Modeling Attitude Control in Microgravity
Building on earlier empirical and simulation-based work, this month focused on defining the mathematical model that describes how internal leg movements can influence the robot's global orientation in microgravity. The system was modelled as a non-holonomic free-floating body, with no external torque or fixed base. As in the classic falling cat problem, reorientation must emerge entirely from internal actuation - specifically, coordinated changes in the robot's limb configuration. The body was described with 6 DoF, but control efforts focused on roll (ϕ) and pitch (θ). Each leg has 2 DoF (extension and swing), giving 8 independent inputs. Using this, the control problem was defined as an underdetermined linear system, where the Jacobian:
maps joint velocities to changes in roll and pitch rates:
