Design and Control of a Two-Degree-of-Freedom Lightweight Flexible Arm

Abstract

This report describes the design and control of a two-joint, two-link flexible arm. Our purpose has been to build an efficient arm in the sense that most of the energy provided by the motors is spent in doing the task (moving the tip mass) instead of moving the arm structure. In order to achieve that, we designed a flexible arm that has most of its mass concentrated on the tip. We wanted also to decouple radial tip motions from angular tip motions. The special mechanical configuration that fulfills all these specifications is described in Sections 2. Section 3 describes the control scheme of this arm. an important problem when controlling it was the large Coulomb friction of the motors. A two- nested-loop multivariable controller has been used. The inner loop controls the position of the motors while the outer loop controls the tip position. The resolved acceleration method is generalized to control this flexible arm. The compliance matrix was used to model the oscillations of the structure, and was included in the decoupling/linearizing term of this controller.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1989
Accession Number
ADA213335

Entities

People

  • H. B. Brown Jr.
  • Kuldip S. Rattan
  • Vincente Feliu

Organizations

  • Carnegie Mellon University

Tags

Communities of Interest

  • Autonomy
  • C4I
  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Amplifiers
  • Angular Motion
  • Cartesian Coordinates
  • Classification
  • Control Systems
  • Decoupling
  • Frequency
  • Friction
  • Geometry
  • Mechanical Structure
  • Mechanics
  • Operating Systems
  • Oscillation
  • Security
  • Specifications
  • Systems Engineering
  • Vibration

Readers

  • Control Systems Engineering.
  • Robotics and Automation.