Analysis of effects of differential gain on dynamic stability of digital force control

L. L. Kovács, J. Kövecses, G. Stépán

Research output: Contribution to journalArticle

23 Citations (Scopus)


The paper presents an analytical investigation of the dynamics of digital force control. A one degree-of-freedom (DoF) mechanical system with low viscous damping is subjected to proportional-derivative (PD) force control. Analytical results are presented in the form of stability charts in the parameter space of sampling time, control gains and mechanical parameters. Simple closed form results include the largest stable proportional gain and the least steady state force error that provide synthesis of mechanical and control system parameter influences for the design of digital force control. Also, a novel analytical explanation is given why even the properly filtered force derivative signal is rarely used in practice, and why the occurring vibrations have frequencies one range smaller than that of the sampling frequency of the digital control.

Original languageEnglish
Pages (from-to)514-520
Number of pages7
JournalInternational Journal of Non-Linear Mechanics
Issue number6
Publication statusPublished - Jul 1 2008



  • Differential gain
  • Dynamic stability
  • Force control
  • Sampling time

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Applied Mathematics

Cite this