An Efficient Approach for Modeling and Control of a Quadrotor

A quadrotor is a four-rotor aircraft capable of vertical take-off and landing, hovering, forward flight, and having great maneuverability. Its platform can be made in a small size make it convenient for indoor applications as well as for outdoor uses. In model there are four input forces that are essentially the thrust provided by each propeller attached to each motor with a fixed angle. The quadrotor is basically considered an unstable system because of the aerodynamic effects; consequently, a close-loop control system is required to achieve stability and autonomy. Such system must enable the quadrotor to reach the desired attitude as fast as possible without any steady state error. In this paper, an optimal controller is designed based on a Proportional Integral Derivative (PID) control method to obtain stability in flying the quadrotor. The dynamic model of this vehicle will be also explained by using Euler-Newton method. The mechanical design was performed along with the design of the controlling algorithm. Matlab Simulink was used to test and analyze the performance of the proposed control strategy. The experimental results on the quadrotor demonstrated the effectiveness of the methodology used.

Quasi-Close Loop Control of NC Machine Tools

There are some problems existing in open loop system with stepping motor as driving motor, such as lower servo precision, without compensation for step losing of stepping motor and so on. This paper presented a new approach called quasi-close loop control. With the help of the method, the control accuracy will be similar to that of close loop system and can be obtained, and the system will have the same stability as that of open loop system. With MCS-51 single-chip microcomputer as control unit and grating scales for measuring displacement, a quasi-close loop control system was built on NC lathe. The practice shows that the quasi-close loop control system has advantages such as high control accuracy, good stability and high cost performance. It is suited to economical NC machine tools and has wide application prospects.

Modeling and Simulation of Brushless DC Motor Adaptive Fuzzy PID Control System for Pure Electric Vehicle

Pure Electric Vehicles (PEV) is an important research direction to solve the problems of auto environment and energy sources. Research double close-loop control system of PEV driven by Brushless Direct Current Motor (BLDCM) has the practical value. Traditional PID controllers have some advantages of being simple, reliable and effective for linear systems, but not for time-varying systems or highly non-linear systems. In order to improve the performances in both steady state and transient state of control system, an Adaptive Fuzzy PID Controller (AFPIDC) can be employed. The dynamic model of PEV and the mathematic model of BLDCM can be analyzed and established. Simulation model of Speed and Current Double Close-Loop Control System are implemented by Matlab7.0/simulink. The simulation results show that the system has rapid response, without static error and overshoot, good performance and strong robustness, high capacity of resisting disturbance.

Responses and Optimization of a PID-Based Speed Regulating System of the Planetary Mixer

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.

Energy Based Characterization of Fatigue Behaviour of Cyclically Unstable Materials

The paper presents a definition of a new energy based parameter which allows to better describe fatigue proprieties of materials, especially cyclically unstable materials in comparison with the Lagoda-Macha parameter. The proposed parameter distinguishes positive and negative work of external force and depends on the sign of the stresses in paths of strain in materials. It is used in laboratory tests for control of a fatigue process on hydraulic stand. A close-loop control system has been equipped with computer program based on MATLAB/Simulink module.