Several Key Issues on Closed-Loop Control for Precision Laser Tracking Device
|School||Harbin Institute of Technology|
|Course||Instrument Science and Technology|
|Keywords||MPC closed-loop servo system angular measurement motion control|
Laser tracking detection which combines laser, precision mechanism, motion control and integrated electronics into an integrated part, embodies many advantages including extensive scope, high precision, high speed and non-contact. It has been utilized in far ranges such as industrial and aerospace measurement. The precision 2 D.O.F. servo mechanism, as the most impotent technology of the whole system, its performance index of the tracking performance, control accuracy has direct impact on the exploration precision of the whole system. Therefore, the research of this technology is significant for the laser tracking detection.High-precision digital closed-loop servo control system which is composed of inductosyn, DC torque motor, DSP digital servo controller has been researched in this paper. The content of the task is in detail as follows.Discuss the basic theory of the Model Predictive Control (MPC). Set up the control model of the MPC based on the initial parameter. Analyze the main factors by emulation in order to find the control strategy adapted to the system.The motor drive circuit based upon the LMD 18200 has been designed on the foundation of the character of the driving theory of servo control and PWM. This electro circuit contains the merits of high gain quick response current feedback and over-temperature protection.By testing each performance of high-precision angle measurement system according to GJB1801-93, in the working spectrum of±30? in servo system, the precision of the testing is±4.92?. Analyze the main error factors of the testing data.Finally, test the experiment precision of the closed-loop servo system control. The experiment proves that utilizes the MPC in the closed-loop servo system is feasible. In the working spectrum of±30? in servo system, the most angle control accuracy is -8.80?,steady ripple is±1.76?,angle control repeatability is±4.40?.