Lonworks Monitor Network And The Smart Node Development Research

The local operation network LonWorks that was developed by American Echelon company in 90s is one of the most competitive fieldbus at the present time. The key of LonWorks technology is intelligent device, namely the development of the control network node. In this paper, we mainly introduced the design procedure of the fuzzy auto-tunning PID control node based on the brief introduction of LonWorks, fuzzy control technology and MCGS, including the soft design and the hardware design. We realized the real-time monitoring to field data in the superior computer. This node is a host-based node. The 16-bit super-low power consumption single chip micro-controller MSP430F149 produced by American TI company is used as the main processor, and the Neuron chip MC143150 is used as the communication processor. The main processor disposes of the more complex I/O events and the application tasks, and the communication processor acts as the network interface and communicates with the host computer or other nodes. The two processors fulfil their respective responsibilities and cooperate with each other. The node makes full use of the powerful processing function that the main processor disposes of application programs and the advantage that the LonTalk protocol of Neuron chip disposes of communication tasks. We adopt the ShortStack between the two processors to realize the serial communication. This smart node used fuzzy auto-tunning PID algorithm. It was realized by single chip micro-controller. It based on the PID algorithm. Through calculating the error e and the rate of change error ec , it adjusted the parameters based on the fuzzy inference and the fuzzy matrix table. It hadn't to establish the mathematic model of the controlled device. To the non-linear and large lag controlled device or the time-variation and exotic environment uncertain system, it had definitive adaptability. It made controlled device have better dynamic and static performance. We adopted MCGS configuration software in the superior computer to monitor the PID parameters in the network and some variables such as output controlled variable. It realized the communication by establishing the DDE between superior computer and the network. At last, combining the fact, we proceeded an engineering study to the application of LonWorks monitor network and the smart node in the automobile drive shaft wearing test-bed. To the fuzzy auto-tunning PID algorithm, we proceeded an emulator study. The emulator result indicated this controlled algorithm had better controlled effect and quality.