Carnegie Mellon University

Vehicle Stability

NREC has developed an easy-to-implement solution to an important problem — stability margin estimation as it relates to vehicular rollover and tip over vulnerabilities.

NREC’s Stability Prediction System (SPS) calculates the effects of lateral acceleration and gravity as either curvature, speed, or slope increase, and when state of motion approaches a tip over condition, the system recognizes the situation and stabilizes the vehicle. 

The Problem
For vehicles operating on slopes, the inherently "reduced stability margin” significantly increases the likelihood of rollover or tip over.

Unmanned ground vehicles (UGVs) are not the only wheeled vehicles that traverse rough terrain and steep slopes. Contemporary, driver-operated mining, forestry, agriculture and military vehicles traverse rough terrain and steep slopes. They do so frequently and at high speeds over extended periods of time. Cranes, excavators and other machines that lift heavy loads also are subject to dramatically increased instability when operating on slopes. Preventing vehicular tip over on flat surfaces (inside a warehouse, for example) is just as important.

The Solution
NREC experts devised a solution featuring a combination of sophisticated software and hardware, including inertial sensors and an inclinometer-type pendulum at the vehicle’s center of gravity.

During vehicular operation, the system continuously and actively calculates stability margin measurements to trigger an alarm, drive a "governor” device or alter the suspension. These algorithms take into account diverse variables such as the aggregate effect of gravity and changing kinematic forces. It calculates lateral acceleration as either curvature or speed increase. When state-of-motion activity reaches rollover / tip over vulnerability, the system recognizes the situation and triggers the desired action.

This system can be deployed on robotic and driver-operated vehicles (including cars) and machinery (cranes, excavators, lift trucks, pallet jacks, etc.).

Photos

Vehicle Stability
Vehicle Stability
Vehicle Stability