A method for on-line soil parameters modification to planetary rover simulation

In planetary exploratory rover simulation, the contact model between wheel and terrain inevitably has some differences in contrast with the real one, which can make rover depart the planned track. To eliminate the dynamic errors caused by it, this paper presents a method for on-line soil parameters modification. This paper classifies data errors between virtual rover and real rover as model errors and asynchronous errors. Before modification, data identification is utilized to eliminate asynchronous errors and get a group of effective data with least additional errors. Based on the simplified terramechanics model, the origins of model errors are analyzed in detail from static status and kinetic status; meanwhile, some soil parameters are decoupled from the complicated model, and it makes on-line soil parameters modification feasible. An effective coefficient is also proposed to maintain the stability and convergence of modification. Lastly, through simulations on ROSTDyn (ROver Simulation based on Terramechanics and Dynamics), it is demonstrated that the soil parameters modification method is effective and useful for rover simulation to eliminate dynamic errors of predictive model.

► We discern and eliminate existing asynchronous errors by data identification. ► We divide and modify soil parameters from static and kinetic status. ► Based on simplified terramechanics model, some soil parameters are decoupled. ► To maintain stability and convergence, an effective coefficient is proposed. ► Simulations verify the effectiveness of this method.