Patent · US Expired

Electro-hydraulic control apparatus for improved hydraulic pressure control

US5264767A · kind A · utility

7Cited by
18References
4Claims
0Family size

Assignees

Inventors

Key dates

Filing dateJan 21, 1992
Grant dateNov 23, 1993
Priority date
Expiry dateJan 21, 2012

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P7/04
  • WIPO fieldTransport
  • WIPO sectorMechanical engineering

Abstract

An improved method of controlling an electro-hydraulic control system by developing a motor control command in relation to the desired force to be exerted by an electric motor on a mechanical element whose displacement determines the hydraulic pressure. The control command is comprised of two magnitude signals. The first magnitude signal must be sufficient to exert enough force to overcome a static friction characteristic of the mechanical element, and the second magnitude signal is selected to achieve a desired average current or voltage over that control period. The time constant for the control command is less than the mechanical time constant of the system, but greater than the the electrical time constant of the system. The control command may be implemented by using either current or voltage control.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.