Method for controlling first and second manipulators (1, 1') of a robot system for gripping an object (3, 3'), comprising the following steps of: - receiving a first visual object representation indicating at least a first object to be gripped; - determining a gripping strategy using the first object representation with a model-free gripping method; - controlling the first manipulator to grip the object (3, 3') using the gripping strategy; - creating an object model using the first object representation for model-based gripping of the first object; - determining a quality indication associated with the first object representation, which indicates the quality of the gripping using the gripping strategy and includes an indication of the number of visual features of the first object representation and an indication of whether the gripping of the object has been successfully carried out; - storing the object model, the object representation and the quality indication in a database; - comparing the determined quality indication with stored quality indication associated with a second stored object representation; as a function of the comparison: ∘ updating the stored object model using the first and second object representations (23, 23'); ∘ controlling the second manipulator to grip at least one second object using a model-based gripping method and using the object model, wherein the first object and the second object are of the same type and thus have at least substantially identical geometric dimensions and/or the same visual features. - receiving a first visual object representation indicating at least a first object to be gripped; - determining a gripping strategy using the first object representation with a model-free gripping method; - controlling the first manipulator to grip the object (3, 3') using the gripping strategy; - creating an object model using the first object representation for model-based gripping of the first object; - determining a quality indication associated with the first object representation, which indicates the quality of the gripping using the gripping strategy and includes an indication of the number of visual features of the first object representation and an indication of whether the gripping of the object has been successfully carried out; - storing the object model, the object representation and the quality indication in a database; - comparing the determined quality indication with stored quality indication associated with a second stored object representation; as a function of the comparison: ∘ updating the stored object model using the first and second object representations (23, 23'); ∘ controlling the second manipulator to grip at least one second object using a model-based gripping method and using the object model, wherein the first object and the second object are of the same type and thus have at least substantially identical geometric dimensions and/or the same visual features. ∘ updating the stored object model using the first and second object representations (23, 23'); ∘ controlling the second manipulator to grip at least one second object using a model-based gripping method and using the object model, wherein the first object and the second object are of the same type and thus have at least substantially identical geometric dimensions and/or the same visual features.