Tag Archives: Cobots

How Good are Cobots at Welding?

The manufacturing industry has been using robots widely for several years as a replacement for the human laborer. Recent advances in this field are the Cobots or collaborative robots. They are called collaborative as their design makes them work alongside an individual as a part of a team rather than replacing the humans.

Cobots are good at operations and activities that cannot be fully automated. However, the process speed does not improve for activities such as workers ferrying parts backwards and forwards between themselves on the assembly line with the robots locked away in cages.

Manufacturers such as Ford are already on the cobot bandwagon, and the new robots could transform the way the industry works. The Ford factory has collaborative robots installing shock absorbers on vehicles on the production line along with humans. The cobots work with accuracy and precision, boosting the human productivity, while saving them valuable time and money.

At present, the industry uses four main types of cobots. They are the Safety Monitored Stop, Speed and Separation Monitoring, Hand Guiding, and Power and Force Limiting.

The Safety Monitored Stop is a collaborative feature used when the cobot works on its own, but sometimes needing assistance from an operator. For instance, in an automated assembly process, the worker may need to step in and perform an operation on a part that the cobot is holding. As soon as the cobot senses the presence of the human within its workspace, it will cease all motion until the worker leaves the predetermined safety zone. The cobot resumes its activities only after receiving a signal from its operator.

Speed and Separation Monitoring is similar to the Safety Monitored Stop, with the cobot operating in a predetermined safety zone. However, this cobot’s reaction to humans is different. The Cobot will not automatically stop because of the human presence, but will slow down until its vision detection system informs it of the location of the person or object. The Cobot stops only if the person is within a predetermined area, and waits for the proximity to increase before resuming its operations. This cobot is useful in areas with several workers are present, at it requires far fewer human interventions.

Although a Hand Guiding cobot works just as a regular industrial robot does, it has additional pressure sensors on its arm device. The operator can therefore teach the cobot to hold an object hard enough and to move it fast enough without damaging the object, while securely working with it. Production lines that handle delicate components find Hand Guide cobots very useful for careful assembly.

Power and Force Limiting cobots are among the most worker-friendly machines. They can sense unnatural forces in their path, such as humans or similar objects. Their joints are programmed to stop all movement at such encounters, and even reverse the movement.

As many skilled workers retire, and replacements are rare, the American Welding Society is working with Universal Robots, to produce a new attachment to their UR+ line of cobots with welding capabilities. The robot moves along the start and stop path of the desired weld, and welds only the specified stitch areas.

What Are The Cobots?

When inventors Joseph Eagleburger and George Devol were discussing about science fiction novels in 1954, they initiated the idea of industrial robots. It took them six years to give shape to their idea and Unimate entered a secure place in the robotic hall of fame, as the world’s first industrial robot. In 1961, Unimate began working on the assembly lines of the General Motors.

At first, people looked on with suspicion on the safety issues related to Unimate. At the time, the only reference people had for robots, was the laser-firing robot from “The Day the Earth Stood Still,” a thriller from the 1950s. Now, 50 years hence, industrial robots are far less scary.

Traditionally, robots were constructed to work under restriction inside robotic work cells with physical barriers for the safety of human workers. However, modern robots work completely outside any cage. On the factory floors today, working safely alongside their human counterparts, you will find unfettered working robots that are termed collaborative robots or cobots. Nevertheless, no robot is entirely devoid of health and safety features.

Unlike in the past, today’s industrial robots or cobots are designed specifically to work safely around humans. In fact, now robots work hand-in-hand with humans on the same assembly tasks and it has been independently certified that this is safe. The two-armed collaborative robot from ABB Robotics, YuMi, contributed largely to this certification.

To prevent accidents with human workers, cobots utilize sensors installed on them. The sensors monitor the location of humans around them on the factory floor and react to human contact. Therefore, even if a person does come too close to the machinery, it simply and automatically shuts down. Moreover, cobots work with strength, speed, and force limited to avoid causing serious injury to humans if there is any contact.

Most cobots are simple enough to require practically no skill in programming them. Anyone, who can operate a smartphone, can program them to operate. In contrast, complex robots of about a decade ago needed a host of highly skilled technicians to program and monitor them while in operation.

Among the industries that are being transformed by such collaborative machinery, the most to benefit is the automotive industry. As such, this sector has always been at the forefront of industrial robotics. Automotive manufacturers have been using robots and robotic equipment since the 1960s, but a lot has changed since then. The competitive nature of the industry forces manufacturing lines to be highly efficient, flexible and more productive than ever before.

Not that all this means any advancement in robotics is a threat to human jobs on the production line. For instance, builders use a concrete mixer to help the bricklayer and not to replace him. In the same way, collaborative robots only assist workers on the assembly line and do not actually replace them. According to some experts, production line workers will ultimately use collaborative robots as helpers in the same way as engineers use computers to further their own work and make their jobs easier.