- 學位論文
壓電蜂鳴片致動器與環形磁陣列霍爾感測器於三軸定位系統之開發探討
Design and Development of A Three-Axes Positioning System Using Piezo-Buzzer Actuators and Hall Sensors with Magnetic Ring Array
摘要
精密定位系統被廣泛地運用於掃描探針顯微術(Scanning Probe Microscopy, SPM)以及奈米尺度加工等領域。精密定位系統提供工具或工件精確的位移控制。除了追求定位範圍和解析度的提升外，將致動器與感測器更緊緻地整合在一起亦成為其擴展在更緊密系統運用範疇的關鍵議題。 因其體積小、高致動解析度和高動態的特性，壓電元件為目前最被廣泛使用的精密致動元件。為了讓我們開發的定位系統以更為經濟化的方式實現，普及且低價之壓電蜂鳴片被用來開發精密致動器以取代昂貴的進口元件。透過慣性滯滑原理，壓電蜂鳴片驅動精密螺旋機構產生長行程且高解析的致動位移。為了緊密整合和避免負载效應，霍爾元件和微小永久磁石被採用來實現非接觸式增量式位移的量測。 本論文開發的三軸精密定位系統由三組致動器和位移感測器建構而成，可分別產生X軸、Y軸方向的位移以及Z軸方向的旋轉。透過我們精心構思的交叉架構概念讓三軸致動器和感測器都能配置在同一平面上，有效地壓縮系統高度使其能應用於掃描探針顯微鏡上進行量測樣品的定位致動。 三軸精密定位系統X和Y兩軸方向總行程達5 mm，最小平均步進量為0.53 nm，往復步進量差異為0.03 nm，θ軸方向總角度行程360度，最小平均步進角度0.25度。低於共振頻2 kHz，平均步進量隨頻率增量而提升。環形磁陣列霍爾感測器於線性位移量測解析度可達10 nm，角度位移量測解析度可達0.02度。線性致動器的最大驅動力是150 gf (=1.5 N )。
並列摘要
Precision positioning systems are extensively used in Scanning Probe Microscopy(SPM), nano-scale processing system and other domains. Precision positioning systems provide precise position control for tool or work piece. Besides the pursuit of long-stroke and high-resolution, the intensive integration of actuator and sensor becomes key issue for widening application fields in more compact systems. Because of its small size, high actuation resolution and high dynamic characteristics, the piezoelectric element becomes the most widely used component of precision actuators. In order to realize our developed economical positioning system, the popular and inexpensive piezo buzzer is chosen to develop precision actuators instead of using expensive imported piezoelements. Through the inertial stick-slip driving principle, the piezo buzzer tangentially and reciprocally drives the precision screw mechanism to induce long-stroke and high resolution motion. For enhancing compact integration and avoiding loading effect of displacement senor, the Hall sensor and tiny magnets are utilized to develop noncontact incremental displacement measurement. The three-axis positioning system developed in this thesis consists of three sets of actuators with displacement sensors, which produce X-axis, Y-axis and Z-axis rotational displacements, respectively. Through our developed ingenious cross structure concept, three sets of actuators with sensors can be well configured on a same plane, thus effectively shrinking the system height to be adapted to any SPM-system for positioning measured sample. The maximum stroke for the X-axis and Y-axis actuators is 5 mm, and its average minimum step is about 0.53 nm, and its reciprocal step error is 0.03 nm. The maximum stroke for Z-axis rotational actuator is 360 degree, and its average minimum angular step is 0.25 degree. Below the resonance frequency of 2 kHz, the average step increases in proportion to frequency increment. For the Hall Sensor with the magnetic ring array, the linear displacement measurement resolution reaches 10 nm, and the angular displacement measurement resolution is about 0.02 degree. The maximum driving force of the linear actuator is 150 gf (=1.5 N ).