by u03b6 these parameters also being preferably stored during a manoeuvre or part of a manoeuvre it is possible to detect said parameters once at the end of a manoeuvre for example temperature or detect and process said parameters so as to create a second mapping of another parameter u03c3 and the stored values thereof u03c3 m and the deviations from the current values u03c3 are used to decide whether to update u03b6 m u03c6 and or the values of the range w the second mapping may be created as a function of the travel movement u03c6 or as a function of the time in this latter case the value of the parameter u03c3 is acquired at regular intervals let us consider the case where samples of u03c3 are acquired along the travel path u03c6 of the roller shutter this therefore gives with reference to the general case u03c8 u2261 u03c3 u03c8 m u03c6 u2261 u03c3 m u03c6 obviously updating may also take into consideration simultaneously several parameters u03c3 1 u03c3 2 u03c3 m each independently and or then combined during processing by way of example of a second accessory parameter a the temperature t is considered here other examples are the speed of the wind direct irradiation of the sun which may deform the materials or the atmospheric humidity useful for establishing whether there may be frost on the guides therefore in this case u03c3 u2261 t it must be mentioned that one of the phenomena which most affects the torque required to move a blind is in fact the temperature in relation to the average room temperature of 25 u00b0 c a temperature which is higher within certain limits.