Assembly line upgrade boosts profitability

Cognex In-Sight® sensors checking the quality of laser welds at Renault – SandouvilleRenault LHA factory Cognex story

The Renault LHA factory is located in the Haute Normandie region, in the town of Sandouville, and more precisely in the port and industrial estate of Le Havre (in the Seine-Maritime Department). This sizeable bodywork-assembly plant is specialized in the manufacture of top-of-the-range vehicles.

The vision application presented here was set up in the pressing workshop. This workshop produces sheet metal parts that make up the body shell of the vehicles. It mainly comprises cutting lines, assembly and sheet welding points, as well as sheet presses which make up the various bodywork components. The pressing workshop supplies the sheet metal workshop which carries out the assembly of the various parts of the body shell. This then passes on to the paint shop before final assembly.

Each side of the body shell is made up of two parts which have been assembled by laser welding. It is around the weld that defects can appear and need to be detected. While the various pressing operations – which give the part its shape – are being carried out, clear or partial breaks can be produced. As the parts are stored manually at the end of the line, those parts showing such faults are easy to spot and remove.

It is not so easy to spot when the faults are small holes, some of which can measure less than 3/10th of a millimeter, which form along the bead of the weld. If the presence of these holes is not detected at the end of the line, and if the part is not removed, breaks can be produced during shaping, causing numerous problems which can have serious effects on the productivity of the assembly line. Sometimes minute holes are enough to give the bodywork an unsightly appearance after the paintwork has been done.

If these defects are not detected before the vehicle is assembled, the consequences can be financially very expensive as it is very difficult to repair…and sometimes there is no other choice but to send the chassis to the scrapyard.

Checking the welding was previously done by several operators who had to struggle to handle parts of a considerable size and weight: the sides of the body shell measure around 3.4 meters in length, 1.6 meters wide and weigh nearly 30kg. To carry out the operation, they used to place a light source on one side of the part and check from the other side that the light did not pass through, showing breaks or holes in the part. This form of control, even when it was done in the optimum way, cannot highlight holes of a very small diameter.

Numerous defective parts passed through these checks, so a solution had to be found which was capable of putting a stop to this situation while carrying out a continual and reliable check of the lower body shells.

Solution:

Four Cognex In-Sight 1000 cameras, each placed in protective casing, are positioned at the top, over the platform, on the cross support beam. A control screen is fixed on one side of the test bench, in a box where the control system is also installed. A marking system for defective parts is fitted at the other end.                                                                   

The parts to be checked – body shell sides – measure around 3.4 meters long, 1.6 meters wide, and weigh nearly 30kg. They are put onto the supports provided for this purpose on the test bench by a robot. There are two areas to be checked. The target areas measure approximately 10 centimeters in length, by 5 centimeters wide, with a covering. Two of the cameras are inclined at 45 °, the part forming a U-shape over the welded area.

The cameras are able to detect very low light levels coming from the back-lighting system and passing through any holes, some of which are only a tenth of a millimeter in diameter.

If the part is declared sound, this is displayed on the control screen. If the part is defective, it is also displayed on the screen, a red light comes on at the end of the line for each fault, and finally, the part is marked by a jet of ink which stops it from being used.

The speed of the control carried out on the line was a determining factor of the project: all the operations – positioning the part, capture and analysis of the image, detection and marking could not reduce the production rate in any case. At this stage, the Cognex systems proved their worth: the production rate specified in the Terms and Conditions was 900 parts per hour; the current production rate is 420 parts per hour for the body shell sides and 850 parts per hour for the side frames.

The system is connected to a PC fitted with a hard drive for saving the photos of the defective parts detected over one year. This procedure allows the problems encountered to be analyzed at a later date; it contributes in ensuring the traceability of parts and for monitoring the various shifts (days, hours, cameras 1 and 2…).

Benefit:

Checking welds reliably for individual parts at full production rates, eliminated entire body shells being scrapped at the end of the line.

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KIA Motors achieves 99% read rates with Cognex barcode readers

Cognex Kia Motors achies99% read rates with Cognex Barcode ReadersKIA Motors, located in Korea, manages their traceability program on their engine and transmission parts using 2-D Data Matrix direct part marked (DPM) codes. A car transmission consists of as many as 300,000 parts. Among them, the key components (e.g., differential gear, T/F driver gear, T/F driven gear, carrier, O/D clutch, transmission case, housing, valve body, etc.) are traced throughout the production process. Additionally key components on the engine, which is comprised of around 200,000 parts (e.g., the piston, cylinder head, engine block, CAM shaft, and crank shaft) are traced throughout the manufacturing and distributing processes.

KIA Motors focused on enhancing 2-D Data Matrix read rates for traceability after it shifted its production system to the 6-speed transmission production line. The company’s conventional transmission production line produced approximately 1,800 units daily but only delivered 96-97% read rates. Their engine line, which produced 1,300-1,400 engines daily, had read rates that were under 97%. KIA Motors knew that an increase in read rates by as little as 2-3% in this production line would deliver various benefits, such production yield and reduction of manufacturing costs as well as improved work efficiency.

