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Assembly order picking with two robots on a 13 metre traversing axis

Task:
Ulrich Rotte developed an extensive system to assemble gate controls for Hörmann, the door and gate specialists. The system is designed for parallel production and consists of manual and fully automatic processes. Two FANUC robots should take care of the order picking.

Solution:
Two M-710iC/45M robots approach different spaces and take parts from large load carriers. As long as the robots do not travel beyond their respective borders, it is enough to protect them using “Dual Check Safety” (DCS). Another safety option from FANUC, Interference Check, prevents the robots from colliding with one another during dynamic operation. The robots are “led” by a 3D Vision System. After the assembly, two LR Mates are used at the test station.

Result:
The two robots not only work together on a task, but rather alongside one another on a 13 metre long linear axis. Thanks to safety software, the two FANUC robots do not cross one another. The plant’s Vision System is on another axis independent of the robots.

Veelzijdige hantering

Met een laadvermogen van 45 kg en een breed bereik is dit model bij uitstek geschikt voor de verwerking van dozen, pallets en panelen.

All-round automatisering

De compacte LRMate 200iD levert een hoge doorvoer en korte cyclustijden, waardoor het een ideale allrounder is voor industriële robottoepassingen.

How the 3D Vision Sensor works

3D Vision Sensor uses structured light projection to create 3D maps. It uses these to identify and pick parts based on what the integrated part manager decides to be the fastest picking option.

Ulrich Rotte Anlagenbau und Fördertechnik GmbH has been around for 25 years. Started in a former petrol station with a focus on materials handling, the company has long since developed into an extensive and multifaceted builder of special facilities in automation technology. In doing so, materials handling is only one of many disciplines which the family company has mastered best. Today, more than 80 employees work at the company’s headquarters in Salzkotten, which achieves an annual turnover of almost ten million euros. At the top of the company’s philosophy is to have knowledge and experience in-house. As “builders of special facilities”, the company sees its great strengths in customised solutions for end customers. Rotte’s focus here is on fully automated production facilities and developments in the field of robotics.

But what makes Rotte facilities so special? Project manager Daniel Bürgermeister opens up: “Each facility is customised specifically to the customer’s requirements”. In this respect it is difficult to describe a common feature. But what they all have in common is high facility availability and at the same time maximum flexibility. The problem-solving expertise with which the Rotte project teams realise their facilities can also be explained in that there is no focus on a particular industry: Automobile, solar and rubber industry, wood technology and laminates are just a few of the most diverse fields of work. “The mix of industries promotes lateral thinking, keeps us on our toes and makes it easier for us to carry over innovative solutions.” In doing so, future-oriented system partners like FANUC play an important role - including in Rotte’s strong international business.

There is now a comprehensive facility to assemble gate controls in Salzkotten for the door and gate specialists Hörmann, Steinhagen. At this facility, the latest generation of controls are assembled, but so are older models and spare parts.

The system is designed for parallel production and is made up of manual and fully automatic processes. Project manager Daniel Bürgermeister: “The assembly line is primarily designed to assemble the current gate controls. In addition, Hörmann places value on a sustainable and customer-oriented product support and also wants to be able to deliver older generation products for longer.” The facility is therefore designed in such a way that both older controls as well as new developments can be assembled.

Two robots on the axis

Order picking is at the start of the assembly line. The robots take the parts from prepared large load carriers from a total of 14 spaces. They are then laid on workpiece carriers. Handling reusable packaging and preparing it to ensure it can be returned is also part of the task. It is possible to select manual or automated supply and disposal of order picking.

14 places means that the robots have long paths. Therefore, both FANUC robots have been assembled on a 13 metre long linear axis. The robots have a load capacity of 45 kg and a maximum reach of 2,606 mm. In principle, the task is divided easily between the two robots M-710iC/45M: Robot 1 approaches spaces 1 to 7, robot 2 approaches spaces 8 to 14. So long as the robots do not travel beyond their respective borders, it is enough to protect them using “Dual Check Safety” (DCS). Another safety option from FANUC, Interference Check, prevents the robots from colliding with one another in dynamic operation. Bürgermeister sees both options as useful: “Either we block the areas or we make a dynamic request. Both are technically feasible.”

The robots are “led” by a 3D Vision System which is installed separately over the facility. Due to the fixed pallet racks, the respective robot “knows” where the container is, but it does not yet know the location of the parts which it should grab and lay on the workpiece carrier.

In the course of the project, different forms of delivery, such as providing the products in trays or pallet cages, were tested. In close coordination with the customer, finally the solution with the flexible usable plastic boxes was realised. In these, the parts are separated in levels by layer pads.

A 3D system delivers the position information required for grabbing and also determines information on the fill level of the respective load carrier. In addition, the camera was installed independently of the robots on its own linear axis above the pallet spaces. The big benefit lies in that the information can be recorded independently from the robots. A camera on the robot’s wrist joint would lengthen the robot’s cycle time. From experience with other Vision Systems, Daniel Bürgermeister reports: “It is significantly easier to work with a system in which CAD models are stored instead of defining image features which have to be checked each time. I’m not a programmer, and I was able to operate it within a few minutes. 2D systems have their strengths and legitimacy for other requirements.”

LR Mate at the test station

The workpiece carrier with all the parts required for the assembly take the product through the entire assembly process. After the assembly there is a complete final inspection at the automated test station.

There the gate controls are checked optically and electronically. Two type LR Mate 200iD robots contact the control and simulate different operating procedures. The test station is set up redundantly in order to avoid bottlenecks. Even if the two LR Mates are “close” in the cell, the safety zones of both robots are limited and there is no overlapping. The integrated software solution Dual Check Safety (DCS) from FANUC is used here. Since no expensive, space-wasting safety equipment is required, the area required for the robot cells is also kept to a minimum.

It is very easy to set up safety zones, which are confirmed by the programmers at Rotte. In addition, the blocked off area on the monitor can be examined and checked virtually.

If the controls have passed the test, the workpiece carrier travels to the so-called storage, which was also developed and realised by Rotte. The control is completed in this cell. A robot places the lid on the bottom part of the housing, applies a type plate and has this verified by image recognition.

If everything is fine, the controls shall be placed in a small load carrier with the same types of controls and handed over to Hörmann intralogistics via a Rotte conveyor. Since range is most important for the robot in this cell, a long-arm M-20iA/12L robot from FANUC was selected.

All facilities are equipped with operating units which visualise management of the facility. If necessary, a robot can act individually in manual mode. In automatic operation, facility management is connected to the Hörmann central production management.

In all other respects, the two M-710iC robots work in order picking with an individual grabber for all 12 products, container lids and layer pads. Rotte itself developed, designed and built the customised robot grabber according to customer requirements. Even if standard components are purchased from relevant manufacturers for the sake of simplicity. Bürgermeister: “But what’s easy? It’s only easy if we have found a solution.”

Benedikt Rotte
+49 5258 9789-0
benedikt.rotte@ulrich-rotte.de
www.ulrich-rotte.de