Collaborative robotics: How to integrate cobots in the workplace

Introduction

Collaborative robotics, or cobots, is a revolutionary advancement in industrial automation that enables harmonious collaboration between humans and machines. These machines operate closely near to humans, responding to their presence and ensuring safety through advanced sensor technology and adaptive control systems. Cobots have gained popularity in various industries due to their ability to address modern manufacturing needs, offering efficiency, flexibility, and cost-effectiveness. They are used in automotive assembly lines, electronics manufacturing, healthcare, agriculture, and logistics. The ease of programming, quick deployment, and adaptability of cobots make them an attractive choice for businesses seeking to streamline operations. Integrating cobots into the workplace can significantly enhance efficiency and productivity, freeing human workers from mundane tasks and allowing them to focus on more complex, creative activities. Additionally, cobots reduce workplace injuries due to their safety features. As cobots continue to evolve, their role in modern industries is set to become increasingly pivotal, reshaping the landscape of automation and collaboration in the workplace.

Robot vs Cobot: the distinction that matters in manufacturing

Cobots and industrial robots differ in manufacturing tasks. Cobots are human powered, enhancing efficiency and productivity through strength, power, precision, and data. They assist employees and automate mundane tasks, while industrial robots require complex reprogramming and are often used in heavy-duty manufacturing. Industrial robots may work in assembly in the automotive industry.

Table 1: Comparison of industrial robots and cobots benefits

Figure 1: Industrial robot(Image source)

Figure 2: Cobot working with human(Image source)

Why to integrate cobots in workplace

Integrating collaborative robots (cobots) in the workplace offers numerous advantages over traditional industrial robots. Some of the key benefits include:

1. Enhanced collaboration: Cobots can work alongside human employees, facilitating a safer and more collaborative work environment.
2. Increased flexibility: They are easily programmable and can adapt to different tasks and processes, enabling more flexible production lines.
3. Cost-effectiveness: Cobots are typically more affordable than traditional industrial robots, making automation accessible to smaller businesses and startups.
4. Space efficiency: Their compact size and ability to work in close proximity to humans allow for optimal utilization of workspace and resources.
5. Quick setup: Cobots are designed for easy integration and require minimal programming, leading to reduced setup time and increased operational efficiency.
6. Improved productivity: By automating repetitive and mundane tasks, cobots can significantly enhance overall productivity and output levels.
7. Enhanced safety features: Built-in safety sensors and features enable cobots to detect human presence and minimize the risk of accidents, ensuring a safer work environment.
8. Easy reprogramming: Cobots can be quickly reprogrammed to perform different tasks, enabling businesses to adapt to changing production needs and market demands.
9. Reduced employee fatigue: By handling physically demanding or monotonous tasks, cobots can help reduce employee fatigue and the risk of work-related injuries.
10. Scalability: They allow for easy scalability, enabling businesses to adjust their automation levels as their production needs evolve without significant reconfiguration or additional investments.

Table 1: Comparison table different types of Cobot

And here are some additional technical specifications that might vary across different cobot models:

Table 2: Technical specification of different types of cobot

These specifications can significantly differ among cobot models and manufacturers. They're tailored to suit specific industrial requirements, emphasizing safety, functionality, and operational adaptability in various work environments.

Parts of Cobots

Collaborative robots, or cobots, consist of several components that work together to enable their functionality. Each component plays a crucial role in the robot's operation. Here are the main parts of a cobot along with example products and their specifications, features, functions, and applications:

1. Robotic arm: A robotic arm is a crucial component of a cobot, responsible for tasks like picking, placing, assembling, and manipulating objects. It typically consists of multiple segments, joints, actuators, and end-effectors. The FESTO 8083931 DC Linear Actuator is a compact, precise stepper motor that converts rotational motion into linear motion. Its 35mm size makes it suitable for limited space requirements. The actuator operates at 24 VDC with a current rating of 5.3 A. While not a complete robotic arm, it can be integrated into the arm as a segment or joint, facilitating joint movement, end-effector adjustment, or serving specific tasks like positioning, gripping, or orienting objects.

