Abstract: Method for the computer-assisted determination of an optimum-fuel control of nozzles according to a control instruction b=Ax. A defined matrix transformation of starting constraints for the mass flow of the nozzles and of the minimization criterion thereby takes place in a computer-assisted manner, a data processing representation of a geometric description of the matrix-transformed starting constraints, a computer-assisted determination of limiting point sets of the geometric description of the starting constraints through a computer-assisted geometric search procedure in the vector space and the application of the matrix-transformed minimization criterion to the points of the limiting point sets.

Abstract: Method for the computer-assisted determination of an optimum-fuel control of nozzles according to a control instruction b=Ax. A defined matrix transformation of starting constraints for the mass flow of the nozzles and of the minimization criterion thereby takes place in a computer-assisted manner, a data processing representation of a geometric description of the matrix-transformed starting constraints, a computer-assisted determination of limiting point sets of the geometric description of the starting constraints through a computer-assisted geometric search procedure in the vector space and the application of the matrix-transformed minimization criterion to the points of the limiting point sets.

Abstract: Method for the computer-assisted determination of an optimum-fuel control of nozzles according to a control instruction b=Ax. A defined matrix transformation of starting constraints for the mass flow of the nozzles and of the minimization criterion thereby takes place in a computer-assisted manner, a data processing representation of a geometric description of the matrix-transformed starting constraints, a computer-assisted determination of limiting point sets of the geometric description of the starting constraints through a computer-assisted geometric search procedure in the vector space and the application of the matrix-transformed minimization criterion to the points of the limiting point sets.

Abstract: In the control of spacecraft, thrusters must generate a commanded force or torque that is computed from the control algorithms in order to maintain a certain attitude or orbit. In general, there is an infinite number of solutions as to how the thrusters are fired in order to achieve the commanded value. However, additional imposed constraints on the mass flow allow only a small subset of those solutions to be feasible. By way of example, two constraints are considered in this invention: first, the mass flow of each thruster must exceed a minimum value and second, the total mass flow of all thrusters for any generated force/torque must be constant. If only a non-feasible solution is found, known methods turn it into a feasible one by reducing the commanded force/torque until the constraints are met. Reducing the commanded force/torque is, however, a disadvantage because the performance may decrease and even lead to instability of the closed loop system.

Abstract: In the control of spacecraft, thrusters must generate a commanded force or torque that is computed from the control algorithms in order to maintain a certain attitude or orbit. In general, there is an infinite number of solutions as to how the thrusters are fired in order to achieve the commanded value. However, additional imposed constraints on the mass flow allow only a small subset of those solutions to be feasible. By way of example, two constraints are considered in this invention: first, the mass flow of each thruster must exceed a minimum value and second, the total mass flow of all thrusters for any generated force/torque must be constant. If only a non-feasible solution is found, known methods turn it into a feasible one by reducing the commanded force/torque until the constraints are met. Reducing the commanded force/torque is, however, a disadvantage because the performance may decrease and even lead to instability of the closed loop system.

Abstract: Method for the computer-assisted determination of an optimum-fuel control of nozzles according to a control instruction b=Ax. A defined matrix transformation of starting constraints for the mass flow of the nozzles and of the minimization criterion thereby takes place in a computer-assisted manner, a data processing representation of a geometric description of the matrix-transformed starting constraints, a computer-assisted determination of limiting point sets of the geometric description of the starting constraints through a computer-assisted geometric search procedure in the vector space and the application of the matrix-transformed minimization criterion to the points of the limiting point sets.

Abstract: An attitude controller for a 3-axis stabilized, Earth oriented bias momentum spacecraft is described, where only 2-axis attitude measurements from the Earth sensor are available. In contrast to the classical spacecrafts that are controlled w.r.t. a fixed orbital Earth pointing reference frame, (possibly large angle) time varying reference signals are considered here, i.e. the control task consists of a tracking problem. The controller design consists of a decoupling controller and axis-related PID controllers based on yaw observer estimates.