Xx00学院毕业设计（论文）外文文献原稿和译文外文文献原稿和译文原 稿Mechanical and Regenerative Braking Integration for a Hybrid Electric VehicleAbstractHybrid electric vehicle technology has become a preferred method for the automotive industry to reduce environmental impact and fuel consumption of their vehicles. Hybrid electric vehicles accomplish these reductions through the use of multiple propulsion systems, namely an electric motor and internal combustion engine, which allow the elimination of idling, operation of the internal combustion engine in a more efficient manner and the use of regenerative braking. However, the added cost of the hybrid electric system has hindered the sales of these vehicles.A more cost effective design of an electro-hydraulic braking system is presented. The system electro-mechanically controlled the boost force created by the brake booster independently of the driver braking force and with adequate time response. The system allowed for the blending of the mechanical and regenerative braking torques in a manner transparent to the driver and allowed for regenerative braking to be conducted efficiently.A systematic design process was followed, with emphasis placed on demonstrating conceptual design feasibility and preliminary design functionality using virtual and physical prototyping. The virtual and physical prototypes were then used in combination as a powerful tool to validate and develop the system. The role of prototyping in the design process is presented and discussed.Through the experiences gained by the author during the design process, it is recommended that students create physical prototypes to enhance their educational experience. These experiences are evident throughout the thesis presented.1.1 Modern Hybrid Electric VehiclesWith rising gas prices and the overwhelming concern for the environment, consumers and the government have forced the automotive industry to start producing more fuel efficient vehicles with less environmental impact. One promising method that is currently being implemented is the hybrid electric vehicle.Hybrid vehicles are defined as vehicles that have two or more power sources 25. There are a large number of possible variations, but the most common layout of hybrid vehicles today combines the power of an internal combustion engine (ICE) with the power of an electric motor and energy storage system (ESS). These vehicles are often referred to as hybrid electric vehicles (HEVs) 25. These two power sources are used in conjunction to optimize the efficiency and performance of the vehicle, which in turn will increase fuel economy and reduce vehicle emissions, all while delivering the performance the consumer requires. In 1997, the Toyota Prius became the first hybrid vehicle introduced into mass production in Japan. It took another three years for the first mass produced hybrid vehicle, the Honda Insight, to be introduced into the North American market. The release of the Honda Insight was closely followed by the release of the Toyota Prius in North America a couple of months later 35.Hybrid electric vehicles have the distinct advantage of regenerative braking. The electric motor, normally used for propulsion, can be used as a generator to convert kinetic energy of the vehicle back into electrical energy during braking, rather than wasting energy as heat. This electrical energy can then be stored in an ESS (e.g. batteries or ultracapacitors) and later released to propel the vehicle using the electric motor.This process becomes even more important when considering the energy density of batteries compared to gasoline or diesel fuel. Energy density is defined as the amount of energy stored in a system per unit volume or mass 44. To illustrate this point, 4 kilograms (4.5 litres) of gasoline will typically give a motor vehicle a range of 50 kilometres. To store the same amount of useful electric energy it requires a lead acid battery with a mass of about 270 kilograms 25. This demonstrates the need for efficient regenerative braking to store electrical energy during driving, which in turn will keep the mass of the energy storage system down and improve the performance and efficiency of the HEV.1.2 Research Scope - Regenerative Braking SystemsThe scope of the research presented is to create a low cost regenerative braking system to be used on future economical hybrid vehicles to study the interaction between regenerative and mechanical braking of the system. This system should be able to control the combination of both regenerative and mechanical braking torque depending on driver demand and should be able to do so smoothly and safely. Controlling the regenerative braking torque can be done using control algorithms and vector control for induction motors. However, controlling the mechanical braking torque independently of the driver pedal force, while maintaining proper safety back-ups, proved to be more of a challenge. To overc