In the context of businesses aiming for production automation, 4-degree-of-freedom robots become the optimal choice to help increase productivity, reduce errors and improve competitiveness. Let's find out more details with Intech Group in the following article:

Definition of 4-degree-of-freedom robot arm

4-degree-of-freedom robot arm (4 Degrees of Freedom - 4DOF) is an industrial robot designed with 4 axes or joints, allowing flexible operations in three-dimensional space such as rotation, picking, moving and placing products. The last axis of the robot is usually located near the base, helping to increase stability and ensure precise movement for the entire arm.

This is a popular choice in packaging production lines, product picking and placing, machine feeding, stacking goods and many other automatic applications in industry.

The importance of 4-degree-of-freedom robot arms

4-degree-of-freedom robots are increasingly widely used in many fields thanks to their flexibility, precision and good load-bearing capacity. Some outstanding advantages include:

- Robots can be reprogrammed to perform many different tasks without changing the hardware structure.

- Helps reduce heavy work for humans in repetitive steps, requiring strength or high precision.

- Especially suitable for automatic production lines such as: electronics, automobiles, precision mechanics, etc.

- With a 4-axis structure, robots can cover large workspaces without moving the base, optimizing the usable area.

Structure of a 4-degree-of-freedom robot arm

A 4-degree-of-freedom robot arm is designed with an optimal structure, ensuring flexible, precise and stable movement during operation. 4-level robots include three main parts:

Manipulator

The manipulator is the main mechanical part of the robot, including joints that allow it to perform operations similar to the human arm such as: reaching, folding, rotating and grabbing. At the joints, the robot is often equipped with sliding joints and rotary joints that allow the robot to easily perform operations during the process of picking - placing, lining up or automatic assembly.

Control system

Depending on the application requirements, the control system can be set up at different levels from basic (determining position, coordinates, paths) to advanced (automatic trajectory calculation, error handling, complex command reading). Most 4-degree-of-freedom robots use servo motors, which help create precise force, respond quickly and ensure stable operation.

Control software

Software is an intermediary tool that helps program and coordinate robot operations. Thanks to the software, robots can be programmed to automatically perform many different tasks, suitable for each production requirement.

4-degree-of-freedom robots are capable of moving and rotating in 4 independent directions, including three translational movements (along the X, Y, Z axes) and one rotational movement around the axis. Thanks to that, robots can operate flexibly in space, ensuring high precision and efficiency in automation applications.

Main components of a 4-degree-of-freedom robot arm

A 4-degree-of-freedom robot arm is made up of many sophisticated mechanical and electronic parts, allowing the robot to perform precise movements and operations in the production line. Below are the important components that make up the structure and flexible operation of the robot:

Base or fixed component

The robot base is the foundation part, keeping the entire robot arm stable and firm, with the ability to rotate left and right flexibly, helping the robot expand its range of operation including both sides and behind.

First joint - Shoulder joint

The first joint is the connection between the base and the internal links of the robot, allowing the rotation of the column and arm, similar to the shoulder movement of a human. This joint has a large rotation angle, about 300° (150° to the left and 150° to the right), allowing the robot to rotate flexibly in space.

Second Joint - Elbow Joint

The second joint is responsible for lifting - lowering and adjusting the length of the robot arm's reach. The elbow joint works similarly to the shoulder joint, also capable of moving about 300°, allowing the robot to flexibly move its arm forward or backward, used in assembling parts or transporting materials.

Third Joint - Wrist Joint

The wrist joint is the part that takes on the most delicate and precise movements, with a rotation range of up to 540°, allowing the robot to rotate, twist or adjust the operating angle like a human wrist, so the robot can tighten bolts, unscrew screws, or rotate small parts accurately and quickly.

End Effector

This is the part that comes into direct contact with the product or material, taking on the role of picking, holding, welding or moving parts during the manufacturing process. Depending on the application, the end effector can be customized in many different forms such as: mechanical grippers, pneumatic grippers, vacuum suction cups, magnetic grippers or automatic welding heads.

Operating principle of 4-degree-of-freedom robots

4-degree-of-freedom robots operate based on the combination of precision mechanical systems and intelligent control software.

Forward Kinematics

By knowing the rotation angles of the shoulder, elbow and wrist, the system can accurately calculate where the robot's gripper is in the workspace. This process is usually done using matrix calculations or geometric models.

