There is a long terms of developement for academics theoretical analyzing and experimental researching by using the Lagrangian method. But for such trajectory experimentalists still have interference with reflected waves because of the length of the water tank is too short or the diameter and the density of the simulate particle , in spite of measuring the trajectory of the fluid particle have done. For there is no quite completed quantification data for the trajectory of fluid particle, this study is aiming at researching the truly movement of the flow field under wave-current interaction by trajectory measuring. This research choosing the simulate particle¡¦s diameter for 1 mm , collocating with a high-speed vedio camera to record the particle¡¦s moving characteristics while the wave-current interaction occured, to proceed a series of qualitative and quantitative testing. And to comple with all these data and improve the modification by using Image Processing to derive and orientate the coordinates . According to the experimental results of the flow field,it has proved that mass transport occured at the same-depth and no-flow condition through the wave progressing direction.The trajectory of the fluid particle of wave-current interaction in co-flow , its curve presenting the cross-convolution increasing and even presenting the cuspidal locus. And the trajectory of the fluid particle of wave-current interaction in inverse ¡Vflow is opposite to the trajectory of the no-flow movement. The results of the experiment is quite accord with to the 3rd order the theoretical analyzing of Chen ¡]1994¡^and Shu¡BChen¡]2006¡^¡CThe fluid particle reproducting the moving period of the high-elevation is greater than the wave¡¦s and increasing by the sharpness of the wave. The mass transport velocity is the same theory results ,and decreased deviation of artificiality in estimating particle position. According to the ratio of the experimental results, root mean square of error Ex and total mass transport displacement. The experimental results compared to the theoretical results obtained by Chen (1994)and Hsu¡BChen(2006) has the similar results as well.

This research focuses primary on recognition of lane-change behaviors using support vector machines (SVMs). Previous research and statistical results show that the vast majority of motor vehicle accidents are caused by driver behavior and errors. Therefore, the interpretation and evaluation of driver behavior is important for road safety analysis and improvement. The main limit to understanding driver behavior is the data availability. In particular, a full-scale lane-change data set is difficult to collect in a real traffic environment because of the safety and cost issues. Considering the data demands of the recognition model development and the obstacles of field data collection, data were collected from two aspects: simulation data and the field data. To obtain field data, an in-vehicle data recorder (IVDR) that integrates a Global Positioning System (GPS) and Inertial Measurement Unit (IMU) are developed to collect data on speed, position, attitude, acceleration, etc. To obtain simulation data, a lane-change simulation with a speed controller and a trajectory tracking controller with preview ability were developed, and sufficient lane-change data were generated. Proportional-Integral-Derivative (PID) control is applied to the speed controller and trajectory tracking controller. Simulation data were divided into two classes: dual lane-change data and single lane-change data; field data were further divided as single lane-change and non-lane-change data. Two-class and three-class classification SVM model are trained by simulation data and field data, and the model parameters were optimized by Genetic Algorithm (GA). A radial basis function and polynomial kernel functions were found that suitable for this recognition task. The recognition results indicate that, the SVM model trained by simulation data and non-lane-change data can correctly classify up to 85 percent of single lane-change field data.

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Advances in machine autonomy hold great promise in advancing technology, economic markets, and general societal well-being. For example, the progression of unmanned air systems (UAS) research has demonstrated the effectiveness and reliability of these autonomous systems in performing complex tasks. UAS have shown to not only outperformed human pilots in some tasks, but have also made novel applications not possible for human pilots practical. Nevertheless, human pilots are still favored when performing specific challenging tasks. For example, transportation of suspended (sometimes called slung or sling) loads requires highly skilled pilots and has only been performed by UAS in highly controlled environments. The presented work begins to bridge this autonomy gap by proposing a trajectory optimization framework for operations involving autonomous rotorcraft with suspended loads. The framework generates optimized vehicle trajectories that are used by existing guidance, navigation, and control systems and estimates the state of the non-instrumented load using a downward facing camera. Data collected from several simulation studies and a flight test demonstrates the proposed framework is able to produce effective guidance during autonomous suspended load operations. In addition, variational integrators are extensively studied in this dissertation. The derivation of a stochastic variational integrator is presented. It is shown that the presented stochastic variational integrator significantly improves the performance of the stochastic differential dynamical programming and the extended Kalman filter algorithms. A variational integrator for the propagation of polynomial chaos expansion coefficients is also presented. As a result, the expectation and variance of the trajectory of an uncertain system can be accurately predicted.

