A cobot or co-robot is a collaborative robot that is intended to work and interact with humans in a shared work space. Whereas robots work autonomously to complete tasks, cobots are able to interact with humans to complete tasks harmoniously.
Cobots were initially developed without motive power to provide a safe work environment with humans, but have since been evolved to use limited motive power without posing a threat to workers in a shared space.
Some general characteristics of cobots include:
- Safe to work directly with humans in the same space
- Awareness of their surroundings
- Easily trained to learn and complete complex tasks
- Adaptable to variable conditions
Cobots have evolved using advanced sensors and servo drive technology to adapt to obstacles in their path. Even if an object is slightly out of place, a co-robot can usually adapt by locating and identifying the object, picking it up, and continuing to use it.
Today’s cobots encompass a very tiny footprint in the factory or work area. Many manufacturers have begun to incorporate cobots into assembly lines to pick and place objects, as well as provide quality control. In large part, cobots have been used to automate repetitive and mundane tasks, ones that humans may tire of quickly.
Of course, cobots can also be used for more advanced applications, including difficult tasks such as mixed-part assemblies and heavy lifting.
Cobots are especially useful for short production runs and situations where there is high variability in setup configurations. A cobot's adaptability can significantly reduce cost when compared with more rigid solutions.
Cobots are Growing in Usage
Via the Robot Report: "The collaborative robot market is expecting an incredibly high growth rate over the next few years. It is expected to grow at a compound annual growth rate of 60.04% between 2016 and 2022, from 110 million USD in 2015 to 3.3 billion USD in 2022.”
Once the fancy of science fiction, now cobots are starting to become a profitable solution across many industries. According to statistics from the Robotic Industries Association, orders for cobots rose by 32% between 2015-2016 in the food industry alone.
Typical Servo Drive Requirements for Cobots
For this reason, ADVANCED Motion Controls® has created sophisticated servo drives well-equipped to support cobot systems and increase their efficiency.
For the sake of safety and efficiency, the cobots need to be able to do their job correctly at all times, which means the servo drives within them need to be trusted to deliver consistent performances. Customers choose AMC because of the reputation we've built for product reliability.
Servo drives embedded into the joints of arms and feature a small design that reduces the size of the casing while retaining the necessary power and precision. AMC's FlexPro™ digital servo drives are designed with compact form-factor and high power density in mind; they have a 1.5"x1" footprint (1/3 the size of a standard business card) while still outputting 25 amps continuous. In other cases custom servo drives can also be created to fit snugly within a cobot arm regardless of shape, including those that utilize FlexPro's IMPACT™ architecture.
In such a small and closed-off space, however, it's important that the servo drives in cobots have good thermal management capabilities to prevent any damage to themselves or other components from overheating. Efficient components should be used in the drives to reduce the thermal output. In addition, equipping servo drives with heat sinks that can be mounted to the inside of the arm frame can improve the heat transfer out of the internal system.
A cobot's operation of course requires that the movement between joints is coordinated. This means each drive needs to be connected to a central controller, or the drives can be linked together via some sort of network field-bus, such as CANopen® or EtherCAT®. When using a network, pass-through connectors allow signals to reach components along the arm through a single pathway, greatly reducing the amount of wiring. AMC supports CANopen, EtherCAT, Modbus®, Ethernet/IP™, Ethernet Powerlink, and RS-232/485 network configurations.
Servo drives in cobots will often rely on absolute position feedback so that the they can immediately determine the position of the joints on power-up. This is far preferable to using relative feedback, since the rotations of every joint performing homing routines could be hazardous to other equipment or humans in the immediate vicinity. ADVANCED Motion Controls has servo drives that can use Biss-C, Hiperface, and EnDat absolute feedback protocols.
Dual-Loop Position Control
While not necessarily a requirement, servo drives using dual-loop position control are able to process position feedback on both the joint motors and the load to eliminate errors caused by backlash or flexing. This enables cobots to become more adaptable and precise, thus increasing its ability to collaborate on tasks in real-time.
As cobots grow in popularity and sophistication, ADVANCED Motion Controls has developed sophisticated servo drives able to assist cobots in precision based operations, all while keeping size, power, and thermal management in mind.
For additional information about the use of cobots for servo drives, contact us today
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May 6th, 2020 - added links to the subsequently published Position Feedback and Dual-Loop Position Control blogs, rewrote Servo Drive Requirements to include FlexPro.