Airplane wheel speed acquisition system and fault detection method

Abstract

The invention provides an airplane wheel speed acquisition system and a fault detection method. An airplane wheel speed sensor and a speed analog signal generating unit are connected to the input endof an input switching unit, at the beginning of detection, the input switching unit is communicated with the speed analog signal generating unit, and the connection between the airplane wheel speed sensor and the input switching unit is cut off, the input switching unit cuts off the connection between the speed analog signal generating unit and the input switching unit through a switching enable signal after the detection is completed, and meanwhile, the airplane wheel speed sensor is communicated with the input switching unit. By adding the input switching unit, an interference signal cannotenter the airplane wheel speed acquisition system from the outside through the airplane wheel speed sensor during detection, and meanwhile, the fault isolation is achieved, so that the rapid isolationis achieved, the maintenance time is shortened, the ground maintenance efficiency is improved, and the overall detection effect is improved.

Description

technical field [0001] The invention relates to the field of aircraft brakes, and relates to a speed acquisition system and a fault detection method. Background technique [0002] The aircraft braking system is an important part of the aircraft electromechanical system. It mainly realizes the braking function used in the landing and rolling stages of the aircraft. At the same time, the anti-skid function of the system shortens the aircraft rolling distance and prevents the aircraft wheels from slipping. [0003] At present, the braking system of domestic aircraft is mainly a digital fly-by-wire anti-skid braking system (the "braking system" mentioned in the following refers to a digital fly-by-wire anti-skid braking system). It is composed of speed sensor, hydraulic servo valve, anti-skid brake control box and brake device and other components. As the core component of the entire braking system, the anti-skid brake control box collects the signals output by other components...

AI Technical Summary

Problems solved by technology

If the wheel speed sensor has a frequency signal or interference signal output during the detection of the wheel speed acquisition circuit, the wheel speed signal and the speed analog signal will be superimposed, resulting in the output of the wheel speed voltage signal from the wheel speed acquisition circuit. The expected voltage does not match, and the anti-skid brake control box mistakenly believes that the wheel speed acquisition system is faulty, forming a false alarm and seriously affecting the normal operation of the braking system

[0008] At the same time, in this detection method, since the connection between the wheel speed sensor and the anti-skid brake control box is not disconnected, even if the wheel speed acquisition circuit is normal, when the wheel speed sensor is short-circuited, the speed analog signal no longer flows into the wheel speed acquisition system. , but directly discharge to the ground wire through the short-circuit point, which will also cause the anti-skid brake control box to think that the wheel speed acquisition system or the wheel speed sensor is faulty, but it cannot be accurately located

[0009] Therefore, this detection method cannot achieve accurate fault isolation, that is, when the wheel speed acquisition system fails, it is impossible to determine whether the fault is caused by the failure of the wheel acquisition system itself or the failure of the wheel speed sensor; at the same time, this detection method is resistant to The interference ability is poor. Once there is an interference signal on the wheel speed sensor, it will lead to false alarms and reduce the maintainability and reliability of the braking system.

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