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Design Of Servo System And Accuracy Study For Three-axis Turntable

Posted on:2011-08-22Degree:MasterType:Thesis
Country:ChinaCandidate:Z F ZhangFull Text:PDF
GTID:2178330332960247Subject:Mechanical and electrical engineering
Abstract/Summary:PDF Full Text Request
In aviation, aerospace, defense and other areas, three-axis turntable plays important roles in the experiment of science research as a critical hardware equipment of simulation testing. The merits of their performance is directly related to simulation and test's reliability and confidence. Presently, turntable's overall performance is developing toward the high-precision, high-frequency, multi-function and automation, therefore, a higher demand for control system design of the turntable will be put forward. Based on the actual project development of 120Kg three-axis turntable, this paper designed mainly AC Servo System based on the YASKAWA servo motors and PMAC, and focused for the issue that backlash caused by non-linear part of system accuracy to study , gave control strategy to improve the accuracy of turntable. The research work of the three-axis turntable's control method, for turntable control method discussion and the improvement of the system frequency response and dynamic servo precision has practical engineering value.This paper introduced the three-axis turntable's overall structure and the working principle of each part firstly, gave the specific engineering implementation methods of control loop system. Next, the text established a mathematical model of servo system which included the linear part of the model and a nonlinear model containing backlash. In the research of backlash, the paper introduced the feedback of angular velocity from the view of classical control theory. The result of simulation showed that the control strategies can improve effectively system accuracy, but can not get rid of the collision caused by the backlash. This paper also proposed switching control strategy after analyzing to the backlash. The PID controller used in contact period to ensure that the output can track the desired target. A sliding control with time optimal surface was switched into when system entered the backlash to ensure the drive part pass backlash quickly and collision-free between drive part and driven part. Then, a switched mechanism based on Lyapunov was designed to make the system switching between PID controller and sliding control at suitable time. The simulation results verified that the effectiveness of the switching control can get rid of the influence of backlash and improve system accuracy.Finally, the paper designed the turntable man-machine interface program, and accomplished the communication between host computer and lower computer, achieved the turntable motion control .
Keywords/Search Tags:three-axis turntable, servo system, backlash compensation, feedback of angular velocity difference, switching control
PDF Full Text Request
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