A method for obtaining a characteristic parameter of a displacement control mechanism for a hydraulic pump, wherein, the displacement control mechanism has an input connected with an outlet of the hydraulic pump, has an output connected with a variable displacement mechanism of the hydraulic pump, and is adapted to control a displacement of the hydraulic pump according to pressure at the outlet of the hydraulic pump, the method comprises:
- constructing a hydraulic system so that the hydraulic pump, driven by a prime mover, outputs hydraulic energy;
- measuring a pressure and obtaining an intermediate parameter, the measuring the pressure comprising measuring the pressure at the output of the displacement control mechanism, and the obtaining the intermediate parameter comprising obtaining the time required for the pressure at the output of the displacement control mechanism, the displacement control mechanism situated in a flow path between the output of the displacement control mechanism and the outlet of the hydraulic pump to have a predetermined change;
- and
- obtaining the characteristic parameter of the displacement control mechanism according to the intermediate parameter,
- wherein the obtaining of the intermediate parameter comprises:
- obtaining the time T1 required for the pressure at the output of the displacement control mechanism to start rising, and the time T2 required for the pressure at the output of the displacement control device to reach a stable state;
- and
- wherein the obtaining of the characteristic parameter of the displacement control mechanism comprises:
- obtaining an operation time parameter TD of the displacement control mechanism, where TD=T2−T1.