| The use of hub motor drive in electric vehicles is a novel type of driving method,which is favored by many automotive manufacturers due to its high transmission efficiency,strong handling,and good steering ability.As a complex multi-motor system,in order to ensure the safety of vehicles,four-wheel motors need to have reliable synchronous control ability.If the drive motors cannot perform appropriate synchronization control and the drive wheels cannot coordinate,contributing to inadequate anti-interference,robustness,and synchronization performance of the multimotor system,ranging from tire wear to traffic accidents.Aiming at the above problems,this paper takes the permanent magnet hub motor as the research object.In order to meet the requirements of safety,reliability and stability in the actual driving process of the vehicle,an improved model free.Sliding mode control algorithm is designed to solve the problem of weak anti-interference ability and poor robustness of the electric vehicle multi motor drive system;Adopting a mean deviation coupling structure to improve the synchronization performance of electric vehicle multi motor drive systems.The specific research content is as following:With a view to the problem that the permanent magnet hub motor control system is vulnerable to lump disturbances,resulting in a decline in system robustness and antiinterference ability,an improved model free sliding mode control algorithm is conceived.Foremost,a novel ultra-local model of permanent magnet hub motor subjected to lumped disturbances is established;In the second place,an improved reaching law is proposed to design a new model free sliding mode controller;Eventually,an extended sliding mode disturbance observer is used to observe the lumped disturbances in the hyper local model.Compared to PI control,the proposed anti-disturbance composite control algorithm can improve the control performance of the system when it is affected by lumped disturbances,ensuring the rotational speed response and anti-disturbance ability of the system when disturbed,and improving the driving stability of electric vehicles.Aiming at the problem of poor synchronization performance of multi-motor drive systems for electric vehicles during straight travel and steering,the proportional synchronization coefficient and mean rotation speed are introduced into the traditional deviation coupling structure,and a mean deviation coupling structure with simple compensation mechanism and easy implementation is proposed.A permanent magnet hub motor speed synchronization control system is intended based on a mean deviation coupling structure,in which the speed loop is designed using a disturbance resistant composite control algorithm.Compared to the traditional deviation coupling structure,the proposed structure achieves complete synchronization control of the rotational speeds of each drive wheel when the vehicle is traveling straight,and proportional synchronization control of the rotational speeds of each drive wheel when turning,improving the robustness and anti-interference ability of the multi motor drive system when disturbed,improving the synchronization performance of the system,and meeting the reliability,stability,and safety requirements of the vehicle during actual driving.With the purpose of further study in the speed proportional synchronization control of electric vehicle multi-motor drive systems,an electronic differential control strategy was introduced into the permanent magnet hub motor speed synchronization control system.This not only addresses the problem of distributing the rotational speed of the inner and outer drive wheels when the vehicle is turning,but also improves the synchronization performance of the multi-motor drive system when the vehicle is turning,ensuring the driving safety of the vehicle.Figure [54] Table [8] Reference [85]... |
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