Sun Qinglin

Semi-physical Simulation Platform of a Parafoil Nonlinear Dynamic System *

Parafoil has good aerodynamic performances which can be used to implement autonomous, precise and fixed point landing through gliding and turning manipulation. It has extensive applications in the fields of vehicle recovery and fixed point airdrop of flying personnel, weapon equipment and lifesaving material. In the course of applied studies on parafoil, the research must be tested repeatedly by simulation and experiment. The simulation is only limited to the computer, so the methods of automobile drag, delivery from the parachute tower and the airdrop experiment are mainly used to verify the effectiveness of the controller and the actuator correctness. The control algorithm cannot be verified adequately, and the methods of delivery from the parachute tower and airdrop experiment have disadvantages of high cost, big risk and long period, which greatly reduce the efficiency of research and development. Semi-physical simulation adds part of the physical objects of the studied system to the loop of the simulation experiment system. The accurate definition is hardware in the loop simulation (HILS). [1] Thus, this kind of simulation is closer to the actual situation. The technology of semi-physical simulation has wide applications in industry and in areas of electronic, communication, shipping, traffic, aeronautics and astronautics. [2−6] In this Letter, combining the nonlinear dynamic model of a parafoil system with the real components of a controller and a motor, a semi-physical simulation platform is designed for the parafoil nonlinear dynamic system. First, the nonlinear dynamic model of the parafoil system, an adaptive generalized predictive control (GPC) algorithm and acoordinate transformation of GPS are introduced. Then, the composition of the simulation platform and the simulation experiment are introduced. As in other semi-physical simulation systems, the simulation model combines a section of the physical object to be verified and the practical working environment that is simulated by a computer. However, this platform is used for autonomous or remote controlled homing of the parafoil airdrop system and has the characteristic of recording data for synchronous analysis. The real working environment for homing of the parafoil airdrop system can be simulated, and the effectiveness of the control algorithm, software and circuit and the correctness of the actuator controlling parachute line are verified comprehensively at the same time. During the semi-physical simulation process, the flight of the parafoil system is simulated by the computer. A six-degree-of-freedom (DOF) dynamic model of the parafoil system is built and the establishment of the coordinate system can be referred to in the literature. [7]

Design of PID and ADRC based quadrotor helicopter control system

In this paper, an active disturbance rejection control (ADRC) and PID based control method is proposed to perform position and attitude control of a small unmanned quadrotor helicopter model. For the double closed-loop control system, ADRC is applied in the inner loop control, and an extended state observer (ESO) is designed to observe and compensate the internal uncertainties and the external disturbances in real time. PID is used in the outer loop control. Simulation experiments are performed to evaluate the efficiency of proposed control system.

Realization of an improved location algorithm based on the Zigbee wireless sensor network

Most of the high-precision location algorithms still remain in the realm of theory and have not been put into practice. The reason is that the computing capability of the MCU of most embedded system is so poor that they fail to meet the requirements of those complex location algorithms. Here we will realize an improved location algorithm with its name The Least Squares Estimation Location Algorithm with Error Compensation. The error compensation is based on the theory of statistics. Although its precision is not as high as other complex algorithms it requires not so much on computing capability of the embedded system.

A Novel Fuzzy Predictive Functional Control Based on T-S Fuzzy model

A method for identifying nonlinear systems is presented, which is based on fuzzy cluster and orthogonal least square method. First, the nonlinear dynamic systemic T-S fuzzy model with this method is identified. Then the predictive controller is designed based on this model. The simulation results indicates that the algorithm is effective and applied, which has the characteristics of fast tracking, high control precision and strong stability.

Fast generalized predictive control algorithm of multivariable system based on decoupling

This paper analyzes systems model and gives a kind of model which can be feedforward decoupled. First, get the parameters by on-line identification to proximately describe the real system. Then, the model is feedforward decoupled. Finally, using the fast algorithm, the control result is calculated. This fast algorithm not needs to compute the Diophantine equation and inverted matrices on line. The paper also present a method to reduce interaction, the simulation results show its efficiency.

The design and realization on control system of micro-arrays printing instrument

The paper introduces the design, hardware structure and software realization of gene chip micro-arrays printing instrument. We discuss the editing method of the control process. We achieve the graphics mode design of the gene chips layout and chip structure. The control system can optimize the route of micro-arrays printing in spite of the chips layout and chip structure. It speeds up the microarrays printing instrument performance.