Robust temporal logic motion control via disturbance observers

The existing motion control systems are largely concerning given reference tracking or stabilization. High-level of autonomy within robotics and autonomous systems demands new motion control methods to realize more complex goals rather than given references, while maintain involved safety conditions. This paper tackles the robust temporal logic motion control problem for a class of disturbed systems. A disturbance observer (DOB) is used for unmatched disturbance estimation, and signal temporal logic (STL) formulas are introduced to express complex sequential tasks. For atomic temporal logic formulas, in order to maximize its robust semantics, a continuous feedback composite controller is constructed by utilizing the transient characteristics of the prescribed performance function and the disturbance observer. We then present a suitable switched control strategy to guarantee the satisfaction of STL specifications consisting of conjunctions of the atomic temporal logic formulas. When the given STL formula is satisfied, the system robustness specified by the user meets the temporal logic specifications. Experimental results are illustrated to verify the effectiveness of the proposed method.