Context & Aim
Industrial robots have until recently always been separated from humans with physical cages. Due to recent advances in technology, a newer trend has emerged enabling closer collaboration between humans and machines and this is possible due to a new type of robot called a Collaborative Robot or Cobot. These Cobots are designed for direct interaction with humans also called Human-Robot Collaboration (HRC) where humans and robots can share the same workspace. Other advantages of these Cobots include improvements in mobility due to their lightweight construction, flexibility due to improved gripping techniques, adaptability due to advanced vision systems, and additional feedback from enhanced sensors and easy programming.
Challenge
Boston Scientific (BSCI) approached Irish Manufacturing Research (IMR) with an opportunity statement to incorporate Collaborative Robots into their Cork facility to focus on areas with high repetitive operations and improve ergonomics. This in turn allowed the team at BSCI to redeploy their Product Builders to higher value-add operations. Very early on in the project, IMR introduced Innovative Total Solutions into the project.
BSCI produces a large range of medical devices at the facility. One of the production lines is fully automated with the exception an end of line packing & palletising cell, where:
- Two different product variants, Single Cartons or Five-Pack Cartons, are produced on a single line.
- The products exit on different conveyors in different locations.
- These products must be placed in a case with the correct type and quantity confirmed by the product builder.
- The case is then sealed and stacked onto a pallet for shipping.
- This process is manually performed by two product builders.
The scope of the project was to:
- Semi-automate this process with the introduction of Collaborative Robots to handle the repetitive handling and packing tasks.
- Reduce the number of product builders to one and allow for the re-purposing of this person to higher value add operations.
One of the main constraints at the facility was the lack of available space in this area as it is confined between a main walkway and another production hall. Approximately 5mt x 4mt was the useable footprint, which initially ruled out standard industrial robots due to the required guarding and lack of operator access. Due to the nature and small space requirements of the application and properties of Collaborative Robots mentioned previously, the decision was made to attempt the project using these.
The Players
Irish Manufacturing Research (IMR)
IMR provides Irish manufacturing companies with the support they need to become ready for the next generation of digital manufacturing. Medical device production is a prevalent industry in Ireland and IMR works with a variety of companies to deliver close to market, application-centric research.
Boston Scientific
Boston Scientific is dedicated to transforming lives through innovative solutions that improve the health of patients. The Cork facility manufactures a diversified portfolio of medical devices for distribution across the globe. The medical devices we produce in Cork positively impact 8 lives per minute. The product portfolio includes active and access catheters, occlusion coils and microspheres, inflation devices, and atherectomy devices.
Innovative Total Solutions
ITS (Innovative Total Solutions) established in 1993 has its roots in mechanical design & build engineering. It is an important foundation for the automation experts they have since become. ITS were the first in Ireland to put the Universal Robot (UR) into action and are UR’s Accredited Training Partner in Ireland. Innovation is at the heart of ITS’s business. This combination made ITS a natural partner in this project.
Solution
Figure 1. Proposed layout for 1 Cobot
At the initial scoping and design stage close collaboration between IMR, BSCI, and ITS resulted in many potential solutions being discussed. All solutions were rigorously assessed to determine the re-duction of product builder input and cycle time associated with the process to determine if they met the criteria.
While initial proposals only consisted of one Cobot (Figure 1), it soon became apparent that more than one Cobot would be required in order to achieve the desired cycle time and reduction of product builder input, as the cases needed to be erected just before packing. This constraint was due to a lack of space for case buffer stock to meet the production times required.
- Implemented Solution
The final solution used three Cobots at various stages in the process:
Figure 2 Case Erector UR5
- The first UR5 Robot arm was employed for case erecting (Figure 2). A novel solution designed by ITS whereby the UR5 Cobot and its specially designed End of Arm Tooling (EOAT) pick an unformed case from a stack and in several operations with the aid of a special and very simple fixture formed the case and presented it to the next Cobot for packing.
Figure 3. Case Packing
- The second UR5 Robot arm was employed for case packing (Figure 3). As there were two different products both the Single and Five Pack, different EOAT’s were required, and these were easily interchanged by the technicians during the product change process.