Challenge:

The previous barcode reader frequently stopped the manufacturing machines due to the failure to read codes. Because it was manually operated, it was hard to match the manufacturing cycle on time, which, in turn, decreased work efficiency and production yield. Furthermore, there was a possibility of using inappropriate parts if the code read was incorrect, which could cause product defects. This particular line had challenging Data Matrix codes to read since the s-speed transmission parts are small. Furthermore, KIA Motors downsized from 10×10 to 5×5, marking space. As a result, marking quality also declined.

Because KIA Motors’ auto parts are assembled with anti-rust oil spray, one of the challenges for the reader to avoid is errors caused by oil on the code. In addition, the 2-D Data Matrix codes can be stained or damaged by dirt or scratches, even though they have been washed and kept clean. And, with the reduced marking size, the codes are very small and have greater variation in marking quality, making them more difficult to read.

Solution:

The Cognex 2DMax+ code reading algorithm can read virtually any barcode regardless of the damage or the surface it is marked on. In addition, Cognex barcode readers offer Ethernet connectivity so they can directly integrate into the factory network, and direct communication with PLC possible without a transmission device.

Benefit:

Improved read rates from 96-97% to 99%, and allowed the manufacturing cycle to match the inspection time.

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Sensors for Forklift and Mobile Equipment

Sensors for forkliftsMobile machines such as forklifts, elevating work platforms, or container stackers, require precise positioning of heavy loads and effective control of rapid movements for transporting materials. Heavy-duty, resilient sensors guarantee precision and reliability both in warehouses and in outdoor applications.

Fork Inclination Monitoring – Inclination Sensor

  • Detects the horizontal angle of the fork while the truck is in motion
  • Prevents the truck tipping when transporting heavy loads

Nonmechanical Hand Detection – Capacitive Grip Sensor

  • If the hand is removed from the joystick, the engine is stopped and hydraulic pressure is lowered
  • Inadvertent joystick actuation is virtually impossible

Fork Height Monitoring – Laser Distance Sensor

  • Height monitoring for safe fork movement
  • Forklift speed can be adjusted according to fork height

Fork Extension Monitoring – Positioning System

  • Monitors the fork positions for controlled fork extension

Tri-Phase Automation is a distributor of Pepperl +Fuchs in Wisconsin.

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Collision Avoidance: Control Networked Laser Scanners Protect Automatic Guided Sensors

Challenge

Laser Scanner ProjectThe Italian company, Elettric 80, is a global supplier of system solutions for packing technology and intralogistics. In the LGV (Laser Guided Vehicle) sector, Elettric 80 was searching for a new vehicle protection system which guaranteed maximum reliability. As such, the company required a development partner which could provide the right safety solution. The 360° protection of a fully-automatic, three-wheeled forklift truck required a complete solution which not only offered the correct sensor technology for the intended function, but was also specifically designed to take into account economic efficiency in procurement, integration and operation. The specifications included an option for central configuration and diagnostics, quick replacement of components in case of failure without the need to reprogram, reduced wiring times and minimum space requirements in the control cabinet. At the same time, the aim was to develop a standardized, modular safety concept which could be flexibly adapted for all LGV variants. SICK was able to complete this automation and technical safety challenge successfully.

Application Solution

Based on these specifications, Elettric 80 and SICK have developed a solution which meets all the requirements given. It consists of two safety laser scanners (S300) which monitor the rear and side vehicle areas, a further safety laser scanner (S3000) for protecting the vehicle routes and the area below the load carrier, and a safety controller (Flexi Soft). All the components have SICK-specific interfaces which enable the devices to communicate with each other directly and safely. While a scanner safely monitors the vehicle’s path in the direction of travel and in docking areas, the other two devices are used to monitor the entire rear and side areas. The scanners are connected to the flexible configurable Flexi Soft, which communicates with the sensors via the CAN bus-based EFI (Enhanced Functional Interface). Its modular hardware also makes it much simpler to project safety system solutions for Elettric 80.

Benefits

  • Protection for automatic guided vehicles which complies to directives and standards
  • Networked, integration-friendly safety solution
  • Can be flexibly adapted to other vehicle types and applications
  • Sensors, control technology and service from a single source guarantees risk-free integration by using safe laser scanners and control technology

Elettric 80 can rely on protection for automatic guided vehicles which complies with directives and standards. The networking of selected safety laser scanners and a configurable safety controller is highly scalable. As all the scanners can be configured and diagnosed centrally the wiring times and the risk of wiring errors are kept to a minimum. Thanks to the openness of the solution, it is also possible to connect further additional safety sensors – even after initial installation. Overall, this solution is currently the only one of its kind in the world, suitable for all Elettric 80 LGVs. “SICK was the only supplier capable of solving the task on its own, drawing on the entire product portfolio,” says Franco Manzini from Elettric 80. “This allowed us to obtain the sensor and control components from a single source, thus minimizing any interfacing risks.”

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
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