General Inner Approximation of Vector-valued Functions

International audienceThis paper addresses the problem of evaluating a subset of the range of a vector-valued function. It is based on a work by Goldsztejn and Jaulin which provides methods based on interval analysis to address this problem when the dimension of the domain and co-domain of the function are equal. This paper extends this result to vector-valued functions with domain and co-domain of different dimensions. This extension requires the knowledge of the rank of the Jacobian function on the whole domain. This leads to the sub-problem of extracting an interval sub-matrix of maximum rank from a given interval matrix. Three different techniques leading to approximate solutions of this extraction are proposed and compared

Set-Membership Computation of Admissible Controls for Trajectory Tracking

International audienceIn a context of predictive control strategy, this paper addresses the computation of admissible control set for a trajectory tracking over a prediction horizon. The proposed method combines numerical methods based on set-membership computation and control methods based on a flatness concept. It makes possible i) to provide a guaranteed computation of admissible controls, ii) to deal with uncertain reference trajectory, iii) to reduce the time complexity of the algorithm compared to the existing approach. Simulations illustrate the efficiency of the developed methods in two different cases. For Single Input-Single Output (SISO) systems, generalized affine forms are computed otherwise a Branch & Prune algorithm with an inner inclusion test is used for Multi Inputs-Multi Outputs (MIMO) systems. The computational time is reduced significantly compared to the one required by the existing approach