Integration of a Chassis Servo-Dynamometer and Simulation to Increase Energy Consumption Accuracy in Vehicles Emulating Road Routes

Abstract

Electric vehicles, particularly those in mass transit systems, make use of accurate power estimations for different routes to calculate powertrain and battery requirements and plan the location and times of charging stations. Hence, chassis dynamometers are a common tool for vehicle designers as they allow for the emulation of vehicle performance and energy consumption by simulating realistic road conditions. In this paper, a method is presented where inertia events and negative slopes can be represented in the dynamometer through a single motor; allowing researchers to perform fast and cheap tests, while also considering the effect of these variables. A dynamic simulation is used to distribute the energy used in three ways: first, accelerating the vehicle by overcoming the forces opposing motion; second, emulating the kinetic energy delivered by the vehicle mass when decelerating; and third, emulating the energy delivered to the vehicle by negative slopes. Tests were carried out on a dynamometer validating the method through an example route, estimating energy consumption and regeneration; this method reduces the error in energy consumption by inertial effects and negative slopes, otherwise not considered in one motor dynamometers, showing a 9.11% difference between total test energy and real bus energy for this route.