Collaborative Robots: How Cobots Are Transforming Industry

Table of Content

• What Are Collaborative Robots?
  
• How Do Collaborative Robots Work?
  
• Four Common Collaborative Robot Operating Methods
  
• ISO/TS 15066 and Collaborative Robots
  
• Why Safety Is Important With Collaborative Robots
  
• Risk Assessment for Collaborative Robot Applications
  
• Applications of Collaborative Robots
• Benefits of Collaborative Robots
• Collaborative Robots vs Traditional Industrial Robots
• How to Choose a Collaborative Robot
• Frequently Asked Questions
• Conclusion

Collaborative robots, commonly called cobots, are robotic systems designed to perform tasks in environments where humans and robots may work in proximity. Unlike traditional industrial robots that often operate inside dedicated safeguarded areas, collaborative robots are designed with features that can support certain human-robot interactions. These systems are increasingly used for assembly, machine tending, inspection, packaging, material handling, and other repetitive manufacturing tasks. However, calling a robot "collaborative" does not automatically mean that it is safe for every situation or application. Proper risk assessment, system design, safeguarding, and compliance with relevant standards are essential. ISO/TS 15066 collaborative robots guidance is particularly important when designing and evaluating collaborative robot applications.

What Are Collaborative Robots?

Collaborative robots are robots designed to operate in applications where human workers and robotic systems can interact more closely than they typically would with conventional industrial robots.

The word "collaborative" refers to the intended application and interaction between humans and robots. It does not simply describe the physical appearance of the robot.

Traditional industrial robots often operate at high speeds and may be separated from workers using fences, guards, scanners, interlocks, or other protective systems. Cobots, on the other hand, can incorporate technologies such as force and torque sensing, speed monitoring, collision detection, and controlled movement to support specific collaborative applications.

A typical collaborative robot may include:

•  Robotic arm: Provides movement and positioning.
•  Sensors: Detect force, torque, position, or environmental conditions.
• Controller: Processes inputs and controls robot movement.
• End effector: Performs the actual task, such as gripping, fastening, or handling.
• Safety functions: Help manage speed, force, separation, or unexpected contact.

How Do Collaborative Robots Work?

The operating principle of collaborative robots is similar to that of other programmable robots: software controls the robot's movements based on predefined instructions and inputs from sensors.

What distinguishes a collaborative application is the way the robot interacts with people and the surrounding workspace. For example, a cobot may perform a repetitive pick-and-place operation while an employee performs another step nearby. Depending on the risk assessment and system design, the robot may operate at a controlled speed and use safety functions to respond to human presence or unexpected contact.

Several technologies can support collaborative operation.

1. Force and Torque Detection: Force sensing can help a robot detect unexpected resistance. If the robot encounters an abnormal force, its control system may trigger a protective response.
2. Speed and Separation Monitoring: Some applications monitor the distance between the worker and robot. The robot can reduce speed or stop when a person enters a defined area.
3. Safety-Rated Monitoring: Safety-related control systems can monitor defined operating conditions and initiate protective measures when required.
4. Controlled Robot Movement: Robot speed, movement limits, workspace restrictions, and programmed paths can be configured according to the application risk. These features are not substitutes for a proper safety assessment. The complete application must be evaluated.

Four Common Collaborative Robot Operating Methods

Collaborative applications are often discussed through different modes of human-robot interaction. The appropriate method depends on the task and risk assessment.

1. Safety-Rated Monitored Stop: The robot stops when a person enters a defined collaborative workspace. The worker can then perform an activity near the robot while it remains stopped. After the person leaves the relevant area, the robot can resume operation according to the system's safety design.
2. Hand Guiding: In hand-guiding applications, an operator can physically guide the robot using an appropriate control device or interface. This can be useful for teaching robot positions or performing certain controlled material-handling tasks.
3. Speed and Separation Monitoring: The system monitors the distance between the human and robot. As the worker approaches, the robot may reduce speed or stop according to the safety configuration. This method can be useful in workspaces where humans and robots need to move around the same general area.
4. Power and Force Limiting: The robot is designed and configured so that certain physical contact conditions remain within defined limits. However, this does not mean that any contact is automatically harmless. The robot, tool, workpiece, speed, movement, and application must all be evaluated.

ISO/TS 15066 and Collaborative Robots

The term iso/ts 15066 collaborative robots is commonly associated with ISO/TS 15066, a technical specification developed to provide guidance for collaborative industrial robot systems.

ISO/TS 15066:2016, titled Robots and robotic devices — Collaborative robots, provides guidance related to collaborative industrial robot systems and supplements the safety requirements established in ISO 10218.

One particularly important aspect of ISO/TS 15066 is its consideration of human-robot contact and biomechanical limits. The specification provides information that can be used during risk assessment and collaborative application design.

It is important to understand that ISO/TS 15066 collaborative robots does not mean that every robot marketed as a cobot automatically complies with every safety requirement. Compliance concerns the complete application and its design, installation, operation, and risk controls. Manufacturers and integrators should consult the current applicable standards and regulations for the specific application.

Why Safety Is Important With Collaborative Robots

The biggest misconception about collaborative robots is that they are inherently safe simply because they are called cobots.

