Rover Attitude Determination Using Kinematics Model and its Applications in Pragyan Operations

Rover plays an important role in planetary exploration missions. They serve as mobile laboratory traversing over challenging terrains to carry out in situ scientific experiments. One crucial part of path planning is to ensure safety of rover as it traverses uneven terrain covered with boulders & craters. This paper deals with kinematic modelling of a 6-wheel rocker-bogie rover and its application in different phases like design & mission operations. A geometric model of the rover inverse kinematics is developed to compute rover attitude as a function of terrain. This model is used to select a path which has less chances of the rover toppling. The model accuracy is proved by carrying out experiments on calibrated test bed. The application of this model during Pragyan mobility operations, post Chandrayaan-3 landing on 23 Aug, 2024 is illustrated.