الفهرس 
Modeling of the Positioning MechanismOnly 14 pages are availabe for public view
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Abstract
In motion control, with the rapid developments in the applicable new technologies, designing of high precision servo systems becomes a pressing necessity. Moreover, servo actuators provided with harmonic drive have been widely used in many industrial applications such as industrial and/or humanoid robots, and precision positioning mechanisms. Harmonic drives can exhibit dynamic behavior surprisingly more turbulent than that of conventional gear transmissions. According to practical issues, those mechanisms generally controlled as semi-closed loop feedback control systems. Semi-closed control is a current practice in industry in which the load position is controlled based on feedback of motor shaft position.
In order to adapt to the increasing demand for high-precision motion, disturbances of the servo actuators provided with harmonic drive, such as nonlinear friction forces and angular transmission error, should be compensated. It is known from literature that simple linear feedback control techniques such as PID are insufficient to compensate for neither the nonlinear friction behavior nor the angular transmission error.
In this thesis, intelligent compensating techniques are proposed to improve the positioning precision of the mechanism. First of all, the modeling of the system is discussed. Second, in order to preserve the load position according to the reference with high precision response, intelligent control algorithms are applied. The proposed control system has been designed as a cascade control system in which the primary variable (position) is controlled by adjusting the set point of the related secondary variable control loop (velocity set point), and therefore, the secondary variable (velocity) affects the primary variable through the process. A proportional controller (P) is designed as position controller where a proportional plus integral controller (PI) is designed as velocity controller. Designing of a proportional controller cascaded with a tuned proportional plus integral fuzzy logic controller (P-PIFLC) is proposed as the first control algorithm. Where, nonlinear scaling of the PIFLC normalizing input scaling factors is proposed as the second control algorithm. The effectiveness of the proposed controllers is verified using MATLAB/SIMULINK simulator and the results were compared with those obtained using conventional P-PI controller. The results show the superiority of the proposed control techniques over the conventional P-PI.