Control Matrix And The Experiment Of A Multi-DOF Micro Positioning Platform Driven By PZT Actuators

Micro position mechanisms refer to those mechanisms who have small journey (less than millimeter order), high precision (sub-micron order or micro millimeter order) and high sensitivity. It's one of the key components of fine mechanics and precision instrument. It can be used as fine control component and static state error compensation or dynamic error compensation component. Lots of high-tech fields depend on micro position technique. Since piezoelectric micro position technique has a great deal strongpoint, it is turning into study hotspot both here and abroad.Base on the research of existing micro position technology, a new technique of multi DOF (degree of freedom) micro position with PZT actuators has been put forward and studied in this paper. The author studied the principle of micro position and created the position control matrix. Multi PZT actuators have been distributed spatially in order to realize three-dimensional shifting and three-dimensional tilting. Nine PZT actuators are distributed among four platforms, and in each layer there are three PZT actuators placed on the vertexes of an equilateral triangle. In terms of the positioning demand to the worktable, the strain of each PZT actuator can be worked out. So, the worktable can realize six DOF micro position by controlling each PZT actuator.Experimental characteristics of PZT actuators were studied and the methods of reducing PZT actuators' error were brought forward.Six DOF micro positioning system with PZT actuators was designed. PZT actuators, inductance sensor, A/D, computer, D/A and power supply were integrated into a experiment micro positioning system. Control software was programming with Visual Basic 6.0.The new technique of multi DOF (degree of freedom) micro position with PZT actuators has no interference with each direction, so the cross coupling error can be reduced to neglectable order of magnitude. The micro positioning system was integrated and it can carry out six DOF micro position highprecisionly. It provides practical new technique for high-tech field such as MEMS and optical communication.The experiment has verified the principal and system of multi DOF micro position with PZT actuators. Advice of improvement and prospect of the next stage study are also presented in this paper.