Adaptive Control For Aircraft Tractor’s Magnetorheological Semi-active Suspension

As the national economy constantly develops, the air transportation industrygrows rapidly, and the demands of aircraft tractors increase with each passing day.Researching on high-tech indicators and high traction friendly aircraft tractors is ofgreat importance. Suspension is the important system to determine the aircrafttractors’ ride comfort and traction friendliness. During the studies of goodperformance suspension systems, semi-active suspension occupies a very importantposition, with superior performance and simple structure. The magneto rheologicaldampers provide a new research approach for semi-active suspension systems, withthe characteristics of fast response, low energy consumption and stable work ability.On the basis of inspecting and studying large numbers of relevant literaturehome and abroad, this paper firstly reviewed and overviewed the development ofsuspension system and MR damper, determined the research direction of the magnetorheological semi-active suspension. Then, the working principle of MR damper wasintroduced, a few of commonly used mathematical model was elaborated. Byanalyzing the characteristic of aircraft tractors, a single-cylinder and single-rod MRdamper model based on mixed working mode was defined, and the damping forceformula based on flat-panel model was derived. The MR dampers works in variablemagnetic field, it is prone to have eddy loss and hysteresis loss, selecting the goodmagnetic materials and reducing the current change rate are the main methods tosolve the heat problem. Finally, refer to the testing results in existing literature, theparameters of each parts of DR damper were chosen, and its three-dimensional solidmodel is established in Pro/E.Adaptive control has advantages in dealing with the problem has variableparameters, nonlinear factors and interference. This paper takes the quarter car bodyas research subject, breaks the limit that the different directions of force and relativemotion in conventional skyhook control. Using optimal control to get the referencemodel, which is better than passive suspension. On this basis, the adaptive controlalgorithm was worked out. The simulation results show that the semi-suspension withadaptive law can accurately and quickly track the reference model, and achieve thesame control goal as the reference model.In order to study the dynamic characteristics more deeply, a half model of theaircraft tractor was built. The application of model reference adaptive control provesthe general adaptability. In order to obtain good control results, this paper combinedadaptive control with other intelligent control to take full play their respectiveadvantages. Adopt adaptive fuzzy algorithm to control MR dampers, take reducingthe body acceleration as control objectives, formulate corresponding fuzzy rules and scaling factors transform law. The effectiveness of the control algorithm is verifiedthrough simulation analysis.In order to facilitate further research and engineering applications, at the end ofthis paper, the build way of test rig was given, including the selection of excitationunits, sensors, data acquisition card and IPC, also introduced the procedures ofcontrol process. Taking data collection and preservation and solving optimal controlforce for example, summarized the software implementation process in LabVIEW.