Oscillating scanning probe with constant contact force

A method for scanning a surface of a workpiece using a scanning probe mounted on a support on a coordinate measuring machine, said support containing one or more drive actuators for actuating the movement of said scanning probe relatively to said support, a control unit coupled to the drive actuators, and a memory for storing theoretical profiles and coordinates of said surface, said method comprising the steps of:

• (i) determining a first range of values for a contact force applied between the tip of said scanning probe and said surface;
• (ii) operating said drive actuators to position said tip in contact with said surface;
• (iii) operating said coordinate measuring machine to move the support along a determined trajectory;
• and
• (iv) operating said drive actuators to produce, simultaneously with the relative movement of the support with respect to the surface, movements of said scanning probe relative to the support;
• whereby said control unit adjust the actuation of the drive actuators along a scanning path in order to maintain said contact force within said first range of values during the whole scanning operation along said scanning path.