Reversing with a trailer is very difficult and many drivers hesitate to even try it. This thesis examines if active steering, particularly AFS (Active Front Steering), can be used to provide assistance. For analysis and controller design a simple geometric model of car and trailer is used. The model seems to be accurate enough at the low speeds relevant for trailer reversing. It is shown that the only trailer dependent model parameter can be estimated while driving. This enables use with different trailers. Different schemes to control the system are tested. The main approach is to use the steering wheel as reference for some appropriate output signal, for example the angle between car and trailer. This makes reversing with a trailer more like reversing without a trailer. To turn left, the driver simply turns the steering wheel left and drives. Test driving, as well as theoretical analysis, shows that the resulting system is stable. Of the eight drivers that have tested this type of control, five found it to be a great advantage while two considered it more confusing than helpful. A major problem with this control approach has to do with the way AFS is constructed. With AFS, the torque required to turn the front wheels results in a reaction torque in the steering wheel. Together with the reference tracking controllers, this makes the steering wheel unstable. Theoretical analysis implies that this problem has to be solved mechanically. One solution would be to combine AFS with electric power steering. This thesis also presents a trajectory tracking scheme to autonomously reverse with a trailer. Starting from the current trailer position and the desired trajectory an appropriate turning radius for the trailer is decided. Within certain limits, this will stabilize the car as well. The desired trajectory can be programmed beforehand, but it can also be saved while driving forward. Both variants have been tested with good results.

Piezoelectric actuators are resonance systems operating principles based on high-frequency oscillations excitation, are used in structures of robots. Observed piezorobots have no additional motion generating structures, but only direct contact points with the static plane. Piezorobot motion trajectory is broken lines, therefore, the classical trajectory formation methods cannot be applied. The main object is motion trajectory formation methods. The main aim of this work is to create motion trajectory formation methods for precision multidimensional piezorobots. The application of these algorithms is piezorobot motion simulation and control software. / Pjezoelektriniai judesio keitikliai – rezonansinės sistemos, kurių veikimo principas pagrįstas aukšto dažnio virpesių žadinimu. Disertacijoje tiriamieji pjezorobotai neturi papildomų judesį generuojančių struktūrų, o tik tiesioginius kontakto su statine plokštuma taškus. Kadangi judesio trajektorija yra laužyta, klasikiniai trajektorijų formavimo metodai netinka. Pagrindinis tyrimo objektas yra judesio trajektorijų formavimo metodai. Pagrindinis disertacijos tikslas – sukurti precizinių daugiamačių pjezorobotų judesio trajektorijų formavimo algoritmus. Sukurtų algoritmų taikymo sritis – pjezorobotų judesio modeliavimo ir valdymo programinė įranga.

