The main focus of this diploma thesis is to design controlling system for robotic chassis moving on horizontal bolt nut of globular elements. This thesis includes analysis of movements of the chassis and definition of instructions for controlling level. Instructions for controlling level are compiled in constructed simulation programme. This thesis also contains design of electronic components and requirements for electronics of controlling subsystems.

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<p>Agricultural tractors make massive use of hydraulic control technology. Being fuel con-sumption a big concern for agricultural applications, tractors typically use the state-of-the-art technology, load-sensing (LS) architecture, to allow good controllability in systems withmultiple actuators while promoting higher energy efficiency. Several variants of LS systemshave been proposed over the years, and research on cost-effective methods to further increasetheir efficiency is of high interest for original equipment manufacturers (OEMs) and the fluidpower community. In this work, several energy-efficient solutions are proposed and demon-strated for the reference agricultural tractor hydraulic system, aiming at reducing the fuelconsumption and increasing the system efficiency, but without affecting the functionalityof the hydraulic control system. More importantly, facing the more stringent regulationson the CO2emission and the rising consciousness of a greener environment in society, bothindustry and academia have investigated the use of electricity as energy carrier and storage.This report also carries out the study on the possibility of electrification of the referencemachine, focusing on the auxiliary hydraulic supply to the planter.</p> <p>To begin with, the quantification of the energy loss within the hydraulic system representsan important step to drive the development of cost-effective solutions. For this purpose, acombined approach of simulation and experimental testing has been undertaken to character-ize the power distribution in the high-pressure circuit. After learning that the remote controlvalves are responsible for up to 25% of power loss in the system, two different energy-efficientsolutions are proposed on the tractor circuit. Both methods target at lowering the pumpdelivery pressure through incorporating electronic proportional pressure reducing valves (ep-PRVs). To support the development of the technology, the research takes into considerationthe circuit of a 400 hp tractor, simulation and experimental results show that among themain working conditions the solution can reach up to 15.6% power saving over the standardLS system.</p> <p>Moreover, the primary purpose of a tractor is to providing power to and controllingvarious implements. Most of their mechanical actuation is performed also with the electro-hydraulic fluid power system that is highly power-dense and versatile, but that has a low energy transmission efficiency. A new control approach of the hydraulic supply units thatpower the implement functions through the hydraulic remote is proposed, which switches thetraditional flow control methodology to an impressed pressure methodology. With a 16-rowplanter connected to the tractor understudy, a simulation model of the two vehicles is imple-mented and validated against experiments. Experiments on the proposed solutions appliedto the reference tractor and planter confirmed how an overall 38% efficiency improvementwas achieved during actual tests.</p> <p>On top of the IPSC strategy, more intelligent control algorithm is explored by proposinga new system architecture to fully incorporate both of the LS pumps with all of the EHRs,to achieve dynamic regrouping control (DRC) or static regrouping control (SRC). The DRCalgorithm determines the best supply configuration to all of the functions with minimumpower loss in time, which eventually leads to 44% power reduction compared to the base-line. On the other hand, the SRC algorithm targets at providing the best planter groupinglayout when connected to the tractor supply to contribute to least throttling losses duringrepresentative planting operations. The restuls from the SRC configuration can serve as asuggestive layout for the OEM when promoting such machines to the market.</p> <p>Last but not least, different scenarios of both selective purely electrification architectureand selective e-pump supply architecture are considered to discover the potential futuredirection of electrification to follow for the reference machine. From the power saving pointof view, replacing the fertilizer and vacuum hydraulic motors with the electric ones couldlead to 72% power reduction from the engine. However, more study on the cost analysiscould be useful to balance the saving and the cost added in the system.</p>

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Afin d'étudier le rôle du Contrôle de Gestion dans la stratégie de développement durable (DD) de l'entreprise, nous proposons dans un premier temps, un cadre d'analyse fondé sur une revue de la littérature, sur la responsabilité sociale de l'entreprise (RSE) et du contrôle, complétée, dans un deuxième temps, par une étude exploratoire. Ces investigations théoriques et empiriques nous conduisent à proposer la thèse suivante : devant le double défi de l'efficience et de la légitimité, l'entreprise met en oeuvre des systèmes de contrôle diagnostic et interactif. Cette juxtaposition permet de répondre rationnellement aux différentes parties prenantes en dissociant les domaines de performance globale. Cette pratique confirme, d'une part, le rôle du Contrôle de Gestion en tant que vérificateur d'une logique managériale financière et d'autre part, elle participe à l'amorce d'un processus de rééquilibrage entre le système de gouvernance, la stratégie et le contrôle. Cette transformation du modèle économique se heurte à des difficultés techniques et culturelles d'où l'observation d'un phénomène de couplage plus ou moins lâche entre les idéaux du DD et les actions quotidiennes de l'entreprise. / So as to study the role of management control in the sustainable development of the firm, we first propose a conceptual framework based on a review dealing with Corporate Social Responsability and Control. Secondly, an exploratory study will complete the research.These theorical and empirical investigations lead us to offer the fallowing proposition : facing the double challenge of efficiency and legitimacy, the firm implements control protocols aiming to both establish a diagnosis and interact. This juxtaposition allows to answer in a rational way to the different stakeholders, while the different domains of the overal performance are isolated. This pratice establishes the part of management control as monotoring financial and managing logics first. It then participates to the processus of balancing the system of governance,the strategy and the control.This changing of the business model clashes with technical and cultural difficulties, hence we can observe a phenomenon of tigher or looser coupling between the ideals of the sustainable development and the every day working of the firm.

