一种AUV并联型矢量推进机构的姿态控制算法

Attitude control algorithm for a 2 DOF parallel vector propulsion mechanism on AUV

摘要:

为克服一些AUV矢量推进方式存在的作动器外置、自由度冗余等缺点,提出一种基于少自由度并联机构、作动器内部布置、满足两自由度矢量推进的结构方案.方案采用RS+2PRS并联机构作为AUV推进系统的主体结构,并联机构的固定平台与AUV的尾部舱壁固联、机构的运动平台安装螺旋桨等推进器,将驱动部件和动力输入单元内置于AUV舱体内部,结构紧凑,刚度性能好,便于推进系统的密封与防护；通过推进机构的运动参数解耦分析可知,该推进机构的自由度为2,独立运动参数为螺旋桨安装平台的进动角和章动角；可以采用两个移动副构件作为机构的驱动输入,建立推进机构欧拉姿态角与两路驱动参数之间的非线性映射模型；利用MATLAB和ADAMS的联合仿真分析,并搭建实物装置实现了螺旋桨姿态角的快速调整,从而实现AUV航向角和俯仰角的改变.研究结果表明,该型两自由度推进机构结构可行,姿态控制算法正确有效,可以有效提升AUV的水下机动性和工作效能,为后续两自由度矢量推进机构的工程化应用奠定理论基础.

Abstract:

To overcome the disadvantages of some vector propulsion methods, such as external acurators and redundant degrees of freedom, a 2 degree-of-freedom(2-DOF) vector propulsion mechanism scheme is introduced, which is based on limited-DOF parallel mechanism and the actuator can be arranged internally. The fixed platform of the RS+2PRS mechanism can be used as the rear bulkhead of AUV, and the movable platform of the mechanism as the mounting base for the propeller. The proposed mechanism has a compact structure, high stiffness, and is well sealed. The movement decoupling analysis shows that the two independent movable parameters of the mechanism are the precession angle and the nutation angle. The nonlinear mapping model can be built between the Euler attitude angles and the driving parameters of the mechanism. The joint simulation analysis was carried out using MATLAB and ADAMS, and the experiment equipment was built. By changing the relative positions of driving components in two prismatic pairs, the 2 DOF attitude adjustment of the AUV rear propeller can be achieved, and the AUV heading and pitch angles can be adjusted rapidly. Research shows that the physical design of the propulsion mechanism is reasonable, and the attitude control algorithm is correct. This propulsion mechanism can improve the maneuverability and capability of the AUV, and this research lays a theoretical foundation for the further 2 DOF vectored thrust engineering application.