Explosive volcanic eruptions frequently expel ballistic projectiles, producing a significant proximal hazard to people, buildings, infrastructure and the environment from their high kinetic and thermal energies. Ballistic hazard assessments are undertaken as a risk mitigation measure, to determine probabilities of eruptions occurring that may produce ballistics, identify areas and elements likely to be impacted by ballistics, and the potential vulnerabilities of elements to ballistics. The 6 August, 2012 hydrothermal eruption of Upper Te Maari Crater, Tongariro, New Zealand ejected blocks over a 6 km2 area, impacting ~2.6 km of the Tongariro Alpine Crossing (TAC), a walking track hiked by ~80,000 people a year, and damaging an overnight hut along the track. In this thesis ballistic hazard and risk from Upper Te Maari Crater are assessed through a review of its eruptive history, field and orthophoto mapping of the 6 August ballistic impact distribution, forward modelling and analysis of possible future eruption scenarios using a calibrated 3D ballistic trajectory model, and analysis of the vulnerability of hikers along the impacted Tongariro Alpine Crossing. Orthophoto mapping of the 6 August ballistic impact crater distribution revealed 3,587 impact craters with a mean diameter of 2.4 m. However, field mapping of accessible regions indicated an average of at least four times more observable impact craters and a smaller mean crater diameter of 1.2 m. By combining the orthophoto and ground-truthed impact frequency and size distribution data, it is estimated that approximately 13,200 ballistic projectiles were generated during the eruption. Ballistic impact distribution was used to calibrate a 3D ballistic trajectory model for the 6 August eruption. The 3D ballistic trajectory model and a series of inverse models were used to constrain the eruption directions, angles and velocities. When combined with eruption observations and geophysical observations and compared to the mapped distribution, the model indicated that the blocks were ejected in five variously directed eruption pulses, in total lasting 19 seconds. The model successfully reproduced the mapped impact distribution using a mean initial particle velocity of 200 m/s with an accompanying average gas flow velocity over a 400 m radius of 150 m/s. Assessment of the vulnerability of hikers to ballistics from the August eruption along the TAC utilised the modelled spatial density of impacts and an assumption that an average ballistic impact will cause serious injury or death (casualty) over an 8 m2 area. It is estimated that the probability of casualty ranged from 1% to 16% along the affected track (assuming an eruption during the time of exposure). Future ballistic hazard and vulnerability along the TAC are also assessed through application of the calibrated model. A magnitude larger eruption (than the 6 August) in which 10x more particles were ejected, doubled the affected length of the TAC and illustrated that the probability of casualty could reach 100% in localised areas of the track. In contrast, ballistics ejected from a smaller eruption did not reach the track as was the case with the 21 November 2012 eruption. The calibrated ballistic model can therefore be used to improve management of ballistic hazards both at Tongariro and also, once recalibrated, to other volcanoes worldwide.

Extensive experimental data is available from previous research into the behaviour of buoyant jets released into an unstratified ambient. The experimental data has been the basis for theoretical and numerical modelling work, and currently several numerical models exist that are employed in the design of engineering structures built for the disposal of wastewater in the ocean. However there are still flow configurations with limited or no available experimental data, and hence confidence in the use of the models under some circumstances is limited. These circumstances include two-dimensional trajectory flows that are discharged at oblique angles to the ambient and buoyant jet flows with three-dimensional trajectories. As part of the current project an experimental investigation is conducted into the behaviour of discharges that have either two-dimensional or three-dimensional trajectories, focussing particularly on those configurations with currently limited available experimental data. A light attenuation technique is developed for the investigation of such flows, largely because it enables the behaviour of discharges with three-dimensional trajectories to be recorded with relative ease. However, this technique provides integrated views of the flow and hence the interpretation of the integrated concentration data is aided by assumed mean cross-sectional concentration profiles. In the strongly advected region (with the exception of the weak-jet) a double-Gaussian approximation is shown to provide a reasonable representation of mean concentration profiles. In the weakly advected regions and the weak-jet region, it is well- known that a single Gaussian adequately represents the mean flow structure. A new numerical model, the Momentum Model, is developed to assist in the design and to monitor the performance of the experimental investigation. Unlike other models, the behaviour of the flow is determined by the relative magnitudes of the initial excess momentum flux, the buoyancy-generated momentum flux and the entrained ambient momentum flux. It is shown that ratios of these momentum fluxes are equivalent to the length-scales traditionally employed for this task. Predictions from the Momentum Model are compared with data from the current and previous experimental investigations and, in addition, predictions from two representative numerical models, VisJet and CorJet. Predictions from the Momentum Model are shown to be consistent with data for a wide variety of discharge configurations. These predictions are also generally consistent with those of VisJet and CorJet. However, the experimental results from the II buoyant jet discharged in a moving ambient show that the spreading rates of the strongly advected flows (puffs and thermals) differ, and while this difference is incorporated into the Momentum Model, it is not evident in the VisJet and CorJet predictions. Numerical model predictions of negatively buoyant discharges are shown to be inadequate. This discharge configuration is investigated in some detail experimentally and additional analytical solutions of the flow behaviour are developed to aid in the interpretation of the flow behaviour. The experimental results show that buoyancy-induced instabilities on the inner side of the jets, which generate additional vertical mixing, significantly alter the form of the mean concentration profiles in this region. This results in considerably higher integrated dilutions along the flow centreline. Another significant difference between the newly developed Momentum Model and the existing numerical models (VisJet and CorJet), is the approach taken to dealing with oblique discharges in a cross-flow. Experimental results in combination with additional analytical solutions show that for initial discharge angles of 20° and less, an oblique discharge in a cross-flow becomes a weak-jet in the strongly advected region, and for angles of 40° and above, the flow becomes a puff. The strongly advected behaviour predicted by the Momentum Model changes abruptly at the transition angle, and is reasonably consistent with the data. The gradual change in strongly advected behaviour employed by VisJet and CorJet does not appear to be appropriate in the puff region. Finally a preliminary experimental investigation of discharges with three-dimensional trajectories shows that there are significant discrepancies between the predicted behaviour and the experimental data. This is surprising given the numerical models are, for the most part, able to predict the behaviour of flows with two-dimensional paths with reasonable accuracy. It is evident that flows with three-dimensional paths are modified more severely by the different directions of the initial, buoyancy-generated, and entrained ambient momentum fluxes than the current models suggest.

