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Considering Mobile Cobots for Machine Tending?

Companies all over the world are taking a look at their production operations and trying to determine how to increase productivity. That’s a big reason why the demand for robotics and automation is increasing at such a fast pace. a crx-20 Fanuc cobot model for machine tending Autonomous machines and mobile robots have taken over as a favored solution for a wide range of industries, including online retail, where the automaton can swiftly traverse between different sites to retrieve items for completing orders. Today, numerous industries are considering the utilization of cobots on a mobile framework to offset the lack of laborers, enhance efficiency, fulfill crucial timeframes, and optimize return on investment (ROI).
Companies that machine parts not only face labor shortages and productivity issues but are now challenged by customer demands to handle low-volume, high-mix work. A very flexible and safe solution is mounting a cobot to a mobile platform like an autonomous mobile robot (AMR).
This category of portable automaton solution simplifies the process for an individual worker to transport the robot to various machines across the factory area and quickly configure it for multiple assignments. This substantial advantage enables companies to fulfill their customers’ requirements, while simultaneously economizing time and finances. Furthermore, it skilled proficient personnel the opportunity to remain within the cobot’s work enclosure, tending to additional responsibilities while the cobot performs the monotonous loading and unloading tasks.

Mobile Manipulator Demonstration

FANUC recently demonstrated flexible machine tending featuring its latest CRX-20iA/L cobot mounted on a platform. An OTTO 100 AMR docked under the platform was used to lift and transport the cobot to autonomously complete a variety of common tasks found in any job shop, including part kitting, washing and machine tending.
This system, designed and built by Capriol (West Bloomfield, MI), is an excellent example of how a cobot’s capabilities can be expanded, turning it into a true mobile manipulator.

Powerful AMR

The OTTO AMR, yielding about two hours of runtime, is used to power the equipment onboard the platform between the cobot and the AMR. Much more than a simple mechanical link between the two, the platform contains the necessary equipment to power the cobot with the AMR’s batteries, wireless communication equipment for the cell PLC and I/O connections for application-specific sensors.
So, in this example, the AMR’s batteries last for two hours. At the two-hour mark, the AMR swaps places with another fully charged AMR. A stable secondary power supply (UPS) enables the cobot to finish its cycle, and the system continues to run with no lost productivity.

Localizing with 2D Vision

When using mobile manipulators, a docking station’s position and orientation must be verified every time using some form of localization to ensure repeatable robot motion. What can impact repeatability?

  • When a mobile robot docks at a station, repeatability can vary by several centimeters.
  • Since floors are not perfectly level, any small dip or bump can significantly change the position of the cobot’s end-of-arm tool.

2D Vision can address the concerns swiftly. This is achieved by incorporating a visual objective (a camera calibration grid) at every station and instructing the positions of all the objectives. Upon the mobile manipulator’s arrival at a station, a 2D camera captures multiple images of the objective and computes its relative position and orientation in relation to the robot. This establishes the target’s position, ensuring that all subsequent robotic movements at the station maintain the same level of precision as during the initial instruction.

CNC Servicing

There are many ways for a CNC machine to communicate with a mobile manipulator. The recent demonstration attempted to mimic a human operator as much as possible, so vision was used for communication between the CNC and the rest of the cell.
Upon the completion of a cycle by the machine, it unlatches the door and employs the stack light to signify the need for maintenance. The portable manipulator approaches the apparatus and inspects the light to validate its readiness. After accomplishing the designated tasks at the apparatus, the robot activates the cycle start button and performs a final inspection of the stack light to ensure the machine is operating before leaving the station.
Another application might use networked communication to talk to the CNC machine, potentially yielding a more efficient solution. In this case, the CNC machine can signal when it is almost finished with a cycle, and a mobile manipulator can be dispatched early so it arrives right as the machining cycle completes, improving efficiency.

Collaborative Technology

The CRX-20iA/L used on the mobile manipulator is a power and force-limited collaborative robot. The mobile manipulator system also has laser scanners mounted on two corners offering 360-degree coverage. These two safety-rated systems (the cobot and the area scanners) can be used together to achieve a safe system.
For low-risk tasks, the FANUC cobot provides safe operation without the need for safety scanners. If higher speeds are required or the task is riskier, such as handling a sharp part, then safety scanners can be used to prevent the arm from moving when operators are near. The key here is flexibility – the power and force-limiting features of the cobot can be augmented by the area scanners to achieve a safe system in a way that makes sense for each unique application.

Mobile Robot Navigation

There are several advantages of utilizing an AMR like the OTTO 100 to transport a mobile cobot/manipulator, including:

  • Flexibility to respond to unexpected obstacles by automatically rerouting around obstructions.
  • Large wheels allow the AMR to travel over factory floors, even those that are cracked or have bumps.
  • Straightforward route map setup – it takes just one manual drive around the site, and the AMR’s map is set. The map is then populated with stations, chargers, and other points of interest.

OTTO’s robust Fleet Manager software enables everything from programming simple waypoints to defining complex factories integrated into building infrastructure. Changing machine location or workflow is as simple as adjusting destinations on the map – the AMR handles everything in between.

Maximizing Return on Investment (ROI)

Prior to committing to a mobile manipulator setup, it is important to collaborate with a dependable automation provider who will undertake a comprehensive assessment of your operational processes to ensure the optimal utilization of automation.
An alternative and possibly more cost-effective approach might be to use fixed robots at each station to perform process tasks and only use the mobile manipulator to move parts between stations and fixtures. This keeps the mobile manipulator moving as much as possible, allowing it to service more stations versus using it to perform tasks at each station.

Mobile equipment tending proves to be a worthwhile investment, yielding benefits in terms of steadfastness and adaptability. Robotic precision governs the loading of machines, ensuring consistent part throughput regardless of shifts. Unlike human counterparts, robots are not bound by meeting schedules and exhibit no qualms about working extended hours.
From a forward-thinking perspective, a mobile solution emerges as the epitome of flexibility: while a robot mounted on rails may offer initial swiftness, any alterations necessitate substantial expenses and extensive modifications. On the other hand, a mobile solution readily adapts to layout adjustments, expansions, and even complete transformations in workflow.
Another way to look at ROI is employee satisfaction and retention. By automating the strenuous and repetitive tasks of loading and unloading CNC machines, you can reduce the risk of employee injury, making their jobs much safer. When your employees can focus on higher value tasks, they will be more satisfied with their workplace, thereby decreasing turnover and limiting your need to specifically hire manual laborers in those positions.

Bottom Line

When considering machine tending, it is essential to conduct thorough evaluations and assessments before introducing novel machinery or procedures. With a future-oriented outlook, a mobile manipulator emerges as an exceptionally adaptable resolution that enables you to fulfill customer deadlines, optimize productivity, and effectively address labor-related obstacles.
Imagine implementing a system like the one highlighted in this article to tend CNC machines, then a couple years later an inspection station is required. With a mobile solution, this workflow change can be quickly implemented by programming the robot at the new inspection station and simply adding a destination to the map.
Alternatively, if you are strictly a manual operation, major changes to the process would require additional manpower and scheduling – but what happens if you’re not able to fill the jobs? And, if a linear rail had been previously installed, an expansion may not even be possible – where would you find the additional floorspace?
A mobile solution’s flexibility is its most important benefit and a key reason behind the growth of mobile robots in automation. If you’re considering automating one or more machining process, you may want to take a closer look at a mobile solution.

Contact TW Automation for Mobile Cobot Support

If you’re interested in learning more how mobile cobots can improve your workflow and efficiency, contact TW Automation today. We have over two decades of experience as a robotics automation systems solutions provider and integrator.