Non-Linear Control Allocation Using Piecewise Linear Functions: A Linear Programming Approach

Abstract

The performance of two different approaches to solving the non-linear control allocation problem is presented. The non-linear control allocation problem is formulated using piecewise linear functions to approximate the control moments produced by a set of control effectors. when the control allocation problem is formulated as a piecewise linear program, an additional set of constraints enter into the problem formation. One approach is to introduce a set of binary variables to enforce these constraints. The result is a mixed- integer linear programming problem that can be solved using any branch-and-bound software. A second approach is to solve the piecewise linear programming problem using a modified simplex method. The simplex algorithm is modified to enforce a subset of the decision variables to enter into the basis only if certain conditions are met. We will show that solving the optimization problem using the simplex based approach is significantly faster than solving the same problem using a mixed-integer formulation. We will then compare the closed-loop performance of a re-entry vehicle using both approaches.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2004
Accession Number
ADA421388

Entities

People

  • David B. Doman
  • Michael A. Bolender

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Aircrafts
  • Algorithms
  • Computer Programming
  • Control Surfaces
  • Control Systems
  • Evolutionary Algorithms
  • Flight Control Systems
  • Linear Programming
  • Military Research
  • Operating Systems
  • Optimization
  • Simplex Method
  • Vehicles

Fields of Study

  • Computer science
  • Mathematics

Readers

  • Operations Research
  • Robotics and Automation.