A collaborative robot can still cause injury depending on:

• Robot speed
• Payload
• Robot configuration
• Tool design
• Workpiece shape
• Sharp edges
• Pinch and crush points
• Workspace layout
• Human position
• Programming
• Unexpected robot movement
•  External equipment

For example, a robot arm may have force-limiting features, but a sharp gripper or heavy workpiece can introduce additional hazards. This is why the complete robotic cell must be evaluated rather than looking only at the robot arm.

Risk Assessment for Collaborative Robot Applications

Before deploying collaborative robots, manufacturers should identify potential hazards and determine how those risks can be controlled.

A typical assessment considers:

1. Robot characteristics: speed, payload, reach, force, and movement.
2. End effector: gripping force, shape, sharp edges, and moving parts.
3. Workpiece: weight, temperature, shape, and surface characteristics.
4. Human interaction: how frequently workers approach the robot and what tasks they perform.
5. Workspace: surrounding machines, tables, conveyors, and restricted areas.
6. Operating conditions: normal production, maintenance, setup, and abnormal situations.
7. Protective measures: safety-rated stops, monitoring, guarding, reduced speeds, or other controls.

Applications of Collaborative Robots

The flexibility of collaborative robots makes them useful across many industries.

• Assembly: Cobots can assist with repetitive assembly operations such as component placement, fastening, and part handling. They can perform repetitive movements while workers handle tasks requiring dexterity or decision-making.
• Machine Tending: A cobot can load and unload components from machines such as CNC equipment. This can reduce repetitive manual handling and allow operators to focus on programming, inspection, or multiple machines.
• Packaging: Cobots can pick products, place them into containers, and perform repetitive packaging operations. Their programmability can be useful when manufacturers handle multiple product variations.
• Quality Inspection: With cameras and other sensors, collaborative systems can support inspection processes. The robot can position a component while a vision system checks specific characteristics.
• Material Handling: Cobots can move parts between workstations or position components for subsequent production stages. The exact payload and workspace requirements determine whether a collaborative robot is appropriate.

Benefits of Collaborative Robots

• Flexible Deployment: Cobots can be easier to integrate into certain production environments than large traditional robotic cells, although the complexity depends on the application.
• Reduced Repetitive Work: They can handle repetitive tasks that may otherwise require workers to perform the same movement throughout a shift.
• Support for Small-Batch Production: Because many cobots can be reprogrammed for different tasks, they may be useful in manufacturing environments with changing product requirements.
• Improved Ergonomics: Moving repetitive lifting, reaching, or handling activities to a robot can potentially reduce physical strain on workers when the application is properly designed.
•  Human-Robot Collaboration: The main advantage is the possibility of combining robotic repeatability with human skills such as judgment, adaptability, problem-solving, and dexterity.

Collaborative Robots vs Traditional Industrial Robots

Feature	Collaborative Robots	Traditional Industrial Robots
Human proximity	Designed for certain collaborative applications	Often separated by safeguarding
Typical setup	Flexible	Often dedicated
Programming	Often designed for easier interaction	Can require specialist programming
Payload	Commonly lower, application-dependent	Can be very high
Speed	Often constrained in collaborative modes	Can operate at high speeds
Flexibility	High in many applications	High but often optimized for specific processes
Safety assessment	Essential	Essential

How to Choose a Collaborative Robot

Businesses considering collaborative robots should begin with the application rather than the robot brand.

Ask the following questions:

●       What task needs to be automated?

●       What is the required payload?

●       How much reach is required?

●       What cycle time is expected?

●       Will people work near the robot?

●       What end effector will be installed?

●       What hazards are associated with the workpiece?

●       What safety functions are required?

●       How easily must the robot be reprogrammed?

●       What training and maintenance support are available?

A proper evaluation can help determine whether a cobot, traditional industrial robot, mobile robot, or another automation solution is the best choice.

Frequently Asked Questions

1. What are collaborative robots?

Collaborative robots are robotic systems designed for applications where robots and humans may interact in proximity under defined safety conditions.

2. What is ISO/TS 15066?

ISO/TS 15066 is a technical specification that guides collaborative industrial robot systems and supplements relevant robot safety requirements.

3. Are collaborative robots completely safe?

No. A cobot is not automatically safe for every application. The complete robot system, tooling, workpiece, workspace, operating conditions, and safeguards must be evaluated.

4. What are cobots commonly used for?

Common applications include assembly, machine tending, packaging, inspection, material handling, and other repetitive manufacturing operations.

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

A cobot is designed for certain human-robot collaborative applications, while conventional industrial robots are often operated in safeguarded areas. Both require appropriate safety measures.

Conclusion

Collaborative robots are changing how manufacturers approach automation by creating opportunities for humans and robots to work in closer proximity within appropriately designed applications. Their flexibility, ease of programming, and ability to handle repetitive tasks make them valuable for manufacturing, assembly, packaging, inspection, and machine tending. Understanding iso/ts 15066 collaborative robots guidance and applying appropriate risk-assessment principles can help manufacturers design safer and more effective robotic applications. As sensing, AI, machine vision, and control technologies continue to advance, collaborative robotics is likely to become an increasingly important part of flexible and human-centered manufacturing.