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 mechanical member (17, 23), said method being managed by a management and control unit and being characterized by two phases: - a first phase of preventing interferences between the mechanical members (17, 23) following trajectories that interfere with each other, in which, at a determinate instant of time, the actual position of each of the mechanical members (17, 23) is detected, as a function of current dynamics and braking or acceleration times and spaces, and the actual position of each of the mechanical members (17, 23) is compared in relation to a future position of possible interference of the mechanical members (17, 23) and if the comparison of the actual position of each of the mechanical members (17, 23) and the future position of possible interference of the mechanical members (17, 23) indicates the possibility of interference, the electric motor (15, 21) of each of the mechanical members (17, 23) is blocked 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, in relation to every sub-phase "n" each actual intensity of current being compared with a reference current in order to identify a current intensity error in absolute terms, for each sub-phase "n" each actual intensity of current at the determinate instant of time for the sub-phase "n" being compared with a window of acceptability made from two thresholds applied to the reference current value, of which one is bigger and one is smaller than the reference current value, wherein if, at the determinate instant of time for the sub-phase "n", at least one of the currents supplied to the electric motors (15, 21) is outside the window of acceptability made from said two thresholds, defined at the determinate instant of time for the sub-phase "n", a collision is detected and the management and control unit 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, in which, at a determinate instant of time, the actual position of each of the mechanical members (17, 23) is detected, as a function of current dynamics and braking or acceleration times and spaces, and the actual position of each of the mechanical members (17, 23) is compared in relation to a future position of possible interference of the mechanical members (17, 23) and if the comparison of the actual position of each of the mechanical members (17, 23) and the future position of possible interference of the mechanical members (17, 23) indicates the possibility of interference, the electric motor (15, 21) of each of the mechanical members (17, 23) is blocked 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, in relation to every sub-phase "n" each actual intensity of current being compared with a reference current in order to identify a current intensity error in absolute terms, for each sub-phase "n" each actual intensity of current at the determinate instant of time for the sub-phase "n" being compared with a window of acceptability made from two thresholds applied to the reference current value, of which one is bigger and one is smaller than the reference current value,