Constraint-Monitoring Estimation Strategies for Dynamic Systems Subject to Equality Constraints

摘要

Sometimes a dynamic system subject to a constraint is configured or undergoes motion such that the constraint is not held for some period of time, often unintentionally. For example, a tether connecting two spacecraft may fail. There exist several estimation strategies for systems in which the constraints are not broken. For example, the constraint can be eliminated from the dynamic equations using a variety of methods, such as employing Lagrange multipliers or quasi velocities. Alternatively, the estimation scheme can be modified to enforce the constraint through projection methods or again using Lagrange multipliers. For rolling systems subject to slip, observer techniques for detecting slip, calculating related forces, or using the constraint as a measurement have been proposed.