Abstract: A method for evaluating whether a measurable disturbance on a process controlled by a feedback controller is suitable for feed-forward control. The disturbance is measured. The controller output signal due to the disturbance is measured. A first reference signal corresponding to the controller output signal is measured when responding to disturbance entering before the process. A second reference signal corresponding to the controller output signal is generated when responding to a disturbance entering after the process. It is estimated where in the process the disturbance enters by comparing the measured controller output signal due to the disturbance with the reference signals. It is evaluated whether the disturbance is suitable for feed-forward control depending on where in the process the disturbance enters.

Abstract: A methodology for process modeling and control and the software system implementation of this methodology, which includes a rigorous, nonlinear process simulation model, the generation of appropriate linear models derived from the rigorous model, and an adaptive, linear model predictive controller (MPC) that utilizes the derived linear models. A state space, multivariable, model predictive controller (MPC) is the preferred choice for the MPC since the nonlinear simulation model is analytically translated into a set of linear state equations and thus simplifies the translation of the linearized simulation equations to the modeling format required by the controller. Various other MPC modeling forms such as transfer functions, impulse response coefficients, and step response coefficients may also be used. The methodology is very general in that any model predictive controller using one of the above modeling forms can be used as the controller.

Abstract: The invention concerns a reflector and a satellite antenna system comprising such a reflector. In the satellite antenna system, microwave radiation from one or more feed horns (5) is emitted at the reflector (1), which comprises first and second reflector elements (2, 3). Upon reflection of the radiation from the reflector elements (2, 3), a distinct beam shape for the reflected microwave energy is generated. The reflector elements (2, 3) are disposed at a fixed distance from one another so that radiation that passes the first reflector element (2) strikes the second element. The first reflector element (2) comprises a lattice structure aimed toward feed horn, which lattice structure consists of plates (8) of electrically conductive material, wherein the distance between the plates and the depth of said plates are adapted for reflection of polarization parallel to the plates.

Abstract: A method for evaluating whether a measurable disturbance (d) on a process (1) controlled by a feedback controller (2) is suitable for feed-forward control, characterized in that it comprises the steps of measuring said disturbance, measuring the controller output signal (u) due to said disturbance, generating a first reference signal (7) corresponding to the output signal from the controller when responding to a disturbance entering before the process, generating a second reference signal (8) corresponding to the output signal from the controller when responding to a disturbance entering after the process, comparing the measured controller output signal due to the disturbance with the reference signals, and evaluating whether the disturbance is suitable for feed-forward control depending on said comparison.