水下滑翔机纵垂面变浮力过程建模与控制优化

Modelling and Control Optimization for Underwater Gliders of Variable Buoyancy Processes in Vertical Plane

基于国产水下滑翔机“海燕-Ⅱ”的结构特点和控制特征,考虑不同深度下的海水密度和压强对水下滑翔机运动的影响,建立了一种精确的水下滑翔机动力学模型。该模型将水下滑翔机的前后导流罩和其他可浸水部分的海水质量作为水下滑翔机本身质量的一部分,并将水下滑翔机的回排油过程作为变质量过程,将海水的深度变化对其浮力的影响过程作为变浮力过程。此外,将电池包的前后移动量作为控制输入量、俯仰角作为控制输出量对该模型进行数值仿真,并结合南海海试数据与仿真结果进行对比,结果验证了该模型的有效性。最后,基于该模型以滑翔角作为控制变量,采用PID控制器进行数值仿真,结果表明通过该优化控制策略能显著提升水下滑翔机的运动性能。

Based on the configuration and control characteristics of Petrel-ⅡUG,an accurate dynamics model of UG was established considering the influences of seawater density and pressure at different depths on UG motion.The seawater mass immersed into the front and rear noses of UG was viewed as part of the mass of UG.The model took the variation process of oil of UG as variable mass process,and the influences of seawater depth on the buoyancy as the variable buoyancy process.Besides,the model was numerically simulated for forward and back movements of battery pack as input parameters,and the pitch angles were adopted as output control parameters.Then simulation results were compared with the sea trial data collected in South China Sea.And the results demonstrate the validity of the model herein.Finally,the PID control simulation was conducted with a gliding angle as a control variable based on the model,and the results show that the motion performance of UG may be enhanced by the optimal control strategy.