Introduction

Assembly lines have transformed the way products are manufactured and have become a cornerstone of modern manufacturing processes. From automobiles to electronics and beyond, assembly lines have made it possible to produce products on a large scale with greater speed and efficiency than ever before.

In this article, we will discuss robotic assembly lines in depth. We will explain the definition of assembly lines, their history, their components, applications in different industries, the advantages and challenges associated with using them, and the developments that are expected to shape their future.

What are Assembly Lines?

An assembly line refers to a systematic arrangement of machines and/or people that fit parts or carry out a repeatable task on a product as it moves along a conveyor. Each machine or worker completes a specific task before passing the product on to the next step in the line. The result is a fully assembled product manufactured quickly and efficiently through the assembly line process.

Assembly line machines are industrial robots designed to carry out repetitive tasks, such as picking, placing, welding, and assembling parts. These robots are equipped with end effectors that enable them to sense and manipulate objects with great precision and accuracy.

Suggested reading: What are End Effectors in Robotics? Types of End Effectors, Applications, Future

Assembly line robots are programmed to carry out specific tasks. They work alongside human operators to perform a wide range of manufacturing operations.

Historic Developments in Assembly Lines

The history of robotic assembly lines can be traced back to the early 1900s. One of the pioneers in this field was Henry Ford, founder of Ford Motors and an American industrialist best known for his development of the modern assembly line that revolutionized manufacturing by allowing for the mass production of automobiles.[^1] While Ford's assembly line primarily relied on human labor rather than robotics, his ideas laid the foundation for the development of automated assembly lines in the following decades.

Fig. 1: Ford assembly line: The Magneto from 1913.

In the 1960s, the first industrial robot, Unimate, was developed by George Devol and Joseph Engelberger.^[2] Unimate was designed to handle heavy materials and perform repetitive tasks, and it quickly found a home on assembly lines in various industries.

Throughout the 1960s and 1970s, the use of robots on assembly lines continued to grow as more advanced robots were developed. In the 1970s, the first microprocessor-controlled robots were introduced, which allowed for precise and complex movements.^[3] As technology continued to advance, robots were able to take on more tasks, such as welding, painting, and material handling.

By the 1980s, robots were a common sight in many manufacturing industries, and their use on assembly lines became widespread. The next decade saw the development of the first collaborative robots, or "cobots," designed to work alongside human workers.^[4]

Suggested Reading: 7 Types of Industrial Robots: Advantages, Disadvantages, Applications, and More

Today, assembly automation is a crucial component of many manufacturing industries, and new developments in robotics continue to drive innovation in this field.

Components of a Robotic Assembly Line

Robotic assembly lines comprise several components that work together to carry out the manufacturing process. Some of the main components of a robotic assembly line include:

1. Conveyors: Conveyors are used to transport raw materials, work-in-progress items, and finished products along the assembly line, allowing the robot to pick them up and move them to the next stage of the process.

2. Industrial Robots: The robots are the primary components of the assembly line and are responsible for carrying out the manufacturing process. Industrial robots used in assembly lines come in different shapes, sizes, and features to suit the application they are supposed to be used for.

3. End Effectors: End effectors are the tools attached to the robot's arms that enable them to manipulate objects and payloads. Just like robots, end effectors too can be customized to carry out the task at hand. For example, grippers are used to pick up and move objects; dispensers can be used to apply adhesives, while welding guns are used to weld parts together.

4. Sensors: Sensors are used to detect the position and orientation of objects, allowing the robot to move them accurately. Sensors and vision systems can also be used to detect defects in parts, ensuring that only high-quality products are produced.

5. Controllers: Controllers are programmed to control the robots and other components of the assembly line. They are responsible for coordinating and operating the entire process in a closed loop.

6. Power Supplies: Power supplies provide the energy required to operate the robots and other components of the assembly line. Depending on the requirements, they can be electric, electronic, hydraulic, or pneumatic.

7. Safety Equipment: Safety equipment, such as fencing, light curtains, and emergency stop buttons, is used to ensure the safety of the workers and the proper operation of the assembly line.

Here is a video showcasing the assembly line and the manufacturing process of the Ford F-150 truck:

Advantages of Robotic Assembly Lines

Robotic assembly lines offer manufacturers numerous advantages, leading to their widespread adoption in various industries. Below are some of the key benefits of robotic assembly lines:

1. Increased Productivity: Robotic assembly lines can work around the clock without needing breaks or rest, resulting in increased productivity. They can also perform tasks faster and more accurately than humans, reducing production time and increasing output.

2. Higher Quality and Repeatability: Robotic assembly lines can perform tasks consistently, producing higher-quality products. They are not prone to human errors, such as fatigue or distractions, which often affect the quality of the products made manually. Robotic assembly lines can produce consistent output regardless of the operator's skill level or experience. This consistency ensures that the products meet the same quality standards every time.