This thesis is devoted to the development of new models for a recently-implemented FACTS (flexible alternating current transmission system) device, the unified power flow controller (UPFC), and the control coordination of power systems with FACTS devices in steady-state operating mode. The key objectives of the research reported in the thesis are, through online control coordination based on the models of power systems having FACTS devices, those of maximising the network operational benefit and restoring system static security following a disturbance or contingency. Based on the novel concept of interpreting the updated voltage solutions at each iteration in the Newton-Raphson (NR) power-flow analysis as dynamic variables, the thesis first develops a procedure for representing the unified power flow controllers (UPFCs) in the steady-state evaluation. Both the shunt converter and series converter control systems of a UPFC are modeled in their dynamical form with the discrete time variable replaced by the NR iterative step in the power-flow analysis. The key advantage of the model developed is that of facilitating the process of UPFC constraint resolution during the NR solution sequence. Any relative priority in control functions pre-set in the UPFC controllers is automatically represented in the power-flow formulation. Although the developed UPFC model based on the dynamic simulation of series and shunt converter controllers is flexible and general, the number of NR iterations required for convergence can be large. Therefore, the model is suitable mainly for power system planning and design studies. For online control coordination, the thesis develops the second UPFC model based on nodal voltages. The model retains all of the flexibility and generality of the dynamic simulation-based approach while the number of iterations required for solution convergence is independent of the UPFC controller dynamic responses. Drawing on the constrained optimisation based on Newton’s method together with the new UPFC model expressed in terms of nodal voltages, a systematic and general method for determining optimal reference inputs to UPFCs in steady-state operation is developed. The method is directly applicable to UPFCs operation with a high-level line optimisation control (LOC) for maximising the network operational benefit. By using a new continuation technique with adaptive parameter, the algorithm for solving the constrained optimisation problem extends substantially the region of convergence achieved with the conventional Newton’s method. Having established the foundation provided by the comprehensive models developed for representing power systems with FACTS devices including the UPFC, the research, in the second part, focuses on real-time control coordination of power system controllers, with the main purpose of restoring power system static security following a disturbance or contingency. At present, as the cost of phasor measurement units (PMUs) and wide-area communication network is on the decrease, the research proposes and develops a new secondary voltage control where voltages at all of the load nodes are directly controlled, using measured voltages.

A robust servo control system based on Integral Variable Structure Model Following Control (IVSMFC) is proposed. The IVSMFC approach comprises a reference model part for specifying the design requirements and an Integral Variable Structure Control (IVSC) part for minimizing the errors between the plant and the model. Sliding mode thus obtained features robustness against external disturbances and parameter variations. Design procedures in both continuous-time and discrete-time have been detailed. The IVSMFC-based servo control system has been successfully applied to a DSP-based brushless DC motor drive for globoidal cam indexing system and to power system. Simulation and experimental results demonstrate that the proposed scheme can achieve fast and robust responses.

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Hydraulic systems are widely applied in industry for position or force control. However, due to hydraulic system nonlinearities, it is difficult to achieve a precise model valid over a large range of frequencies and movements. The work in this dissertation focuses on a high performance hydraulic test bench which involves three main hydraulic components, i.e. two high performance servovalves, a double rod actuator, and a specific intermediate block connecting the servovalves and actuator. This rig has been designed for testing aerospace or automotive components in real conditions (e.g. wear and ageing effects). The main objectives of this dissertation are first the development of a virtual prototype based on a precise model which is derived from the physical principles and experimental works, and then second the synthesis of several nonlinear control laws of this actuation system in a large operating range with a good robustness to the perturbations. The proposed model based on Bond Graph shows a very good agreement with experimental results not only at low frequencies, but also at high frequencies. Moreover, its performances are improved at high frequencies by introducing the dynamic effects due to the intermediate block. Besides, multivariable and monovariable control strategies, based on respectively the backstepping and the model-free method, are developed and implemented on the test bench. All the control strategies proposed have been validated by simulations and experiments. Results show they lead to better tracking precision and robustness performance compared to the conventional control techniques.

This master thesis is focused on design of control stick grip and rudder pedals extension. These components are equipped with active elements, which provide pilot with haptic feedback. The purpose of the introduced design is to allow prototype to be built into the aeroplane so that the proposed concept of haptic feedback can be tested onboard. It shall verify used technical solutions as well to allow for their application on following development stages that aim at certification of the proposed haptic feedback system to be used in general aviation aeroplanes. The designed components are the successors of prototypes used for experiments carried on flight simulator. The design process follows the requirements of legislation and outcomes of the previous experiments. This thesis follows the design process from setting of the design requirements to mechanical test of 3D printed prototypes.