根域营养雾滴的粒径及时空分布是决定雾培效果甚至成败的最关键因素。针对目前国内外雾培系统"粗放式"喷雾现状，项目将开展雾培系统的根域雾场最优调控机理研究。①项目原创性地提出有势力场低频超声二次雾化原理，研究有势力场下的营养液二次雾化机理，以实现营养雾滴尺寸广谱、精密调控，突破传统超声雾化栽培系统难以调节营养雾滴大小以及难以生成小于1微米超细营养雾滴的两个技术瓶颈。②针对目前国内外雾培系统喷雾调控技术的不足，提出基于超声直线步进电机技术的茎直径微变化测量原理，建立基于混沌算法的茎秆微位移实时数据处理数学模型，以茎直径微胀落位移计算作物的叶水势，以作物的叶水势确定喷雾量和喷雾时间，实现以作物实时需水信息为判断依据的雾培精准喷雾调控。通过以上研究，探明雾培系统根域雾场最优调控机理，从而实现雾培系统的雾场最优调控。

Nutrition droplet size 、space and time distributions in root zone are vital factors to decide aeroponic efficiency even success or failure. To counter the "crude atomizition" situation of aeroponic system currently, a study on optimal atomization control principle in low-frequency ultrasonic aeroponic system will be conducted in this project.In order to realize broad pectrum controlling nutrition droplet size precisely,the principle of low-frequency ultrasonic dual-atomiztion in potential force field will be originally proposed to study the low-frequency ultrasonic dual-atomiztion mechanism of nutrition droplet. This study will be expected to break through the bottlenecks of hardly generating ultra-tiny droplet whose dimameter is less than 1 micrometer in aeroponic system.The measurement principle of micro-variations in plant stem diameter based on ultrasonic linear motor will be proposed to improve spraying accuracy and efficiency in aeroponic system.The micro-variations in plant will be processed based on a real time chaos mathematical model. The micro-variations processed by chaos model will be used to calculate water potential changes in plant. Based on those water potential changes,spraying time and volume will be decided in this project. Based on above work, the optimal atomization control principle may be proved and optimal atomization control in low-frequency ultrasonic aeroponic system may be realized.