Research On Auxiliary Steering Control Of Vehicle Driving With Force/Haptic Guidance

Vehicle active safety technology is an important component of the auto-auxiliarydrivingsystem,which aims at eliminating accidental potential by telling the driver upcoming obstacles in advance.New sensingtechnologies allow modern vehicles to perceive theenvironment around them,Sb Wsystemwhich implements active steering of vehicle is a sort of teleoperation system with force feedback.Therefore,it has been proved to be possible to introduce the haptic guidance control technology in the field of teleoperation into the device of vehiclecontrol and assist the driver in manipulating correctly and timely by means of haptic feedback at the steering wheel.Compared with the driving assistant technique based on auditory and vision,it can provide the driver with more effective assistance with less interference to pass information to the driver using a haptic approach.Combined with the National Key R&D Plan Foundation(No.2016YFC0802902)“Research on the key technology of the Special Chassis and Suspension for High Mobility Emergency Rescue Vehicle(including Fire Fighting Vehicle)”,the method of generating the haptic guiding force of the steering wheel based on the mission planning system is studied.the shared control method which fusing guidance force and manipulating force is presented anda hapticassistedsteering interface thatusing this method was designed,which can assists the driver by applying a torque on the steering wheel to guide proper and well-timed steering and increase intelligence and safety in vehicle manipulating.The research works in this thesis is stated mainly from the following aspects:1.According to function demand and control procedures of intelligent assisted steering interface based on haptic guidance,designed the mechanism,which has active veering function and meanwhile satisfies its aligning and limiting displacement functions.2.The thesis model the mathematical models from force sense motor to steering wheel of the designed assist interface.On the basis of established model,unknown mechanical parameters are estimated according to input and output parameters of system using least square method.3.Path planning based on improved RRT algorithm is generating an executable track that can be used for path tracking.This algorithm combines the nonholonomic constraints and the dynamic models of vehicle with RRTs.Furthermore,a goal-biased sampling strategy a reasonable metric function are introduced to greatly increase the planning speed and quality.4.To control the vehicle path planning for target tracking without deviation,the model predictive controller is designed;constructed the haptic guidance force that is proportional to the difference between the driver’s steering input and controller’s desired steering action.Besides in order to realize the smooth cooperation between the driver and controller,the influence degree of driver manipulating force and haptic feedback force on the lateral motion of vehicle as a selected index of fusion weight coefficient,the shared control strategy based on force fusion is presented.5.Set up the fixed base simulator experiment platform with the assisted steering interface based on haptic guidance and write relevant control program,and qualitatively verify superiority of the control strategy based on haptic guidance by the experiment comparing which with manipulating of virtual vehicle guided without haptic guidance.