现代汽车电子控制技术

随着时代的进步和现代高科技技术在现代汽车上的应用,电子控制技术在汽车上的地位日益重要,本文主要从现代汽车电子控制技术的发展历史、应用现状和未来展望三个方面进行介绍和分析,为我们更好地使用和享受现代汽车拓宽了视野。     

Simulation, experimental evaluation and performance improvement of a cone dielectric elastomer actuator

Dielectric elastomer actuators （DEAs） are an emerging class of polymer actuation devices and have extensive application prospect in the field of robotics because of their light weight, high efficiency and large deformation. A cone DEA is manufactured and its working principle is analyzed. To obtain the deformation of elastomer and movement of DEA in advance, a finite element method （FEM） simulation is performed first. According to the working principle, two working equilibrium points of DEA, corresponding to the displacements of DEA with voltage off and on, are obtained and validated by experiments, thus work output in a workcycle is computed. Experiments show that the actuator can respond quickly when voltage is applied and can return to its original position rapidly when voltage is released. Simulation results agree well with experimental ones and the feasibility of DEA simulation is proved, and causes for the small difference between them in displacement output are analyzed. The performance of the actuator is improved from the aspects of both displacement and force output. A diamond four-bar linkage mechanism is used as the preload part and a displacement output of 17 mm is obtained. The force output of one actuating unit is about 1.77 N, so three actuating units are assembled in parallel and the force output is heightened to as high as 5.07 N.     

Invariant ellipsoids for single-input system with actuator saturation by employing output feedback

In this paper, the invariant ellipsoids theorem is introduced into a class of common saturated single-input system by employing output feedback with state-delay, and as a result, a sufficient condition is presented for stability analysis. The result is given in forms of linear matrix inequalities (LMI).     

Guaranteed-cost reliable control with regional pole placement of a power system

This paper deals with the simultaneous coordinated design of power system stabilizer (PSS) and the flexible ac transmission systems (FACTS) controller. The problem of guaranteed cost reliable control with regional pole constraint against actuator failures is investigated. The state feedback controllers are designed to guarantee the closed loop system satisfying the desired pole region, thus achieving satisfactory oscillation damping and settling time, and having the guaranteed cost performance simultaneously. The proposed controllers satisfy desired dynamic characteristics even in faults cases. The controller's parameters are obtained using the linear matrix inequalities (LMI) optimization. Simulation results validate the effectiveness of this approach.     

Hysteresis model of magnetostrictive actuators and its numerical realization

This paper presents two numerical realization of Preisach model by Density Function Method (DFM) and F Function Method (FFM) for a giant magnetostrictive actuator (GMA). Experiment and simulation showed that FFM is better than DFM for predicting precision of hysteresis loops. Lagrange bilinear interpolation algorithm is used in Preisach numerical realization to enhance prediction performance. A set of hysteresis loops and higher order reversal curves are predicted and experimentally verified. The good agreement between the measured and predicted curves shows that the classical Preisach model is effective for modelling the quasi-static hysteresis of the GMA.     

Nonlinear stochastic optimal bounded control of hysteretic systems with actuator saturation

A modified nonlinear stochastic optimal bounded control strategy for random excited hysteretic systems with actuator saturation is proposed. First, a controlled hysteretic system is converted into an equivalent nonlinear nonhysteretic stochastic system. Then, the partially averaged Itoe stochastic differential equation and dynamical programming equation are established, respectively, by using the stochastic averaging method for quasi non-integrable Hamiltonian systems and stochastic dynamical programming principle, from which the optimal control law consisting of optimal unbounded control and bang-bang control is derived. Finally, the response of optimally controlled system is predicted by solving the Fokker-Planck-Kolmogorov （FPK） equation associated with the fully averaged Itoe equation. Numerical results show that the proposed control strategy has high control effectiveness and efficiency.     

一种新型精密回摆装置的设计

本文介绍了一种新型回摆装置,采用了磁致伸缩驱动器作为能量转换装置,利用曲柄滑块机构作为运动转换装置,将直线运动转化为圆周运动,并对其原理进行了可行性分析,进行了结构建模。相比传统的回摆装置,其体型小,可直接控制电流的变化对其进行调速,且反应速度快。     

现场总线与执行器集成方法研究

针对在工程中出现的现场总线与具备不同现场总线接口的执行器在系统集成方面存在的问题,详细讨论了同族多现场总线、异族多现场总线与执行器的集成问题解决方法,给出了集成模型。