# US 11,440,643 B2 · Nonlinear fly-by-wire aircraft control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,643 B2 - Document ID: US11440643B2 - Status: Granted - Kind: B2 - Application number: 17/083,900 - Filed: 2020-10-29 - Published: 2022-05-05 - Granted: 2022-09-13 - Earliest claimed: 2020-10-29 - Assignees: Textron Innovations Inc. - Applicants: Bell Textron Inc. - Inventors: Cody Fegely; Kenneth Stephen Wittmer - Web page: https://patentgrep.com/patent/US11440643B2 ## CPC - B64C 13/503: {Fly-by-Wire} - B64C 27/04: Helicopters - B64C 27/57: automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust - B64C 2027/8209: {Electrically driven tail rotors} - B64C: AEROPLANES; HELICOPTERS ## Abstract There is disclosed in one example a flight control computer for a rotary aircraft, including: a first interface to communicatively couple to a flight control input; a second interface to communicatively couple to flight geometry actuators; a data source; a multi-dimensional lookup table including a data structure to correlate flight control inputs to flight geometry actuator outputs according to a third-factor; and circuitry and logic instructions to: receive an input via the first interface; query the data source for the third-factor; query the multi-dimensional lookup table for a control input modifier according to the flight control input and the third-factor; and compute and send via a third interface a flight geometry output according to the control input modifier. ## Claims ### Claim 1 A flight control computer for a rotary aircraft, comprising: a first interface to communicatively couple to a flight control input; a second interface to communicatively couple to flight geometry actuators; a data source; a multi-dimensional lookup table comprising a data structure to correlate flight control inputs to flight geometry actuator outputs according to a third-factor; and circuitry and logic instructions to: receive an input via the first interface; query the data source for the third-factor; query the multi-dimensional lookup table for a control input modifier according to the flight control input and the third-factor; and compute and send via a third interface a flight geometry output according to the control input modifier. ### Claim 2 (depends on 1) The flight control computer of claim 1, wherein the control input modifier is a gain. ### Claim 3 (depends on 1) The flight control computer of claim 1, wherein the flight geometry output comprises an actuator to control blade position. ### Claim 4 (depends on 1) The flight control computer of claim 1, wherein the flight geometry output comprises an actuator to control a tail rotor. ### Claim 5 (depends on 1) The flight control computer of claim 1, wherein the circuitry and logic instructions are further to provide a virtual hard stop. ### Claim 6 (depends on 1) The flight control computer of claim 1, wherein the third-factor comprises airspeed. ### Claim 7 (depends on 1) The flight control computer of claim 1, wherein the data structure comprises bucketized gain curves according to ranges of the third-factor. ### Claim 8 A method of electronically controlling a rotorcraft, comprising: receiving via a first data source a flight control displacement; receiving via a second data source a secondary condition; querying a data structure with the flight control displacement and the secondary condition; and translating the flight control displacement into an actuator displacement according to a gain value received from the data structure. ### Claim 9 (depends on 8) The method of claim 8, further comprising driving an actuator according to the actuator displacement. ### Claim 10 (depends on 8) The method of claim 8, wherein the first data source comprises an inceptor. ### Claim 11 (depends on 8) The method of claim 8, wherein the data structure comprises bucketized gain curves according to ranges of the secondary condition. ### Claim 12 (depends on 11) The method of claim 11, wherein the secondary condition comprises airspeed. ### Claim 13 (depends on 12) The method of claim 12, wherein the ranges include substantially 0-80 knots, 80-120 knots, 120-160 knots, 160-180 knots, 180-216 knots, and greater than 216 knots. ### Claim 14 (depends on 8) The method of claim 8, wherein the secondary condition comprises at least one of airspeed, acceleration, adverse environment, inceptor acceleration, air temperature, ambient pressure, and weapon status. ### Claim 15 (depends on 8) The method of claim 8, wherein the first data source is a collective input position, the secondary condition is an airspeed, and translating the flight control displacement comprises applying the gain according to the collective input position and the airspeed, and adding a yaw modifier to compute the actuator displacement. ### Claim 16 A rotary aircraft, comprising: an operator flight control system; an engine; a rotor blade drive system mechanically coupled to the engine; a fly-by-wire control system comprising electronically controllable actuators to adjust flight control surfaces to affect yaw, pitch, and roll of the rotary aircraft; an environmental sensor; and a flight computer comprising a processor microcircuit and logic to: receive an input from the flight control system; receive an environmental datum from the environmental sensor; query an n-dimensional ratio table, n>2, for an actuator ratio according to the input and the environmental datum; and actuate the fly-by-wire control system according to the actuator ratio. ### Claim 17 (depends on 16) The rotary aircraft of claim 16, wherein the flight control system comprises an inceptor. ### Claim 18 (depends on 16) The rotary aircraft of claim 16, wherein the flight control system comprises a collective, a cyclic, and pedals. ### Claim 19 (depends on 16) The rotary aircraft of claim 16, wherein the actuator ratio comprises an actuator gain to control blade position. ### Claim 20 (depends on 16) The rotary aircraft of claim 16, wherein the actuator ratio comprises an actuator gain to control a tail rotor.