Figure 3: FESTO 8083931-DC Linear Actuator ELGE Gantry Axis Series(Image source)

2. End-Effector or Gripper: Cobot grippers are versatile tools used in various industries, including transporting hazardous items, small, breakable objects, and delicate items. Magnetic grippers can lift metal items, while vacuum grippers use suction to move cumbersome or oddly shaped items. Soft robotics cobot grippers are gentle enough to be used in production lines with fragile components or products.

Here's a detailed comparison of various types of robotic grippers available for cobots, including their features, functionalities, specifications, and real-world applications, along with a corresponding product from Festo for each gripper type:

Table 3: Types of Cobot grippers

Figure 4: Soft material handling gripper(Image source)

The technologies and gripper systems are highly adaptable and customized to meet specific industry needs, considering factors like object fragility, weight, shape, and production requirements in collaborative robot environments. The below given table provides a comprehensive overview of the technology used in various grippers for handling various materials.

Table 4: grippers for handling various materials

3. Sensors: Vision systems in collaborative robots (cobots) refer to the integration of cameras and sensors that enable these robots to perceive and understand their environment. These systems enhance cobots' capabilities by providing visual feedback, enabling tasks such as object detection, recognition, localization, and quality inspection.

There are several types of vision systems and sensors commonly used in cobots:

• Example: Cognex in-sight 2000 series
• Technical specifications:
• Resolution: 800x600 pixels
• Frame rate: Up to 60 fps
• Communication: ethernet/IP, profinet, TCP/IP
• Features & functionalities: Offers pattern recognition, part positioning, barcode reading, and defect detection.

Figure 5: Cognex in-sight 2000 series vision sensor(Image source)

• Example: Ensenso XR Series
• Technical specifications:
• Technology: Stereo vision
• Resolution: Varies (e.g., 1280x1024 pixels)
• Frame Rate: Up to 30 fps
• Communication: GigE Vision
• Features & Functionalities: Provides 3D point clouds, depth information for object localization, shape recognition, and volume measurement.

Figure 6: Ensenso XR Series 3D camera(Image source)

• Example: Keyence LJ-V Series
• Technical Specifications:
• Measurement Range: Up to several meters
• Accuracy: Sub-millimeter precision
• Communication: Ethernet/IP, Profinet
• Features & Functionalities: Offers precise distance measurement, object profiling, and surface inspection.

Figure 7: High Speed Keyence LJ-V Series Laser sensor(Image source)

• Example: Intel RealSense D455
• Technical specifications:
• Technology: Depth and RGB camera combined
• Resolution: 1280x720 pixels (RGB), up to 640x480 pixels (depth)
• Frame Rate: Up to 90 fps (RGB), up to 90 fps (depth)
• Features & functionalities: Provides color and depth information simultaneously, suitable for gesture recognition, object tracking, and augmented reality applications.

Figure 8: Intel RealSense Depth Camera D435(Image source)

• Example: SICK Ranger E
• Technical specifications:
• Range: Several meters
• Accuracy: Millimeter-level precision
• Communication: Ethernet/IP, Profinet
• Features & functionalities: Detects objects even in challenging lighting conditions, suitable for distance measurement, collision avoidance, and navigation.

Figure 9: SICK Ranger-E40414(Image source)

• Product example: Pilz PSENscan Safety Laser Scanner
• Technical specifications: Safety-rated, configurable warning and safety fields, certified according to safety standards.
• Features: Real-time monitoring, safe zone detection, quick response to hazards.
• Functions: Ensures safe operation around humans, stops or slows down the robot in case of detected hazards.
• Applications: Collaborative robotics, safety-critical environments.

Figure 10: Pilz PSENscan Safety Laser Scanner(Image source)

Each of these sensors has its own technical specifications and features, tailored for different applications within cobots. For instance, 2D cameras excel in tasks like part identification, barcode reading, and surface inspection, while 3D cameras provide depth information crucial for bin picking, assembly verification, and more complex manipulation tasks. Laser sensors, RGB-D sensors, and infrared sensors offer their own unique capabilities suited for diverse industrial applications, enhancing the cobots' ability to interact with their environment safely and efficiently.

