Model predictive control for path tracking in cable driven parallel robots with flexible cables: collocated vs. noncollocated control

Abstract This paper proposes a novel control scheme for precise path tracking in cable driven parallel robots (CDPRs) with axially-flexible cables, particular focus to the challenging case of suspended (CSPRs). To handle model nonlinearities while ensuring small computational effort, controller made by two sequential actions is developed. The first term position-dependent, predictive (MPC) embedded integrator compute optimal tensions accurate and fulfilling feasibility constraints; bounds on feasible are also included. second transforms into commanded motor torques, hence currents, that evaluated through kinetostatic electric motors used winding unwinding cables. Control design performed robot dynamics model, formulated assumption rigid Moreover, proposed strategy presented different architectures, collocated noncollocated control. Flexibility handled penalizing large tension variations cost function adopted design, plus some hard constraints maximum derivatives. These features, together embedding within MPC formulation, ensure smooth allow handling axial flexibility although it not explicitly considered design. assess performances algorithm, kinematically-determined suspended, lumped end-effector simulated adopting very flexible Additionally, simplified dynamic electrical sensor quantization included provide realistic representation real environments. results, fair comparison benchmark, corroborate effectiveness approach, its robustness, real-time controllers due wise reduction effort.