Semi-automation of a rockbreaker system: dynamic modeling and optimal collision-free trajectory planning

Abstract

In light of technological advancements, the mining industry is seeing an increase in equipment automation. A hydraulic rockbreaker is a machine that would bene t from automation. The goal of this research is to develop some of the necessary algorithms to render a rockbreaker semi-autonomous. Semi-automation of such systems would allow for improved ease of use, increased productivity and e ciency of rock breaking operations, reduced maintenance costs while also removing the operator from harm's way. Several components are necessary to make semi-automation feasible, including a dynamic model as well as trajectory planning algorithms which generate collision-free trajectories to be used by a controller. The development of a complete dynamic model for such a system would allow for better control when using model-based controllers. However, such a model is di cult to develop in practice, has added complexity and may be computationally expensive. In this work, simpli ed dynamic models are developed and compared with respect to a complete dynamic model of the rockbreaker. One of the resulting simpli ed dynamic models, which only considers the inertial and gravitational e ects of the rockbreaker's mechanical links as well as the gravitational e ects of its hydraulic actuators, is shown to provide adequate representation of the system so as to be used in a model-based controller. The work also develops a set of o ine trajectory planning algorithms that generate time-optimal trajectories which ensure smooth motions and hydraulic valve actuation while satisfying the system's ow rate constraints. With the addition of a collision avoidance strategy and collision detection algorithm, the generated trajectories within the system's work environment can be expected to be collision-free.