Applied Mechanics and Materials Vols. 278-280

Abstract: The general flight control laws are designed by static designs and dynamic fits. To improve the adaptive capability, the method of control laws design was introduced by using dynamic optimization genetic algorithms. The control parameters were adjusted online in the flight envelope. The dynamic optimization model was built for aircraft longitudinal function. The fitness was set up by applying order track. And then the control parameters were regulated by dynamic optimization genetic algorithms. Finally an example of a longitudinal control augmented stability system of an aircraft is used with a simulation.

Abstract: Based on the analysis of thickness control theory, a controller combined fuzzy neural network with intellectual integration was designed in consideration of the nonlinear, large time delay, varying time characteristics of tandem cold mill thickness control. The controller adopted three layers BP network to realize fuzzy control and linked with intelligent integration in parallel for forming a three-dimensional full intelligent composite controller which enables the cold tandem rolling thickness fuzzy neural network control based on intelligent integration. Simulation results show that, compared with the conventional PID control, the compound intelligent control strategy can remarkable improved performance of control system of cold tandem rolling thickness.

Abstract: In order to ensure the quad-rotor can track moving targets or desire trajectory accurately and quickly when face external disturbance, sliding mode control is used to overcome the system uncertainties and external disturbances. A fuzzy controller is introduced to decrease the chattering and improve performance of the system. The simulation considering external disturbance is used to test the performance of the fuzzy sliding mode trajectory tracking controller and the result shows that the fuzzy sliding mode trajectory tracking controller is feasible.

Abstract: Discrete-time NCSs in multiple-packet transmission with random delays were discussed. The random delays from the sensors to the controllers and from the controllers to the actuators were considered. A novel random delay model in multiple-packet transmission was proposed and the relationship of the delays and the system performance was studied. The state feedback H_∞ controller can be constructed via solving a linear matrix inequality, such that the closed-loop system with random delays exponentially mean-square stable and with a prescribed H_∞ performance bound. The result shows that an example presented here illustrates the effectiveness of the proposed method.

Abstract: In this paper, we have investigated the impulsive controller of suspension system of single magnet. The variable system parameters are formulated through matrix analysis. The sufficient conditions of the robust asymptotical stability are established by employing the method of Lyapunov functions, so as to be applied more flexibly. The effectiveness of our methods has been shown by computer simulation.

Abstract: To share the loads and restrain circumfluence among parallel inverters in Stand- alone photovoltaic system (PV), it is described that a digital current sharing control technique for inverter parallel operation in detail in this paper. After the analysis of circumfluence of paralleled system on distributed-logical-control, characteristic of the power regulation, a novel digital power detection technique is deduced. With measuring and analyzing the instantaneous average current of all inverters and the output current of each inverter, both of the current components are used to control and regulate the amplitude and the phase of the output voltage. The proposed control technique on current sharing in the inverter paralleling system has been verified the good characteristic of restraining circumfluence by the results of the experiment.

Abstract: The brushless dc motor position tracking system to be controlled includes a friction and a backlash as disturbances. In this paper, we propose a robust linear quadratic sliding-mode controller for precision positioning in a brushless dc motor system. The control algorithm includes a linear quadratic control for an optimal feedback gain and an integral nonlinear sliding-surface based on a new reaching law to remove the reaching phase. It has robust performance against parameter variation which causes an oscillation in case of linear quadratic control. Simulation results show that the proposed controller gives an improved accurate driving tracking result and is robust to plant parameter variation and load torque disturbances.

Abstract: In order to determine the high-speed Computer Numerical Control (CNC) lathe linear servo system control parameters reasonably, the linear motor feed system control model was established based on analysis of high-speed linear feed system control principle, and the linear motor feed system transfer function was established, and servo dynamic stiffness factors were analyzed. The control parameters of the servo system and actuating mechanism parameters of feed system on the effect of the linear motor servo dynamic stiffness were analyzed using MATLAB software. The simulation results show that the position loop proportional gain, speed loop proportional gain and speed loop integral response time are the biggest Influence factors on servo dynamic stiffness. The displacement response is reduced under the cutting interference force step inputting, while the position loop proportional gain, speed loop proportional gain and speed loop integral response time are increased, and the servo dynamic stiffness is increased, the number of system oscillation is also reduced, and the system tends to be stable.

Abstract: In order to solve the problem that how to adjust the operation of all units of the pump station and control the speed of pumps on time, in the changing condition of manufacture procedure, to optimize the pumps combination and adjusting-speed strategy, this paper builds a mathematic model of pumps operation control system, adopts the method of system identification to calculate system parameters on-line, and brings forward a optimal control arithmetic for saving energy. The data analysis of running spot indicates that the arithmetic can save energy of pump station obviously, and also has the good function of equipment maintenance, so it has the high engineering application value.

Abstract: Take the Plug-in Parallel Hybrid Electrical Vehicle as research object, matching with the parameter of its power system. Then designs a two—parameter fuzzy control unit for torque split between engine and electric motor. The input parameters are the torque needs of the drive system and the battery State Of Charge. Doing the simulation analysis in the simulation software ADVISOR, the results show that the control strategy has improved the dynamic property and fuel economy of the vehicle effectively.