More and more automotive manufacturers secure highest precision results, maximum availability and even cost benefits: 3D robot guidance combined with highly accurate in-line measurement technology from one source leads to optimal fitting accuracy of automotive bodies. Using the best-fit method the dimensions of the car body are measured, the components geometry determined and their optimum position calculated. Temperature-compensated sensor technology is used for in-line quality inspection and gauging and consistent quality management of the measured process data guarantees the fastest possible means to maximize quality results.

Fast assembly processes in automotive manufacturing need to be executed reliably, including those of alternating vehicle types. Examples include the assembly process of doors, front, rear and side windows, the installation of glass modules in the vehicle‘s roof or assembling a panorama glass roof. During these assembly steps, flexible best-fit manufacturing methods are being used more and more often.
The goal of this process is to actively control and regulate the robot in each of its movements, i.e. to guide it. This reduces the need for rework of the car body parts to a minimum. Quality measurement is also integrated into the process directly after assembly. Both tasks are performed by the field-proven robot guidance sensors (RGS) of Isra Vision and their smart "brothers" in the SGS3D series. Both can either be used at a stationary location or mobile by being integrated directly into the robot gripper. These rugged sensors are so compact that they can even perform reliably in hard to reach places, as well as irrespective of surface types and color of the body part.

Combination of Multi-line and LED Surface Projection Technology
The sensors offer the highest possible flexibility because of the combination of multi-line and LED surface projection technology. It is even possible to perform measuring tasks in motion. The multi-line projection based on 3D form matching and the LED technology guarantee the highest possible precision in 2D/3D quality and coordinate measurement technology. This is why the sensors can also be utilized when placing especially demanding visible seams, for example near the door seam, in the trunk area or the engine hood. They achieve tolerances of +/- 0.1 mm or better and combine the exact determination of a position of any free-form surface with the possibilities of gauging with 3D technology. With this technology, the final assembly position can be inspected three-dimensionally for quality during a production run. Because the use of an image processing sensor makes it possible to realize both 3D robot vision as well as inspection functions at the same time, this intelligent combination provides the customer with added cost benefits.
The image acquisition and analysis with the optical gauging systems is performed very quickly. The teaching process is simple. Interfaces are available for all established robot control systems.

In-line Gauging Technology: Maximum Reliability
Measurement technology pack­ages consisting of the measurement cell computer, geometry gauging sensors (GGS) and temperature compensation technology represent a significant enhancement and complement the best-fit systems. They offer maximum reliability at lowest possible defect tolerance levels. Six LED lines and the 3D form matching option ensure highly precise results. The perfectly matched in-line gauging systems are also very well suited for measuring large sub-assemblies such as car bodies. One of these systems, for example, is integrated directly in the Fiesta body-in-white assembly line at the Ford plant in Cologne, Germany and is used there for demanding measuring tasks. The reason: These systems score in comparison at speed, ease-of-use and accuracy. The high robustness reduces the number of downtimes.
The gauging system provides results immediately after installation and excels, as does the best-fit system, in system stability and linearity. Even the most difficult to access areas in the engine compartment, the dashboard area and the car interior can be reached. Even larger features can be measured efficiently and accurately by having
the robot approach several measu­ring points and then analyzing the measurement data intelligently. In summary: a highly reliable system for best possible quality in every application.
The systems take on a variety of different gauging tasks: They range from 3D bolt inspection and the inspection of door lock holes to determining the center of a circle of large openings, for example in the assembly access for the fuel level sensor or the opening for the longitudinal column. Thanks to the most accurate measuring results, the quality of car bodies can be increased dramatically.

From Gauging Technology to Optimized Production Processes
The overall potential of this in-line measurement technology is unlocked as soon as the amount of measuring data generated from the individual stations (cells) is combined to create valuable knowledge that can be used to optimize production processes. This function is performed by the intelligent, cross-process quality management software Q-Vis, offered either as a stand-alone solution or in combination with the in-line gauging technology package.
The production quality database is installed separately from the sensor and robot technology on a central server to be used for various different in-line gauging stations. The client programs of the modular database system can be run on any office computer. The modular system monitors seamlessly, it visualizes, analyzes and optimizes - from the local measurement cell throughout all production lines in each plant around the world with both local as well as global access options. Among the separate modules are a control station, an analysis, a visualization, a reporting and a management module. The control station module presents the most recent quality status and aggregates the various measured data: At one glance, the operator can determine whether or not the measured object complies entirely with the specified tolerances. With only three mouse clicks, the operator is able to navigate from the visualized overall status to the individual measurement results. The operator can quickly determine whether the defect is a single outlier or if a certain trend can be established. The analysis module performs the task of processing the 2D and 3D data, rapidly displaying the characteristic parameters for a given day, and is equally capable of providing an accurate analysis of longer-term variations. Complex mathematical calculations and pro­cess analyses assist in production optimization. The ­reporting module provides ­informative statistics. The management module allows the preparation of high quality documents as a basis for decision making.

Proven Standard System in Automotive Production
Q-Vis is already being used as a standard system at Mercedes production plants in Rastatt, Sindelfingen and Bremen, Germany and also in East London, South Africa, and with great success. A typical application involves the measured results generated using the visualization module that can then be compared with the car body's CAD model and any deviations determined in this manner are used directly for optimization measures used in the welding systems. Audi in Ingolstadt also benefits from the advantages offered by the analysis system. The intuitive GUI is widely accepted among users. In addition, Ford is now also considering expanding its measurement cell network and introducing the Q-Vis analysis system, and by doing so taking advantage of the particular strength of the combined in-line measuring technology and quality management opportunities. The combination of the in-line measuring technology and production decision intelligence makes it possible to immediately implement routine quality processes that react quickly and can be well documented. The benefits of the in-line gauging technology are increased many times over. Along with the many technical advantages of the 3D robot vision, the in-line measuring systems and the analysis software, the user benefits from the Isra Vision expertise in designing solutions, which ensures that an investment in these systems is quickly amortized.