collaborative robot (cobot)

What is a collaborative robot (cobot)?

A collaborative robot, also known as a cobot, is an industrial robot that can safely operate alongside humans in a shared workspace. In contrast, autonomous robots are hard-coded to repeatedly perform one task, work independently and remain stationary.

Advances in mobile technology, artificial intelligence (AI), machine vision, cognitive computing and touch technology are making it possible for small, lower-power robots to be aware of their surroundings and perform multiple types of tasks safely in close proximity to human workers. In addition to being programmed to protect the safety of their human coworkers, cobots can quickly learn tasks through demonstration and reinforcement learning.

Cobots frequently carry out manufacturing-related tasks, including assembly, packaging automation, material handling, machine tending and product quality control.

Due to shortages of qualified workers and increasing labor costs, the market for cobots continues to grow. According to Maya Xiao, a senior analyst with Interact Analysis, the global collaborative robot market is set to grow 20-30% annually between 2025-2026.

What makes a cobot safe?

Unlike typical industrial robots, which are often confined to safety cages and can only work on preprogrammed tasks, collaborative robot systems are designed to work safely in close proximity to human operators. This enables a more flexible, secure and adaptable industrial environment.

Cobots are equipped with software-controlled sensors that enable them to detect objects, people and potential collisions. The software monitors every movement of a cobot and immediately shuts it down if it detects something unexpected. The majority of industrial cobots are power and force limitation (PFL) cobots, which means that in the case of an unexpected collision, their built-in sensors can identify when abnormal force is applied, causing the cobot to either slow down or cease operating to prevent accidents and injuries. Usually, the edges of these cobots are rounded to mitigate any potential collisions with human workers.

Additional methods to minimize dangers can include camera vision, torque sensors, laser scanners, LED and audio feedback, and machine learning-enhanced pattern recognition.

Types of cobots

According to ISO 10218, from the International Organization for Standardization, there are the following four types of cobots:

Power and force limiting. Built to reduce the risk of injury, these cobots are restrained in the amount of force they can exert on their environment. They're built with rounded corners and no sharp edges because they're designed to work alongside humans without additional safety measures such as barriers, vision systems or external scanners. These cobots further improve human safety by not having exposed motors or pinch points where a person or part of their body could get caught.

Because of their built-in intelligent collision sensors, these collaborative cobots automatically stop working when they come in contact with a human coworker. They're typically more flexible but also smaller, slower and less powerful than conventional robots.

Safety-rated monitored stop. These cobots employ sensors to detect the presence of human beings and automatically stop working when a worker enters a predefined area. The human workers can resume the cobot's operation with the push of a button.

These cobots are ideal for industrial tasks requiring help with little human involvement. They employ a variety of safety sensors in addition to stopping the cobot when it gets too close to its human coworker.

Hand guiding. These cobots enable operators to physically guide them through a task. For example, the programmer can show the cobot how to complete the tasks by guiding it with their hand. With this function, it's simple to reprogram the cobot without having to change the software. These cooperative cobots have a short learning curve, which reduces downtime.

Speed and separation monitoring. These cobots employ sensors to keep a safe distance from human workers and have features comparable to the safety-rated monitored cobots. But these cobots have more advanced features. For instance, a machine vision system continuously monitors its two operational zones -- the warning zone and the stop zone. When it notices motion in close proximity to the warning zone, the cobot's vision system slows it down to a safe speed. The cobot promptly stops working when a person enters the stop zone and resumes once the person has left the area.

What is the difference between a cobot and an industrial robot?

Industrial robots and cobots have many similarities as well as some unique features. The primary features and variations between a cobot and an industrial robot are as follows:

• Industrial robots are intended to work independently, while cobots are designed to collaborate with humans.
• Unlike industrial robots, which are built for speed and accuracy in repetitive tasks, cobots are outfitted with a variety of sensors and safety features to ensure they can interact with people safely.
• The design of a cobot is more lightweight and flexible than traditional industrial robots, which are generally larger and more powerful than cobots.
• Cobots are frequently employed for tasks such as assembly line, packaging and Quality control. Industrial robots are typically designed to perform specific tasks in a highly structured, automated environment.
• Unlike cobots, industrial robots are usually caged off to prevent humans from entering the workspace while the robot is in operation.
• The majority of industrial robots are autonomous, large and expensive. Usually, smaller businesses gain more from a cobot's flexibility and cost-effectiveness.

Although industrial robots play an important role in the automotive industry and its suppliers, their high cost, large size, weight and complex programming requirements have limited their use in other vertical industries.

Another barrier to adoption is the cultural fear of robots dominating the workplace and replacing human employees. Cobots are purposely designed to address this fear. A collaborative robot is intended to augment the human worker's capabilities, not take their place. In many cases, the cobot takes the form of a robot arm, providing the worker with an extra set of hands.

