شناسايي سيستمي و پارامتري يك بازوي مكانيكي دو ميله اي

چكيده انگليسي :

Parameter and System Identification of a Two Link Manipulator Javad Bahrami Javadbahrami ch@gmail com Date of Submission 2010 05 10 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M S Language Farsi Supervisor Mehdi Keshmiri mehdik@cc iut ac ir Abstract This research has focused on the system identification of a two link manipulator After a broad review in methods models and classifications of the system identification and nonlinear grey box identification approaches recent works on identification of mechanical manipulators as well as modeling of backlash and friction in the joint s was studied in more details In order to identify more accurately the system under consideration and comprehend the system complexity the manipulator identification was completed in four stages Stages 1 and 2 correspond to identification of link 1 and 2 as two different single link manipulators In stage 3 the complete system i e the two link manipulator was identified In the final stage the identified model of the system was used to control either single link manipulator practically Due to the different behavior of the system in high and low velocity regimes al the identification process were repeated for these two cases thus a switching model was developed to consider both regimes The identification process started with collecting motors voltage and joint s position as the input and output data of the manipulators Although a time domain approach has been taken into account in the system identification filtering and differentiation of the joints position was carried out in the frequency domain using a cutting window in the FFT of the data The joints velocity and acceleration data were obtained with multiplying the filtered position data by and respectively In the nonlinear grey box structure utilized in this research the presented model considers dynamics of the DC motors flexibility friction and backlash of the joints Friction and backlash are modeled by newly introduced anti symmetric nonlinear models A two mass flexible model is used to model the joints flexibility Following the optimization process for test data and proposed model a statistical approach has been implemented to assess the model as well as to select the most appropriate parameters obtained from the optimization process In the final stage of the research the identified model and parameters was utilized to design and implement controllers for both single link and two link manipulators The controllers were designed using a CTM approach For the sake of comparison three different models of the system were used to design the controllers The first one is a mathematical model with calculated parameters from design softwares The second model is similar to mathematical model however instead of the calculated parameters we have used the parameters that identified in this research For the last case the identified model and its parameters were used Comparison of the experiment results showed a great improvement about 95 in the closed loop system performance from the mathematical model based controller to identified model based controller Keywords Nonlinear grey box system identification identification of mechanical manipulators friction model flexible backlash model

بهرامي، جواد

شناسايي سيستمي و پارامتري يك بازوي مكانيكي دو ميله اي

شناسايي جعبه خاكستري , مدل اصطكاك , مدل لقي , تخمين پارامتر , مدل موتور DC