针对定速地形跟随飞行全局离线规划方案数据存储量大、机动飞行油耗大等问题，提出基于级联模型预测控制(cascaded model predictive control，CMPC)的能量协调在线轨迹规划与跟踪方案。首先，利用飞行器纵向质点运动学模型设计模型预测控制(model predictive control，MPC)在线轨迹规划器。从能量分配原理出发确定速度变化规律，对于飞行时总能量不变而导致能量分配不合理的情况，引入虚拟控制量实现总能量动态调节，完成能量协调策略设计。其次，引入地形粗糙度概念描述地形起伏程度，基于此提出规划器自适应时域方案，对于不同地形实现预测时域动态调节。结合MPC轨迹跟踪控制器，并利用真实地形数据进行仿真实验。实验结果表明，所提方案可在与全局离线规划方案航迹差异不大的前提下，实现在线轨迹规划，显著降低油耗，提高航程极限，完成复杂地形的机动飞行任务。
Energy coordinated online trajectory planning and tracking for terrain following flight
Aiming at the problems such as large data storage volume and high flight fuel consumption in the global offline planning scheme for terrain following flight with invariant speed,an energy coordinated online trajectory planning and tracking scheme based on cascaded model predictive control(CMPC)is proposed.Firstly,the model predictive control(MPC)online trajectory planner is designed using the longitudinal kinematic model of the aircraft.Based on the principle of energy distribution,the velocity variation law is determined.For the situation where the total energy is unchanged during flight and the energy distribution is unreasonable,virtual control volume is introduced to realize the dynamic adjustment of total energy and the design of energy coordination strategy is completed.Secondly,the concept of terrain roughness is introduced to describe the topographic relief,based on this,the adaptive time-domain scheme of the planner is proposed to realize the dynamic adjustment of predictive time-domain for different terrain.Simulation test is conducted by MPC trajectory tracking controller and real terrain data.The simulation results show that the proposed scheme can realize online trajectory planning,significantly reduce fuel consumption,improve voyage range,and realize maneuvering flight missions in complex terrain under the premise of little difference in flight trajectory from the global offline planning scheme.
万方数据
维普
