| Stability is an important concern
for vehicles which move heavy loads, accelerate or brake aggressively, turn
at speed, or operate on sloped terrain. In many cases, vehicles face more
than one of these challenges simultaneously. Some are obliged to execute
these maneuvers when their high centers of gravity leave them particularly
vulnerable to tipover or rollover. A methodology is presented to estimate
proximity to tipover for autonomous field robots that must be productive,
effective, and self-reliant under such challenging circumstances. While
the physical principles governing the computation of stability margin have
been known for some time, the realization of these principles in practice
raises issues which are at once similar to those of attitude estimation
while contrasting heavily with inertial guidance. The problem of stability
margin estimation is posed in the fairly general case of accelerated articulating
motion over rough terrain. Compatibility with and distinctions from attitude
estimation lead to a proposed integrated solution to both problems based
on the fusion of inertial, articulation, and terrain relative velocity sensing
inan optimal estimation framework. An implementation of a device targeted
to an industrial lift truck is presented. |
