Co-evolution of morphology and control in developing structures

The continuous need to increase the efficiency of technical systems requires the utilization of complex adaptive systems which operate in environments which are not completely predictable. Reasons are often random nature of the environment and the fact that not all phenomena which influence the performance of the system can be explained in full detail. As a consequence, the developer often gets confronted with the task to design an adaptive system with the lack of prior knowledge about the problem at hand. The design of adaptive systems, which react autonomously to changes in their environment, requires the coordinated generation of sensors, providing information about the environment, actuators which change the current state of the system and signal processing structures thereby generating suitable reactions to changed conditions. Within the scope of the thesis, the new system growth method has been introduced. It is based on the evolutionary optimization design technique, which can automatically produce the efficient systems with optimal initially non-defined configuration. The final solutions produced by the novel growth method have low dimensional perception, actuation and signal processing structures optimally adjusted to each other during combined evolutionary optimization process. The co-evolutionary system design approach has been realized by the concurrent development and gradual complexification of the sensory, actuation and corresponding signal processing systems during entire optimization. The evolution of flexible system configuration is performed with the standard evolutionary strategies by means of adaptable representation of variable length and therewith variable complexity of the system which it can represent in the further optimization progress. The co-evolution of morphology and control of complex adaptive systems has been successfully performed for the examples of a complex aerodynamic problem of a morphing wing and a virtual intelligent autonomously driving vehicle. The thesis demonstrates the applicability of the concurrent evolutionary design of the optimal morphological configuration, presented as sensory and actuation systems, and the corresponding optimal system controller. Meanwhile, it underlines the potentials of direct genotype – phenotype encodings for the design of complex engineering real-world applications. The thesis argues that often better, cheaper, more robust and adaptive systems can be developed if the entire system is the design target rather than its separate functional parts, like sensors, actuators or controller structure. The simulation results demonstrate that co-evolutionary methods are able to generate systems which can optimally adapt to the unpredicted environmental conditions while at the same time shedding light on the precise synchronization of all functional system parts during its co-developmental process

Atmospheric Boundary Layer Classification With Doppler Lidar

We present a method using Doppler lidar data for identifying the main sources of turbulent mixing within the atmospheric boundary layer. The method identifies the presence of turbulence and then assigns a turbulent source by combining several lidar quantities: attenuated backscatter coefficient, vertical velocity skewness, dissipation rate of turbulent kinetic energy, and vector wind shear. Both buoyancy-driven and shear-driven situations are identified, and the method operates in both clear-sky and cloud-topped conditions, with some reservations in precipitation. To capture the full seasonal cycle, the classification method was applied to more than 1year of data from two sites, Hyytiala, Finland, and Julich, Germany. Analysis showed seasonal variation in the diurnal cycle at both sites; a clear diurnal cycle was observed in spring, summer, and autumn seasons, but due to their respective latitudes, a weaker cycle in winter at Julich, and almost non-existent at Hyytiala. Additionally, there are significant contributions from sources other than convective mixing, with cloud-driven mixing being observed even within the first 500m above ground. Also evident is the considerable amount of nocturnal mixing within the lowest 500m at both sites, especially during the winter. The presence of a low-level jet was often detected when sources of nocturnal mixing were diagnosed as wind shear. The classification scheme and the climatology extracted from the classification provide insight into the processes responsible for mixing within the atmospheric boundary layer, how variable in space and time these can be, and how they vary with location. Key PointsPeer reviewe

Ground-based and air-borne lidar for wake vortex detection and characterisation

In the last two years several ground based and airborne wake vortex campaigns have been performed with the DLR coherent Doppler Lidar. The objectives of those cam-paigns were measurements for comparison with the wake vortex prediction and monitoring system WSVBS, the measurement and description of wakes generated by the new Airbus A380 aircraft and a reference aircraft for the ICAO aircraft separa-tion, and the observation of the influence of different aircraft configurations on the vortex life time in the project AWIATOR

