Process for weighing the harvested crop stored in a tank on a harvesting machine

A harvesting machine, comprising:

• a wheel set on which a frame supporting at least one crop storage tank is mounted by a lifting device operable by a hydraulic system, said machine being characterized in that it further comprises a controller operable to control the hydraulic system for performing a process for weighing the harvested crop stored in said tank before the unloading of said crop, the process comprising an acquisition procedure wherein, upon controlling the hydraulic system for lowering and raising the frame on a displacement course, the process including the steps of:
• halting a displacement of the wheel set before performing the acquisition procedure;
• determining at least one height position of the frame on said displacement course;
• measuring a lowering pressure and a raising pressure in the hydraulic system at said position;
• calculating, from said measured pressures, a balancing pressure for said frame;
• wherein:
• said acquisition procedure is performed before unloading the stored crop in order to calculate a loaded balancing pressure and after said unloading in order to calculate an empty balancing pressure;
• and
• the weight of the stored crop is calculated from a pressure variation between said loaded balancing pressure and said empty balancing pressure.