What are the applications of proximity sensors in aircraft landing gear systems?

Last Update Time: 2021-02-25 10:38:55

   Aviation power units, landing gear systems, and navigation systems are among the top three systems in the aircraft use difficulty report data reported by airlines. Among them, the failure of the landing gear system is likely to cause abnormal events such as aircraft return flight, backup landing, etc., which will bring economic losses to the company and bring hidden dangers to aviation safety.

   In general Airbus aircraft landing gear control systems, digital telex control systems are commonly used. The basic principle is to send the sensor signal to the control box (control computer), and send instructions to the executing agency after comprehensive calculation and comparison, and the control link is margin control.

   The landing gear of modern civil aircraft includes two systems of normal retracting and emergency releasing. The landing gear control system uses telex control in the control mode and is cross-linked with other systems. Inductive proximity sensors are widely used to detect the position of the landing gear.

   There are two sensors that each landing gear plays the main role, namely the lock-up sensor and the drop-down sensor, which are used to switch on the transmission position signal when the lock-up and lock-down are completed. This type of sensor is a magnetoresistive proximity sensor, which is mainly composed of two parts: the sensor body and the sensor excitation plate.

   The sensor body converts electrical energy into a magnetic field, and the excitation sheet mainly plays the role of increasing the magnetic permeability. When the landing gear and the excitation plate approach a certain distance, the magnetic permeability increases, and the sensor sends a signal to warn the component to indicate the landing gear position. The distance between them directly affects the accuracy of the indication, and the general adjustment requirements are also stricter. In addition, there are slight differences between different models, you need to refer to the AMM manual of the model when adjusting.

   The inductive proximity sensor is used to detect the position of the landing gear, which increases the life of the sensor. In addition, the control computer facilitates information transmission and information sharing with the avionics system.

   Application of Proximity Sensor in Rail Track Entrance Monitoring

   Train collisions account for a large proportion of all railway accidents and often have serious consequences. The use of proximity sensors to monitor passing trains at intersections has become a very important link in improving railway safety measures.

   In practical applications, the characteristics of non-contact position measurement of proximity sensors can be used to install them symmetrically at both ends of railroads at intersections. When a train passes, the proximity sensors at both ends of the track can detect changes caused by the wheels at the respective ends. By analyzing the sensor signals through the level crossing monitoring micro-processing system, you can determine the direction of the vehicle and the state of passing (pass or fail, stay or not). Finally, the information is sent to the traffic management control center by cable or wireless communication in order to transfer the train.

   The application of proximity sensors in automatic packaging machinery mechanized production has created a demand for automatic packaging technology, and the manual packaging method is far from meeting mass production operations. Automatic packaging machinery can complete the packaging process of a series of articles under the guidance of the control system, which improves the packaging efficiency of the product and reduces the packaging cost, but it still inevitably causes leaks. For this reason, automatic packaging inspection has become an important link to ensure packaging quality. Among them, for the case of ferromagnetic substances in the packaging process, non-contact detection using a proximity sensor is often used.

   The coil that can generate an alternating magnetic field near the sensor. When the detected ferromagnetic object is in this environment, it will form an eddy current inside due to the principle of electromagnetic induction. When the magnetic field generated by the eddy current is sufficiently large, it will in turn change the original circuit parameters of the proximity sensor, thereby generating a signal output. Therefore, the use of a proximity sensor can identify whether there is a magnetic or easily magnetizable substance in a certain range in the vicinity. In some automatic packaging processes, such as chocolate metal foil packaging, the presence of magnetic substances can be detected by the proximity sensor to determine whether there are unqualified products with packaging errors or process omissions, thereby improving packaging quality.

 

If you want to know more, our website has product specifications for proximity sensor you can go to ALLICDATA ELECTRONICS LIMITED to get more information