Research On Fosmc Control Strategy Based On Magnetorheological Semi-active Suspension

In today’s society,the automobile has become a universal means of transportation,at the same time,people put forward higher requirements for the riding comfort and driving safety of the automobile.Suspension is a key component affecting the vibration damping performance of vehicles.The intelligent suspension which can be controlled in real time according to road conditions and vehicle running state is one of the main research directions to improve the ride comfort and safety of vehicles.Using Mr Technology,Mr Semi-active suspension has the advantages of continuous control of damping,low energy consumption,fast response speed and relatively simple structure,which has become a research hotspot of semi-active intelligent suspension.Due to the strong nonlinear,external disturbance and timevarying parameters of magnetorheological suspension,the conventional control strategy is difficult to meet the constantly improving performance requirements of suspension.Therefore,designing the control strategy with high anti-interference and robustness is an urgent problem to be solved in current suspension vibration reduction control.Based on this,this paper takes Mr Semi-active suspension as the research object and carries out the following researches:1.A Mr Damper(MRD)was designed for use in a semi-active suspension scenario for automobiles.According to the application requirements of MRD,the working mode of MRD was determined,and the relevant structural materials and materials of Mr Fluid were determined.The key structural parameters of MRD are designed,and magnetic circuit analysis is carried out.Based on this,the simulation analysis of the designed MRD is carried out to verify the effectiveness of the design.2.The dynamic characteristics of the designed MRD were tested and analyzed,and the forward and reverse mechanical models of MRD were established.According to the structure design of MRD,the prototype of MRD was processed,and the damping characteristics of the test analysis,the test results show that the designed MRD can meet the requirements of automobile suspension.An improved hyperbolic tangent model of MRD was selected,and its parameters were identified using a particle swarm optimization algorithm.The identification results are compared with the experimental data,and the accuracy of the model is verified.At the same time,the ANFIS reverse model of MRD is designed.The simulation results show that the reasoning error of the ANFIS reverse model is small,which can be used in the followup control research.3.According to the magnetorheological semi-active suspension model of 1/4 car,the proposed control strategy is simulated and analyzed.A magnetorheological semi-active suspension model was established for the vertical motion of the body.On this basis,fractional order theory was incorporated into the PID control strategy to enhance its precision,and a fractional sliding mode control(FOSMC)strategy was proposed to further validate the effectiveness of the fractional order theory and reduce chattering.Through the simulation analysis on random pavement and convex hull pavement,it can be seen that the proposed control strategy can effectively improve the damping effect of Mr Suspension.4.According to the magnetorheological damper designed above,the two-degree of freedom magnetorheological semi-active suspension structure was designed and processed,and the test system and control system of the semi-active suspension were built.The effectiveness of the proposed semi-active control strategy is verified under sinusoidal road excitation of suspension test system.The results show that FOSMC control has obvious vibration reduction effect and is better than the traditional SMC control,which verifies the effectiveness of FOSMC control in the application of Mr Semi-active suspension.