A method for measuring the diameter of a circular track with a center on a component, this method comprising: a) a step for moving the component along a measurement trajectory, b) when the component is moved along the measurement trajectory, a step for measuring, without contact with the component, at least one quantity that is a function of the diameter of the circular track, c) a step for determining the diameter of the circular track based on the quantities measured at several measurement points along the measurement trajectory, characterized in that • the step a) is carried out by means of a robot formed from a fixed base and from a manipulator arm articulated about at least two axes, the end of the manipulator arm being equipped with a gripping mechanism capable of grasping and holding the component, • during the measurement step, at least two quantities (C1, C2) are simultaneously measured at each measurement point along the measurement trajectory, with a measurement head including two sensors which are located on either side of an axis Z and separated by a distance kept constant and which measure each, along a measurement direction (Y1, Y2) perpendicular to the axis Z, a quantity (C1 or C2) representative of the distance which separates the corresponding sensor from the circular track, the measurement directions (Y1, Y2) being opposite and defining, with the axis Z, a measurement plane, • during the step a), the robot moves the component in a continuous manner in such a way that the trajectory of the center passes through the measurement plane, and with an instantaneous speed which is never zero along the measurement trajectory and an instantaneous acceleration which never changes sign along the measurement trajectory. a) a step for moving the component along a measurement trajectory, b) when the component is moved along the measurement trajectory, a step for measuring, without contact with the component, at least one quantity that is a function of the diameter of the circular track, c) a step for determining the diameter of the circular track based on the quantities measured at several measurement points along the measurement trajectory, characterized in that • the step a) is carried out by means of a robot formed from a fixed base and from a manipulator arm articulated about at least two axes, the end of the manipulator arm being equipped with a gripping mechanism capable of grasping and holding the component, • during the measurement step, at least two quantities (C1, C2) are simultaneously measured at each measurement point along the measurement trajectory, with a measurement head including two sensors which are located on either side of an axis Z and separated by a distance kept constant and which measure each, along a measurement direction (Y1, Y2) perpendicular to the axis Z, a quantity (C1 or C2) representative of the distance which separates the corresponding sensor from the circular track, the measurement directions (Y1, Y2) being opposite and defining, with the axis Z, a measurement plane, • during the step a), the robot moves the component in a continuous manner in such a way that the trajectory of the center passes through the measurement plane, and with an instantaneous speed which is never zero along the measurement trajectory and an instantaneous acceleration which never changes sign along the measurement trajectory. • the step a) is carried out by means of a robot formed from a fixed base and from a manipulator arm articulated about at least two axes, the end of the manipulator arm being equipped with a gripping mechanism capable of grasping and holding the component, • during the measurement step, at least two quantities (C1, C2) are simultaneously measured at each measurement point along the measurement trajectory, with a measurement head including two sensors which are located on either side of an axis Z and separated by a distance kept constant and which measure each, along a measurement direction (Y1, Y2) perpendicular to the axis Z, a quantity (C1 or C2) representative of the distance which separates the corresponding sensor from the circular track, the measurement directions (Y1, Y2) being opposite and defining, with the axis Z, a measurement plane, • during the step a), the robot moves the component in a continuous manner in such a way that the trajectory of the center passes through the measurement plane, and with an instantaneous speed which is never zero along the measurement trajectory and an instantaneous acceleration which never changes sign along the measurement trajectory.