Feedback PDM encoder and method for actuating a pneumatic actuator with a digital autopilot

US4033525A · kind A · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• John P. Leonard · Huntsville, US
• Robert E. Yates · Huntsville, US

Key dates

• Filing date: Dec 8, 1975
• Grant date: Jul 5, 1977
• Expiry date: Dec 8, 1995

Classification

• Technology area (CPC G): Physics
• CPC primary: G05D3/18
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A feedback PDM encoder and method is presented which permits utilization of neumatic pulse duration modulation (PDM) actuators with potentiometer position pickoffs in a digital autopilot loop. The actuator is directly driven by a signal derived in the digital autopilot which is in the pulse duration modulation (PDM) format. This signal is derived within the autopilot digital computer using conventional digital techniques. Analog feedback from the potentiometer which indicates angular excursion of the actuator is formatted into a PDM format. This method yields all signals necessary to operate the actuator in a closed loop missile control system.