Silent Subdivision Driver Of Hybrid Stepping Motor And Its Application

Hybrid stepping motors have both the advantages of reactive and permanentmagnet stepping motors, and can be applied in many areas because they can get highopen-loop control performance without speed sensor. But due to the noise generatedby stepping motion and other reasons, its work noise is significantly higher than othermotors, so it can not able to meet some application which need low noise. Accordingto the mechanism of stepping motor noise, the driver performance is the decisivefactor besides its own parameters, so it is meaningful to design a low noise steppingmotor driver.This dissertation analysis the background, meaning and the research status bothabroad and home first, then describes the composition and structure of the driver,especially analysis the main circuit, the detail of the noise causes and noise reductiontechnologies. Next the overall framework of silent stepping motor driver and thehardware, software technology implementation are given.Followed by a detailed analysis of the characteristics of stepping motor noise weget the result that electromagnetic noise is the main source. Then the noise model isestablished and the noise suppression measures are proposed. Next the current vectorconstant amplitude and equality rotation subdivision drive method is adopted as thedriver scheme and the winding filter circuits are designed to filter the high-frequencyelectromagnetic noise generated by PWM.Because stepping motor may over step in acceleration or out of step indeceleration process, so the improved S acceleration and deceleration control curve isproposed by the analysis of torque frequency characteristic and the compare ofvarious acceleration and deceleration curve. Then the closed-loop control systemmathematic model of current is established. The PI regulator is chosen as the currentloop controller and the regulator parameters are designed because the PID controllerhas good performance of both dynamic and static characteristics.Finally the hardware and software technology implementation of stepping motorsilent subdivision driver is designed by the high-performance embeddedmicrocontroller STM32F103RCT6as the core and a prototype has been build. Thehardware part includes controller board circuit design and driver board circuit design. Controller board includes the MCU and its peripheral circuit, serial communicationcircuit, human-computer interface circuit and error alarm circuit; Driver boardincludes power configuration circuit, main drive circuit, optocoupler isolation circuit,signal processing circuit and winding filter circuit. Software part is based on theSTM32firmware library and the real-time operation system μC/OS-II. It containsthe system main program, data acquisition task, PWM wave generation task,algorithm task of internal control, algorithm task of external control and humancomputer interface task. The maximum subdivision number of the prototype is up to512, and the number of subdivision, current as well as speed can be set by keys.Through the test of the experimental apparatus and the application on micro-injectionpump, we can find the running noise of injection pump is significantly reduced.