A Microprocessor controller to Provide Low Cost Numerical Control

  • R. H. Weston
  • G. P. Charles


The cost effectiveness and flexibility of microprocessors, used as central processing units, will result in their replacing many of the numerical and computer numerical controls used in the machine tool industry. Further, microprocessors can now be used to provide the control of some processes which formerly did not warrant fully the capital expense of numerical controls.

Two such processes, electron beam welding and cutter grinding are considered here and microprocessor controls developed for them. The controls were developed with low cost and ease of operator use as primary objectives. For both processes contour generation is required in the positioning of an open-loop system. With the electron beam welder, beam deflection is achieved in two axes with compensation made for change in workpiece height. Cutter grinding is achieved using three step-motor driven axes on an attachment to a universal cutter grinding machine. The contour generation has been achieved primarily in software and demonstrates excellent performance characteristics in terms of speed and accuracy. Part-programming facilities are considered for the two systems, as too are methods whereby the cost of peripheral equipment, for data input, can be reduced.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    A.A. SHUMSHERUDDIN (1968) A New Generation of Continuous Path NC Systems, M.T.D.R. Conference 9, p. 1191.Google Scholar
  2. 2.
    W. ARNSTEIN, H.W. MERGLER and D. SINGER (1964) Digital Linear Interpolation and the Binary Rate Multiplier, Control Eng. June, p. 302 Google Scholar
  3. 3.
    J.C. GRANT (1972) The Digital Differential Analyser, MSc Thesis Heriot-Watt University Google Scholar
  4. 4.
    R.E. BYWATER, (1970) One-Step Integration Method of Digital Differential Analysers, Electronic Letters Vol. 6 No. 9 p.613 CrossRefGoogle Scholar
  5. 5.
    G.R. RANKINE (1976) Midpoint — A Microprogrammed Differential Polynomial Interpolator, PhD Thesis Heriot-Watt University Google Scholar
  6. 6.
    C. BERGREN (1971) A Simple Algorithm for Circular Interpolation, Control Engineering, Sept. p. 57 Google Scholar
  7. 7.
    E.W. JORDEN Jr., W.J. LEMMON and B.D. HOLM (1973) An Improved Algorithm for the Generation of Non Parametric Curves, I.E.E. Transactions on Computers Vo. C22, No. 12 p. 1052.CrossRefGoogle Scholar
  8. 8.
    D.A. MILNER (1976) Some Aspects of CNC With Reference to Interpolation, J.Eng. for Industry, Aug., p.883 Google Scholar
  9. 9.
    A.E. MIDDLEDITCH (1972) The Design of a Digital Computer Contouring Control System, PhD Thesis Carnegie Mellon Google Scholar
  10. 10.
    A.N. POO and J.G. BOLLINGER (1972) Dynamic Errors in Type 1 Contouring Systems, I.E.E. Transactions on Industrial App. Vol. 1A-8, No. 4 Google Scholar
  11. 11.
    ENGINEERING STAFF OF TEXAS INSTRUMENTS (1977) Semiconductor Circuit Design Vol. V. Texas Instruments Ltd., p. 150 Google Scholar

Copyright information

© Department of Mechanical Engineering, University of Manchester Institute of Science and Technology 1979

Authors and Affiliations

  • R. H. Weston
    • 1
  • G. P. Charles
    • 1
  1. 1.Department of Engineering ProductionUniversity of TechnologyLoughboroughUK

Personalised recommendations