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The objective of this research is to create a new brake system with fewer mechanical parts, higher performance, greater flexibility for adaptation to new functions, and lower cost. A simple/series electro-hydrostatic brake system is investigated as an inexpensive, reliable, and redundant integrated brake system that can include the functions; Boost, ABS, TCS, VDC, etc. Production issues are considered. The required motor power is the most critical and is estimated by simulation based on data from experiments. To reduce this power a flow boost self-energizing mechanism with computer control is explored, and it is found that the effect is significant. Robustness of the control for pad friction fluctuation is also analyzed, and the limitation is estimated. The result of analysis shows that a competitive commercial product can be developed.

The last few years have been an exciting time for alternative vehicle development. New concerns about the environmental impact of personal transportation and about the United States' dependence on imported oil have pushed energy efficient, ultra-low, and zero emissions vehicles to the forefront of automotive design. California's own mandate for Zero Emissions Vehicles (ZEV) takes effect in 1998, creating a tremendous push towards the difficult goal of producing a commercially viable, practical electric vehicle for sale in 1998. Beyond California, most of the world's automakers are simultaneously committing tremendous research and development resources towards the technology necessary for a viable electric vehicle. The University of California at Davis is one of seven California universities participating in the 1993 Ford Hybrid Electric Vehicle Challenge.

The flywheel energy-storage unit is examined as a tool for engine load management. The control decision to store or retrieve energy is formulated and discussed. Vehicle dynamics are simulated on a digital computer in combination with dynamic programming techniques to obtain optimal operation policy. The simplified algorithm is explained, as well as the cost-function criteria and optimization constraints. The sensitivity of the optimal path and the vehicle gas-mileage improvements are elaborated. The study of losses indicates that the transmission is the largest energy sink in the power train. The result of this study provides an indication of the appropriate real-time control policy.

A flywheel to manage energy between a prime mover and a load has been used in many engineering applications. Automotive applications, however, pose a number of difficult problems which can be overcome only with proper design. Substantial mileage and performance improvements while meeting emission constraints can then be accomplished with the concept. An experimental flywheel car has been designed and built at the University of Wisconsin that has demonstrated a mileage improvement of about 50% over a corresponding production vehicle on the EPA/FUDC. With continued research and development gains of 100% appear feasible.

Hybrid vehicles, i.e., those containing two or more sources of power, have the potential of increased fuel economy under certain types of driving conditions. Systems currently being investigated include combinations of heat engines, electric drives, fly-wheels, and accumulators. In order to obtain fuel economy improvements over conventional vehicles, efficient components are required as well as a good system design. Hybrid powerplants appear more promising for heavier vehicles.

The electric car has many features that make it attractive for urban use. Currently, its principal shortcomings are its short range and poor efficiency for a realistic driving cycle. An electric hybrid car of advanced design, such as the University of Wisconsin model described here, can overcome the limitations of the all-electric car, while retaining most of its advantages, but only at the expense of greater complexity. More research and development is required before either version can be an adequate replacement for our present internal combustion engine cars.