Use cases of cobots

Cobots are used in numerous applications and sectors around the world. The following are the four most common applications of cobots:

• Assembly. Cobots are used during accurate and repetitive assembly processes such as screwdriving, part fitting and insertion.
• Dispensing. By using torque sensing, cobots can be used for dispensing projects such as gluing, sealing and painting. This helps reduce waste and increases the accuracy of dispensing.
• Finishing. With force control that automatically adjusts to the required force, cobots ensure consistent polishing, sanding and buffing of materials.
• Machine tending. Cobots are used for machine-tending projects, including computer numerical control (CNC), injection molding and in-circuit-testing, which checks each component individually for damage.

Which industries use cobots?

Cobots generally have lower power requirements than their larger, autonomous counterparts, are often mobile and use collision detection to prevent injury to their human colleagues and other cobots.

Cobots are typically used in the following industries:

• Electronics.
• Automotive.
• General manufacturing.
• Supply chain management.
• Healthcare.
• Plastics.
• Food and agriculture.
• Furniture and equipment.
• Scientific research.
• Pharmaceutical.
• Packaging and co-packaging.
• Metal fabrication.

Popular robotics providers and cobot manufacturers include FANUC, Yaskawa Electric Corp., Universal Robots, KUKA, Rethink Robotics and Techman Robot.

Benefits of cobots

Cobots enhance the work environment for people and offer a range of advantages for industrial and manufacturing applications. The following are the most common benefits of cobots:

• Human worker safety. Cobots can perform dangerous and repetitive tasks that can otherwise be unsafe or difficult for human workers. Common examples include welding, soldering, working with chemicals, foundry work or lifting heavy objects.
• Flexibility. Cobots are highly adaptable and can be quickly programmed to perform new tasks. Typically, a human worker uses a human-machine interface attached to a mobile tablet to reprogram the cobot as needed. This reduces downtime and improves flexibility.
• Accuracy. Cobots consistently operate with the same amount of force and in the same manner. This guarantees that parts are of identical quality, accurate and positioned correctly.
• Increased productivity. Since boring, dangerous and repetitive jobs are usually assigned to cobots, they can be completed quickly, which increases productivity.
• Reduced production costs. Cobots are designed to streamline and optimize processes in production environments, which ultimately improves the bottom line.

Limitations of cobots

Cobots also have the following drawbacks:

• Lower payloads. Cobots normally carry payloads of 6 to 22 pounds, while some variations may be able to handle up to 78 pounds.
• Human dependency. A cobot can theoretically operate around the clock but it still needs human supervision or assistance at times. Industrial robots, on the other hand, can operate to capacity without the need for human intervention.
• Limited speed. Since a cobot's primary goal is safety, speed is secondary, especially when additional safety precautions are adopted. The average cobot moves at 250 millimeters per second, which is four times slower than a conventional industrial robot. The cobot slows down when users engage with it in order to maintain safety, but this increases cycle time. As a result, cobots often aren't suggested for applications that require speed.
• Safety clearances. Getting a safety clearance for a cobot can be challenging. Along with meeting safety regulations, relocating a cobot and changing its tasks or its tool set often requires additional safety accreditations. Cobots marketed in the European Union (EU) must be approved by a notifying body as part of the CE-marking procedure that attests a product complies with EU environmental, health and safety standards, thereby guaranteeing consumer safety. For instance, adding a new gripper with pointed edges requires modifying the cobot's original goal. Due to the need for additional safety authorization, the organization may incur time and cost.

How to program a cobot

Traditional robots require expensive labor because the programming is normally carried out by professional robotics engineers. A cobot is significantly simpler to program because it doesn't require specialist programming knowledge and can be programmed without the need for a robotic integration company. This also keeps the deployment cost of cobots to a minimum.

Drag-and-drop programming, where a user's actions are translated into code, is the simplest method of programming a cobot. Simply dragging and dropping the action the user wants the cobot to perform in the proper order completes the task. For certain cobots, users can sketch the general layout of the program using simple buttons to steer the robot toward program points or tasks. Either method is easy to learn and enables more workers to interact with the robot in a useful way. Some cobot manufacturers go beyond the straightforward programming approach by providing application wizards, which can simplify a difficult operation such as setting up an end-of-line palletizing robot so that it takes less time.

Because collaborative robots are easier to program, people can autonomously install and maintain them as well as reuse them for new tasks as industrial processes evolve.

How much does a cobot cost?

The price of cobots varies according to the maker, the functionality, features and the end-of-arm tooling used. When considering the use of a cobot in manufacturing, an organization should determine the precise ROI that justifies the expense.

Cobots typically cost between $10,000 and $50,000 USD. When selecting a platform, the cobot's manufacturing quality should also be considered because the additional tooling will increase the cost.

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