Multiple objective genetic algorithms (MOGAs) simultaneously optimize a control law and geometrical features of a set of homopolar magnetic bearings (HOMB) supporting a generic flexible, spinning shaft. The minimization objectives include shaft dynamic response (vibration), actuator mass and total actuator power losses. Levitation of the spinning rotor and dynamic stability are constraint condi...

This paper considers two aspects of the nonlinear H∞ control problem: the use of weighting functions for performance and robustness improvement, as in the linear case, and the development of a Galerkin approximation method for the solution of the Hamilton-Jacobi-Isaacs Equation (HJIE) that arises in the output feedback case. Design of nonlinear H∞ controllers obtained by Taylor approximation an...

Twenty years after the discovery of high temperature superconductors, practical superconducting wires made of these materials are now being manufactured, and trials of electrical and industrial applications including a train supported by magnetic levitation, a transmission line, a ship ’ s engine, and many others are being implemented. High temperature superconductors have again taken central s...

This paper benchmarks a midrange MCU from Microchip (dsPIC33FJ family) used as a controller for a magnetic levitation plant. Basic control algorithms (slightly modified PID and State Space) are tested to present a rough idea of how long it takes to compute one iteration of the control algorithm loop. Beside this, the significance of various optimisation parameters for the code generation proces...

We point out that a spatially varying electric field can be used to cancel the effect of gravity in liquid mixtures by coupling to the different components' permittivities. Cancellation occurs if the system under consideration is small enough. For a simple "wedge" electrode geometry we show that the required system size and voltage are practical, and easily realizable in the laboratory. Thus th...