Research On Steering Maneuver Control And Road Feeling Simulation Technology Of Lunar Rover Vehicle

Almost every nations in the world are exploring planets outside the earth actively at present,and the manned LRV(Lunar Rover Vehicle)has become the heated concentration as the transportation tool for astronauts to explore the moon and finish the scientific mission.The trend of the development for ordinary ground vehicle steering system is lighter weight and SBW(Steer-by-Wire).Similar to it,LRV also need steering stability improvement and tunable road feeling.Here comes the problem of maneuvering control and road feeling simulation for LRV.So the paper combines the road feeling simulation technology on ground vehicles and steering mechanism of LRV,finishing the steering wheel maneuvering control and road feeling simulation of LRV,and testing the built road feeling platform.Firstly,the paper analyzes the special steering mechanism of LRV,and build the model for this SBW system.And it combines the handling dynamics of LRV,getting the4-DOF handling dynamics model that consists steering wheel rotation,LRV body lateral translation,yaw and roll.And it finishes the simulation analysis for wheel rotation,LRV body lateral acceleration and yaw under the specific steering wheel rotation input.Then the paper gets the broken point force and torque of the central steering rod via simulation,comparing the different road feeling under different running conditions and with different gravity.Secondly,the maneuvering control of steering system has been realized.And the paper designs the PD controller according to the major control aim.The paper generates a reference angular position for peripheral steering wheel,as its tracking trajectory.In this part,it utilizes a new differential method to resolve the angular velocity and angular acceleration of steering wheel,designing the torque observer to realize the observation of wheel moments while running and human hands torque on the steering wheel.And all these are for the enhancement of the control model.The simulation analysis for observer and control system has been finished within the built Matlab/Simulink platform.Thirdly,the road feeling model has been established.Based on specific parameters of LRV steering mechanism,the paper calculates the ratio of the translation of torque from the wheel to the broken point,and get parameters for wheel steering moments calculation according to experiment data.Referring to the content of ground vehicle road feeling,the road feeling parts and their calculation functions have been designed.And weighting parameters are also designed,along with other road feeling parts calculation parameters,providing the convenience for tuning afterwards.Finally,the building of LRV road feeling simulation system is finished within theVortex Multi-body Dynamics simulation platform,and the road feeling model and control model are also integrated.Besides,in order to achieve the visual stimuli for drivers,lunar surface terrain,universe with starry sky and rotating Earth in the distance are also added.According to the evaluation criteria,the paper finished the simulation analysis to get the road feeling,which can reflect the load condition of wheels while running on the moon.And it can be suitable within certain velocity range,through tuning road feeling calculation parameters and weighting parameters.Then it proves that the road feeling can reflect different road conditions by simulation tests with different terrains.