Study on Interpolation Principle and Method for 1PS+4TPS Type Hybrid Machine Tool

This paper presents a novel hybrid machine tool (HMT) based on a 4-dof 1PS+4TPS type spatial hybrid mechanism and a x-y worktable. This type HMT enjoys some advantages relative to its conventional counterparts: large workspace, good dexterity, etc. Closed-form solutions for both the inverse displacement model and inverse kinematic model are derived. A computerized numerical control (CNC) system scheme for motion control of HMTs is proposed focusing on motion control characteristics of HMTs and based on research fruits of traditional numerical control machine tool. Real-time five-axis interpolator, which is composed of cutter path calculation, inverse displacement analysis model, inverse kinematic analysis model and PVT fine interpolation mode, are constructed. Cutter path interval calculation and interpolate error analysis are also discussed, Feasibility and efficiency of above real-time interpolator are confirmed by numerical examples.