4. Cobot Controller: The Omron SmartController EX is a sophisticated and compact controller specifically designed for controlling up to four robots in a collaborative environment. It boasts several technical specifications, features, and functionalities that contribute to its versatility and efficiency in managing cobots.

Figure 11: Omron SmartController EX(Image source)

Table 3 : Omron SmartController EX Technical Specification

The Omron SmartController EX is a robust, user-friendly robot that offers advanced algorithms, real-time processing, and AI integration. Its robust hardware, versatile connectivity options, and user-friendly software make it suitable for various industrial automation applications, enabling efficient control and coordination of multiple robots.

5. Motors: Motors play a fundamental role in the functionality of the robotic arm in a cobot. They are responsible for providing the necessary power and motion to move the various joints and links of the arm. Different types of motors may be used in cobots, depending on the design and requirements:

a. Electric Motors: Electric motors are commonly used in robotic arms due to their controllability, precision, and efficiency. Types of electric motors include:

• DC Motors: These motors convert electrical energy into rotational motion. They are often used for simpler applications in cobots due to their straightforward control and cost-effectiveness.
• Brushless DC Motors (BLDC): BLDC motors offer higher efficiency and reliability compared to traditional brushed DC motors. They are often preferred for more demanding applications in cobots due to their durability and better control.
• Stepper Motors: Stepper motors move in precise increments, allowing for accurate control of position and speed. They are commonly used in cobots for applications that require precise movements, such as in pick-and-place tasks.

b. Servo Motors: Servo motors are highly precise and offer better control over position, speed, and torque. They contain built-in feedback mechanisms (encoders) that enable accurate positioning and movement control. Cobots often use servo motors in joints where precise control and accuracy are crucial.

The motors in a robotic arm are connected to the joints and links, enabling the arm to move in various directions and perform tasks. The control system of the cobot sends signals to these motors, commanding them to rotate or move to specific positions or angles.

Additionally, motors may work in conjunction with gear systems to increase torque or reduce speed, ensuring the arm can handle various payloads and perform tasks with the necessary force or delicacy.

The proper selection and control of motors are essential in cobots to ensure smooth, accurate, and safe operation. The motors allow the robotic arm to execute programmed tasks, interact with its environment, and collaborate safely with humans in shared workspaces.

Figure 12: Trinamic / Analog Devices - Stepper Motor(Image source)

The TRINAMIC / ANALOG DEVICES PD28-3-1021-TMCL stepper motor is a crucial component in cobots, offering high precision and control due to its stepwise motion. Its compact size allows easy integration into cobot structures, while its bipolar configurations provide precise control. The 12 N-cm holding torque ensures stability and accuracy in cobot operations. The motor's 670 mA current rating optimizes performance and prevents overheating or damage. Its single shaft design simplifies assembly and reduces assembly complexity, making it easier to integrate into cobots.

• Refers to the equipment attached to the robot's arm for performing specific tasks.
• Includes various tools such as suction cups, welding tools, and cutting devices.
• Enhances the robot's capabilities for handling different materials and completing diverse tasks.

Figure 13: Different types of EOAT(Image source)

4. Software: Cobot programming software, like UR Software,ABB and Intera Software, is designed to help program and control collaborative robots. These platforms use graphical interfaces, allowing users to program cobots with ease. They offer features like waypoint programming and teach-by-demonstration capabilities, and safety features like collision detection and force-limiting technology. They support various communication protocols and are compatible with different operating systems, multiple robot models, and regular updates. They also offer simulation environments for offline programming, reducing downtime and enabling testing of new tasks before deployment.

Figure 14: Cobot Programming Software(Image source)

Case Studies: Successful Cobots Integration

In the automotive industry, Cobots have been successfully integrated into assembly lines to work alongside human workers. These Cobots are equipped with precision and speed, making them ideal for tasks like spot welding, fastening, and material handling. They are often programmed with high repeatability and accuracy, ensuring the consistent quality of assembled components. These Cobots use advanced vision systems and sensors to adapt to changes in the manufacturing process and collaborate safely with human workers. They can also be equipped with end-effectors tailored to specific tasks, such as grippers for handling car parts or torque sensors for precise fastening. The seamless integration of Cobots in the automotive sector has led to increased productivity, reduced ergonomic strain on workers, and improved product quality.

