Method to prevent interferences and to control collisions between mechanical members (17, 23) of at least two operating units (11, 111) for executing an operating cycle, each of the at least two operating units (11, 111) being associated with a position detector or with a position simulator, and being equipped with at least one electric motor (15, 21) supplied with a corresponding current for driving a respective mechanical member (17, 23), said method being managed by a management and control unit, said method comprising two phases: - a first phase of preventing interferences between the mechanical members (17, 23) following trajectories that interfere with each other, said first phase comprising comparing, at a determinate instant of time, the actual position of each of the mechanical members (17, 23) with the future position of possible interference of the mechanical members (17, 23), wherein if the comparison indicates the possibility of interference, the management and control unit intervenes to block the electric motor (15, 21) of each of the mechanical members (17, 23) in order to decelerate or stop the respective mechanical member (17, 23); - a second phase of detecting collisions in which, at said determinate instant of time, the actual intensity of current supplied to the at least one electric motor (15, 21) of each of the at least two operating units (11, 111) is verified, dividing said operating cycle into "n" sub-phases, for each sub-phase "n" each actual intensity of current being compared with a reference current value, wherein if, at the determinate instant of time for the sub-phase "n", at least one of the current supplied to the electric motors (15, 21) is outside a window of acceptability made from two thresholds applied to the reference current value, defined at the determinate instant of time, one threshold being bigger and one threshold being smaller than the reference current value, a collision is detected and the management and control unit then controls the intensity of current supplied to each electric motor (15, 21) in order to decelerate or stop the respective mechanical member (17, 23). - a first phase of preventing interferences between the mechanical members (17, 23) following trajectories that interfere with each other, said first phase comprising comparing, at a determinate instant of time, the actual position of each of the mechanical members (17, 23) with the future position of possible interference of the mechanical members (17, 23), wherein if the comparison indicates the possibility of interference, the management and control unit intervenes to block the electric motor (15, 21) of each of the mechanical members (17, 23) in order to decelerate or stop the respective mechanical member (17, 23); - a second phase of detecting collisions in which, at said determinate instant of time, the actual intensity of current supplied to the at least one electric motor (15, 21) of each of the at least two operating units (11, 111) is verified, dividing said operating cycle into "n" sub-phases, for each sub-phase "n" each actual intensity of current being compared with a reference current value, wherein if, at the determinate instant of time for the sub-phase "n", at least one of the current supplied to the electric motors (15, 21) is outside a window of acceptability made from two thresholds applied to the reference current value, defined at the determinate instant of time, one threshold being bigger and one threshold being smaller than the reference current value, a collision is detected and the management and control unit then controls the intensity of current supplied to each electric motor (15, 21) in order to decelerate or stop the respective mechanical member (17, 23).