ADAPTIVE CONTROL FOR SAFE AND QUALITY REBAR FABRICATION

Rebar fabrication is a labor intensive operation that uses scrap steel for raw materials and therefore can benefit greatly from improvements in safety, productivity, and quality. Shared control through a human-machine interface may be the best alternative for achieving highest quality standards and improving worker performance in safety and productivity. This paper develops a control scheme for automated rebar bending within the framework of computer integrated construction and presents research focused on the task level control to compensate for springback in the bent rebar. Three major problems are addressed: conception of a hierarchical computer integrated construction control structure that links rebar fabrication to the other construction project functions, comparative evaluation of alternative algorithms for prediction of springback, and portability of a springback control model that uses real-time electronic sensing. Bending tests were conducted with both a laboratory prototype and an actual shop table bender to experiment with alternative models for in-process springback prediction including a neural network model. Limitations in control system portability were realized in the transfer from the laboratory prototype bender to the shop bender. Springback model evaluations revealed that empirical statistical models, neural networks, and in-process relaxation performed equally well.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/8675438
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Dunston, P S
  • Bernold, L E
• Publication Date: 2000-3

Language

• English

Media Info

• Features: Appendices; Figures; Photos; References;
• Pagination: p. 122-129
• Serial:
  • Journal of Construction Engineering and Management
  • Volume: 126
  • Issue Number: 2
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9364
  • EISSN: 1943-7862
  • Serial URL: http://ascelibrary.org/journal/jcemd4

Subject/Index Terms

• TRT Terms: Adaptive control; Algorithms; Automation; Bending; Bending moments; Computer aided manufacturing; Control systems; Curvature; Electronics; Experiments; Fabrication; Human machine systems; Interfaces; Machine learning; Mathematical models; Neural networks; Productivity; Prototypes; Quality assurance; Real time control; Regression analysis; Reinforcing bars; Reinforcing steel; Safety
• Subject Areas: Bridges and other structures; Data and Information Technology; Geotechnology; Highways; Materials; Safety and Human Factors; I34: Steels and Metals;

Filing Info

• Accession Number: 00794009
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 19 2000 12:00AM