CONTROL SYSTEM INTERFACE.pdf

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL CONTROL SYSTEM INTERFACE — SYSTEM DESCRIPTION 1. General A. Description The control system interface consists of conventional control wheels, control columns and rudder pedal assemblies. The position of each control inceptor is sensed by five RVDTs that pr...

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL CONTROL SYSTEM INTERFACE — SYSTEM DESCRIPTION 1. General A. Description The control system interface consists of conventional control wheels, control columns and rudder pedal assemblies. The position of each control inceptor is sensed by five RVDTs that provide control data to Flight Control Computers (FCCs) and Backup Control Unit (BFCU). There are two RVDTs for each FCC and one RVDT for the BFCU. See Figure 1 and Figure 2. The Primary Flight Controls System (PFCS) is an integrated three axis Fly-By-Wire (FBW) flight system that provides the following control: Pitch control through the elevator control system. See Elevator Control, 27-30-00, System Description. Pitch control is supported by the horizontal stabilizer control system. See Horizontal Stabilizer Control, 27-40-00, System Description. Roll control through the aileron control system. See Aileron Control, 27-10-00, System Description. Roll control is supported by the spoiler control system. See Spoiler Control System, 27-60-00, System Description. Yaw control through the rudder control system. See Rudder Control, 27-20-00, System Description. The PFCS includes control wheel, column and rudder pedals. The PFCS provides control for the following: Ailerons (2) Spoilers (6) Elevators (2) Rudder Horizontal Stabilizer Control Unit (HSCU) The FCCs interface with force sensors installed on each inceptor. Data is used for Autopilot (AP) disconnect function and reporting to Flight Data Recorder (FDR). Each control column has one stick shaker motor. Each stick shaker motor is driven by one FCC. The AP has servos that move column / wheel assemblies. The FCCs output data through shielded electrical wiring to Remote Electronic Units (REUs) that control aircraft movement. 2. Component Location COMPONENT ATA QTY PER A/C LOCATION Trim control module 27-03-01 1 Pedestal, center aft section Aileron and elevator control module assembly (pilot) 27-03-03 1 Aft end of cockpit, below center floor panels Aileron and elevator control module assembly (copilot) 27-03-03 1 Aft end of cockpit, below center floor panels Rudder control module assembly 27-03-05 1 Above floor, forward of pedestal 27-03-00 Page 1 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL 3. Component Details A. Trim Control Module The trim control module interfaces with the FCC for pitch, roll and yaw functions. Pitch function also interfaces with the HSCU. Trim control module includes the following switches: BACKUP PITCH - NOSE DOWN, NOSE UP ROLL - LWD, RWD ROLL MOTOR CONTROL RUDDER - NOSE L, NOSE R RUDDER - AUTO CENTER Switch placement and actuation is designed to provide pilot and copilot with intuitive recognition of all three trim axis. Trim switch actuation direction corresponds to aircraft rotation. The trim control module has a rudder AUTO CENTER switch, which automatically centers rudder trim. See Figure 3. B. Aileron and Elevator Control Module Assembly (Pilot) Pilot and copilot columns are coupled through a breakout mechanism that lets the pilot override a jammed side. The position of each column is sensed by the following five RVDTs: Two for FCC 1 Two for FCC 2 One for BFCU For each assembly five RVDTs are mounted in a pack and share a common attachment point to the torque tube. This is refered to as an RVDT cluster. If a mechanical disconnect occurs, the RVDT cluster is moved to a neutral position by a centering spring. Force sensors are installed to enable pilot input force to be recorded. If FCCs detect pilot input when AP is engaged, FCCs signal AP to disconnect. Two servo actuators are controlled by the AP system. Two stick shaker motors are controlled by FCCs. One of each is installed on the pilot side, the other is installed on the copilot side. This arrangement allows continuous operation if a jam occurs. The 28 Vdc stick shaker motor power enters the FCC and passes through internal switches controlled by FCC software. See Figure 4. C. Aileron and Elevator Control Module Assembly (Copilot) See Aileron and