Parameter Optimization Of Energy-Harvesting Shock Absorber With Low Speed And Heavy Load Capacity

Electric vehicles have become an important direction for the development of passenger vehicles,and their energy-saving and emission reduction technologies are particularly important for increasing driving range.Traditional car shock absorbers cause waste of vibration energy while reducing vibration,increasing issues such as carbon emissions and environmental pollution.They also have problems such as oil leakage,which can lead to damping failure.Therefore,this thesis designs an energy feedback shock absorber based on ball screw pairs to alleviate the "mileage anxiety" of electric vehicles,studies its damping and energy feedback characteristics,and conducts parameter optimization analysis for its performance.The specific content is as follows:Firstly,based on the theory of electromechanical coupling,a theoretical model of damping and electrical characteristics of shock absorbers is established based on sinusoidal displacement excitation and road random displacement excitation.The damping force is divided into inertial damping force,electromagnetic damping force,and mechanical damping force.The impact of different working conditions and external load resistors on the damping output of energy fed shock absorbers is analyzed in detail,And the energy recovery performance of shock absorbers under diffferent working conditions and road surface levels.Secondly,a global sensitivity analysis method based on variance is used to conduct parameter sensitivity analysis on the damping and energy feedback characteristics of the energy feedback damper.The excitation amplitude,frequency,load resistance,motor back electromotive force constant,motor electromagnetic torque constant,lead screw,motor reducer transmission ratio,and other parameters are comprehensively studied.The results show that for damping characteristics,under external conditions,the load resistance has the greatest impact on the equivalent damping coefficient,while for structural parameters,the motor deceleration ratio has the greatest impact on the equivalent damping coefficient;For the energy feedback characteristics,under external conditions,the load resistance also has the greatest impact on the output power,while for structural parameters,the back electromotive force constant of the motor has the greatest impact on the output power.Based on the results of parameter sensitivity analysis,taking a certain type of light truck as an example,a method for determining the optimal external resistance and range of external resistance under different structural parameters was proposed for the smoothness of the vehicle and the energy feedback characteristics of the shock absorber.Genetic algorithm Ⅱwas used for parameter optimization matching to balance vibration reduction performance and energy feedback performance.The optimized vehicle’s root mean square value of vertical acceleration on A-level road surface was reduced by an average of 25.2%,The feedback power of the shock absorber has increased by 51.5%.Finally,experimental analysis was conducted on the energy feedback damper,including bench tests and actual vehicle tests.The initial prototype of the damper was processed and bench tests were conducted to verify the correctness of the theoretical model of the damper,and a comparative analysis of the energy feedback performance of the damper before and after parameter optimization was conducted.Design and process the second-generation prototype of the shock absorber,install it on an electric beach vehicle,and conduct actual vehicle energy recovery performance testing on a relatively flat runway.