基于扩张观测器的倾转旋翼无人机非线性滑模姿态控制

倾转旋翼无人机具有垂直起降和长续航的特点,其潜在的应用前景受到了广泛的关注。但倾转旋翼无人机存在强耦合、非线性和扰动不匹配等问题,这给其姿态控制器设计带来了很大的挑战。本文基于改进的自抗扰算法,将扩展状态观测器(ESO)与非线性滑模控制(NSMC)相结合,利用ESO-NSMC(ENC)设计了倾转旋翼无人机姿态控制器,建立了倾转旋翼无人机六自由度非线性数学模型,利用扩张状态观测器对系统的状态和扰动进行估计,设计了非线性滑模控制器以实现有限时间收敛。仿真结果表明,与RSM相比,ENC在悬停、前飞和过渡模式下的平均收敛时间提升率为58.6%、19.6%和3.28%,抗干扰能力分别提升83.5%、25.6%和66.4%,证明该方法具有较好的控制效果和鲁棒性。

基于Simulink软件的组合滑模控制仿真实验

设计结合快速终端滑模控制器和线性滑模控制器的组合滑模控制器,用于二阶非线性系统的平衡控制。首先采用快速终端滑模控制器进行二阶非线性系统的平衡控制,当状态变量接近平衡状态时,切换为线性滑模控制器。采用Simulink软件建立仿真实验系统,进行数值仿真,并对实验结果进行分析。

基于纳什均衡量子粒子群算法的分布式能源系统频率控制方法

含风能、太阳能等可再生能源的分布式能源系统存在频率波动过大和混合储能难以控制的问题。为此,文章提出了一种基于纳什均衡量子粒子群算法(NEQPSO)的分布式能源系统频率控制方法。首先,建立了一种含新能源和混合储能的分布式能源系统模型,并将滑模控制器(SMC)与LADRC观测器的输出共同作用于LADRC的PD控制器,实现滑模线性自抗扰控制器(SM-LADRC)的改进;接着,采用NEQPSO对控制器参数进行优化,以获取最优控制器参数;最后,设置不同情况下的对比验证实验。实验结果表明,优化控制器的控制效果明显优于常规PID和PI控制的;NEQPSO的寻优能力明显优于粒子群算法(PSO)和遗传算法(GA)的;同时,由负荷实验和灵敏度验证实验结果可知,基于NEQPSO滑模线性自抗扰控制的分布式能源系统响应快速、抗扰能力更强、频率效果更好且具有良好的稳态性能。

Application of composite nonlinear feedback control approach to linear and nonlinear systems

The objective of this research is to realize a composite nonlinear feedback control approach for a class of linear and nonlinear systems with parallel-distributed compensation along with sliding mode control technique.The proposed composite nonlinear feedback control approach consists of two parts.In a word,the first part provides the stability of the closed-loop system and the fast convergence response,as long as the second one improves transient response.In this research,the genetic algorithm in line with the fuzzy logic is designed to calculate constant controller coefficients and optimize the control effort.The effectiveness of the proposed design is demonstrated by servo position control system and inverted pendulum system with DC motor simulation results.

Serret-Frenet frame based on path following control for underactuated unmanned surface vehicles with dynamic uncertainties

The path following problem for an underactuated unmanned surface vehicle(USV) in the Serret-Frenet frame is addressed. The control system takes account of the uncertain influence induced by model perturbation, external disturbance, etc. By introducing the Serret-Frenet frame and global coordinate transformation, the control problem of underactuated system(a nonlinear system with single-input and ternate-output) is transformed into the control problem of actuated system(a single-input and single-output nonlinear system), which simplifies the controller design. A backstepping adaptive sliding mode controller(BADSMC)is proposed based on backstepping design technique, adaptive method and theory of dynamic slide model control(DSMC). Then, it is proven that the state of closed loop system is globally stabilized to the desired configuration with the proposed controller. Simulation results are presented to illustrate the effectiveness of the proposed controller.

An adaptive neuro-fuzzy sliding mode controller for MIMO systems with disturbance

This paper introduces the mathematical model of ammonia and urea reactors and suggested three methods for designing a special purpose controller. The first proposed method is Adaptive model predictive controller, the second is Adaptive Neural Network Model Predictive Control, and the third is Adaptive neuro-fuzzy sliding mode controller. These methods are applied to a multivariable nonlinear system as an ammonia–urea reactor system. The main target of these controllers is to achieve stabilization of the outlet concentration of ammonia and urea, a stable reaction rate, an increase in the conversion of carbon monoxide(CO) into carbon dioxide(CO_2) to reduce the pollution effect, and an increase in the ammonia and urea productions, keeping the NH_3/CO_2 ratio equal to 3 to reduce the unreacted CO_2 and NH_3, and the two reactors' temperature in the suitable operating ranges due to the change in reactor parameters or external disturbance. Simulation results of the three controllers are compared. Comparative analysis proves the effectiveness of the suggested Adaptive neurofuzzy sliding mode controller than the two other controllers according to external disturbance and the change of parameters. Moreover, the suggested methods when compared with other controllers in the literature show great success in overcoming the external disturbance and the change of parameters.

Study of Comparative Saturated Sliding Mode Control and LQR Controller

The saturation problem is the one of the most common handicaps for applying to real applications, especially the actuator saturation. This paper focuses on the robustness of the sliding mode control （SMC） which incorporates a saturation constraint technique compared to classical linear quadratic regulator （LQR） with saturation. In the first step, the authors present a design methodology of SMC of a class of linear saturated systems. The authors present the structure of the saturation, after that the synthesis of the sliding surface is formulate as a problem of root clustering, which leads to the development of a continuous and non-linear control law that ensures the reaching condition of the sliding mode. The second step is devoted to present briefly the LQR controller technique. Finally, to validate results, the authors demonstrate an example of a quarter of vehicle system.