Research Of Stepper Motor Control Technique Based On Speed Reference Curve

The three-dimensional workbench is a kind of mechanotronics equipment integrating machine-electricity,hardware and software into one;it is the decisive factor of capturing market to guarantee the high speed and high precision of equipment performance.The stepping motor generally adopts the trapezoidal speed curve-driven algorithm,but the output torque use ratio of motor is insufficient and the system stability is not good,which affects the control precision of motor.The thesis makes the stepping motor speed-given curve control technique as the research object to improve the motor's control precision.According to the analysis and research of the existing speed control algorithm,a real-time parabolic velocity given curve algorithm with online calculation function is designed.Three kinds of speed given curve algorithms were simulated and analyzed on the established simulation model.In order to verify the accuracy of the simulation results,a two-phase hybrid stepping motor control experiment platform was established based on the three-coordinate working platform,and the parabolic type control effect was better.The specific work is as follows:(1)Introduce the working principle and internal structure of two-phase mixed stepping motor,establish the mathematical model of stepping motor,and analyze the stepping motor's subdivision driving technology.Through the research on stepping motor speed curve control algorithm,the thesis designs a parabola speed curve with real-time control function.(2)Take the mathematical model of stepping motor as reference,establish the Simulink simulation model of motor and modify the motor's parameters to realize generalization.According to the stepping motor subdivision driving model established,modify the subdividing number,voltage value and current peak value as required to realize the simulation of stepping motor subdivision driving control.(3)Study the speed control method of stepping motor,refer to the torque-frequency characteristics,take in consideration of real-time requirements,design and derive the mathematical model of parabola speed curve and carry out simulation contrastive analysis to triangle and trapezoid speed curves.The simulation results show that the parabola speed given curve has a higher starting frequency,a larger starting torque,a shorter acceleration time and better high speed performance.(4)Establish the control system experimental platform of stepping motor and do experimental verification to simulation results of three-speed curves.The experimental results show that the stepper motor with parabola speed given algorithm has better open loop control performance.