演化硬件技术中时序电路的遗传算法实现

本文在讨论了EHW的运行机制的基础上,提出了一种了适合“外进化”方式的可进化的闭环结构,即基于FPGA芯片和QUARTUSⅡ开发工具的EHW平台。详细讨论了如何利用遗传算法实现时序电路,目前演化硬件的研究主要还处于理论分析、演化算法优化、软件模拟的阶段,本文将演化硬件技术应用到时序数字电路的设计中,这对于演化硬件技术及时序数字电路设计来说都是成功的探索。     

Adaptive sliding mode control of switched systems with different input matrix

This paper investigates the sliding mode control (SMC) problem for switched systems. The parameter uncertainties are norm-bounded, and the upper bound of the nonlinear term and the loss of effectiveness of actuator faults are unknown. A novel adaptive sliding mode controller is constructed such that the influences of actuator faults and unknown nonlinearity can be effectively attenuated and the state variables can reach the predefined common sliding surface. Based on average dwell time strategy, the exponential stability condition of the switched systems is obtained. Finally, simulation results are presented to show the effectiveness of the proposed techniques.     

Adaptive sliding mode control for variable structure systems with constraint control input

In this paper, the problems in sliding mode control systems with constraint control input are described, and then we utilize selecting a switching surface with an integrator to solve this problem and to derive a bound for the existence of sliding motion. Additionally, we propose an adaptive sliding mode controller in order to reduce settling time and also maintain the sliding motion in a larger bound. Finally, an illustrative example is given to demonstrate the effect of proposed controller.     

Sliding mode control design for discrete multivariable systems with time-delayed input signals

A discrete variable structure control method is developed for discrete multivariable systems. The switching functions are defined using the output and delayed signals. In the quasi-sliding mode, the closed-loop eigenvalues are proven to be within the unit circle in the z-plane. Therefore, the stability of this control system is guaranteed and the robust output performance is ensured in the quasi-sliding mode. In special cases, particular system transformations are carried out. Time-delayed input signals are applied. It is proven that the proposed control method assures robustness against system uncertainties and disturbances.     

Un-symmetric input temperature control by using fuzzy sliding mode controller with gain auto-tuning

In order to obtain the desired product quality, temperature is an important control parameter in chemical and semiconductor manufacturing processes. Generally, the temperature control system has nonlinear time-varying, slow response speed, time-delay and un-symmetric control input dynamic characteristics. It is difficult to accurately establish the dynamic model for designing a general purpose temperature controller to achieve good control performance. Here a model-free fuzzy sliding mode control strategy is employed to design an intelligent temperature controller with gain-scheduling scheme or gain auto-tuning algorithm for a closed chamber with heater one-way input only. The concept of gain scheduling is employed to adjust the mapping ranges of the input and output fuzzy membership functions during the control process for improving the transient and steady-state control performances. The experimental results show that the steady state error of the step input response is always less than 0.2°C without overshoot by using this intelligent control schemes. It is suitable for industrial temperature control systems.     

基于恒流驱动模式的宽电压输入串联型开关电源

提出了一种基于恒流驱动模式的能在10V～100V宽电压范围内工作的串联型开关稳压电源,这种开关电源采用MOSFET和特殊的恒流开关驱动方式,使开关管在宽电压范围内始终得到理想的驱动电压,因此效率高、工作稳定、成本低。可应用在工业用各种报警器产品和爆闪式信号灯中。     

Design of uncertain multi-input systems with state delay and input deadzone nonlinearity via sliding mode control

The problem of robust stabilization of a class of uncertain multi-input time-delayed systems with deadzone nonlinearity in the actuator is considered. To achieve a stable uncertain multi-input system, sliding mode control (SMC) is adopted in the controller design. The proposed controller guarantees the global reaching condition of the sliding mode in the uncertain multi-input system. In the sliding mode, the investigated time-delayed systems with deadzone nonlinearity still possess the insensitivity to the uncertainties and/or disturbances, which can be seen in the systems with linear inputs. In addition, the proposed controller can work effectively for systems no matter whether sector nonlinearity and/or deadzone exists in the actuator or not. However, such property cannot be obtained by the controller design through traditional SMC for the systems without input nonlinearity. Besides, the traditional SMC controller might produce limit cycles once the system contains deadzone in the input. Furthermore, the presented controller ensures the system trajectories globally exponentially converged in the sliding mode. Finally, two examples are illustrated to demonstrate the effectiveness of the proposed sliding mode controller.     

二阶滑模控制在远程网络控制时滞系统中的应用

针对直流无刷电机的远程网络控制系统中的控制时滞和参数不确定的问题,采用线性非奇异变换将控制存在时滞的线性系统转化为无时滞系统;借助于二次型时间最优的方法,利用二阶超螺旋算法,设计出简单、易于实现的二阶滑模控制器。仿真结果表明,二阶滑模变结构控制器的有效性和正确性,算法对负载和参数的变化具有很强的鲁棒性。     

Model predictive and adaptive neural sliding mode control for three-dimensional path following of autonomous underwater vehicle with input saturation

With model uncertainties and input saturation, a novel control method is developed to steer an underactuated autonomous underwater vehicle that realizes the following of the planned path in three-dimensional (3D) space. Firstly, Serret–Frenet frame is applied as virtual target, and the path following errors model in 3D is built. Secondly, the control method which includes kinematic controller and dynamic controller was presented based on cascade control strategy. The kinematic controller, which is responsible for generating a series of constrained velocity signals, is designed based on model predictive control. The adaptive radial basis function neural network is used to estimate the model uncertainty caused by hydrodynamic parameters. Moreover, sliding mode control technology is applied in the design of dynamic controller to improve its robustness. Then, the control effect is compared with that of LOS guidance law and PID controller by simulation experiment. The comparison results show that the proposed algorithm can improve path following effect and reduce input saturation.