3. Reduced Labor Costs: Using robotic assembly lines reduces the need for manual labor. While the initial investment in robotics technology may seem high, the long-term cost savings can be significant.

4. Improved Safety: Besides reducing labor costs, robotic assembly lines also make the work safer for the workers. They perform tasks that are hazardous to humans, such as welding or handling toxic substances, resulting in improved workplace safety. This drastically reduces the risk of workplace accidents and injuries.

5. Increased Flexibility: Robotic assembly lines can be programmed to perform a wide range of tasks, making them highly flexible. They can also be reprogrammed quickly to adapt to changes in the production process.

6. Improved Efficiency: Robotic assembly lines can perform tasks in parallel, reducing the time required to complete a production run. Robotic assembly lines can be optimized to use materials more efficiently, reducing waste and lowering material costs. They can also be used to identify defective products, reducing the amount of scrap produced.

7. Improved Data Collection: Robotic assembly lines can be equipped with sensors and other monitoring devices that collect data on the production process. This data can help identify inefficiencies and improvement areas in the production process, resulting in continuous improvement and optimization.

8. Enhanced Customization: Robotic assembly lines can be programmed to perform highly specialized tasks, allowing for greater customization of products. This customization can result in a competitive advantage for manufacturers, as they can offer unique products to their customers.

9. Improved Time-to-Market: Robotic assembly lines can significantly reduce the time required to bring a product to market. They can perform tasks faster and more accurately than humans, allowing manufacturers to meet tight deadlines and respond quickly to changes in demand.

The advantages of robotic assembly lines are numerous, and they have transformed the way manufacturers produce goods.

Challenges with Robotic Assembly Lines

While robotic assembly lines offer numerous advantages, they also present some challenges that manufacturers must address to ensure effective operation. Below are some of the common difficulties with robotic assembly lines:

1. Initial Investment Cost: One of the main challenges with implementing the robotic assembly process is the high initial investment cost. Purchasing and installing robotic equipment may get expensive and not be feasible for small and medium-sized manufacturers.

2. Maintenance and Repair Costs: In addition to the initial investment cost, the maintenance and repair costs of robotic assembly lines may also be high. As with any machinery, robots require regular maintenance and occasional repairs, which can be expensive and time-consuming.

3. Integration with Existing Systems and Retrofitting: Integrating robotic assembly lines with existing production systems can be challenging. The robots must be integrated seamlessly with the existing systems to ensure smooth operation, which can be complicated to achieve.

4. Workforce Training: Implementing robotic assembly lines requires retraining the existing workforce. Workers need to be trained in operating and maintaining the robots.

5. Safety Concerns: Robotic assembly lines offer increased safety to the workers and the products being handled. However, the benefit only applies if the manufacturers set up the system properly and ensure proper measures are in place to prevent accidents and injuries.

6. Dependence on Power Supply: Robotic assembly lines depend on a reliable power supply. Power outages or other electrical issues can cause downtime and productivity loss.

7. Limited Flexibility: Robotic assembly lines are designed to perform specific tasks, limiting their flexibility. Changes to the production process or product design may require significant reprogramming or reconfiguration of the robotic equipment.

8. Programming Complexity: Programming robots can be complex and time-consuming. Robotic assembly lines require specialized programming skills and software, which can be difficult to master. Additionally, changes to the production process may require reprogramming of the robots, which can result in downtime and lost productivity.

In conclusion, while robotic assembly lines offer numerous advantages, manufacturers must address these challenges to ensure continued operation.

Applications of Robotic Assembly Lines in different industries

Robotic assembly lines have a wide range of applications across various industries. Below are some examples of industries where robotic assembly lines are most commonly used:

• Automotive Industry: Robotic assembly lines are extensively used in automotive manufacturing for welding, painting, and assembly applications of car components. Robotic assembly systems can perform repetitive tasks with high accuracy and speed, resulting in increased productivity and consistency. They can also handle heavy and hazardous tasks that would otherwise require human workers to use protective gear.

• Electronics Industry: The electronics industry heavily relies on robotic assembly lines for tasks such as pick-and-place operations, soldering, and inspection. Robots can handle small parts and components with high precision, reducing the risk of errors and improving quality control. They can also operate at high speeds, resulting in faster production cycles and reduced costs.

• Food and Beverage Industry: Robotic assembly lines are used in the food and beverage industry for tasks like packaging, sorting, and inspection. Robots can handle delicate items such as eggs or fruits without damaging them. They can also operate in harsh environments, like refrigerated warehouses or high-temperature processing lines.

