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A novel, fully flexible engine valve actuation mechanism was built and tested for the first time. It consists of a permanent magnet brushless dc motor driving a cam mechanism to actuate each engine poppet valve. This mechanism has the advantages of low friction, low seating velocity and speed range comparable to that of production valve trains. The electromechanical system has also regeneration capabilities which result in an energy requirement that is equivalent to or lower than the valve-train friction of current production engines. The valve event duration is changed by increasing or decreasing the cam/motor angular velocity during valve opening in order to shorten or lengthen the valve event, respectively. Part-lift operation is also possible by oscillating the mechanism around the valve opening or closing points. The prototype mechanism was run on the bench on an actual engine cylinder head at speeds of up to 3225 r/min, equivalent to 6450 engine r/min.

This paper explores issues related with the design and implementation of belt-driven starter-generators for future 42-V systems. Belt-driven starter-generators can offer many advantages including smooth restarts, high efficiency, and convenient packaging. Future vehicle systems require these characteristics to enable fuel economy functions like “engine off at idle” and “x-by-wire.” Belt-driven starter-generators are often easier to package in contrast with flywheel-mounted systems, which require powertrain modifications and in many cases a longer package. A prototype system based on a belt-driven induction machine mounted on a small, European engine is described in the paper. Test results for both cranking and generation are shown and analyzed. Efficient, high-power generation was confirmed and high-speed (beyond 400 engine rpm) cranking was demonstrated down to the targeted -20°C.

The purposes of this research were to demonstrate new electromagnetic valve actuators on a running engine and to explore the efficiency and emissions advantages of variable valve actuation. A single-cylinder research engine was equipped with programmable electromagnetic valve actuators and operated with early intake-valve closing in addition to conventional throttling, both methods with and without exhaust gas recirculation. The engine was run at a fixed speed of 1500 r/min over varying load at stoichiometric air-fuel mixture, with and without swirl generated by a shrouded intake valve. Engine performance and emissions were measured with spark timing adjusted to minimum advance for best torque. Early intake-valve closing showed a net-efficiency gain over conventional throttling without EGR, but essentially no gain over conventional throttling with heavy EGR dilution in the test engine.

MAGNECODE uses laser surface heating to pattern permanent magnets for position sensor applications. Thermal and magnetic models provide good predictions of the geometry of the laser heated regions and the resulting spatial variations in the magnetic field. Important design factors are discussed and a comparison with other magnetic sensor technologies is given.

This paper describes a dual-track magnetic crankshaft and camshaft position sensor configuration. It uses semiconductor sensors such as magnetoresistors to pick up the magnetic flux modulation created by a toothed wheel rotating across a permanent magnet. This sen-sor's magnetic configuration, with a complementary geometry, enhances the accuracy and repeatability of the position pulses. This is critical in obtaining the engine-velocity measurement precision necessary to detect engine misfires as mandated by the OBD-II legislation. The complementary geometry also makes for a more robust design. Finally, the concept can be used for cam-shaft position sensing, with power-on capability.