Hydro-pneumatic suspension fault diagnosis method and system based on nonlinear threshold

The invention discloses a hydro-pneumatic suspension fault diagnosis method and system based on a nonlinear threshold value, and the method comprises the following steps: S1, obtaining the corresponding relation data of the pressure in a cylinder barrel of hydro-pneumatic suspension and the extension amount of a piston rod through a test method, obtaining a corresponding relation data reference nonlinear function expression of the pressure in the cylinder barrel and the extension amount of the piston rod through fitting; s2, setting upper and lower threshold values of the reference nonlinear function expression of the corresponding relation data of the pressure in the cylinder barrel and the extension amount of the piston rod; s3, monitoring data of the corresponding relation between the pressure in the hydro-pneumatic suspension cylinder barrel and the extension amount of the piston rod, and when the data exceed upper and lower threshold values of the reference nonlinear function expression of the data of th