Abstract: To satisfy the increasing demands on the reliability of dynamic positioning system for deepwater oil and gas exploration, a threeredundant dynamic positioning control system was established based on the realtime operating system Vxworks according to the classification specification of class notation DP3 for dynamic positioning system. Hardware architecture of the tripleredundancy control system was designed based on the
PC104 bus. Control calculation and faulttolerant management of threeredundant realtime control computers were implemented by software. The reliability of control system was analyzed by using Markov process, and the effects of various hardware fault parameters on the reliability measures were investigated. The analysis results show that the reliability of DP3 dynamic positioning control system can be greatly improved.  

Key words: dynamic positioning (DP), control architecture, fault tolerance, system reliability