Research On Key Technologies Of Small DC Servo Driver

In the fields of multi-axis robots and multi-rotor UAVs,servo control systems are developing towards high speed,high precision,miniaturization and lightweight.In view of the large size of domestic drives,single drive,expensive price of foreign drives and complex control,a drive was designed to cater to the domestic market.The driver can drive DC brush motor,DC brushless motor,and support Hall sensor and encoder.The position loop,speed loop and current loop control strategy as well as,the latest SVPWM(Space Voltage Vector Control)algorithm was used,and the sweep frequency motor parameter automatic identification technology was adopted to improve the current loop to achieve automatic control purposes.This thesis introduced the development of servo control system and the research status of DC servo motor driver at home and abroad,and elaborated the research contents.The established mathematical model of DC brushless motor,the control principle of SVPWM motor obtained through CLARK and PARK transformation,and the realization of motor control algorithm was introduced in this thesis in detail.The hardware and software design of the motor driver were elaborated in this thesis.In the part of hardware design,the overall design scheme was given to detail,all hardware modules including power module,control subsystem,drive subsystem,sensor subsystem and detection circuit.And the miniaturization of motor driver was realized through the reasonable layout.With STM32F103RCT6 used as controller,a four-way bridge MOSEFT switch circuit was designed which could support peripherals such as Hall sensor and encoder.In the part of software design,the whole design scheme was also provided which includes the main program and subprogram.The main program mainly includes fixed control algorithm,and the subprogram includes communication subroutine,interruption subroutine,motor start-stop subroutine,etc.The design ideas of each program and the flow of software control were introduced in detail.An experimental platform was built on the basis of hardware.This thesis analyzed the position loop,speed loop and current loop control strategies of DC servo driver in detail,and proposed an automatic parameter identification strategy of current loop based on sweep frequency.The strategy was based on the online identification of parameters,and the adaptive control strategy was applied to the identification result to establish motor control parameters.In this way,it was easy to debug any motor and made the system have good dynamic performance.The simulation and experimental results showed that the proposed automatic parameter identification method of current loop could achieve good control effect,and the parameters of automatic identification made the whole system have better dynamic stability.This thesis provided the experimental results and data of no-load and loading of the servo driver,described the following performance of the speed and current of the driver and its dynamic response performance,summarized some details of the design of the DC servo driver,and presented the prospects of the research subject.