This new 3-D surface measurement technology has the potential to significantly reduce die development and maintenance cost and time, and provides new opportunities for a wide range of sheet metal panel quality control applications.

Parts and tools inspection is an integral part of quality assurance. In automotive manufacturing, one of the major quality control activities is measuring die faces and stamped sheet metal parts to ensure that the sheet metal parts produced accurately represent the CAD model.

This is typically done with a Coordinate Measuring Machine (CMM) equipped with a touch probe. The current CMM systems, however, are slow and a touch probe can only collect one point at a time. The use of a touch probe also involves contact with parts under inspection.

To overcome theses limitations, Ford has developed a non-contact, optical-based, area sensor system that is lightweight, accurate, and can acquire an data for an entire region in the time previously required to obtain a single point. In addition, it can be included in the magazine of existing CMM's for automatic exchange during CMM operation.

 

Images

Top view of the Ford prototype of the sensor system

The Area Sensor System

The Liquid Crystal Light Modulator

Fringe pattern projected onto an object.

Technology Summary

The optical sensor includes a laser gun that emits a laser beam. The laser beam passes through a lens and a liquid crystal system that generates a fringe pattern on object under inspection. The liquid crystal system communicates with a computer that controls the pitch of the fringe pattern. The computer can shift the fringe pattern in a predetermined fashion. The results are captured by a camera. These phase-shifted images are input to a fringe analysis program to determine the shape of the object under inspection. An off-line programming capability was also developed that allows for automatic positioning of the area sensor so that optical imagery of the part under inspection can be generated with good visibility, in-focus, and with a sufficient resolution. has used electrically conductive polymers in facilities in North America and Europe.

Advantage and Features

1. Non-contact
2. Solid-state (less vibration and wear)
3. High accuracy
4. Large area data collection (as vs. line scanner or touch probe.)
5. Automated sensor planning

Applications

1. Die face inspection
2. Sheet metal inspection
3. Body-in-white
4. Clay models in design studios

Development Status

Ford is currently partnering with outside vendors to productize this system.

Patent Information

Licensee Support

Ford is willing to license this technology to other partners through it's licensing agent, Ford Global Technologies, Inc.