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The history of off-road equipment manufacturing has been based on proven designs and long times between model updates. In sharp contrast with this strategy is the electronic manufacturing services (EMS) industry. The EMS industry is driven by the larger consumer product industry's continuing pressure for lower costs. Because of this, EMS tools, processes, and practices have evolved to support rapid technology and component changes. However the increasing consumer demand for features like better user-interfaces, more efficient fuel consumption, and the desire for increased operational controls in equipment have forced the off-road industry to increase the frequency of product updates to meet customers' needs. Equipment manufacturers make running changes leading to a “Learning-by-doing” development and manufacturing process. But rapid changes sometimes have an unpredictable impact on the reliability of the final product.

Hydraulic systems, as power source and transmission, offer many advantages over electromechanical or purely mechanical counterparts in terms of power density, flexibility and portability. Many hydraulic systems require touching and contacting the physical environments; and many of these systems are directly controlled by human. If hydraulic systems are passive, they would be safer to interact with, and easier for human to control. In this paper, we describe our current research in developing bilateral passive teleoperated hydraulic machines which a human operator controls via a force feedback joystick. Two key developments are 1) methodologies to passify the electrohydraulic valves as a two-port device, and 2) the passive teleoperation controllers.

Particulate emissions from heavy-duty buses were measured in real time under conditions encountered during the standard Central Business District (CBD) driving cycle. The buses tested were equipped with 1994 Detroit Diesel Engine Corporation 6V92-TA engines, and some included after treatment devices on the exhaust. Instantaneous, time-resolved measurements of CO2 and amorphous carbon concentrations were obtained using an optical extinction technique and compared to simultaneous results obtained using conventional dilution tunnel sampling methods. Good agreement was obtained between the real-time extinction measurements and the diluted CO2 and cycle-integrated filter measurements. The instantaneous measurements revealed that acceleration transients accounted for roughly 80% of the particulate mass emitted during the cycle but only about 45% of the fuel consumption.