Easy installation for vision system

An Oxford Sensor Technology product story

Edited by the Engineeringtalk editorial team Nov 25, 2003

Valmet Automotive has successfully installed its own fully automated glazing cell without the need for assistance of system integrators.

Valmet Automotive, a niche car contract manufacturer currently producing Boxster model for Porsche, has successfully installed its own fully automated glazing cell without the need for assistance of system integrators.

Valmet Automotive, based in Uusikaupunki Finland, the world's most northerly vehicle manufacturer, installed the glazing cell this summer.

Robot programming assistance was provided by RDS Robotics, Sweden and only telephone support was necessary from Oxford Sensor Technology, which produced vision sensor systems for robot guidance.

The installation project, headed by Mika Raitio, demonstrates the technical ability of Valmet's Manufacturing Engineering team and the simplistic setup and operation procedures of the specular reflection sensor system supplied by Oxford Sensor Technology based in Oxfordshire UK.

Unlike other vision system used to guide industrial robots on vehicle assembly lines, the SRS specular reflection sensor mounts on the robot's gripper, removing the need for camera gantries together with their associated cost, complexity of camera alignment and dependency on master vehicle bodies.

The unique SRS uses specular reflections to locate the aperture into which the glass must be fitted.

Specular reflections are the highlights which can be seem running along a curved surface any shiny material, even stems of wine glasses.

They occur irrespective of colour making the SRS completely unaffected by vehicle colour.

Installation of the vision system comprises only four stages and can be completed in a matter of hours rather than days.

First, the sensors are mounted on the robot's gripper frame, which holds the screen.

The sensors can be mounted to look around the glass or through it.

Secondly, the gripper frame is positioned approximately 250mm away from the nominal aperture position.

Thirdly, the sensors are manually adjusted to give the best image.

Information about surface being viewed is stored.

Finally, the robot is automatically moved through a series of up/down, left/right steps.

The system is then fully calibrated and ready to use.

In operation the gripper is positioned in the measurement position, the specular reflection sensors measure the actual position of the vehicle, calculate the best fit for the glass and modify the decking position accordingly.

The robot then fits the glass.

The whole measurement process takes only a fraction of a second to complete.

Although the installation at Valmet was a complete glazing cell, the ease of installation and operation of the SRS system means that any existing cell, which uses a robot to apply the PU (polyurethane bead) to a vehicle glass, could be simply and cost effectively upgraded to a fully automated system, offering both cost savings and improvements in quality.

The specular reflection sensor system has also been successfully used to fit windscreen while the car is moving along the production line, offering significant potential cost savings over static cells.