Biomedical Engineering Reference
In-Depth Information
CHAPTER 4
OPTIMAL SHOCK ISOLATION FOR
MULTI-DEGREE-OF-FREEDOM
SYSTEMS
In this chapter, a number of optimal shock isolation problems are formu-
lated and solved for systems with several degrees of freedom. It is not
possible to create a complete consistent theory of optimal shock isolation
for multi-degree-of-freedom systems that would cover all possible struc-
tures and tasks encountered in engineering practice. This chapter pursues
more modest goals. Some features that are typical for optimal control prob-
lems associated with shock isolation of multi-degree-of-freedom objects
but are absent from similar problems for single-degree-of-freedom systems
will be illustrated. Also, procedures will be presented to simplify optimiza-
tion of multi-degree-of-freedom dynamical systems. Section 4.1 deals with
shock isolation of flexible objects. For a two-degree-of-freedom model of
an object, an algorithm for calculating the optimal control is presented and
substantiated. This algorithm is based on the solution of an optimal control
problem for a rigid (single-degree-of-freedom) model of an object that was
discussed in Chapter 3. However, the optimal control for a flexible object
has important qualitative differences from the control for a rigid object. It
contains impulse components and, hence, cannot be provided by constant
force. Section 4.2 presents a general concept for a limiting performance
analysis of systems that involve three structural components: a base, a con-
tainer in which the object is placed, and the object. Shock isolators separate
the container from the base and the object from the container. Such a struc-
ture is typical of vehicles equipped with shock isolation systems to reduce
injuries to occupants in a crash.
Search WWH ::
Custom Search