多关节深海潜水器纵垂面建模与俯仰控制

Vertical Profile Modeling and Pitch Attitude Control for Multi-Joint Autonomous Underwater Vehicle

为实现深海纵向剖面探测,给出了一种多关节潜水器的设计方案,并对潜水器的纵垂面建模与俯仰姿态控制问题进行了研究。针对浮力和重力不平衡的情况,根据牛顿第二定律和力矩平衡原理建立了多关节潜水器在纵垂面上的运动学和动力学模型。考虑到多关节潜水器在纵倾运动控制过程中存在未知干扰和过驱动等问题,提出了一种线性二次型最优自抗扰控制方案。根据实验样机硬件设计要求,将关节摆动角度作为被控系统输入。将系统内力与外部扰动作为系统总扰动,采用线性扩张状态观测器对总扰动进行估计。针对系统过驱动问题,采用奇异值分解法求解控制系数矩阵的伪逆矩阵,实现总扰动补偿与输入合理分配。采用线性二次最优控制优化线性反馈控制增益,实现控制增益按照期望输入输出效果达到最优。在SIMULINK平台上,搭建模型仿真环境,在有、无输入扰动两种情况下,使用线性二次型最优自抗扰控制器实现俯仰控制仿真。结果表明,所设计的控制器具有低超调、抗干扰和精准度高的特性。

To achieve vertical profile exploration of deep-sea, a multi-joint autonomous underwater vehicle(MJ-AUV) was designed, and the vertical profile modeling and pitch control method of the vehicle were studied. Considering the situation of gravity and buoyancy imbalance, the dynamics model of the MJ-AUV in vertical profile was established according to Newton’s second law and torque balance principle. To solve the problems of unknown disturbance and input redundancy in the pitch control of the MJ-AUV,a linear quadratic regulator active disturbance rejection control(LQR-ADRC) method was proposed. The joint angle of the MJ-AUV was taken as the input of the model to satisfy the design requirements of the prototype;The linear extended state observer was designed to estimate the total disturbance consisting of internal forces and external disturbances;The pseudo-inverse matrix of the control coefficient matrix was obtained by singular value decomposition(SVD) method to achieve total disturbance compensation and reasonable allocation of input;The LQR was adopted to optimize the linear feedback control gains according to the expected input and output effects. The simulation environment of MJ-AUV was built on SIMULINK platform, and the pitch control of MJ-AUV was simulated using the LQR-ADRC controller with and without input disturbance. The simulation results demonstrate that the proposed controller has the characteristics of low overshoot, anti-interference and high accuracy.