Sensor Fault Diagnosis And Fault-tolerant Control Of Electric Forklift EPS System

As a loading and unloading equipment,electric forklifts are widely used in factories,airports,logistics distribution centers and other fields.The steering of the electric forklift is controlled by signals such as the speed of the forklift,the turning torque of the steering wheel,the current of the booster motor,and the load of the electric forklift,which are collected by the electronic control unit of the electric forklift EPS system.The loss of power steering of an electric forklift may cause a collision and affect the handling performance of the vehicle.The failure of the EPS system of the electric forklift is mainly related to the torque sensor,the current sensor of the booster motor and the voltage of the booster motor.More serious is that the sensor failure in the EPS system will reduce the mobility and maneuverability of the vehicle,and serious safety hazards will occur.Therefore,can the sensor failure in the EPS system of the electric forklift be more accurately diagnosed and achieve corresponding fault-tolerant control It is a key issue to improve the reliability of electric forklift EPS.In this paper,the main work and research results of sensor fault diagnosis and fault-tolerant control of the electric forklift EPS system are as follows: First,establish the mathematical model,dynamic model,three-degree-of-freedom vehicle model of the electric forklift EPS system,and the sensor failure model.The fault diagnosis research in this paper has certain reference significance.Second,a model-and data-driven FDD framework is proposed to detect,isolate,and estimate the severity of failures in EPS systems.Third,the failure model of the EPS system consists of actuator and sensor failures.According to linear transformation,the original system is decoupled into two reduced-order subsystems to design adaptive sliding mode observers and generalized views for the two reduced-order subsystems Observer.Fourth,adopt the state feedback design method,combined with the principles of sliding mode controller,etc,use the amount of sensor signal reconstruction of the forklift EPS system to replace the sensor fault output signal as the input of the output feedback controller,to achieve active fault tolerance control of the electric forklift EPS system After reconstructing the sensor signal,the faulty EPS system still has a good control effect under the control of the original controller or recovers to a level close to the intact fault-free situation,and finally realizes the active fault-tolerant control of the electric forklift EPS system.