A system for recording the trajectories of non-planar shocks and particle tracers within a shock tube flow has been developed. The optics consists of a double-pass schlieren system with a multiply pulsed ruby laser as light source. The laser is synchronized with a high speed framing camera. A grid of ammonium chloride tracers is injected into the flow field, and the motion of the tracers behind the Mach reflection of intermediate strength shocks has been recorded. Analysis of the trajectories has yielded the space and time variation of the physical properties within the flow field. / Graduate / 0605

Commercial aviation and air traffic is still expected to grow by 4-5% annually in the future and thus the effect of aircraft operation on the environment and its consequences for the climate change is a major concern for all parties involved in the aviation industry. One important aspect of aircraft engine operation is the performance degradation of such engines over their lifetime while another aspect involves the aircraft flight trajectory itself. Therefore, the first aim of this work is to evaluate and quantify the effect of engine performance degradation on the overall aircraft flight mission and hence quantify the impact on the environment with regards to the following two objectives: fuel burned and NOxemissions. The second part of this study then aims at identifying the potential for optimised aircraft flight trajectories with respect to those two objectives. A typical two-spool high bypass ratio turbofan engine in three thrust variants (low, medium and high) and a typical narrow body single-aisle aircraft similar to the A320 series were modelled as a basis for this study. In addition, an existing emissions predictions model has been adapted for the three engine variants. Detailed parametric and off-design analyses were carried out to define and validate the performance of the aircraft, engine and emissions models. The obtained results from a short and medium range flight missions study showed that engine degradation and engine take-off thrust reduction significantly affect total mission fuel burn and total mission NOx emissions (including take-off) generated. A 2% degradation of compressor, combustor and turbine component parameters caused an increase in total mission fuel burn of up to 5.3% and an increase in NOx emissions of up to 5.9% depending on the particular mission and aircraft. However, take-off thrust reduction led to a decrease in NOx emissions of up to 41% at the expense of an increase in take-off distance of up to 12%. Subsequently, a basic multi-disciplinary aircraft trajectory optimisation framework was developed and employed to analyse short and medium range flight trajectories using one aircraft and engine configuration. Two different optimisation case studies were performed: (1) fuel burned vs. flight time and (2) fuel burned vs. NOx emitted. The results from a short range flight mission suggested a trade-off between fuel burned versus flight time and showed a fuel burn reduction of 3.0% or a reduction in flight time of 6.7% when compared to a “non-optimised” trajectory. Whereas the optimisation of fuel burn versus NOx emissions revealed those objectives to be non- conflicting. The medium range mission showed similar results with fuel burn reductions of 1.8% or flight time reductions of 7.7% when compared to a “non- optimised” trajectory. Accordingly, non-conflicting solutions for fuel burn versus NOx emissions have been achieved. Based on the assumptions introduced for the trajectory optimisation analyses, the identified optimised trajectories represent possible solutions with the potential to reduce the environmental impact. In order to increase the simulation quality in the future and to provide more comprehensive results, a refinement and extension of the framework also with additional models taking into account engine life, noise, weather or operational procedures, is required. This will then also allow the assessment of the implications for airline operators in terms of Direct Operating Costs (DOC). In addition, the degree of optimisation could be improved by increasing the number and type of optimisation variables.