BACKGROUND:

Helicopter Main Gear Box (MGB) load testing is necessary to evaluate the performance of the MGB under various flight load conditions. The automation system should cater to acquire data from various types of sensors such as pressure sensors, flow sensors, load cells, temperature sensors, strain gage based sensors, encoders etc during testing on ground and to control equipment's like motors, hydraulic valves to simulate flight condition loads on MGB. All parameters are to be stored for offline data analysis and generation of test reports. Online troubleshooting and stopping of the test to be available for operator easiness and safety of the Test rig, MGB & the operator.

During load test, the operator needs to monitor and control various parameters of MGB and the test rig. It is difficult to carry out the following actions simultaneously.

1) Monitor all the measuring parameters of MGB and test rig.
2) Control the Loading parameters for defined ,time period as per the acceptance test procedure (ATP).

3) Check the test rig and MGB healthiness.

4) Immediately stop the test in case of emergency or component prone to fail/failed.

5) Troubleshoot the system faults based on values of critical parameter and take corrective action and stop the test if necessary.

6) At present the following challenges are faced while testing MGB.

1) Around 150 parameters have to be monitored simultaneously during the test.

2) Loading parameters are mechanically linked; change in one parameter will affect values of other parameters.

3) It is difficult to take decision to stop the load testing whenever the monitored values cross the limits.

4) To identify problems in MGB during testing and take a decision to stop the test for removal for further analysis and rectification.

5) Requires system expert for system-testing, analysis and troubleshooting.

6) Requires thorough understanding of control logics such as closed loop PID controls, open loop control, etc.

7) Requires experience in the Test equipment operation such as gearbox, hydraulic systems, Variable frequency drives, motors and safety limits.

8) N on-avail ability of on-line trouble shooting procedures for problem rectification.
Hence an automated tool is required to monitor, analyze the values of critical parameters and give appropriate warning and command if required for stopping the test.

DETAILED DESCRIPTION
1. DEVELOPMENT ENVIRONMENT

1) LUH MGB Load test Rig

2) Parker Multi drive system with Siemens PLC

3) National instruments- PXIe data acquisition system

4) LabVlEW Full development system 2013

5) Loading hydraulic power packs and other sub systems.

11. SOFTWARE DEVELOPMENT PROCESS FOR THE TOOL

The automated too! consist of

1) Data Acquisition, online monitoring, data storage and report generation tool.

2) Online vibration analysis tool.

3) Online alarm notification, condition monitoring and troubleshooting tool.

i) Data Acquisition, online monitoring, data storage and report generation tool.

The MGB load test rig is integrated with automation software, the application tool is developed in-house by using National instruments LabVlEW software. The data acquisition system acquires all the test rig parameters such as process switches (pressure switches, temperature switches, oil level switches and motor status, over loading relays) and MGB parameters such as pressure, flow, temperature, vibration, torque, speed and gives appropriate control commands to various subsystems of the load test rig to attain" the specific loading. The tool takes ail necessary safety aspects of test specimen and test rig. It does not allow to ignore the safety issues and force the operator to follow the standard procedure for test starting, test conduction and test stopping to avoid the accidents/damage. All the test data will be stored in predefined interval and test report will be generated automatically after completion of test.

2) Online vibration analysis tool
Online vibration analysis tool is part of the automation system which is an application tool which utilizes the system hardware & supporting software and it provides the frequency spectrum of vibration signal, frequencies at vibration in rms peaks and overall vibration in rms values on line during testing. Vibration data will be acquired at six locations on the MGB at 20000 samples per second per channel and the vibration data will be plotted against torque, speed and other parameters. Data is stored in pre-defined time (every 10s or 1 s) / alarm condition' (during any tripping) / user requirement instant (based on need basis by user). Online vibration analysis tool will help the designer to predict and analyze the behavior of the MGB gear meshes, improve the overall system safety and the time reduction in fault finding.

4) Online alarm notification, condition monitoring and troubleshooting tool.

The automation system tool is aimed to provide the maximum possible data to user to
evaluate the condition of the test rig. This software acquires all the parameters of test rig and
analyses the parameters by comparing the safety levels by data analyzing software, code
behind the screen which will compare the various parameters such as temperatures, pressures
in similar load levels with the previous testing data and try to figure out signs of failure in near
future, 'earlyWarning system-'' message will be displayed by the software on the monitor. If
Ithere is any violation of critical parameters, it is quickly detected by the system which brings the system to standstill (trip) and displays the reason causing the test to trip and reasons for system failure/problem will be displayed through ''alarm cause to trip the iest^ message. This facilitates operator to look into the root cause of the failure and so time taken for the troubleshooting will be reduced.

CLAIMS

The following are the claims of the patent:

1. Data Acquisition, monitoring, analysis, testing, and automation of Acceptance Test Procedure (ATP) report generation and troubleshooting by developing user-friendly Graphical User Interface (GUI) system tool.

2. Online vibration analysis tool helps the designer to analyze the MGB design and helps to estimate the severity of problem and avoid unnecessary stoppage and disassemblies.

3. Online monitoring and troubleshooting tools helps to identify the problem in advance and reduce stoppages during testing and time in clearing system faults.

4. Reduction in time for the load testing of MGB as per Acceptance Test Procedure (ATP).

SUMMARY

The present invention automates the process of MGB "Load testing", "data
acquisition", "data monitoring", "data analysis" and "automation of Acceptance Test
Procedure (ATP) report generation and troubleshooting". It provides means to monitor
I
the health and safety of the complete test rig and MGB. It provides remedy for all the above
problems.