The Research Of Key Technology Of Intelligent Electric Actuator Based On PROFIBUS-DP Fieldbus

Electric actuator is a kind of important terminal-control instrument in automatic control system. It effects on the independence of the automatic control system. It plays an important role in the credibility of the control system. But now traditional electric actuator which are widely used in many factories in our country can't carry out fieldbus communication. Low precision, wide insensitive area and complicated connection are also traditional electric actuator't innate defects. Traditional electric actuator's capability can't meet modern industry production needs. With the development of fieldbus technology, the electric actuator is developed very fast. Fieldbus and intellectualization are general trend of the electric actuator development. Because of that, the development of the intelligent electric actuator based on the PROFIBUS-DP fieldbus technology is valuable.The main subject of this paper is using embedded systems design technology to develop the electric actuator which has independent intellectual property right and design PROFIBUS-DP interface module appling to electric actuator.After looking back the developing history of industrial automation instruments, especially electric actuator, this paper first introduces the application of embedded system and fieldbus for intellectualized instrument to make us design this actuator in reason.Secondly, CMX-Scheduler RTOS becomes the object of study.The paper analysed the source code of CMX-Scheduler. We studied the user programming on the embedded system, including system principles and transplanting details, so that the job prepared for the development of electric actuator.The stress of paper is using Fieldbus technology to develop the electric actuator. Firstly, the paper mainly discussed how the electric actuator is designed and and developed. The main control software and hardware of the actuator are analyzed and designed in brief. The main control circuit is designed and developed in detail mainly including the realization of location measurement circuit, the realization of motor drivering circuit, the realization of infrared communication circuit and the development of PROFIBUS-DP fieldbus communication interface.The paper introduced how to transplant CMX-Scheduler RTOS to the hardware platform of electric actuator and how to realize the software design of electric actuator.At the same time, we designed the PROFIBUS-DP network to test the functions of electric actuator. The result of experiment indicated that the electric actuator can realize the function of PROFIBUS-DP fieldbus communication.In this paper, the PROFIBUS-DP fieldbus control systerm is chosen as research subject. We first analyzed fault, the root that causes the unreliability of the system. The main faults of PROFIBUS-DP fieldbus control systerm are categorized and studied. The thesis studies the effective measurements to improve the reliability of PROFIBUS-DP through fault prevention and fault tolerant, especially redundancy technology. We realized the redundancy systerm of PROFIBUS-DP fieldbus control systerm, i.e. master redundancy, slave redundancy. This involves the definitions, architectures, functioning mechanisms of the three aspects. The respective functions of each are analyzed in detail.We constructed the redundancy systerm of PROFIBUS-DP fieldbus control systerm to test the functions of redundancy technology.The result of experiment indicated that the methods improve the reliability of PROFIBUS-DP very well.