Auto-tuning for high performance autopilot design

A novel auto-tuning method for the RIDE controller algorithm is presented. The RIDE controller is applied to a high performance aircraft model. The tuner utilises a constrained genetic algorithm to automate the tuning process. The results of the tuner are compared with that of another tuning method which utilises unconstrained optimisation so as to highlight the efficacy of constrained optimisation for this application. It is shown from the results that the constrained genetic algorithm optimisation scheme offers a highly effective tuning solution which can be used to attain safe and high performance control with the RIDE control algorithm

Discussion note by Prof. Joop Evers: Profile of new intercity transport

The massive use of private cars causes serious problems. Despite parking problems and traffic congestions, for many the private car remains favourable. As an alternative, a new type of public intercity transport has been proposed, called Fast Transport on Request (FTR). Specific elements are: dedicated tracks for high speed bus driving between the cities; booking via Internet or intelligent telephone; intelligent logistics control reducing the number of stops and excluding detours; adaptive seats and digital facilities

Probing Vortex Unbinding via Dipole Fluctuations

We develop a numerical method for detecting a vortex unbinding transition in a two-dimensional system by measuring large scale fluctuations in the total vortex dipole moment ${\vec P}$ of the system. These are characterized by a quantity $\cal F$ which measures the number of configurations in a simulation for which the either $P_x$ or $P_y$ is half the system size. It is shown that $\cal F$ tends to a non-vanishing constant for large system sizes in the unbound phase, and vanishes in the bound phase. The method is applied to the XY model both in the absence and presence of a magnetic field. In the latter case, the system size dependence of $\cal F$ suggests that there exist three distinct phases, one unbound vortex phase, a logarithmically bound phase, and a linearly bound phase.Comment: 6 pages, 2 figure

More with the Lemke complementarity algorithm

In the case that the matrix of a linear complementarity problem consists of the sum of a positive semi-definite matrix and a co-positive matrix a general condition is deduced implying that the Lemke algorithm will terminate with a complementarity solution. Applications are presented on bi-matrix games, convex quadratic programming and multi-period programs

Response by Prof. Joop Evers

The remarks by professor Weidmann concern: (1) Trip booking (discussed in III); The unmanageable number of O/D-relations (discussed in I); (2) Relations with other PTmodalities (discussed in II); (3) Capacity (see I and Profile paper: ‘State of art of fast transport by buses’); (4) Political feasibility (discussed in V and VI); (5) Speed (discussed in II) and (6) Infrastructure (discussed in II, VI and VII). The remarks of professor Bookhuis concern: (1) FTR as an alternative for car travelling (discussed in IV) and (2) Opportunities (discussed in VII). The author thanks professor Brookhuis and professor Weidmann for their interesting and stimulating remarks