考虑约束非线性系统,提出一种新的具有稳定性保证的经济模型预测控制(Economic model predictive control,EMPC)策略.由于经济性能指标的非凸性和非正定性,引入关于经济最优平衡点的正定辅助函数.利用辅助函数的最优值函数定义原始EMPC优化问题的稳定性约束.应用终端约束集、终端代价函数和局部控制器三要素,建立闭环系统关于经济最优平衡点的渐近稳定性和渐近平均性能.进一步,结合多目标理想点概念,将提出的控制策略用于多个经济性能指标的优化控制,得到稳定多目标EMPC策略.最后,以连续搅拌反应器为例,比较仿真结果验证本文策略的有效性.
This paper proposes a novelty economic model predictive control (EMPC) scheme with guaranteed stability for constrained nonlinear systems. Some auxiliary positive-definite functions at economy optimal equilibrium points are introduced for economic performance functions that are generally non-convex and non-positive-definite. The optimal value function of the auxiliary function is used to define an adjustable stability constraint which is imposed on the original EMPC optimization problem. By the triplet of terminal constrained sets, terminal penalty functions and local controllers, it is proved that the closed-loop system is asymptotically stable at the economically optimal equilibrium point and has an asymptotic average performance. Moreover, the proposed EMPC scheme is extended to optimization control of multiple economic performance functions, together with the concept of multi-objective utopia points. Then a stabilizing multi- objective EMPC scheme is presented. Finally, the effectiveness of the obtained results is illustrated by a simulation example of a continuously stirred tank reactor.