Analysis for the Indicator Light Indicating Abnormality of the Electronic Programmable Controller

During installing the seat on fighter, the electronic programmable controller of the seat can receive the atmosphere data, but the indicator light indicates abnormally. The phenomenon is considered, the atmosphere data signal from the electronic programmable controller is analyzed and the cause is gotten by going deep into the mechanism of the problem. KeywordsAtmosphere data; RS429 signal; RS422 signal I. SOURCE OF PROBLEMS During joint debugging of seat, it has been found seats program-receives exception signal programmable led display for atmospheric data (irregular flashing) and program-receive LED indicate abnormal failure when air data signals, LED indicate status, fault status indicator is not clear, is not easy to identify the problem. These issues directly affect the aircraft's flight safety, such as unable to locate and solve the problem in a timely manner will result in the aircraft fully grounded, impact research training and the work of a successful test flight. II. WORKING PRINCIPLES OF ELECTRONIC PROGRAMMABLE CONTROLLER ON SEATS When the aircraft is during normal flight, program automatically receives air data system parameters from the aircraft, and can feel the speed from the airplane's airspeed, height parameters and to determine whether the ejection seat pull off the true signal and the start signal. After ejection seat emergency start, programmable thermal battery receives a start signal and a seat pull off the start signal, will feel instantly catapult spacewalk from the airplane's pitot speed, altitude parameters and ejection posterity which seat systems height argument and ejection from the environment from the atmosphere before the machine system on the aircraft system parameters are compared, the arithmetic processing, in accordance with a predetermined speed control box height delay state, the delay time depends on the launch of the aircraft speed and altitude given shot umbrella separation time. Date of Receival: May 27, 2014 Introduction to the Author: Deng Guopeng (1977), male, undergraduate, engineer, mainly engaged in flight organization and management Program-RS429 signal processing modules running and monitoring module consists of two parts. Monitor running module main reception on board, pitot signals and seat signals and handling, speed, highly effective value, delayed control, and other functions. KS429 receives air, bus RS429 signal receiving and processing modules (including barometric altitude, barometric altitude, Mach number, the correct airspeed, true airspeed, stable temperature, total pressure and static pressure), converted to a RS422 data for RS422 after data processing, sent to monitor running module. Send atmospheric air data parameters, electronic programmable device receives atmospheric systems RS429 data, determine, packaging them into a RS422 signal data formats, and then sends the data to run program-monitoring module, electronic controlled atmospheric data receiving and processing signal process as shown in Fig. 1. Monitoring run the module initialization after the self test to enter the system monitoring program, are in a wait state (seat no ejection seat), press the cycle signal on the query in the order received, State inspection and testing have no start/start signal, collecting the airspeed pitot/static pressure. Monitor idle time to determine inorganic signal if International Conference on Logistics Engineering, Management and Computer Science (LEMCS 2015) © 2015. The authors Published by Atlantis Press 1616 signal on organic, receive RS422 signal indicates the data if that data is processed; otherwise an error signal/alarm indication. If there is no signal on, the monitor order status checking, testing has no start/start signal, collection storage total static pressure from the pitot tube system signals. Figure 1. Diagram of Processing Atmosphere Data and Signals When the ejection seat starts, monitor running module detects starting / start signal into the delay control module, the received signal is parsed machine, select the ejection start signal the last valid calibration and true airspeed static atmospheric parameters as RMS signal on board, pitot speed before starting the acquisition of catapult, height signal value is determined according to a predetermined decision logic speed, altitude RMS, to delay control. System is in a power-on self test, or while waiting for a State, control module self test results in a different state of the system display output status led, indicates work State separately. When there are organic signals, each receives a set of atmospheric monitoring module RS422 data, if it is normal, 7K light flashes once. III. PRELINIMARY ANALYSIS The seat was taken by the electronic program-receives work principle analysis of atmospheric data signal, programmable status indicator to indicate that the exception from two aspects; (1) When seat electronic control device is not connected to atmosphere signal, the status of electronic control electronic control device status LED indicates normal judging program-control system works properly (from the status indicator light flashes only). (2) Seat electronic program-air signals, electronic programmable device status is: electronic programmable device status LED indicate does not comply with the technical documentation requirements, determine the program-control system is not working properly. Preliminary analysis of this fault is the atmospheric systems and seat electronic control device caused by cross-linking, cross-linking relationships analyzed on two systems 1 Both atmosphere data system and seat electronic programmable controller are powered on, and judge whether they are normal through self test; 2 If both of the two systems are working properly, make further test into the technical indexes of atmosphere data computer and seat electronic programmable controller according to technical protocol to find out where the problem lies. After processing the problem, air data computer electronic programmable device and seat of cross-linking checks, protection systems in accordance with the technical agreement is cross-linked properly curing technology. IV. POSITIONING OF FAULTS Through preliminary analysis, both seat electronic programmable controller and atmosphere data system are powered on with their respective systems running normally. The electronic program-control system and air data computers removed from the plane, and check the specification of each system separately. To detect the air data computer sends a signal, signal is properly formatted, the signal cycle of instability, sent under cycle requirements are not met, leading to run program-monitoring procedures for receiving and processing data drop-frame air data signals, status LED indicates the fault exception. Program-receive send order data order and air data computer is inconsistent. Program-format according to RS422 signal receiving and processing of air data computer