Development Of Motor Servo System Based On CANopen DS402 Protocol

CANopen DS402 protocol(hereinafter referred to as DS402 protocol)is a fieldbus protocol that is very suitable for applications in the field of motor servo systems.Although it has been proposed as early as the 1990 s and related international standards have been formulated by the German Ci A Association.At present,in the domestic motor servo drive system,the field bus is still based on the RS-485 interface.There are two main rea sons for this phenomenon: First,from the perspective of the protocol itself,compared to the simple RS-485 protocol,the DS402 protocol,as a standard protocol,contains more extensive and comprehensive content,and the protocol has strict standard specif ications.The development presents the characteristics of complex technology,high requirements,large workload,and long cycle.Second,from the system point of view,DS402 fieldbus and motor vector control system are two relatively independent and interactive subsystems.This interaction research on the impact of their respective system performance needs to be strengthened.In order to facilitate the research,considering that the original products have a large number of upgrades and the need to provide a technical basis for further integrated development,this topic adopts the implementation of the DS402 communication card on the basis of the existing servo drive to solve the above two problems.Focused research and experimental verification,and reached effective conclusions.The specific research content is as follows:First of all,on the basis of studying the vector control algorithm of permanent magnet synchronous motor,the MATLAB servo motor vector control system simulation model is designed,and the control cycle composition of the servo motor vector control system is given.Lay the foundation for the research on the influence of the interaction between the two subsystems.Secondly,based on the circuit analysis of the existing servo drive,according to the requirements of the DS402 protocol and the interface characteristics of the servo drive,the DS402 communication card hardware device with STM32F407 as the processing unit was designed and manufactured,which is the realization and related control of the DS402 protocol stack experiments provide hardware foundation.Then,detailed theoretical analysis of communication modules such as the communication model,object dictionary,communication objects(SDO,PDO,NMT)and state machine in the DS402 protocol;on this basis,the software development of the DS402 protocol stack was completed with reference to the DS402 protocol specification.And successfully applied it to DS402 communication card.Finally,the performance impact of the interaction between the DS402 fieldbus and the motor vector control system was studied and a conclusion was reached.When the shortest single synchronous PDO transmission cycle is the boundary condition,the message transmission time is 148 us,and the CPU real-time response time to the data message about 7.5us,that is,in a single PWM switching cycle,the CPU needs to guarantee the remaining time resources of7.5us to respond to data messages in real time under extreme conditions and complete the task requirements of the servo motor vector control system.