Automatic outer loop centering of aircraft inner loop

US4385355A · kind A · utility

Assignee

• UNITED TECHNOLOGIES CORPORATION · US

Inventors

• David J. Verzella · Guilford, US
• William C. Fischer · Monroe, US
• Don L. Adams · Bartlesville, US
• Stuart C. Wright · Woodbridge, US

Key dates

• Filing date: Mar 30, 1981
• Grant date: May 24, 1983
• Expiry date: Mar 30, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G05D1/0833
• WIPO field: Control
• WIPO sector: Instruments

Abstract

An aircraft automatic flight control system includes a pair of fast, limited authority inner loop actuators (12, 13) responsive to signals (52-55) indicative of aircraft attitude (68, 69) or other flight parameters such as airspeed (84), the inner loop being recentered by an outer loop actuator (37) responsive to attitude or other aircraft parameter-indicating signals (54, 55). Commands (40) applied to the outer loop are applied in a lagged fashion (58, 59) in opposite direction so as to drive the inner loop actuators (12, 13) back toward the center of their authority. The rate of response of the outer loop (FIG. 2, FIG. 5) is adaptive in dependence upon airspeed (93, 96, 212, 213) and in response to magnitude of inner loop input (101, FIG. 2). An integral gain (41), pulsed (39), open loop drive of the outer loop actuator (37) and outer loop automatic shutdown (38) are disclosed.