General Purpose Automotive Vehicle Performance and Economy Simulator

GPSIM is an automotive vehicle simulator that computes the operating conditions of the engine and transmission and the performance and economy of the vehicle as the vehicle is operated in a prescribed manner.

The program can simulate a large variety of vehicles. The vehicle to be simulated is described by the user with a combination of steady-state test results and vehicle specifications. The simulator makes predictions from limited data for proposed vehicle combinations, or it makes more accurate computations based on component tests for production vehicles.

This paper tells how the simulator computes the operating conditions and how these computations compare with test results. It also describes how engineers using the simulator have decreased developmental lead time, decreased the number of full vehicle tests, and focused developmental work on the best alternatives.

The techniques that can be applied in other areas such as the data library control and the command language are described.