Ac motorized wheel control system

Abstract

Torque is distributed by calculating first and second torque commands using a requested torque and a ratio of speeds of first and second wheels and limiting them in accordance with respective torque command approved ranges and approved change rates; converting the limited torque commands to horsepower commands and limiting them in accordance with respective horsepower command approved ranges and approved change rates; and converting the limited horsepower commands to present torque commands. Maximum horsepower available is determined by using an engine speed to determine a nominal amount of available horsepower; applying a desired load status signal and an actual engine load status signal to a proportional-integral A regulator; and using the nominal amount of available horsepower and an output signal of the regulator to determine the maximum amount of available horsepower. Thermal protection is provided by obtaining component temperatures of a plurality of components; normalizing each component temperature; obtaining a normalized drive system temperature by determining a maximum value of the normalized component temperatures; and comparing the normalized drive system temperature with at least one predetermined maximum normalized temperature and using a result of the comparison to determine whether a corrective action is needed. A truck is started on an incline by determining whether its speed is below a predetermined speed limit, a service brake is applied, and an accelerator pedal is depressed, and, if so, permitting a propulsion torque to build without requiring an operator override action.