The concept of workspace optimization is nothing new. For decades, plant managers have been tasked with assessing current space utilization and implementing new technologies, including robots, to improve production processes. Proven to increase efficiency and quality, the addition of robots to manufacturing facilities has helped perform many time-consuming and large-scale tasks.
Over the years, as these benefits and subsequent financial gains were realized, manufacturers continued to look for more ways to automate, addressing market pressures along the way. This is especially true for many small to medium-size enterprises that have taken advantage of the more affordable, robust and easy-to-use robotic tools available, tackling operational road bumps such as limited workspace availability while adding new equipment.
For many manufacturers, modernizing capital equipment (sometimes 50-plus years old) by adding a single robot arm to an existing work area is highly effective at optimizing floorspace. Whether added to an existing robotic workcell or another location along the production line, extremely flexible robots excel at a range of repetitive and often injury-prone tasks, including in tight spaces, that are typically required to reach the throughput needed for meeting demand. Regardless of the task, manufacturers must carefully weigh certain criteria before taking the leap to using robotics to optimize small workspaces.
Safety features
When a robot is introduced into an existing application, safety should be the top priority. While large safety units with physical barriers are effective, they are not always practical. Manufacturers may need to consider “out of the box” safety concepts to facilitate the ideal robotic solution. Highly advantageous to enabling unique safety configurations are built-in features on newer industrial robot controllers. Integrated safety technologies such as machine and functional safety allow a robot to be quickly and affordably integrated into existing lines or workcells, ensuring workers remain unharmed.
Similarly, advanced functional safety helps users to create “safe zones” where a robot can operate as well as define “no-go” areas where obstacles exist. Functional safety unit technology can also interface with other safety-rated devices such as light curtains and laser scanners to slow or halt a robot’s movement within the work envelope, as needed, and then automatically resume operation when it is deemed safe.
Another helpful feature is multiple robot control which enables two or more robots to be controlled and taught from the same teach pendant. This functionality prevents crashes and runaway conditions via the constant monitoring of the robot positions, eliminating interference.
Due to greater contract work commitments for a variety of products, manufacturers are now implementing robotics that operate in safe collaborative modes. These collaborative safety modes are known as:
- Safety monitored stop – stops a robot upon the user breaking a safe distance plane
- Speed and separation monitoring – slows the robot as the user approaches the area
- Power and force limiting (PFL) – allows the robot to stop motion upon light impact
- Hand guiding – allows the user to manipulate the robot arm using only the force of their hand
Use of any one of these four modes qualifies a robot as being collaborative, enabling a robot or cobot to safely operate near workers. Keep in mind, an entire robotic system must be assessed to determine if an application is truly collaborative, including the robots, end-of-arm tooling, workpiece and work area. If any of these fails to adhere to the standards for collaborative operation, then the application is not safe for collaborative operation.
Cobots have been especially beneficial to assembly lines and existing weld booths – all without adding a new workcell. These “cell-less” robots provide the no-physical barrier solution many manufacturers need for processing large parts in small workspaces.
Robot designs
From welding to painting, press handling and more, many applications benefit from space saving innovations where robot design is concerned.
Welding robots. Powerful yet compact arc welding robots equipped with an over-arm torch setup help manufacturers produce small parts with complicated angles. Slender profiles allow for reaching into tight spaces and enable close proximity placement of robots for high-density layouts, while slim wrist designs and base axis radii reduce turning interference for efficient use of space. Reduced profile spot welding robots are also being used in job shops, saving floorspace.
Alternatively, the use of welding cobots allows the user to introduce a robot in an area that may not be conducive to a large robotic workcell.
Parts inspection and assembly robots. Well-suited to fit inside an assembly workcell, compact robots help manufacturers across various industries maintain cycle times. Highly compact 6-axis robots like the MotoMini offer space saving features. Weighing 15 lbs. with a 7.5-in.-by-4.8-in. footprint, this robot is easy to install close to workpieces and other machinery.
Other multi-purpose robots are more streamlined than ever, offering small footprint slim body designs that allow for minimum installation space and close proximity placement of robots. Internal cabling and air lines routed through the robot base to the upper arm not only serve to enhance workspace utilization, but also to enhance maintenance, safety and teaching time.
Because of their extremely fast and precise operation capability for small parts handling applications, 4-axis SCARA (Selective Compliance Articulated Robot Arm) robots are widely used in multi-process systems. Ideal for inspection, insertion, pick-and-place and sortation, the small footprint of a SCARA robot permits easy integration to expand current processes.