Figure 15 :Cobots in Assembly Line(Image source)

In the healthcare sector, Cobots are employed to assist with repetitive and physically demanding tasks. These tasks may include patient lifting, medication delivery, or specimen transportation. Cobots are designed to ensure the safety and well-being of patients and healthcare professionals. They are equipped with sensitive force and torque sensors to handle delicate tasks like patient care. Moreover, they can be programmed to work in close proximity to humans, adapting their movements based on human interactions. The integration of Cobots in healthcare settings involves extensive training and programming to meet stringent safety and hygiene standards. The successful deployment of Cobots in healthcare has led to reduced physical strain on healthcare staff, improved patient care, and enhanced operational efficiency.

Figure 16: Cobot in Medical Sector(Image source)

In logistics and warehousing, Cobots are employed to optimize order picking and inventory management. These Cobots are equipped with advanced vision systems and navigation technologies, allowing them to efficiently navigate complex warehouse environments. They can identify and pick items from shelves, transport them to packing stations, and manage inventory levels. Integration with warehouse management systems (WMS) and inventory control software enables real-time tracking and efficient order fulfillment. The success of Cobots in logistics and warehousing hinges on their ability to adapt to changing order volumes and inventory layouts. These robotic systems also play a vital role in reducing errors in order fulfillment, improving inventory accuracy, and increasing the overall efficiency of supply chain operations.

These case studies highlight how Cobots, through their technical capabilities and collaborative features, have been integrated successfully in diverse industries to enhance productivity, reduce physical strain, and improve overall operational efficiency. In each case, the choice of Cobots, their programming, and safety measures are critical technical factors that contribute to their successful integration.

Figure 17 :Cobots on Warehouse(Image source)

Advantages of cobots in Manufacturing

Collaborative robots in manufacturing offer numerous benefits, including enhanced quality control, streamlined operational efficiency, and increased production output. They can be implemented remotely, allowing for more flexibility and adaptability. AI also enhances employee safety by assuming responsibility for less desirable tasks. Cobots are particularly beneficial for small and medium-sized enterprises (SMEs) due to their cost-effectiveness and ability to enhance human labor. Overall, cobots offer significant advantages in the manufacturing industry.

Disadvantages of cobots in manufacturing

Collaborative robots in the manufacturing industry have limitations due to their operational capabilities and their suitability for specific business contexts. They are not designed for high-intensity manufacturing tasks and heavy lifting operations. Additionally, cobots are not fully automated. However, these attributes are advantageous in factory environments where human workers need assistance. Cobots have limitations in cognitive and finesse tasks, but with technological advancements, they are expected to address these limitations through skilled engineers and developers.

Safety Standards of Collaborative Robots

The RIA ISO/TS 15066 technical specifications and ISO 10218 safety standards provide guidance on the safety performance and functions of collaborative robots. The 2016 RIA TR15.606-2016 Cobots document outlines safety needs for robot systems and collaborative robots, while the RIA TR15.806-2018 Guidance to Testing Force and Pressure in Collaborative Robot Application provides guidelines for measuring forces and pressures in transient and quasi-static contact actions.

Future of Cobots in the Manufacturing Industry

Advancements in technology will lead to more sophisticated cobots capable of handling a wider range of tasks. Integrating artificial intelligence and machine learning will enhance cobots' efficiency and adaptability. Early adopters will have a competitive advantage, focusing on productivity and product quality. Collaborative robots are transforming the manufacturing industry, offering benefits for businesses, workers, and the economy. They will enhance efficiency and growth opportunities.

Conclusion

Collaborative robotics (cobots) have gained momentum in the manufacturing industry, enabling small and medium businesses to streamline tasks and increase productivity. The ease of use and flexibility of cobots make them an attractive option for manufacturers. Traditional industrial robot makers offer cobot options, but it's crucial to weigh the pros and cons, financial investment, and company needs before investing. A clear implementation strategy and current limitations are essential for optimal performance. Cobots will continue to be workers' extensions and industrial robots' companions, and as productions become more digital and automated, they will bring more value if employed adequately. As productions become more automated, it's essential to employ cobots appropriately for optimal performance.