The Research Of The Test Platform And Its Data Acquisition System For Helicopter With Airbag Landing On Water

Helicopters often have to undergo an emergency landing in the sea due to mechanical failure,the control system failure or extreme weather.If the lack of effective protective manners,It usually results in a loss of the plane crash.Therefore,it is significant to study the emergency protection device of helicopter.The helicopter emergency airbag water test is the use of the helicopter and the airbag model and made a forced landing in a water condition.Simulation of the helicopter landing water condition and attitude parameters,The collection of the mechanical data of the joint part of the helicopter and airbag,as the design calculation and analysis basis of the airbag.In this paper,a multi-chanel and multi-signal DAQ system is aimed to be designed.According to the test requirements,the parameters of the tested helicopter's landing on water and its attitude parameters are: maximum horizontal velocity of 10 m/s,vertical speed is no less than 1.5m/s,helicopter model elevation is not more than 10 degrees,the yaw angle is not greater than 15 degrees when the helicopter lands on water.Horizontal velocity of the helicopter model test is provided by a traction trolley along the railway,vertical velocity is obtained by a distance of a free fall of the helicopter to the surface of the water after dismissed,helicopter elevation and yaw angle are obtained by the attitude adjustment devices.Installed in airbag internal and surface pressure sensor to collect the pressure changes of the airbag;the forces of the joint between the helicopter model and the airbag are obtained by the six component balance installed at the joint site.In this paper,the requirements of data acquisition system is to collect these data,because the kinds of data to be acquired is more,it requires the data acquisition system to support 72 channels data acquisition,there are two types of input signals which are voltage and current signal in the data acquisition system.In order to reduce the volume of the acquisition system the PC104 PLUS bus data acquisition card and computer motherboard are used.In order to increase the flexibility of the acquisition system,data acquisition board adopt the products of the professional company,and the data acquisition channel signal types can be designed to be flexible to set type,at the same time the acquisition channels can be defined in the test,the whole acquisition system hardware design with flexible universal characteristics.Software design used the Visual C++ 6.0 programming environment and the programming language used VC++,the main purpose is to realize the communication between the host computer and the slave computer,as well as to save the acquired data.The communication,on the one hand,the slave computer transfer the three angle data acquired by the gyroscope to the host computer,on the other hand the host computer transfer the command data bytes to the slave computer,through the program control of the slave computer to save the acquired data.According to the result of the test,the DAQ system works well to acquisite the data of the test.