Offering a broad range of motion in a small footprint, dual-arm robots with 15 axes are installed to help with more complex assembly, part transfer, machine tending and packaging tasks. With seven degrees of freedom in each arm and slim body designs, these dexterous robots copy human motion by holding a part with one arm while performing an additional operation with the other.
These compact yet robust robots utilize controllers, such as the YRC1000micro, that can be installed in a vertical or horizontal position as well as within a 19-in. rack. Not only do smaller controllers optimize floorspace, but they typically offer a lightweight teach pendant with intuitive programming.
More robot designs
Press handling robots. Specifically designed to work in tight spaces, newer, more robust press handling robots now feature streamlined long-reach arm designs to address the rigors of press room environments and eliminate the inconsistencies of a manual process. When needed, shelf-mounted capability on some robots serves to expand the work envelope and save floorspace, adding to their appeal.
Painting robots. Ideal for locations where minimum installation space is required, compact footprint, slim arm robot designs offer reduced interference work envelopes to manufacturers that need to install robots close to workpieces. Well-suited for mounting a variety of spray guns and small applicators, newer robot models that are Factory Mutual-approved for Class 1, Division 1 use in hazardous environments can expertly coat the small to medium-size parts often produced at smaller facilities.
Many innovative painting options such as multi-functional rotary feeders and SCARA-style openers also provide flexible yet compact options for tight spaces.
Seven-axis robots. Used for welding and multi-purpose tasks, 7-axis robots with reduced interference designs enable high-density robot placement. Unlike 6-axis robots, these robots are built with a seventh axis between the second and third axes to allow shortening or lengthening of the overall arm reach. Capable of a variety of product handling tasks, 7-axis robots such as the GP110B offer an increased motion range in a sleek package, expertly avoiding obstacles and reaching workpieces in challenging spaces.
On the welding side, versatile and powerful robots such as the SP100B help with large and heavy welding applications. Ideal for arc welding or spot welding as well as adhesive or grinding applications, robots like this offer a slim profile design for reaching into tight spaces. A wide wrist motion range improves application flexibility and optimizes floorspace utilization, as well. It is not uncommon to find a robot like this working in a tight space, such as a window frame in an automotive door panel.
When it comes to the term “seventh axis,” this can also refer to a floor track that allows a robot to travel along a long plane. While track utilization is not typically suited to small spaces overall, it can save space compared to multiple robotic workcells when it is needed.
Cobots. Roughly the same size as workers, easy-to-program cobots with pinchless designs and smooth surfaces are quickly becoming the “go to” when space is scarce and production throughput needs a boost. This is especially true for welding environments looking to add capacity to current production. Built-in safety-rated PFL sensors in certain cobots allow the monitoring of external forces, stopping robot motion when needed to protect workers from potentially harmful contact situations.
Furthermore, the use of PFL robots reduces the requirements for items such as external barriers and light curtains, saving floorspace while lowering costs. Please note: A welder working with a cobot should still be mindful of risk mitigation requirements for the welding application being performed.
Compact workcells
With any of these robots, it is always important to consider how it will be mounted. Whether a robot is ceiling- or shelf-mounted, unique mounting options are quite effective at overcoming limited floorspace. As mentioned, manufacturers should also consider cable and air routing options. Regular or floor mounting may allow cables to be routed from below a robot base (through the table or the floor) rather than out the back of the arm. Right-angle cable adapters and high-flex cables can help with this, as well. For welding, through-arm cables for torches and utilities (water, air and power) should be considered.
While retrofitting with robots alone can be a financially sound move, it is not always the most cost-effective or efficient solution. Sometimes, the implementation of a new robotic system is the best option. Aside from more traditional robotic workcells, extremely compact welding systems are filling a large gap that has existed for many small shops for decades.
Ideal for replacing or supplementing manual welding, such as pre-assembly before welding in larger robotic workcells, these pre-engineered solutions optimize high-mix production of small to medium-size parts. With some only requiring 4.6 to 7.5 sq. ft. of floorspace, these space saving systems offer robust robots and technology on a very compact base that is easy to install, operate and relocate.
Whether a manufacturer is considering workspace optimization through the addition of space saving robots or workcells, contacting an experienced robot vendor to conduct a thorough plant audit is a good place to start. This should provide the knowledge needed to make an informed decision that aligns with the company goals, enhancing the current workspace to yield transformative results.
