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Hino Motors had developed an electronically controlled mechanical automatic transmission and employed it for the ′85 models of large size buses, and also ′86 models of heavy/ medium duty trucks. This system gives minimum fuel consumption and even smoother/easier driving than an automatic transmission with torque converter, by controlling an engine also with a transmission and employing an oil spray clutch. The trade name of this system is EE-Drive which means easy and economy drive.

Four years have passed since the automated mechanical transmission was first introduced in city buses, and this system is now making steady inroads into the market. The development of this system was a result of the cooperation between Kinki Nippon Railway Co., Ltd., the largest bus and coach transportation company, and Hino Motors Ltd., the largest truck and bus manufacturer in Japan. First an investigation was conducted of the topography and traffic conditions of the bus routes, then trial runs and refinement of the computer control software was carried out using three chosen routes, and finally the actual performance of the system was tested according to the finalized specifications. This paper introduces the development process, provides a background to the city bus service, and describes the benefits brought by this system and the successful results of this cooperation.

In the '97 Dakar Rally, Hino FT model, 8,000cc engine truck, won 1st, 2nd and 3rd places by defeating upper class trucks having engine of 19,000cc. The average speed of the '97 Hino model was increased more than 15 km/h over the '96 model by improving the riding comfort and handling stability. Larger diameter tires, and softer parabolic leaf springs with long and inclined axle-locus for reducing road impact, gas charged dampers, suspension rods which control compliance-steer-motion and wind-up motion of unsprung masses were adopted for the '97 model.

The driving performance of a vehicle with front wheel steering system is enhanced by controlling the gain and/or phase-lag characteristics. A vehicle with rear axle steering system has an even or higher effect than that. The compliance steer control effect in mechanical system is the key technology for enhancing the on-center stability Driver's error compensating system by steering and/or brake system control will be in future, and the manual and automonous control hybrid driving system will follow it.

Vehicle responsiveness to the driver's steering maneuvers and external turbulences caused by irregularities in the road surface and wind gusts are two opposing factors to be studied for better stability and controllability of vehicles. The cruising speeds of vehicles on freeways have been becoming higher, and wider physiological differences in the driving ability of drivers are appearing with the increase in elderly drivers. Therefore, to meet the requirements of higher cruising speeds and the expanding physiological differences between drivers, an electro-hydraulic feedforward control power steering system has been developed for trucks and buses. This is a parallel operating system consisting of a mechanical route and an electronic route, and improves vehicle responsiveness so as to absorb the physiological differences of drivers.

The 1st stage of automated mechanical transmission (AMT) was initiated in 1985 by Hino's development of EE-Drive, featuring a pneumatically-stroke-controlled, oil-sprayed coil spring type clutch.[1] [2]* This system made its way into city buses, thus expanding the market for automatic transmission (AT) in Japan. This paper introduces EE-Drive 2nd stage, to be installed mainly on medium-duty trucks, and featuring a hydraulic-pressure-controlled, oil-sprayed clutch. This system is characterized by smooth starting through controlling the pressure of the clutch disk directly. It also features quick shifting, because it allows gears to be shifted with no clutch stroke, but rather through decreasing the pressure. This will prove competitive with AT with a torque converter (HAT) which will appear in the 1990's as a sophisticated electronically controlled AT (ECT).