humans and robots unite

Teaching Robots and Humans to Play Nice

May 2, 2013
Replacing bulky physical barriers with new technologies that make safety intrinsic to the robot not only protects operators and other workers more effectively – it improves productivity. All while allowing the use of robots in situations where it was once cost-prohibitive, helping drive down overall costs while delivering greater ROI on those units.

In Isaac Asimov’s classic series of short stories "I, Robot," he lists the first law of robotics as, “A robot may not injure a human being or, through inaction, allow a human being to come to harm.”

Yet in the real world of warehouses and distribution centers, there is no such caveat. As a result, robotics are usually either isolated completely or cordoned off by fences, light curtains or other barriers in order to prevent humans from putting themselves in harm’s way.

While creating a “no fly zone” for humans makes sense from a safety standpoint, and may even be required by Robotics Industry Association (RIA) standards (which OSHA follows), it takes up valuable floor space that could be put too much better use.

In short, although robotic isolation works, it’s the equivalent of not allowing any development on the valuable land around airports just in case a plane crashes. The effect in an operating environment is that valuable space is routinely rendered unusable.

This approach also gets in the way of efficiency. Currently, when a robot needs help to correct an error, the operator must enter the safety zone through a gate in the physical barrier. Many times entry calls for following a lock-out procedure to ensure the system is not inadvertently re-energized by someone else.

This approach limits the way an operator can access the system to correct the error, which adds time to recover, lengthening downtime and reducing overall productivity.

Rather than building safety zones, the smarter solution is to re-think how humans and robots interact – or should interact – to integrate that first law of robotics as part of the fundamental design of the unit.

That is where the human/robot interaction is headed.

Sensors, Alarms and Safety

 As early as 2006, a presentation at NASA’s Space Exploration Conference focused on how to increase the autonomy of robots in situations where cost or manpower concerns limit human control.

Yet with increased autonomy comes increased risk to those humans who will be working closely with the robots.

The question NASA scientists sought to answer was how to provide the required autonomy while minimizing that risk.

The solution presented was to create a safety partition at the software level that overrides any other programming; if a decision has to be made between completing the mission and human safety, the programming is set to make safety the priority.

These principles are already being adopted in the supply chain industry.

For example, some manufacturers of automation equipment are designing cutting-edge robotics that incorporate laser sensors which will immediately stop the robot if a human approaches too closely.

It’s a similar technology to the laser-based alarm systems often shown in high-tech spy and “caper” movies.

The difference (and more complicating factor)is that rather than having the lasers on the perimeter of the area pointing inwardly at the object to be protected, the lasers originate from the robotics and then must  project up to a 360 degree protection field – in three dimensions.  After all, humans can approach from any angle.

A laser-based perimeter offers greater flexibility than physical barriers, allowing it to be adjusted to the conditions. For example, a robotic truck loader can have a narrow field when deep inside the truck, where the walls of the truck form a natural barrier, and then need to expand the field once it’s working outside the truck.

If humans are required to load the last row, humans can approach quickly to assist with that task.

This way of thinking will revolutionize supply chain design. In order for humans and robotics to work in close proximity, the robotics must be intrinsically safe. Having sensing devices – whether based on lasers, RFID tags worn by workers or a technology that hasn’t been created yet – will use space more efficiently and allow related tasks in the same area to be performed by the entity (human or robot) that is best-suited to it.

In the event of an error, it also offers more paths to the robotic equipment (instead of having to approach through a single gate in a physical barrier), which will make recovery quicker, reducing downtime.

Yet a full stop and reset may not be the only answer, at least in the future. As software and sensing technologies improve, new strategies may have the robotics slowing down to safe levels (i.e. those that will not cause damage to humans if there is an impact) when danger is sensed.

Once the human has moved a safe distance away, the robot will resume working at its normal pace without the need for a re-start.

Driving Humans and Robots Together

Why the need for such close interaction between humans and robots? It’s all part of the evolution of the modern supply chain and the never-ending battle to improve productivity. The considerations are both practical and economic.

It is well-established that robots are the best choice for large-volume, repetitive tasks where they can do 90% or more of the work. When there are no decisions to be made, no criteria to be considered other than what was pre-programmed, robots can deliver significant labor savings.

In situations where robots can only perform 80% of the work, however, the economics break down. If a human operator needs to get in and out quickly to handle the other 20%, the difficulties with implementing a safety system can negate any savings from using robots and may even drive the total cost higher.  

As a result, robotics applications are usually all or nothing.

A 2007 study by NASA’s Ames Research Center bears out the value of humans and robots working together. The pilot project, which focused on extravehicular tasks, found that a team of humans and robots could accomplish more work than either a team of humans or a team of robots working without the other.  

Another factor driving the need for humans and robots to work in closer proximity is simplifying the design of the facilities themselves.

Traditionally, the incorporation of robotics requires re-thinking floor plans and a certain amount of planning around the technology. In other words, because of safety considerations the technology often dictates the workflow and use of floor space, which can reduce the overall benefit of adding robotics to the facility.

If safety is intrinsic to the robots, however, facility designs can be based purely on productivity considerations, optimizing them to deliver the highest output per square foot.

The use of multiple robots to perform the same task can further complicate matters if a physical safety barrier must be employed. The difficulty of breaking down and re-establishing the barriers can limit the flexibility of the system.

Take a linear palletizing system, for example. Suppose there are five robots working on the system and each is enclosed in a physical barrier safety system.

In this case the robots can only service the lines within the physical barrier. If the safety system is intrinsic to the robots, however, they can be dynamically allocated depending on the current production workload.

Additionally, if one robot were to go down for some reason, the others could be re-allocated to take on a portion of the work of the one that’s down until it is operational again.

Asimov’s vision of humans and robots working side-by-side is no longer the stuff of science fiction. In the supply chain, it’s science fact.

Replacing bulky physical barriers with new technologies that make safety intrinsic to the robot not only protects operators and other workers more effectively – it improves productivity. All while allowing the use of robots in situations where it was once cost-prohibitive, helping drive down overall costs while delivering greater ROI on those units.

Humans and robots unite!

Tim Criswell is president, Wynright Robotics at intelligent material handling systems provider, Wynright Corporation.

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