Intelligent Controlling Method Of Frictional-magnetic Compound Braking Performance Based On Magnetic Field

Frictional braking is one of the most common braking mode used in mechanical systems.Mechanical systems can be decelerated and stopped through the friction effect between frictional pairs.Related researches demonstrate that braking performance tend to be declined and even braking failure will occur because braking conditions have great influences on tribological properties of frictional brakes.Nevertheless,magnetic braking,a non-contact braking mode,can make up for the shortcomings of frictional braking effectively,and it has been applied in vehicles.Gradually,a novel braking mode composed of these two braking modes is established but they are structurally independent,which greatly increases the structural complexity of braking system.Therefore,it is necessary to study the influential law of braking conditions on frictional-magnetic compound braking performance based on the reasonable combination of frictional and magnetic braking modes.Then,an intelligent control system of frictional-magnetic compound braking performance can be designed and established with artificial intelligence technology.It will provide great theoretical value and practical significance for the rapid development of multi-source braking systems and the improvement of braking performance and reliability of mechanical devices.In this thesis,the automotive disc brake was selected as the research object,and a novel frictional-magnetic compound brake was designed.Braking performance of the brake was analyzed by conducting the inspection experiment of braking performance,and the intelligent control method for frictional-magnetic compound braking performance was also studied based on the influential laws of magnetic field on braking performance.Firstly,in order to carry out the inspection experiment,the frictional-magnetic compound brake was designed.The mechanical hardware of frictional-magnetic compound braking performance inspection test bench was designed from three aspects including power drive system,inertia load system and frictional-magnetic compound braking system.The lower computer program and display and control interface of control system were designed with STEP7 and iFIX respectively.As a result,an integrated inspection test bench for frictional-magnetic compound braking performance was established.Secondly,the inspection experiment with and without magnetic field for frictional-magnetic compound braking performance was conducted to analyze the braking performance under different working conditions.Three typical characteristic parameters applied to characterize braking performance were extracted,and the influential laws of various working conditionparameters on the characteristic parameters were deeply analyzed.Thirdly,in order to make the mechanical system brake with the constant braking torque,a decision-making system was designed based on BP neural network,and a feedback control system was fuzzy PID as well.Accordingly,an intelligent control method for frictional-magnetic compound braking performance was built.Finally,the software system of the intelligent control system was designed with iFIX,and the braking experiment with constant braking torque was conducted.Experimental results demonstrated that the intelligent control system for frictional-magnetic compound braking performance is able to forecast the final frictional braking torque effectively,and wide fluctuations of braking torque can be weakened by the feedback control system,which makes the braking system brake with a nearly constant braking torque.