Vehicle Stability Prediction
Description



NREC's test vehicle was a lift truck incorporating the Stability Prediction System.

NREC researchers developed algorithms for a stability margin estimation system. These algorithms take into account diverse variables such as the aggregate effect of gravity and changing kinematic forces. NREC scientists then developed animated simulations to test models for maneuver-based stability of vehicles and machinery (lift trucks, excavators, cranes, etc.) at various slopes, speeds and payload articulations.

Further testing involved the use of test-bed hardware, including a lift truck. The lift truck underwent major retrofitting to incorporate sensors, (gyro, axis accelerometer and inclinometer), stabilizing equipment, computer hardware and control software. As part of the hardware platform, NREC created a data logger system for use in simulation scenarios. NREC testers calibrated the models used in simulation to minimize risk of tipover of the actual test vehicles.

The sensing/driver control system was developed in Matlab/Simulink and included models for inertial sensors and a user interface to simulate input driver commands to the lift truck, including steer, speed, lift height, side-shift and tilt. Furthermore, a software interface layer was defined to connect the stability-prediction algorithms to the sensing system. Through the driver control interface, the user can input drive commands to the truck, which results in the dynamic model responding to these commands. As the vehicle executes the user commands, the sensing system monitors vehicle stability.