Fig. 2: Making doughnuts with an assembly line at Krispy Kreme, a popular American multinational doughnut brand. Source: Steve Jurvetson - Flickr

• Pharmaceuticals Industry: The pharmaceutical industry uses robotic assembly lines to dispense, label, and pack medicines. Assembly lines can also help with surgical procedures and robotic automation in laboratories. Being able to handle hazardous materials and operate in sterile environments reduces the risk of contamination and improves overall safety.

• Aerospace Industry: One of the most notable applications of robotic assembly lines is in the aerospace industry. In the aerospace industry, robotic assembly lines can be used to drill, fasten, and assemble airplane components. Robots can handle large and heavy parts with high precision and speed. They operate in hazardous areas with toxic fumes or extreme temperatures. Robotic assembly lines can also be used to build space shuttles and satellites, where the tolerances are even tighter.

Fig. 3: The first Australian registered Boeing 787 aircraft in final assembly in Seattle (2013). Source: Jetstar Airways - Flickr

Robotic assembly lines are increasingly being used across various industries, and their applications are expected to continue to expand in the future.

Developments in Assembly Line and the Future

The future of robotic assembly lines looks promising, with technological advances expected to bring significant improvements in the domain. Below are some of the key developments and trends that are likely to shape the future of robotic assembly lines:

1. Collaborative Robots: Collaborative robots, also known as cobots, are designed to work alongside human operators. These robots have advanced sensors and safety features that enable them to work safely and effectively with humans. As the technology continues to improve, we can expect to see more widespread adoption of cobots in manufacturing settings.

2. Artificial Intelligence (AI) and Machine Learning (ML): AI and ML algorithms are expected to play a significant role in the future of robotic assembly lines. These technologies can help robots learn and adapt to changing production requirements, making them more flexible and responsive to changing market demands.

3. Integration with the Internet of Things (IoT): Robotic assembly lines are becoming more interconnected with IoT. This enables robots to collect and share data with other machines and systems, providing manufacturers with real-time insights into production processes and allowing them to make data-driven decisions.

4. Improved Safety: Safety continues to be a key consideration in the design and implementation of robotic assembly lines. Advances in sensor technology, materials, and safety features will make robots even more safer to work with, which shall further reduce the risk of accidents.

5. Increased Customization: As consumers demand more customized products, manufacturers will need to be able to produce smaller batches of products more efficiently. Robotic assembly lines will play a key role in meeting this demand by enabling manufacturers to quickly and easily reconfigure their production lines and scale them to produce a broader range of products.

6. Energy Efficiency: As concerns about climate change continue to grow, manufacturers must find ways to reduce their energy consumption and carbon footprint. Robotic assembly lines can help by improving energy efficiency and reducing waste, making them a more sustainable option for manufacturers.

The future of robotic assembly lines looks bright, with technological advances expected to bring significant performance improvements. As manufacturers look to stay competitive in an increasingly fast-paced and demanding market, robotic assembly lines will continue to play a critical role in helping them meet their production goals.

Key Takeaways

An assembly line refers to a systematic arrangement of machines and/or people that fit parts or carry out a repeatable task on a product as it moves along a conveyor. The idea was conceptualized by Henry Ford back in the early 1900s. 

Robotic assembly lines consist of several components, including conveyors, industrial robots, end effectors, sensors, controllers, power supplies, safety equipment, and more.

They offer numerous benefits to manufacturers, including increased productivity, higher quality and repeatability, reduced labor costs, improved safety, increased flexibility, efficiency, data collection, customization, and time-to-market. 

While there are challenges associated with using robotic assembly lines, such as high initial investment costs, maintenance and repair costs, integration with existing systems, workforce training, safety concerns, dependence on power supply, limited flexibility, programming complexity, proper planning, training, and maintenance can help overcome these challenges.

They have applications in various industries, including the automotive, electronics, food, beverage, pharmaceutical, and aerospace industries. 

Present-day developments in the assembly line are focused on integrating technologies like collaborative robots, AI, ML, and IoT to improve the productivity and performance of the system they are a part of. Continued research in the domain shall ensure the technology gets safer, customized, and energy efficient.

References

[1] The Moving Assembly Line and the Five-Dollar Workday, Ford, [Online], Available from: https://corporate.ford.com/articles/history/moving-assembly-line.html

[2] Unimate, IEEE Robots - Your guide to the world of robotics, [Online], Available from: https://robots.ieee.org/robots/unimate/

[3] ABB Technologies that Changed the World, ABB, [Online], Available from: https://new.abb.com/innovation/industrial-robots

[4] Sophie Hand, ‘A Brief History of Collaborative Robots’, 26 Feb 2020, [Online], Available from: https://www.mhlnews.com/technology-automation/article/21124077/a-brief-history-of-collaborative-robots