Applied Mechanics and Materials Vol. 740

Abstract: In this paper, a delay-independent synchronization controller is proposed for the synchronization of memristor-based competitive neural networks with different time scales. By constructing a proper Lyapunov functional, as well as employing differential inclusion theory, a delay-independent controller is designed to achieve the asymptotic synchronization of coupled competitive neural networks. A simulation example is given to show the effectiveness of the theoretical results.

Abstract: Considering the limitations of traditional control methods on the steering control of intelligent car, such as insensitiveness in steering, a big large overshoot and oscillation, a new control approach is proposed in this work by utilizing the I/O data to detect the position deviation of the lane with the least square algorithm. In the sequel, an improved PID controller for the steering control is introduced to enhance the stability and response speed of the steering control system. As shown by the test results, the proposed approach is efficient to improve the adaptability and stability of the intelligent car, as well as the dynamic performance of the steering control system.

Abstract: In this paper, a multi-level adaptive control algorithm using parameters self-tuning is proposed for improving the tracking performance of a class of SISO nonlinear systems. This scheme is comprised of the pseudo partial derivative estimation law and the adaptive control law. The adaptive control law is derived from a novel higher order weighted one-step-ahead criterion function which exploits more previous control information. In order to identify the laws’ penalty factors which partly imply the dynamics of the system, an approach of parameters self-tuning is proposed with on-line recursive gradient algorithm. This design is model free and depends directly on the pseudo partial derivative updating on-line with the input and output data Simulation examples are provided to illustrate the effectiveness of the proposed method.

Abstract: Based on Motohawk rapid prototype development platform and “Development to Production (D2P)”development process, an integrated control system has been built, adapting to the principle and configuration of extended-range electric vehicle. This control system integrated traditional vehicle controller, drive motor controller, APU controller, engine controller and generator controller. The development of this control system is based on ControlCore underlying operation system and designed by Simulink/Stateflow software. Production-level automotive ECU has also been used as the hardware platform. This development method can significantly simplify the topology structure of control system, decrease the develop cycle of extended-range electric vehicle, and reduce the cost in development, production and aftermarket maintenance.

Abstract: In this paper, a fuzzy state observer with an appropriate adaptive law is developed for a class of uncertain nonlinear system. The uncertain nonlinear system is represented by Takagi-Sugeno (T-S) fuzzy model, and the adaptive law is derived based on Lyapunov synthesis approach. It is shown that under appropriate assumptions, the state error between plant system state and desired linear model state converges to zero as time increases. The results of numerical simulation and the experiment on the magnetic levitation system show the effectiveness of this approach.

Abstract: As one of the most important parameters of Direct Current (DC) power supply, Load regulation determines the performance of whole system. In this paper, the internal structure as well as performance parameters of LM2577 boosting converter were deeply investigated and based on this investigation we proposed two new methods of improving its Load Regulation. One method (method 1) is to replace the resistor connected to the feedback pin of LM2577 with a programmable potentiometer and sample the variation of output voltage using an AD converter. The potentiometer is adjusted under the control of feedback algorithm to keep the output voltage stable, thus the load regulation enhanced. In the other method (method 2), the feedback pin of LM2577 is connected to an adder to stabilize the output voltage of DC power supply and increase the load regulation. A voltage divider made up of resistors divides the output voltage and provide the divided voltage to one input of the adder. The other adder input comes from DA converter controlled by microcontroller. To reduce the adjust time and increase the efficiency, PID algorithm is applied in the software part of the system. We use 12-bit AD (ADS1115), 12-bit DA (TLV 5638) and 10-bit programmable potentiometer (AD5293) to test the methods above under the condition of 5V input voltage and 600mA load current. When output is set to 7V, the load regulation is improved from 1.043%, the rate from application circuit in LM2577’s Datasheet, to 0.700% and 0.042% by applying the first and second method, respectively. When output voltage equals 12V, the improvement is from 0.658% to 0.008% and 0.008%. Meanwhile, the method 2 suppresses output voltage ripple to be less than 10mV.

Abstract: In this paper, the author does a study on the China tobacco Zhejiang Industrial co., LTD(ZJ) through building the IDEF0 & IDEF3 models, which can well present ZJ’s logistics process and function. By analyzing the model, the author find the bottleneck link and problems which will affects the efficiency of tobacco manufacturing process, and put forward the author's suggestions according to the actual situation.

Abstract: In order to make the dynamically tuned gyroscope of Strap-down North-seeking working on the best temperature environment, reduce errors caused by temperature changes, a high-precision temperature control system is built up on the base of control theory and engineering. This system is a two-stage temperature control system. In order to realize high precision temperature control at a predetermined temperature range, temperature measurement circuit is analyzed and calculated on a two-stage temperature control had different measurement circuit match. Experimental results show that the accuracy of can achieve ± 0.1 °Cwhen the environment temperature within the range of-40 °C ~ + 60 °C. It can meet the temperature requirements of Strap-down North-seeking system.

Abstract: This paper considers the sliding mode control for discrete uncertain system with time delay. First, the discrete uncertain system is transformed into a simplified form; then some sufficient conditions of guaranteeing the asymptotic stability of the uncertain system are given; finally the effectiveness of the proposed method is confirmed by the simulations.

Abstract: This Paper deals with the sliding mode control of a class of uncertain Markov switched systems. By using linear transformation, the system is transformed into standard type. A sufficient condition of the existence of a sliding mode dynamics is derived, and an explicit parameterization of desired sliding surface is also given. A sliding mode controller is then designed to guarantee exponential stability of the overall switched closed-loop system. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approaches.