1. A system for recognising unstable objects transported resting on a conveyor, comprising: means for detecting the bottom designed for detecting a shape of a bottom of an object transported; upper acquisition means set up for acquiring at least an outline seen from above or from below of the entire transported object; and a processing unit connected to said means for detecting the bottom and connected to said upper acquisition means and comprising: a lower shape module configured for defining one or more flat base surfaces representing the bottom of the object detected by the upper acquisition means; an upper shape module configured for defining an overall flat surface which represents the outline, seen from below or from above, of the entire object detected by the upper acquisition means; the system being characterized in that the processing unit is configured for obtaining shape parameters starting at least from the flat base surface and the overall flat surface and further comprises a classification module configured for determining whether an object detected is stable or unstable as a function of the fact that one or more of the respective shape parameters is greater than or less than a relative predetermined discrimination threshold. means for detecting the bottom designed for detecting a shape of a bottom of an object transported; upper acquisition means set up for acquiring at least an outline seen from above or from below of the entire transported object; and a processing unit connected to said means for detecting the bottom and connected to said upper acquisition means and comprising: a lower shape module configured for defining one or more flat base surfaces representing the bottom of the object detected by the upper acquisition means; an upper shape module configured for defining an overall flat surface which represents the outline, seen from below or from above, of the entire object detected by the upper acquisition means; the system being characterized in that the processing unit is configured for obtaining shape parameters starting at least from the flat base surface and the overall flat surface and further comprises a classification module configured for determining whether an object detected is stable or unstable as a function of the fact that one or more of the respective shape parameters is greater than or less than a relative predetermined discrimination threshold. a lower shape module configured for defining one or more flat base surfaces representing the bottom of the object detected by the upper acquisition means; an upper shape module configured for defining an overall flat surface which represents the outline, seen from below or from above, of the entire object detected by the upper acquisition means; the system being characterized in that the processing unit is configured for obtaining shape parameters starting at least from the flat base surface and the overall flat surface and further comprises a classification module configured for determining whether an object detected is stable or unstable as a function of the fact that one or more of the respective shape parameters is greater than or less than a relative predetermined discrimination threshold.