摘要：This paper presents a nonlinear observer-based control design approach for gasoline engines equipped with exhaust gas recirculation (EGR) system. A mean value engine model is designed for control which includes both the in take manifold and exhaust manifold dynamic focused on gas mass flows. Then, the nonlinear feedback controller based on the developed model is designed for the state tracking control, and the stability of the close loop system is guaranteed by a constructed Lyapunov function. Since the exhaust manifold pressure is usually unmeasurable in the production engines, a nonlinear observer-based feedback controller is proposed by using standard sensors equipped on the engine, and the asymptotic stability of the both observer dynamic system and control dynamic system are guaranteed with Lyapunov design assisted by the detail analysis of the model. The experimental validations show that the observer-based nonlinear feedback controller is able to regulate the in take pressure and exhaust pressure state to the desired values during both the steady-state and transient conditions quickly by only using the standard sensors.

摘要：In this paper, we concern the approaching condition of sliding mode control （SMC） with a Lipschitz switching surface that may be nonsmooth. New criteria on the relation between phase trajectories and an arbitrary Lipschitz continuous surface are examined firstly. Filippov＇s differential inclusion is adopted to describe the dynamics of trajectories of the closed-loop system with SMC. Compared with Filippov＇s criteria for only smooth surface, new criteria are proposed by utilizing the cone conditions that allow the surface to be nonsmooth. This result also yields a new approaching condition of SMC design. Based on the new approaching condition, we develop the sliding mode controller for a class of nonlinear single-input single-output （SISO） systems, of which the switching surface is designed Lips- chitz continuous for the nonsmooth sliding motion. Finally, we provide a numerical example to verify the new design method.

摘要：印刷机上的卷筒控制技术对于改善印刷品的性能来说是一个重要的议题。多色印刷机包含了多个印刷单元,每个印刷单元的原动力都是耦合的,而信号的传播总是有所滞后。本文介绍了一种针对三色印刷机的基于信号滞后的非线性控制方法。首先,为状态变量设计了一种非线性坐标变换,可描绘出压力的原动力和印刷缺陷。然后根据新坐标,绘制出基于滞后的反馈规律,这样封闭的循环系统归于零。最后,与传统的控制方法相对比,得出一些模拟结果。

摘要：3 m多长的伸杆机构是天问一号火星磁强计的一个重要组成部分,用于将磁通门磁强计探头伸离卫星本体以减小卫星对磁场测量的影响。火星磁强计伸杆机构是一种多关节、铰链转轴驱动的一次性展开机构。在设计时充分考虑到了其功能性、可靠性和系统约束要求等因素。力学分析和地面验证试验表明火星磁强计伸杆机构足以承受最坏情况下的在轨环境。在经历了漫长的地火转移旅程后,火星磁强计伸杆机构于2021年5月25日成功展开。展开过程耗时约4.6 s,两个探头被送至远离环绕器本体位置,其中外侧探头距离环绕器3.19 m,内侧探头距离环绕器2.29 m。展开到位后,外侧探头处所测得的磁场大小由1250 nT减弱至不到6 nT。火星磁强计伸杆机构为后续探测任务中需在低温环境下长期贮存的空间展开机构的研制提供了宝贵的工程经验。