Multi-Variable Control for Engine Transmission Systems with Infinitely Variable Ratios

Two systems involving an infinitely variable connection between engine and output shaft are investigated, viz:

1. (a)
   the Differential Compound Engine (DCE)
2. (b)
   the shunt-hydrostatic transmission coupled to a turbocharged Diesel engine.

In both cases a given demanded input shaft condition can be met with a wide range of engine operating conditions. Since at least three external controls are available in both cases, viz:

1. (a)
   fuel pump metering valve or governor set point
2. (b)
   turbine nozzle angle (DCE) or hydrostatic motor swash
3. (c)
   engine bypass (DCE) or hydrostatic pump swash

optimisation of these control settings for best overall efficiency, torque backup or minimum emissions becomes a necessity and will form an important element in traction power plant design in the future.