Optimal control for open-pit mine planning: A control parametrization approach

This paper considers the pit shell optimization problem in open-pit mine planning within an optimal control framework. From a control perspective, we formulate the optimization problem by incorporating not only the actual workflows of open-pit mining activities but also various real-world constraints of operational and geological origin. Spatial discretization is applied to transform the continuous optimal control problem with partial differential equation dynamics into an ordinary differential equation. The resulting continuous optimal control problem is subsequently discretized into a nonlinear programming problem using the control parametrization method together with the constraint transcription technique. The nonlinear programming problem is then solved using a standard gradient-based method. Numerical simulations are conducted to evaluate the validity of the model and transformation, as well as the effectiveness of the gradient-based solution technique. Additionally, the limitations of the study and potential directions for future research are discussed.