quality.However,the current stream of variations(SOV) theory can only solve the problem that a single SOV affects the product quality. Due to the existence of multiple variation streams,limited research has been done on the quality con- trol in serial-parallel hybrid multi-stage manufacturing systems(SPH-MMSs).A state space model and its modeling strategies are developed to describe the multiple variation streams stack-up in an SPH-MMS.The SOV theory is extended to SPH-MMS.The dimensions of system model are reduced to the production-reality level,and the effect and feasibility of the model is validated by a machining case.