Aircraft wake vortex measurement with airborne coherent Doppler lidar

An experiment for airborne Doppler lidar measurement of wake vortices generated by a large transport aircraft in the free atmosphere has been successfully carried out. In this paper, the description of the experiment, data processing procedure, and measurement results are given. It was shown that the use of smoke generators placed on large transport aircraft wings allows some high-quality wake vortex measurements with 2 μm coherent Doppler lidar installed in a second aircraft

Co-evolution of morphology and control in developing structures

The continuous need to increase the efficiency of technical systems requires the utilization of complex adaptive systems which operate in environments which are not completely predictable. Reasons are often random nature of the environment and the fact that not all phenomena which influence the performance of the system can be explained in full detail. As a consequence, the developer often gets confronted with the task to design an adaptive system with the lack of prior knowledge about the problem at hand. The design of adaptive systems, which react autonomously to changes in their environment, requires the coordinated generation of sensors, providing information about the environment, actuators which change the current state of the system and signal processing structures thereby generating suitable reactions to changed conditions. Within the scope of the thesis, the new system growth method has been introduced. It is based on the evolutionary optimization design technique, which can automatically produce the efficient systems with optimal initially non-defined configuration. The final solutions produced by the novel growth method have low dimensional perception, actuation and signal processing structures optimally adjusted to each other during combined evolutionary optimization process. The co-evolutionary system design approach has been realized by the concurrent development and gradual complexification of the sensory, actuation and corresponding signal processing systems during entire optimization. The evolution of flexible system configuration is performed with the standard evolutionary strategies by means of adaptable representation of variable length and therewith variable complexity of the system which it can represent in the further optimization progress. The co-evolution of morphology and control of complex adaptive systems has been successfully performed for the examples of a complex aerodynamic problem of a morphing wing and a virtual intelligent autonomously driving vehicle. The thesis demonstrates the applicability of the concurrent evolutionary design of the optimal morphological configuration, presented as sensory and actuation systems, and the corresponding optimal system controller. Meanwhile, it underlines the potentials of direct genotype – phenotype encodings for the design of complex engineering real-world applications. The thesis argues that often better, cheaper, more robust and adaptive systems can be developed if the entire system is the design target rather than its separate functional parts, like sensors, actuators or controller structure. The simulation results demonstrate that co-evolutionary methods are able to generate systems which can optimally adapt to the unpredicted environmental conditions while at the same time shedding light on the precise synchronization of all functional system parts during its co-developmental process

Method of radial velocities for the estimation of aircraft wake vortex parameters from data measured by coherent Doppler lidar

The method of radial velocities (RV) is applied to estimate aircraft wake vortex parameters from measurements conducted with pulsed coherent Doppler lidar (PCDL). Operations of the Stream Line lidar and the 2-μm PCDL are simulated numerically to analyze the accuracy of the estimated wake vortex parameters with the RV method. The RV method is also used to estimate wake vortex trajectories and circulation from lidar measurements at Tomsk and Munich airports. The method of velocity envelopes and the RV method are compared employing data gathered with the 2-μm PCDL. The domain of applicability of the RV method is determined

The wake vortex prediction and monitoring system WSVBS Part I: design

The design of the Wake Vortex Prediction and Monitoring System WSVBS is described with all its components and their interaction. The WSVBS has been developed to tactically increase airport capacity for approach and landing on closely-spaced parallel runways. It is thought to dynamically adjust aircraft separations dependent on weather conditions and the resulting wake vortex behaviour without compromising safety. Dedicated meteorological instrumentation and short-term numerical terminal weather prediction provide the input to the prediction of wake-vortex behaviour and respective safety areas. The prediction tools employ a number of conservative aircraft parameter combinations that represent the aircraft weight categories medium and heavy. Predictions of the time when all approach corridors along the final approach do not overlap with safety areas determine aircraft separations for follower aircraft of categories medium and heavy. As a safety net a LIDAR monitors the correctness of WSVBS predictions in the most critical gates at low altitude