Fill degree control for a bulk material gripper of a crane

A method for filling a gripper with bulk material, the gripper being suspended on holding cables, raised and lowered by a crane via a tension force controller, and acting on the bulk material with its own weight during a closing and filling procedure, wherein by reducing the effect of the weight of the gripper on the bulk material, a fill degree of the gripper is influenced by adjusting a tensile force acting on the holding cables, the method comprising:

• determining in a crane controller a tensile force target value for the holding cables;
• supplying the tensile force target value as a first input variable to the tension force controller;
• controlling an electric motor via the tensile force controller using the tensile force target value for lifting and lowering the gripper via the holding cables;
• ascertaining a tensile force actual value of the holding cables while the gripper is lifted or lowered during said controlling the electric motor via the tensile force controller;
• supplying the tensile force actual value as a second input variable to the tensile force controller for controlling the electric motor to adjust the fill degree of the gripper for a subsequent gripping procedure based on differences between the tensile force target value and the tensile force actual value;
• determining in the crane controller (i) when a change in the tensile force target value is to be made and (ii) an amount of change of the tensile force target value, based on determining working loads of the crane for a plurality of gripping procedures after the gripper is filled and raised and determining the number of overload cut-offs and/or the number of working loads exceeding a maximum permissible working load for the plurality of gripping procedures to dynamically adjust the tensile force target value, and supplying the amount of change of the tensile force target value to the tension force controller.