||Synchronized Servo Motors Controller Micro-Precision Servo Press
||Institue of Manufacturing Information and Systems
||Dinh Hoai Nam
Synchronized servo motors controller on Micro-precision servo press to make high precision and high formability of servo presses, as well as high productivity of general purpose mechanical presses. The mechanical servo-drive press is operated by two AC servo motors and simulation results are presented. Pressure and position are controlled though a load cell and an encoder, respectively. Here, micro-precision servo press converts torque to linear force due to ball screw. The rotational motion of the system is converted to the slide using ball screws. By the reciprocating motion of motors and ball screws, the press slide moves down and up flexibility. From these feature, two servo motors are controlled by the method which combines feedback and feed-forward control. Based on an available process model the feedback control makes the system stabilize; the feed-forward control reduce tracking error due to frictional and cogging force based on identified model of the linear motor drive system. The research tracks the errors among the input signals of motor and output signals of servo press machine, improve transient response times, reduce the steady state errors and reduce the sensitivity to load parameters. Two servo motors synchronize their speed, the encoder error of two motors get approximate about 10-300 rpm in comparison with 500 rpm _ the encoder error standard that system can accept. Servo press is its low energy consumption, only 10-20% compering with others press machine. Another advantage is a quiet and clean work environment.
List of figures V
List of tables VIII
List of symbols IX
Chapter One Introduction 1
1.1 Press machine 1
1.1.1 Structure 1
1.1.2 Press machine with six links 2
1.1.3 Slide- crank mechanism drive servo press 3
1.1.4 High-speed press in the five kinds 5
1.1.5 Micro-precision servo press 5
1.2 Principle of press machine 6
1.3 Theory of control 7
1.3.1 Control of DC servo press 7
1.3.2 Control of AC servo press 10
Chapter Two Kinematic and dynamic analysis 12
2.1 Position analysis 12
2.2 Velocity and Acceleration analysis 16
2.3 Force analysis 17
2.3.1 Kinematic analysis on crank rotation 17
2.3.2 Kinematic analysis on connecting rod 17
2.3.3 Kinematic analysis on piston 18
2.4 Moment analysis 18
2.4.1 Moment analysis on crank rotation 18
2.4.2 Moment analysis on rod connecting 18
2.4.3 Moment analysis on piston 19
2.5 Analysis of motion of the center of mass 19
2.6 Lagrange’s equation 20
Chapter Three Motion control 28
3.1 Dynamic equation of mechanisms 28
3.2 Feed-back (FB) plus feed-forward (FF) controller 31
3.3 Synchronized two servo motors 42
Chapter Four Experiments and results 48
4.1 Experiment results 48
4.2 Remark 55
Chapter Five Conclusions and future works 56
5.1 Conclusions 56
5.2 Future works 56
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