Methods and systems for contactless object measurement

A system for contactless object measurement comprising:

• a workpiece, at least one assembly, and a central control unit;
• wherein the central control unit comprises a power source and an image processor;
• the assembly and the control unit are attached on a surface of the workpiece;
• the assembly comprises:
• a main axis directed to a first direction and approximately parallel to the surface of the workpiece to intersect the inner surface of a nearby object;
• a first and a second projector for projecting a first and a second electromagnetic beam onto an object;
• wherein the first and the second beam are configured to be symmetrical about the main axis and to intersect with each other at a reference plane;
• the projections of the first and second beam produce a first and second beam spots on the inner surface of the object;
• the separation between the first and second spot along a second direction is proportional to the distance from the surface of the object to the reference plane;
• a focusing element centered on the main axis for focusing the reflected beams of the first and the second spots from the object surface, and forming images of the spots on an image plane;
• an imaging sensor array placed at the image plane and coupled with the image processor in the control unit for determining the position of the images of the spots on the image plane;
• and
• wherein the height of the entire system is configured to have a low-profile constrained within 10 mm in a third direction, wherein the beam paths generated by the system are constrained within said low-profile.