Elevator Control Module Assembly (Pilot) for component details. D. Rudder Control Module Assembly Pilot and copilot rudder controls provide rudder position commands to the FCCs and BFCU. The FBW system has artificial feel design for human factors operation. Control module dampers provide smooth operation and alleviate oscillations. Force sensors for each flightcrew station satisfy FAA / EASA flight data recording requirements. See Figure 5. The rudder control system has the following major components: One pedal assembly each for the pilot and copilot One feel and centering unit The pedal assembly contains the following: Two independent rudder / brake pedals Brake pedal position sensor interface Manual rudder pedal stature adjust The feel and centering unit contains the following: 27-03-00 Page 2 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL Feel and centering mechanism One sensor cluster contains five RVDTs Connection to petal assemblies via pushrods with integrated force sensors Damping The pilot and copilot rudder pedals are coupled. Rudder position is sensed by the following five RVDTs: Two for FCC 1 Two for FCC 2 One for BFCU The RVDT sensors are mounted in a pack (RVDT cluster) and share a common attachment point to the rudder pedal torque tube. If a mechanical disconnect with the pedals occurs, the RVDT cluster is moved to a neutral position by a centering spring. Two force sensors (strain gauges) are installed on the rudder pedal assembly, one at each pedal. Each FCC interfaces with one sensor for reporting to the FDR. Pilot pedal force is read by FCC 1. Copilot pedal force is read by FCC 2. The rudder trim actuator is commanded by the trim switches on the trim control module. The position RVDT interfaces with FCC 1 for reporting to CAS and the FDR. 4. Operation A. Control System Interface The control system interface includes the following: Aileron control Aileron trim control Elevator control Elevator trim control Rudder control Rudder trim control (1) Aileron Control Each aileron surface is moved by two actuators operating in active / active manner. Inboard actuators are EBHA and outboard actuators are EHSA. The EBHAs are configured with one R/T and one receive bus interface. The EHSAs have one R/T and one receive bus interface. Each of the two FCCs provides two BD429 buses to aileron REUs. Both FCCs transmit on all their REU buses unless two channels in one FCC are invalid or in a lower capability operational mode to the other FCC. The REUs average surface position commands from the primary and secondary bus. The REU takes status commands from the primary bus by default and switches to the secondary bus if primary bus is faulted. The FCCs compute pilot and copilot wheel positions. Each RVDT is monitored for detection of electrical failure (open or short circuit). Each FCC also performs a two step scheme for mechanical fault detection. If all RVDTs are valid, FCC uses a quadriplex voter to determine average value of the two middle valued RVDTs. If only three RVDTs are valid, the FCC uses the middle value. If only two RVDTs are valid, FCC averages the two. In autoflight mode columns are positioned by two AP servo actuators operating in active / standby. The FCCs receive AP position commands through wheel RVDTs. The FCCs monitor pilot and copilot forces to detect an attempt to override servos. In this event, the FCCs command the AP to disengage. The command is passed over the A429 buses. Force sensor data is transmitted from the FCC to the modular avionics unit for transmission to the FDR. 27-03-00 Page 3 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL Four FCC channels separately compute aileron commands. To minimize force fight between two adjacent actuators, FCC channels synchronize their integrators to minimize split. Each FCC independently transmits aileron commands. If one FCC fails, remaining FCC continues aileron control. (2) Aileron Trim Control Aileron trim control operates in the following two modes: Normal operation Reversion mode In normal operation the trim motor is commanded by ROLL trim switches on the pedestal trim control module. The switch controls 28 Vdc and electrical ground lines with polarity according to desired direction of roll, Left Wing Down (LWD) or Right Wing Down (RWD). The trim motor moves the control wheels and FCCs process control wheel position through RVDT