Helicopter Airborne Electronics 155D Steering Gear Amplifier Virtualized Instrumentation Tester Design-7
Helicopter airborne electronics 155D steering gear amplifier working principle-F
Author: He Jun
1. Overview
"155D steering gear amplifier" is installed on the helicopter for the automatic driving system of a component, the main function of the component is to control the control signal of the self-driving computer to control the various flight attitude changes of the helicopter into the control signal of various steering gears, so that the various steering gears work synchronously to control the aircraft in accordance with the instructions of the computer to change the flight attitude.
The servo amplifier performs the following functions:
It amplifies two simple stabilization signals from the roll-over and pitch circuitry and is relayed by the self-driving computer.
The motors of a dual-motor servo (pitch circuit) or a two-motor servo (rolling) are controlled by the average amplification of the stable signal transmitted by the two circuits.
It monitors the operation of the roll and pitch circuits of the automatic vehicle, warns in case of failure and cuts off automatic correction.
It monitors the operation of heading circuit control and correction of steering gear delivered from the installation of computers and other components, and monitors circuit operation.
It can control the speed of the helicopter to maintain at a value, chosen by the pilot if he uses the "speed hold" function.
Servo amplifier It enables pitch and roll dual motor steering gear and yaw longitudinal tilt AC sensors to be controlled from the stable signal set by the self-driving computer and generate various signals used by the computer (speed retention, electronic yaw longitudinal tilt, etc.).
It also includes system monitoring circuitry.
The steering gear amplifier components P/N: 418-00468-106 and 418-00468-206 are the same, except in relation to the speed-keeping function.
For the former, airspeed is expressed in knots (Kt) and for the latter, it is expressed in kilometers per hour (Km/h).
Units P/N418-00468-700 and unitSP/N418-00468-106 differ only due to different gain values for speed hold and attitude control/yaw coupling.
This is because they are installed on helicopters with slightly different dynamic characteristics.
"Airborne Electronic Equipment 155D Steering Gear Amplifier Virtualized Instrument Tester" is a test device designed with virtualized instrument control mode to detect and test "155D Steering Gear Amplifier".
The "Airborne Electronic Equipment 155D Steering Gear Amplifier Virtualization Instrument Tester" detection system composition is shown in the figure:
"Airborne electronic equipment 155D servo amplifier virtualization instrument tester" due to the test of the steering gear amplifier project, the design is divided into automatic detection "ATE" and manual detection 2 ways, automatic detection is to start the "automatic detection function" automatically in accordance with the predetermined program automatic detection, the detection process only shows the running steps and detection items, until the end of the test to give the test report, and provide test result data for printing.
Manual inspection is the use of sub-project manual detection, detection of different functions in the virtual instrument display screen to display different virtual instrument structure, maintenance personnel can be divided into screen display detection of different items, easy to identify accurate fault points.
For example, the "Airborne Electronic Equipment 155D Servo Amplifier Virtualization Instrumentation Tester" test program-1 screen is displayed as shown in the figure:
3.C. (4) Monitoring of rolling adjustment device (see Figure 7)
Figure 7:
Pitch adjustment and yaw adjustment monitoring are provided by circuits similar to the roll adjustment monitoring circuit, which is also located on the "adjustment" card PL101. Therefore, only the roll-over trimming monitoring circuit is described below.
The actuator motor position return signal is applied to the input of the forming circuit M1b of the interface board PL100.
If channel 2 is engaged, Relay K2 applies the average of the motor 2 position return signals of the two actuators to the input of circuit M1b, which then uses the reference signal REF2 set by the +15V2 supply voltage M7c.
If only channel 1 is bonded, M1b will use the signal REF1 transmitted by M8c to reshape the motor 1 position of the two actuators to return the average of the signals.
The current generator Mb, which controls the galvanometer, tells the pilot the location of the actuator in series.
Its output signal is applied to the input of the amplifier of the offset card. The signal at the output of this amplifier is applied to the inputs of M2d and M2c, comparing it to two voltage thresholds: one positive and the other negative.
When the series actuator is centered, the output voltage from M1b (close to "0") is below the thresholds for M2d and M2c. The positive potential output of the latter comparator circuit charges capacitor C3 heavily through CR1, while the nearly "0" V potential of the M1d output does not turn off switch Q4.
The absence of a "0" V potential at the output indicates the correct operation of the trim control circuitry.
When the series actuator deviates from the center, the signal transmitted by M1b crosses a threshold of the comparators M2c and M2d according to the direction of the deviation from the center. The negative potential of the output in the latter comparison circuit allows capacitor C3 to discharge through R19. If the actuator is off center for about 4 seconds, the potential reached at the M1d input sets its output to a positive potential, turning off Q4. The 0V potential transmission constitutes warning C3R, indicating that the trim circuit is operating incorrectly.
When the scroll lever is turned on, switch Q2 is turned off. It transmits a positive potential that permanently charges capacitor C3. The output and warning indication of the middle open switch Q4 is suppressed. Even if the series actuator is off-center (the time it takes for C3 to discharge), this situation can continue for about 4 seconds after the roller returns to that position.
3. D. Yaw circuit (Figure 8):
(1) Overview:
Various functions related to yaw circuits are provided by electronic trimming and transparency PL109, route trim control PL108, and circuits in route pre-control and PL110.
PL109：
PL108：
PL110：
These circuits provide the following:
- Control and adjustment of the actuator motor (transparency) via computer-supplied specific signals (electronic trimming) and trimming cutoff signals (heading deviation, acceleration, total distance control).
- Monitor and fine-tune actuator motor control.
- Check the circuit during the automatic test sequence.
- Generate a pre-control signal from the total distance control and its monitor.
(2) Control and adjust the control of the actuator during normal flight (see Figure 8)
(a) Swap operation:
In normal flight, the electronic limiting transparent circuit receives the following signals from other units:
Input signal -1:
Input Signal -2:
Input signal -3:
。 +28V auto trim function engagement.
。 +28V yaw circuit channel 2 engagement.
。 +28V channel 1 of the yaw circuit is engaged to 0V. Airspeed equal to or higher than VI SUP.
。 +28V yaw bar contact closure (lever is not energized).
And does not receive positive voltages indicating that the unit is turning (CONFψ), that the automatic test sequence is running, or that the computer (C2L) or pre-controlled (C4L) is faulty.
Under these conditions, the output of Q1 is set to positive potential,
It has the following effects:
。 It shuts down the bonding circuit that maintains the load.
。 The electronic contact M4a is turned off, enabling the actuator to control heading deviations and accelerometer signals generated by automatic pilots.
。 Limit the pruning cutoff by setting the output of M5b to state "1".
If the driver activates the pedal to change heading, the yaw bar contact opens and no longer transmits +28V potential, pin Z or J50, where the input of Q2 is in state "0", so the outputs Q1 of M1a, M1b and CR5 switch to state "0".