this paper proposes an efficient tracking method for velocity control of an electro-hydraulic servo system (ehss) in the presence of flow nonlinearities and internal friction. the tracking method controller is a kind of feedback error learning structure. in the proposed method, the feedback error learning (fel) algorithm is used to control the velocity. there is no need to compute the system ja...

in this paper a new method is introduced and investigated for removing the destabilizing effects of time-delay parameter in control loops. the concept of the method is taken from the knowledge concerning the dynamic behaviour of irrational transfer functions (ir-tf), which is discussed and investigated elswhere in frequency response domain and is explained briefly here. ir-tfs, which are well c...

TWO-POINT boundary-value problems (TPBVPs) form an important ingredient in the solution of several multiphysics modeling and control analyses, including but not limited to guidance, navigation, and control problems of aerospace engineering. Several techniques to solve TPBVPs have been developed so far and the workhorse at the core of each has been Newton’s method (cf. Bryson and Ho [1]). In thi...

This paper analyzes the local properties of the symmetric interior penalty upwind discontinuous Galerkin method (SIPG) for the numerical solution of optimal control problems governed by linear reaction-advection-diffusion equations with distributed controls. The theoretical and numerical results presented in this paper show that for advection-dominated problems the convergence properties of the...

We introduce a family of highly efficient (non-iterative) numerical methods for a wide class of hybrid control systems. The application of Dijkstra’s classical method to a discrete optimal trajectory problem on a network obtains the solution in O(M logM) operations. The key idea behind the method is a careful use of the direction of information propagation, stemming from the optimality principl...

In this paper we consider multigrid methods for solving saddle point problems. The choice of an appropriate smoothing strategy is a key issue in this case. Here we focus on the widely used class of collective point smoothers. These methods are constructed by a point-wise grouping of the unknowns leading to, e.g., collective Richardson, Jacobi or Gauss-Seidel relaxation methods. Their smoothing ...