Industrial robots have been characterized by high price tags and significant integration requirements. However, an emerging class of robots lowers throughput but provides the distinct advantage of being able to be co-located with human workers. They are also less expensive and require little to no integration or programming.
This new breed of “collaborative robots” cannot compete with traditional robots based on ultimate speed or precision, but they can work safely alongside humans ungated. Such human-assisting robots are, by design, low-speed and low-skill but perform cooperative tasks with human workers directly alongside them, performing tasks such as picking and placing.
Due to their significantly lower prices and integration requirements, these robots are now true options for small- and medium-sized businesses with limited automation skills and budgets. In the mobile solutions space, robots are gaining traction against traditional automated-guided-vehicle (AGV) and fixed-conveyor solutions. Along the spectrum of autonomy, solutions range from one supplier’s coordinated robotic fleet to another’s driverless forklifts.
This expansion of the robotics industry also increases acceptance of automation and new technology into previously untapped and sometimes more resistant or less skilled markets. A key selling point for these new classifications of robots is that they do not require significant integration, enabling users to be trained on these typically out-of-the-box solutions in a matter of days as opposed to months.
Safety standard compliance
In the past, serious safety concerns limited acceptance of this type of technology, but the industry is rapidly embracing a more modern, effective safeguarding strategy that evaluates the use of equipment from a task-oriented perspective (i.e., how the operator has to interact with the machinery). This approach lends itself to the use of an integrated system solution that relies on intelligent automation components. It minimizes the risk of operator injury to a tolerable level in specific operational modes of the machine, while allowing the operator to work more efficiently than would be possible using absolute safety measures such as physical guards and interlocks.
Modern safety systems let operators and maintenance personnel access an operating machine’s work zone by setting programmable limits on actuator speeds, forces and torques to mitigate the risk of injury from these devices. Studies performed in Sweden and Japan justify this approach.
These studies concluded that many robot-related accidents do not occur under normal operating conditions but rather during programming, maintenance, repair, testing, setup or adjustment. In most instances, work procedures required the operator or maintenance worker to temporarily enter the robot’s working envelope, where unintended operations could result in injuries. Perimeter guarding or light curtains are temporarily overridden, exposing the worker to possible injury as he enters the work zone while the machine is still operational.
Respecting behavior of personnel
In contrast, a modern safety approach respects the behavior of factory personnel and implements safety solutions that allow safe access to work zones. This approach enables significant improvements in manufacturing productivity and expands the market for the new breed of robotic solutions.
The Robotics Industry Association is in the process of revising the ANSI/RIA R15.06 standard to recognize a class of robots defined as “collaborative robotic systems.” To achieve this, the standard has adopted the safety standards developed for ISO 10218, in which risk assessment is graded on performance levels as outlined in the ISO 13849 machine safety standard.
Collaborative robot capabilities have been modified significantly to comply with the safety standards that address environments in which robots work in conjunction with humans. Lower speeds and lighter loads, for example, have reduced forces to within tolerable limits of the safety standards, and bump sensors or vision sensors have been incorporated to avoid or mitigate collisions.
The innovations emerging from a new breed of suppliers challenge our traditional view of robotic applications. Clearly, robots can no longer just be considered for repetitive tasks. Manufacturers need to evaluate the use of robotics in applications that can benefit from dynamic decision making and autonomous behavior.
>> David Lavieri, [email protected], is a research analyst with ARC Advisory Group. Reports on a variety of topics are available at www.arcweb.com.
