Re(2): sequential gearboxes

[Robert D. Devlin]

A normal H pattern gearshift can be made to function as a sequential by
the use of two hydraulic actuators. One actuator operates the clutch ( to
disengage / engage ), the other operates the gear selector directly. A
system of this type was developed jointly by Isuzu motors and Fujitsu. The
actuators each consist of a hydraulic cylinder that is fed by a  fluid
supply from a resevoir pressurised by a pump driven from the engine. Each
cylinder has two solenoid operated valves controlled by pulse width
modulation. One valve is of large diameter to allow rapid fluid movement
and the other a smaller valve to permit more accurate control. Hence,
reaction time and gear change duration can be suprisingly short, yet
dimensional control very accurate. The system software is relatively
simple so some sort of ignition retarding control could be easily
incorporated to allow flat out shifts. The system, having the benefit of
clutchless changes could also be put to use to aid those who cannot
operate foot pedals but want to drive a 'manual' car. I recently read a
technical paper on the subject and if I can find a reference will pass it
on. I hope this may be of some use. Cheers, Rob Devlin, England.