Method for obtaining the deformation of a tire under load during running

A method for obtaining the deformation of a tire casing subjected to a load, in an inflated and laden state rotating at a rotational speed W, the tire casing having a crown, two sidewalls and two beads of revolution about a natural axis of rotation and a median plane, an intersection between the median plane and the natural axis of rotation defining a wheel center, the method comprising the following steps:

• fixing at least one sensor on the tire casing in line with the crown at a radial position R with respect to the natural axis of rotation, the sensor being configured to generate at least one output signal proportional to acceleration experienced by the sensor in the tire casing;
• acquiring a first signal comprising at least the amplitude of the acceleration in a direction normal to the crown when running at the rotational speed W;
• delimiting the first signal over a number NTdR of wheel revolutions, NTdR being greater than or equal to 1, so as to construct a wheel revolution signal;
• determining a reference acceleration γreference that is a function of the rotational speed W and of the position of the at least one sensor;
• defining a first energy density S which is a function of the wheel revolution signal, and of the reference acceleration γreference, and which is denoted S+ when the wheel revolution signal is above a threshold value A, or is denoted S− when the wheel revolution signal is below or equal to the threshold value A;
• and
• identifying the deformation of the tire casing, which deformation is generated by the load as a function of the reference acceleration γreference and of the first energy density S which are associated with a position of the at least one sensor.