feedback, resulting in LWD or RWD as commanded. The FCCs makes no distinction between the control wheel being displaced by direct pilot control or by trim motor control. Reversion mode is entered when the ROLL MOTOR CONTROL switch is activated. The ROLL MOTOR CONTROL switch is used if a motor jam or runaway occurs. The FCCs accept direct trim switch inputs and applies an electronic roll trim bias by detecting an electrical ground on the switch poles. For integrity, two switches are used for trim inputs. A trim command is qualified by an electrical ground on two inputs. NOTE: In normal operation the trim command inputs are open-circuit. (3) Elevator Control Each of the two FCCs provide three bidirectional ARINC 429 (BD429) buses to elevator REUs. the buses are named X, Y and Z. The FCCs transmit the same commands on all three buses. Bus selection is done at the REU level according to the following logic: In normal operation FCCs control onside EHSA through bus X and cross side EBHA through bus Y When one FCC fails, remaining FCC feeds onside EBHA through bus Z and cross side EHSA secondary input (receive only) through derivation of bus Y Pilot commands generates RVDTs inputs, which are acquired in software. The RVDT data is monitored and voted. A column input is generated to feed the pitch Control Law (CLAW). Aircraft sensors and system inputs are acquired in software. The ARINC 429 (A429) labels are monitored for freshness and validity. Air data and inertial data are voted, before being used by the pitch CLAW. Four FCC channels compute elevator commands separately. To minimize force fight between two adjacent actuators, FCC channels synchronize their integrators to minimize split. Processing is duplicated at the same rate in command and monitor lanes. Each FCC transmits the elevator command independently. If one FCC fails, remaining FCC continues elevator control. (4) Elevator Trim Control Elevator trim is initially accomplished with elevator movement. At a predetermined amount of elevator trim the horizontal stabilizer is moved to off load and neutralize the elevator. Elevator trim control is accomplished using inputs from pitch trim buttons found in the following three locations: 27-03-00 Page 4 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL Pilot wheel Copilot wheel Pedestal trim control module Elevator trim switches provide data to the FCCs. The FCCs direct elevators to move as commanded. When the elevator command exceeds a preset value for a predetermined time (for example 1° for 30 seconds), FCCs provides a rate command to the HSCU while simultaneously commanding the elevator to faired position (0°) relative to horizontal stabilizer surface. Trim control module switches provide BACKUP PITCH (NOSE DOWN or NOSE UP) data to the HSCU for directly controlling the horizontal stabilizer. See Figure 3. (5) Rudder Control The FCC 1 provides two BD429 buses to rudder REUs, named X and Y. The FCC 2 provides only one bus, named X. Bus selection is done at the REU level according to the following logics: In normal operation FCC 1 controls EHSA through bus X and FCC 2 controls EBHA through bus X If FCC 1 fails, FCC 2 feeds EHSA secondary input (receive only) through derivation of its bus X If FCC 2 fails, FCC 1 feeds EBHA through bus Y The RVDT processing in hardware and software is similar to the elevator. The FCCs compute rudder pedal position. Each RVDT is monitored for detection of electrical failure (open or short circuit). The FCC also performs a failure detection scheme for mechanical failures between the two RVDTs. If valid, positions are averaged and used as input to CLAWs. If an RVDT split occurs, FCCs report a CAS message and stops transmission of commands to the rudder. Four FCC channels separately compute rudder commands. The FCC channels synchronize their integrators to minimize force fight between two adjacent actuators. Each FCC independently transmits rudder commands. If one FCC fails, remaining FCC continues rudder control. (6) Rudder Trim Control No motor positions the rudder pedal assembly. The FCCs accepts trim control module RUDDER switch inputs (NOSE L or NOSE R). The FCCs applies an electronic yaw trim bias by detecting an electrical ground on the switch poles. For integrity, there are two switches for trim inputs. A trim command is qualified by an electrical ground on two inputs. 27-03-00 Page 5 August 15/14