Figure 4. Palletising UR10
- The third Cobot, a UR10 Robot arm was employed for palletising (Figure 4). The load capability of the UR10 was insufficient to cater for the weight of the packed case and the EOAT which was nearly 14kg, exceeding the limit of the Cobot by some 40% and ITS engineered a novel solution with the addition of a Bal-Trol pneumatic lift assistant that carries the load while the UR10 picks and palletises the supported case.
The reach of the UR10 was also insufficient to cater for the height requirements of the pallet. To overcome this technical obstacle a novel solution was designed by ITS with the addition of a 7th axis in the vertical plane onto which the UR10 was mounted. This axis was a 600mm stroke pneumatic 2 position system that was used for the top 3 layers of the pallet.
Figure 5. Final Solution Implemented
- Risk Assessment and Reduction
- Robots and Cobots are incomplete machines and fall under the Machinery Directive 2006/42/EC. The application of the two standards ISO 10218 “Safety of Industrial Robots” Part 1: “Robots” and Part 2: “Robot systems and integration” induce the presumption of conformity. In addition to these, the Technical Specification ISO/TS 15066 for Collaborative Robots has also been developed as the specific requirements for collaborative robot systems are not yet comprehensively described in ISO 10218. Risk Assessment & Risk Reduction
- The risk assessment is a procedure specifically required by the Machinery directive. Corresponding guiding principles for risk assessment and mitigation are defined in ISO 12100 Safety of Machinery and ISO 14121 Safety of Machinery Risk Assessment.
The risk assessment comprises of:
- Determination of the limits of the machine;
- Hazard identification;
- Risk estimation; and
- Risk evaluation.
If risk reduction is required, then appropriate protective measures shall be selected and applied. Risk reduction can be achieved:
- By eliminating the hazards;
- Or by separately or simultaneously reducing the severity of harm and the probability of occurrence of that harm.
For traditional robotic systems, risk reduction is typically achieved through safeguards that separate the operator from the robot system. For collaborative operation, the risk reduction is mainly addressed by the design and application of the robot system and of the collaborative workspace.
In this case, it was determined that the EOAT design did not allow for the operator and the Cobot to share the workstation while in operation. This then resulted in the operation being defined as a “Co-existence” application.
In a coexistent application, the human operates at a workstation near the robot workstation without any workspace overlap and with no physical contact allowed when used in accordance with its intended purpose.
- Safety Requirements
A combination of various safety methods is possible for Coexistence applications, including:
- Safety-rated monitored stop,
- Speed and separation monitoring, and
- Power and force limiting.
Figure 6. Safety-rated monitoring stop
In this application, the Safety-rated monitored stop method is selected to achieve safety (Figure 6), preventing any collision by allowing the operator access to the robot only when it is at a standstill.
The Safety-rated monitored stop method was achieved by implementing Safety Laser Scanners and a Safety PLC with one scanner at the entry point to each Cobot area.
- Customer acceptance
The involvement of the product builders and maintenance technicians at a very early stage was crucial to the success of the overall project. The design team clearly explained the project, from the tasks the Collaborative Robot application will complete, how it will operate, and how it will look. Ultimately, one of the impacts of the Cobots implementation will be a reduction in the manual workload, which the product builders were very accepting of, as they said themselves, “it took away the worst part of the job”.
During the design and build process, the product builders were brought to the vendor site to see the progress and to get actively involved, increasing in doing so the acceptance on their side.
The maintenance technicians were given the opportunity to suggest changes and to confirm that everything was acceptable on their side so as to ensure site standard components were used. Spare parts required, and maintenance routines are all established before implementation of the cell into production. “Overall the maintenance team is very accepting and happy with this system”. The training was completed with the maintenance technicians to ensure they knew how to use and program the Cobots.
Conclusion
While truly collaborative robot applications are not actually that common and some degree of external safety guarding is required, the flexibility of small and easy to program Cobots make them an ideal choice for many existing and new applications to be automated.
The collaboration between IMR, BSCI and ITS was very fruitful, leading to a very successful project that was implemented and commissioned on time and is currently operating faultlessly. The management team were so satisfied with the solution that a viewing window was placed in the wall to allow both staff and visitors to see the Cobots in operation from the main corridor.
“Our project has exceeded the expectations we originally envisaged as a result of the collaboration and guidance of the IMR team.”
Kieran Hogan, Boston Scientific
THEMATIC PILLAR
Robotics and Automation
