Collaborative Robot Safety
Collaborative robots (cobots) arrived on the market in 2008 and are expected to continue grow at explosive rates. They provide the operator with direct access and interaction during operational conditions. This union of man and machine on the production line complements the specific and unique abilities of each, while also providing increased flexibility and productivity.
Cobots also open the work area with the removal of safety barriers such as fencing, scanners, and light curtains in order to enable human and robots to work more closely together. This will help to improve application functionality and cut down on the amount of space necessary for a robotic unit.
Furthermore, collaborative robots are becoming cheaper while simultaneously advancing in their capability and ease of integration. Automated production lines are quickly realizing that integrating collaborative robots alongside their industrial robots will help them stay competitive on a global level.
So how do we ensure that the cobots are safe with such close interaction with humans?
The introduction of a technical specification for collaborative robots, ISO/TS 15066: 2016, created the opportunity for safe human and robot system interaction in industrial settings. ISO/TS 15066 provides specific, data-driven safety guidance to help evaluate and control risks. It's basic premise is if there were any accidental contact between man and machine, no pain or injury should result.
These regulations combined with quickly advancing technology creates the perfect team of power, precision and human's unique problem-solving ability. ISO/TS 15066 will help to provide measures of safety during the development and use of collaborative robot systems.
Setting the Foundation with ISO/TS 15066
When designing a collaborative work space, ISO/TS 15066 provides guidelines that include: Definitions, Important characteristics of safety control systems, Factors to be considered in the design of collaborative robot systems, Built-in safety-related systems and their effective use, and Guidance on implementing the following collaborative techniques: safety-rated monitored stop; hand guiding; speed and separation monitoring; power and force limiting.
Studies were conducted on pain thresholds for different parts of the human body which helps to implement collaborative power and force-limited robot applications. Cobots can detect nonstandard activity and limit its force accordingly using the force sensors in their joints. This provides the opportunity for robots to operate at full speed without any apprehension of human injury.
They rely on artificial intelligence to make sense of the environment with machine vision or sensor systems. The senses often involve a single visual sensor such as a camera, laser, or infrared sensor that constantly conduct a speed and separation monitoring. They can detect their 360-degree environment and slow down or stop once the worker is in a certain area or space.
Human and robot system collaboration safety is further enhanced through speed and separation monitoring techniques. There is a minimum required safety distance and maximum allowed speed between the robot system and the person. This specification has required innovation in improved motion control, development of new robot covering materials, and better sensors.
Furthermore, sharp edges and protrusions must be minimized on the entire system to avoid injury if a collision were to occur if the robot system was accidentally impacted by a human.
Collaborative robots are key players in a wide range of applications such as packing, quality testing, material handling, machine tending, assembly, welding and others. The material handling industry is seeing the fastest integration of collaborative robots.
Solutions using Cobots
Collaborative robots are reducing initial integration time as the quickly advancing technology is creating a quicker and easier to program robot. This also enables them to be moved from one work assignment to another with great ease. For instance, a cobot can be fitted with suction cups for the unpacking of infant formula and then a few hours later be switched to working with boxes of spaghetti.
These collaborative robots can also accomplish tasks such as lifting and holding a part while it is being installed or worked on by a human worker. A worker on an assembly line can increase his/her efficiency by teaching the cobot different ways to conduct the job.
Human workers can also guide robots and resolve technical hiccups that would normally stop operations, enabling a faster and better end result. They can continue to control and monitor the production process while enabling the robot to perform the physically strenuous work and reduce the risk of injury.
Cobots truly provide the perfect solution for tasks that require a combination of manual work and automation where it is important for a worker to see, feel, and react as needed while the cobot handles the physically taxiing work.
These collaborative robots are very efficient, user-friendly, and provide a great value to replace the boring and repetitive tasks while also providing for a very nice return on investment. The manufacturing paradigm is shifting, proving that manufacturers are desiring the added flexibility and ease that collaborative robots can offer.
If you are interested in learning more about the collaborative robots, then contact RobotWorx experts. We are integrators for a variety of robots for Fanuc, Motoman, Universal Robots, KUKA, and ABB. Our staff will work with you to help you design and build the best robotic system for you and your facility.