Research And Design Of Measurement And Control System On Wheel-soil Interaction For Rover

As an indispensible tool for outer space exploration, rover is required to runon the surface of planet independently. The slip and sinkage phenomenon iseasily produced because of the complexity and uncertainty of planet surfaceenvironment, which increase many challenges for rover exploration task. Thewheel of planetary rover, which contacts directly with the soil, is of decisiveinfluence for mobile performance of the vehicle. It is greatly significant foranalysis on driving performance of wheel and mobile control of planet vehicle todeeply research the mechanical properties of wheel-soil interaction. Therefore,it’s very necessary to design a measurement and control system on wheel-soilinteraction with perfect function based on building terramechanics models.The influence of wheel-soil interaction mechanics caused by movementparameters of wheel and mechanical properties of soil is analyzed based onterramechanics theory. To simulate the running state of wheel, forward model,side slip rolling model and steering model are builded and analytical expressionsof concentrated force and torque in integral model are derived. The relationshipbetween parameters is analyzed aimed at the highly coupling characteristic andcomplexly nonlinear characteristics of the forward model equations. Theestimation method for wheel slip ratio of planetary rover is researched combinedwith analytical result and forced slip theory.The simulation methods on rugged terrain of planet surface environment areproposed and test tasks of wheel-soil interaction based on mechanics model areascertained by introducing the motion device of pitching soil tank and themeasurement and control device on wheel slip. According to the tasksrequirement, the architecture of measurement and control system on wheel-soilinteraction is designed, which is divided into motion control system and data acquisition system. Then the hardware system platform is builded and specifichardware configuration is given. The modular system of software is constructedby analyzing the overall design scheme of measurement and control system, andthe software program is developed based on hierarchical and encapsulation mode.The experiments of wheel-soil interaction are carried out after analyzing theexperiment system, experiment procedures and data processing method. Therelationship between the test data and the slip ratio is researched based on wheelforward experiments and side slip rolling experiments, which can lay thefoundation for driving performance of wheel. The theoretical value and actualvalue of slip ratio are compared based on passive slip experiments. Theexperimental results validated the rationality and validity of mechanics modeland estimation method for wheel slip ratio.