To design a robust controller for active suspension systems is very important for guaranteeing the riding comfort for passengers and road handling quality for a vehicle. In this thesis, the mathematical model of full vehicle nonlinear active suspension systems with hydraulic actuators is derived to take into account all the motions of the vehicle and the nonlinearity behaviours of the active suspension system and hydraulic actuators. Four robust control types are designed and the comparisons among the robustness of those controllers against different disturbance types are investigated to select the best controller among them. The MATLAB SIMULINK toolboxes are used to simulate the proposed controllers with the controlled model and to display the responses of the controlled model under different types of disturbance. The results show that the neurofuzzy controller is more effective and robust than the other controller types. The implementation of the neurofuzzy controller using FPGA boards has been investigated in this work. The Xilinx ISE program is employed to synthesis the VHDL codes that describe the operation of the neurofuzzy controller and to generate the configuration file used to program the FPGA. The ModelSim program is used to simulate the operation of the VHDL codes and to obtain the expected output data of the FPGA boards. To confirm that FPGA the board used as the neurofuzzy controller system operated as expected, a MATLAB script file is used to compare the set of data obtained from the ModelSim program and the set of data obtained from the MATLAB SIMULINK model. The results show that the FPGA board is effective to be used as a neurofuzzy controller for full vehicle nonlinear active suspension systems. The active suspension system has a great performance for vibration isolation. However the main drawback of the active suspension is that it is high energy consumptive. Therefore, to use this suspension system in the proposed model, this drawback should be solved. Electromagnetic actuators are used to convert the vibration energy that arises from the rough road to useful electrical energy to reduce the energy consumption by the active suspension systems. The results show that the electromagnetic devices act as a power generator, i.e. the vibration energy excited by the rough road surface has been converted to a useful electrical energy supply for the actuators. Furthermore, when the nonlinear damper models are replaced by the electromagnetic actuators, riding comfort and the road handling quality are improved. As a result, two targets have been achieved by using hydraulic actuators with electromagnetic suspension systems: increasing fuel economy and improving the vehicle performance.

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This thesis contributes to closing a gap in the field of science, technology and innovation (STI) policy research: despite many theoretical advances in the field, we still do not know why some urgent societal issues (or ‘challenges') remain unaddressed, notwithstanding the technological advances that could potentially address them. In particular, radical technological innovations – innovations that depart from the established technological trajectory – would offer greatest potential to address societal challenges. While the source of radical innovations is often new entrepreneurial firms, established firms (‘incumbents') are likely to play an important role in developing them because of the vast resources and complementary assets they possess. Incumbents however, face few immediate incentives to develop radical innovations in response to societal challenges. The analytical puzzle of this thesis is thus to explain how, when, and why industries change (or not) their strategies (in particular, their technological strategy) in order to address a societal problem. This puzzle is disentangled into interrelated research questions: A) How do societal issue­‐related pressures (on the incumbent industry) from different domains (namely, civil society, science, political arena, economy) evolve? B) How does the incumbent industry respond to changing pressures around societal issues, in terms of technological, political, cultural and economic strategies? C) In particular, when and why do industry actors decide to develop substantive technological responses? To answer these questions, the thesis develops a new analytical perspective that combines insights from (a) issue life­‐cycle and issue attention cycle theories (from the Business & Society field) with (b) the so­‐called ‘Triple Embeddedness Framework' and (c) concepts from business strategies, innovation management, corporate political strategies, and technology policy. This novel perspective represents an ideal­‐typical model of issue evolution (‘issue life ­‐cycle'). The model, which I call the Dialectic Issue Life­‐Cycle (DILC) model, is applied to three case studies of the American automobile industry's responses to various societal problems (local air pollution, auto and highway safety, and climate change). Combining qualitative and quantitative research methods in an original way, the case studies aim not only to investigate the validity of the framework, which also provides conceptual answers to the research questions, but also to further refine it and nuance the conceptual answers. By explaining how incumbent industry actors respond to societal challenges, this thesis ultimately contributes to the practical policy debate of how incumbents can be stimulated to develop radical innovations that help address societal challenges.