A sampling anti-interference method for aircraft electric brake system

Abstract

The invention relates to an anti-interference method for sampling of an aircraft electric braking system. Because of an infinite dv / dt value, interference of a measured signal mainly happens at the edges of PWM waves, it no measure is taken, an interference point is very likely to be acquired, and error braking is caused. According to the method, an AD sampling point is placed in the position away from the PWM edges as much as possible, when the PWM duty ratio is smaller than 50 percent, the AD sampling period is located in the middle of a high level of the PWM waves, and as is shown in the second graph, when the PWM duty ratio is larger than 50 percent, the AD sampling period is located in the middle of a low level of the PWM waves.

Description

technical field [0001] The invention belongs to a data sampling method of an aircraft electric brake, relates to an anti-interference processing of aircraft electric brake data, in particular to an aircraft electric brake system sampling anti-interference method. Background technique [0002] The aircraft braking system is a subsystem with relatively independent functions on the aircraft. Its function is to absorb the kinetic energy of the aircraft during landing and taxiing, so as to make the aircraft brake quickly. The all-electric braking system is to use the electronic drive device to drive the brake actuator, and use the electronic transmission line to replace the original oil pipeline to realize the braking and control functions of the brake. [0003] The aircraft all-electric braking system has better safety, reliability, maintainability and potentially better braking performance, which can greatly reduce the weight of the system. However, it also brings many problem...

AI Technical Summary

Problems solved by technology

The ASD system generally adopts the voltage pulse width modulation (PWM, Pulse Width Modulated) control method. PWM control improves the motor drive performance, but it becomes the main source of conducted and radiated electromagnetic interference. Using this control method will cause Generate dv / dt pulse wave above 6kV / μs, which will cause great interference to surrounding circuits

Among them, conduction interference may affect the normal operation of other electrical equipment, while radiation interference will cause malfunction and failure of equipment around the interference source

[0005] The given braking command and position feedback signal in the all-electric braking system are the key signals in the system control, which are easily disturbed. If the AD sampling detects the interference point of the given command or feedback signal, the system will brake by mistake, and the braking system The actuating distance is very small, and accidental braking will cause serious consequences such as mechanism jamming or mechanism damage

However, the interference signal superimposed on the instruction is difficult to completely filter out by hardware, and the filtering method will cause adverse consequences such as signal delay and large amount of calculation.

[0006] Through searching, there are currently no related patents and documents on the anti-jamming treatment of the all-electric brake system in China, but some domestic research institutions have studied the sampling anti-jamming technology, such as the patent "Rapid anti-jamming technology based on differential structure" applied by Xi'an Jiaotong University. Interference Current Sampling Circuit" (application publication number CN101976949A, application publication date February 16, 2011) proposes a fast anti-interference current sampling circuit based on differential structure, which can effectively filter out the power supply itself or multi-channel DC-DC switching action However, the anti-interference is realized by hardware, which increases the cost and increases the circuit volume, which is not conducive to the application in occasions with high volume and weight requirements.

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