Synchronization optimization on dual-axis systems by variable gain cross-coupled controller

Fast and accurate trajectory control is fundamental for modern machines such as CNC machinery, pick and place robots, path following unmanned vehicles and gantries. For one axis, satisfactory trajectory control can be accomplished easily. But for multi-axis systems, getting adequate trajectory control and low contour error can be tricky. Friction, inner or inner disturbances, gear backlash, servo lag can cause uncoordinated motion which will lead inter-axial uncoordinated motion and contour error. In many cases, lowering or controlling unwanted effects by individual control techniques cannot be enough to get required accuracy. Excelling coordinated motion requires a comprehensive and structural approach. In this thesis, a two-axis system is introduced and different trajectories such as linear, circular, elliptic and parabolic trajectories are followed. Then proposed method is applied for eliminating contour error by variable gain cross-coupled controller. Control structure's block diagram and variable gain calculation steps are explained comprehen-sively. Finally, suggested structure is simulated under friction, inner disturbance and both friction and inner disturbance simultaneously. Results indicate proposed systems' efficiency to increase inter-axial coordination and decrease contour error.