Abstract: In view of the real-time, reliable and efficient requirements in data transmission of the automatic meter reading system, a remote automatic meter reading scheme based on the technology of Wi-Fi is proposed. Wi-Fi (sometimes spelled Wifi or WiFi) is a popular technology that allows an electronic device to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connections. Based on the transmission technology of Wi-Fi, this article introduces a remote automatic meter reading system, which takes UART-WiFi module as core and allows the meter connected to the Internet, so as to realize the function of network remote automatic meter reading.
Abstract: In the automation industry, the data collection used in the site is the key basic technology to ensure the product quality and normal operation of the production system.With the development of information technology, data acquisition technology is widely used in industry field. High-speed, real-time data acquisition has a very important application in the field of industrial automation.The speed of A/D chip is becoming faster and data acquisition system requires higher transmission speed.Traditional communications style is restricted by the slow transmitting rate,weak anti-jamming ability and will be replaced by USB, the new generation Universal Serial Bus.This thesis analyzed characteristics of Universal Serial Bus and the requirement of data acquisition system based on USB. Lastly, a data acquisition system based on STM32 MCU was designed.
Abstract: In the three-phase voltage-type pulse width modulation (PWM) inverter system, the steady DC-bus voltage is significant for normal operation of PWM converter. With traditional control method, DC-bus voltage has poor anti-disturbance performance and large steady-state error generated by parametric uncertainties of inductive resistance and switching devices’ equivalent resistance. To cope with these problems, a linear active disturbance rejection control (LADRC) controller is designed based on the advantages of the LADRC in processing system internal perturbation and external disturbance. The simulation study shows that under the same disturbance the proposed method can realize not only faster dynamic response and better property of anti-disturbance performance, but also unity power factor control. For the uncertainties of AC equivalent resistance and inductance, the method shows strong adaptability and robustness.
Abstract: The work characteristics of forward converters are described. Presented the theoretical and practical details by means of the state space averaging method, the small signal model of forward converters under peak current mode controlled is constructed. The design of the controller is given to be used in this converter with the maximum control bandwidth of 10 kHz as well as an adequate phase margin. A closed loop simulink model for the converter is constructed on Matlab and the stability and dynamical performance demonstrated. The theoretical predictions of this paper are supported by computer simulations graphically represented and analyzed as practical evidences. Simulation results show the feasibility of the design, thus providing a solution seamless implemented the applications of peak current mode controlled forward converters.
Abstract: A comprehensive performance testing table, on which 9 testing items can be done, of the constant velocity joint drive shaft assembly is developed. The principle of the system is introduced and the mechanical structure and the computer measuring and control system of it are discussed particularly. Some intelligent measuring methods, such as fuzzy method, are used in the system and an example of testing the slip curve characteristic of the joint assembly by fuzzy measuring method is presented in detail, including its membership function and fuzzy rules of fuzzy reasoning. The slip curve measured by traditional method compared with that by fuzzy method. The experimental results show that the measurement precision by fuzzy method is more accurate than that by the traditional one.
Abstract: The industrial robot is a highly nonlinear and highly coupled device, and the calculation of the dynamic model needs to spend a lot of time, which result in difficult to achieve dynamic control. Using of intelligent algorithm to model the robot dynamics has been the field of robotics research focus. This paper proposes a method based on support vector machine regression algorithm to model the robot dynamics. The angle acceleration coefficient, and the centripetal acceleration and Coriolis acceleration coefficient, and the gravity in the robot dynamics equation are predicted based on support vector machine regression. When the support vector machine is trained, parameters in the robot dynamics equation don’t rely on the position of each joint any more. Modeling process was described in detail by using a two degree of freedom robot. All the parameters are simulated. Simulation results show that the method has the characteristic of high precision, and short training time.
Abstract: To satisfy the need of high speed machining, according to machine's features and turning angle between micro-lines, constraining conditions of micro-lines turning feed speed are established in this paper. The algorithm is calculating the resolution of the end velocity of last line and the startup velocity of next line, and then deduce the acceleration on each axis. The resolution acceleration of each axis reflects the loading capacity of them and should not over a given value. Then a S-shape curve speed control algorithm of continuous micro-line interpolation based on adjustable real-time feed-speed is designed. When maximum feed velocity in a line changes from a low value to a high one suddenly, the velocity also tends to target smoothly by S-shape curve, and the velocity decreases to the end speed value in advance, and the total interpolation time decreases, machining efficiency rises evidently. At last, experiment which performed on the CNC system verifies the control algorithm. The result indicates that the algorithm can enhance the machining efficiency and improve surface quality based on assuring the machining precision.
Abstract: This paper aims to solve the problem of stabilization about a switched affine system with stable and unstable subsystems. We show that if the switching signal satisfies the so called average dwell time approach, the uniform stabilization of the switched affine system under specific switching signal is guaranteed with explicit bound, and the switched autonomous system is a special case which is asymptotically stabilization. Then, we applied this result to Dc-Dc converters; the results verify that the peak-current control boost is uniform stabilization. Simulate results verify the theoretical analysis. The proposed Theoretical analytical methods can apply to other Dc-Dc converters under specific switching signals.
Abstract: As to the optimum of extremum value controlled plant, if the transfer function of its linear part is only with the high order dynamic elements, the optimum of extremum value control system could be dynamically pre-estimated by using the method based on correlation identification we presented, the pre-estimating method has the estimate speed quickly, anti-jamming ability strong, accurate, highly effective and so on the merits. However, if the controlled plant is simultaneously with high order dynamic elements and a large time delay element, the method could not be used directly to pre-estimate dynamically the optimum of the extremum value control system. A new improved pre-estimating method is presented so as to resolve the problem above. After we have in detail analyzed the derivation process of the pre-estimating method we presented, Fully taking into account the effects of large time-delay element, a number of conditions have been improved, the algorithm based on correlation identification has been extended, the optimum of extremum value control system with a large time delay element is well resolved by the extended algorithm.
Abstract: Load follow is necessary in the operation of a power plant due to the need of power changing with time. In the load following of a nuclear plant, many special factors have to be considered, which makes the control strategy particularly difficult as well as important. Among many strategies, Linear Quadratic Gaussian and Loop Transfer Recovery (LQG/LTR) design approach is an efficient method for L-F, and is applied to a model of a practical nuclear reactor. The simulation shows the robust control method LQG/LTR meet the control requirements of the neutron flux spatial distribution during load following. And a Kalman-filter based feedback control is also applied in this approach to eliminate the oscillations caused by Xenon poisoning within the nuclear reactor.