Network Based Multi-Motor Speed Synchronization Via Multi-Agent Consensus Protocol

The problem of achieving synchronous speed in the multi-motor system received foremost attention in control engineering due to their wide application in the industrial sector.The multiple motor synchronous speed system found application in paper making machines,textile printing machines,offset printing and etc.The main problem that arises with multiple motors is to attain and maintain the synchronous speed of motors in the system because,in the majority of the cases,the stability of the motor holds with synchronous speed.In order to maintain the synchronize speed,real-time data communication is necessary,and therefore,usually signaling(motor speed and the desired speed)is made to transfer data via communication wires.The main drawback of this methodology is the transmission delay,congestion,asynchronous and other issues of the signal,which in turn bring challenges to achieving the goal of multi-motor networked speed synchronization.The multi-agent system(MAS)can be defined as a collection of identical sub-systems called agents,connected with each other through a network,designed to accomplish a common task.The aim of cooperative control scheme is to make the system of autonomous agent' s effort collectively in order to attain a group task by interacting with each other.Whereas individual autonomous agent represents any dynamical system which can be an unmanned aerial vehicle(UAV),a sensor,an airplane,a satellite or etc.In the presented work,the agent consists of the motor along with its speed control scheme.Aiming at the speed synchronization of networked multi-motor system,the thesis modeled the networked multi-motor system from MAS point of view firstly,then by using various control methods proposed in this study,the MAS consensus protocol are designed correspondingly.The control methods includes the state feedback control,state feedback with LQR control,event triggered state feedback control,the adaptive control and etc.Thus,the goal of the synchronous speed in the networked multi-motor system is achieved.The main research contents are as follows:1.For the DC motor with the buck chopper control methodology,the thesis presents a leader following MAS consensus with the state feedback scheme.At first,for the ith agent,the DC motor model is linearized by variable transformation approach.Since the linearized system is using chopper circuit,it is understood that the MAS that consists of the linearized systems is said to be a switched system.Then,by designing a common lyapunov function,the MAS based consensus control design and analysis are carried out.2.Moreover,another controller design concept is proposed,which uses a Linear Quadratic Control(LQR)design along with the MAS consensus control scheme.In this approach,an LQR cost function is proposed such that the system is said to achieve synchronous speed.As well as,for the stability,combining with the method of designing a common lyapunov function,the MAS based consensus control design is carried out.Compared with traditional analysis methods,the proposed method achieve synchronization simply by monitoring whether the LQR cost function decays or not.3.Furthermore,for the limited bandwidth problem of the network communication issues,the thesis proposes another system design,which includes a non-inverting buck boost chopper circuit,and designing of the event based controller.The speed synchronization error is considered as trigger of incident in the triggering conditions design,while the stability of the proposed switched system is ensured by designing a common lyapunov function.4.For multi-Motor system,the proposed adaptive controllers are said to be hybrid due to the combination of two kinds of control design i-e Regulation,Pole Placement and Tracking(RST)control with Model reference adaptive control(MRAC),called as RST-MRAC,and Variable Structure(VS)control with MRAC,called as VS-MRAC.Afterwards,these hybrid controllers are utilized for the aforesaid synchronization problem using the IM,BLDC motor and brush DC motor based systems,respectively,which verifies the validity of the method.Finally,the study carried out in this thesis can be concluded as more robust and flexible than traditional methods,and achieve consensus i-e synchronous speed.The proposed study also open a wide area for future work by considering different scenarios that may encounter in the system and their industrial application.Some possible future extension of the proposed study may include,incorporating WSN based network system with output sensors to transmit real time data(speed)to the relay node which eventually send it to sink node which conveys the data to NCC located at the remote station,considering network induced delays,network dropout,and external disturbances in the system.