A Dynamic Simulation of the Detroit Diesel Electronic Control System in Heavy Duty Truck Powertrains

A comprehensive simulation has been developed which describes the dynamic behavior of truck powertrains employing. Detroit Diesel Allison heavy duty diesel engines equipped with the Detroit Diesel Electronic Control System (DDEC). The simulation, was developed to address those issues related to DDEC fuel control that impact upon engine smoke production and upon vehicle driveability and responsiveness, and to identify components in the powertrain which interact with the control system. The simulation contains four major submodels: (1) torque and transient air system model of the 8V-92 turbocharged/inter-cooled two-stroke engine; (2) discrete event, DDEC controller/governor model; (3) tandem rear axle drive, torsionally compliant, manual transmission driveline model; and (4) flexible driver simulator and external event module. The formulations and salient characteristics of the various submodels are discussed and the important dynamic characteristics of the independent subsystems are identified. Several examples of the interaction between the engine, control system and driveline are presented which demonstrate the applicability of dynamic simulation to evaluating and optimizing control system performance.