Health Evaluation And Life Rediction Method Study Of The Dual-axis Drive Mechanism For Satellite Antenna

The dual-axis drive is typical space mechanism in tracking, positioning andservo function act and its health status and the length of life expectancy will directlyimpact the remaining life of the whole satellite. For a large and complex satellitesystem, a key component fault could cause a chain reactions and the entire systemcould not run and even be paralyzed. With the satellite’s long life, high reliabilitymission requirements proposed urgently, health management system is widelyvalued because it mainly consists of fault diagnosis, health evaluation and lifeprediction. For the above, the research of health evaluation and life prediction hasgreat engineering value.First of all, in order to establish the foundation of the fault diagnosis, healthassessment and life prediction, this paper analyzes the structure and failuremechanism of the biaxial drive mechanism with fault tree method. Then, a completefault tree is established based on the failure bottom events. Finally, the key faultycomponents are obtained according to the importance degree.Secondly, this paper adopts the dynamic fuzzy comprehensive evaluationmethod for the system health evaluation. The method overcomes the staticcharacteristics defects of the traditional fuzzy evaluation, the weight matrix anddynamic membership functions are introduced to achieve the real-time evaluation.In addition, for the blindness of the maximum degree principle, the principle is notapplicable for the results analysis. Finally, the weighted average method isintroduced and a reasonable evaluation result is achieved.Then, the remaining life of the drive mechanism is based on virtual prototypingtechnology. Bearing wear is the key factor affecting the life. Therefore, this paperestablishes the clearance joints mathematical model and contact-impact force model.Dynamics simulation data are obtained based on ADAMS. The fitting function iscreated with MATLAB，and life prediction model is established according to theclearance mathematical model and the contact force function. The loop iterationsfunction can be programmed until the wear threshold is achieved. The iterative timesare obtained and the remaining lifetime can be calculated.Finally, this paper designs and develops the software system for health evaluation and life prediction. In any state for the dual-axis drive mechanism, thehealth evaluation and life prediction functions are achieved based on mixedprogramming with VC++, SQL Server2000as well as Matlab.