Company: HIS GmbH – Handke Industrial Solutions GmbH
Application: Quality inspection of assembled automotive components

Industry: Automotive
DENSO Products Used: VS-087 
Company Location: Germany

Website: www.his-handke.com

THE CHALLENGE

For automotive suppliers, quality management is one of the key factors determining a company’s technical and economic success. In this industry, for both quality and safety reasons, the high-precision installation and fitting of a large number of very different, pre-fabricated components into a specific mechanical setting are particularly important.

In the past, manual quality checks have been too costly and time-consuming, as well as being relatively unsafe, given the likelihood of human error. In addition, today’s extensive variety of models and components would present a real challenge to any employee. And fitting delicate components into relatively inaccessible areas is almost impossible without the adequate tools.

THE SOLUTION

Automotive suppliers are therefore relying increasingly on fully automated, robot-based test cells, where components are quality-checked and then correctly assembled using image processing and software to ensure precise integration and functionality. 

Such a test cell has been developed by Handke Industrial Solution GmbH (HIS GmbH) for a client in the automotive supply industry. HIS GmbH, based in Garbsen near Hannover in Northern Germany, has been distributing und manufacturing products and software for the automation and electronics markets since 1979.

The test cell has been in operation since late 2016. It inspects the correct assembly of parking heaters (each component measuring up to 60x60x60 mm) for vehicles and trucks. While the actual base component is always quite similar, its mechanical fittings, i.e. the mounting, the waste gas extraction and the vacuum exhaust, vary widely, depending on the vehicle model. In total, the test call has to master 250 different versions. It currently manages a total of 1,500 components each day (in a three-shift cycle). 

The assembled component carriers are transported automatically into the 3x3 m test cell where they are inspected by cameras mounted on two VS-087 DENSO robots.

These camera systems are installed instead of the gripper at the end of the robot arm and consist of a Gigabit Ethernet camera (The Imaging Source) and a lighting circle. The system delivers high-definition contrast images in various colours. The actual quality test is carried out by a number of image processing tools in an image-processing library (Halcon by MVTec). The camera and the library check the image data and indicate to what extent the base sample and the work components (i.e. the different components of the parking heater) correspond. Most importantly, they inspect its correct positioning. If the system detects any errors, the component carrier is removed automatically.

HIS GmbH opted for DENSO robots due to their easy integration and uncomplicated interface communications based on ORiN (Open Resource interface for the Network), offered by DENSO Robotics. Originally, ORiN had been developed as a standard platform for robot-based applications. Today, it serves as development software in industrial production for a number of applications – from robots to other production elements such as PLC and numeric control (NC). Used together with the DENSO RC8 Controller, ORiN supports the interworking of external devices such as cameras and many more. The programming of this system is in .NET C# and WPF.

Thanks to this set-up, it was very easy to operate the test cell right away and also to control the whole system using a high-level programming language. This meant that the robots did not have to be programmed. The system is ultimately controlled by a software developed by HID GmbH, which coordinates the robot, the camera and image processing systems as well as the lighting. Together with the image-processing library, this allows for a modular, individual test cycle, depending on the client’s requirements or the different components.

Another decisive factor for choosing DENSO robots were the six axes of the VS-087 model, which provide the greatest possible manoeuvrability in all directions – a significant feature, given that the components to be checked are usually installed in relatively inaccessible positions in the parking heaters. Equally important for HIS GmbH was the slim mechanical design of DENSO robots, with their integrated compact motors. 

In addition, the communication between the robots and the attached Gigabit Ethernet cameras is very simple. The cable feed setup is also straightforward, as the VS robots are equipped with an optional communication interface flange, which enables cameras and grippers to be mounted directly onto the robot’s sixth axis. DENSO Robotics is the only manufacturer offering this patented technology.

All data generated in the test cell are stored in a MES system for both monitoring and analysis, so that IoT services and integration into Industry 4.0 settings can be easily implemented.

THE BENEFITS

In the past, the quality check required three camera systems and was only carried out on a linear axis. Today, however, the same check is managed using a single system. Thanks to the six-axis VS-087 robots, even relatively inaccessible areas can now be reached during the test cycle. This makes the quality check highly flexible. And for each component, the quality check only takes 30 seconds.  

In addition to the improvement in both efficiency and quality, the supplier also saves considerable costs on the return of wrongly installed components sent back by the car manufacturer and the automated quality control eliminates any human error. All camera images are saved and labelled for an individually definable period in order to document the  correct assembly of the products upon leaving the factory in case of dispute.

The application can be easily adapted to different groups of components, such as car alternators or AC systems. Last but not least, applications outside the automotive industry are also conceivable. A similar test cell is currently being used to inspect seals.