Inverse Kinematics

Inverse kinematics helps determine the joint angles that need to be achieved for the workhead to move to a desired position, ensuring the robot operates in the right direction, in the right position and avoiding mechanical limits.

Control and feedback principles

The robot's central controller (Controller) plays the role of:

- Receiving movement commands from the operator or pre-programmed program.

- Solving the inverse kinematics problem to calculate the angle for each joint.

- Sending control signals to the servo motor or stepper motor.

- Receiving feedback from the position sensor (encoder) to compare and continuously calibrate in the feedback loop to ensure high accuracy.

Movement and joint coordination process

When performing tasks such as picking up objects from point A to point B, the 4-degree-of-freedom robot will program the optimal movement trajectory. Thanks to the coordination between powerful actuators, sensitive sensors, and intelligent controllers, the 4-degree-of-freedom robot becomes an effective automation solution.

Applications of 4-degree-of-freedom robots in industrial production and life

With a compact structure and precise programming capabilities, this type of robot is widely used in many different fields.

Applications in industrial production

4-degree-of-freedom robots play an important role in automating production lines. Some typical applications include:

• Picking - placing and assembling components: Robots undertake precise repetitive operations in electronic, mechanical, and automotive lines.
• Packaging and classifying products: Especially in the food and logistics industries, they can handle high speeds, saving labor.
• Painting, welding, plastic injection, metal casting: Robots help improve safety, ensuring product uniformity.
• Transporting and unloading goods: Robots can replace humans in dangerous areas or areas requiring high precision.

Applications in the field of healthcare

4-degree-of-freedom robots not only serve industry but also provide smart medical support solutions.

• Rehabilitation: Robots are programmed to support patients in exercising after injury.
• Precision surgery: Robotic arms help doctors perform microsurgery with high precision, reducing risks and shortening recovery time.
• Support for the elderly and disabled: Robots can help with eating, moving, reminding medication schedules or supporting remote care.

Applications in Agriculture

Automation is dramatically changing the agricultural industry, and 4-degree-of-freedom robots play a role in many processes:

• Sowing, harvesting, and sorting agricultural products.
• Automatic spraying and fertilizing.
• Monitoring and collecting data on crops and livestock.

Applications in the aerospace industry

4-degree-of-freedom robots are used in processes that require absolute precision:

• Assembling and maintaining aircraft and space station components.
• Inspecting and collecting technical data.
• Handling and moving heavy or complex-shaped objects in confined spaces.

Advantages of using 4-degree-of-freedom robots

Increase productivity and work efficiency

4-degree-of-freedom robots can work continuously 24/7, not affected by fatigue or human errors, helping to shorten production time, improve productivity and maintain stable product quality.

Reduce errors and labor risks

Using robots in stages such as picking, welding, spraying paint or transporting heavy goods helps to limit work accidents and errors, especially useful in dangerous, toxic or high-precision environments such as electronic component manufacturing, precision mechanics, and the automotive industry.

Flexible, adaptable to many working environments

4-degree-of-freedom robots have the ability to reconfigure quickly, suitable for frequently changing production processes, and can be flexibly applied in many different stages.

Long-term cost-saving solution

The average payback period is only about 1.5 years, after which businesses can reduce labor costs, save factory space and cut labor protection costs while still ensuring high efficiency.

Limitations when using 4-degree-of-freedom robots

Complex programming and control requirements

The more modern the robot, the higher the requirements for programming, integration and control skills. Therefore, businesses need a team of specialized technicians to operate and optimize robot performance.

Limited payload capacity

4-degree-of-freedom robots often have a payload limit, so they are more suitable for tasks such as picking, assembling, packaging or light manipulation, rather than jobs that require heavy lifting.

Lack of human dexterity

4-degree-of-freedom robots cannot completely replace humans in jobs that require delicacy, force perception or the ability to adapt flexibly in complex production processes.

The future of 4-degree-of-freedom robots in industrial automation

4-degree-of-freedom robots are integrated with artificial intelligence, smart sensors and advanced connectivity technologies, opening up an era of comprehensive automation for all industrial fields.

Integrating artificial intelligence (AI) and machine learning

Thanks to the ability to combine AI and machine learning, robots can:

- Automatically adjust flexible movements, adapt to new environments and tasks.

- Identify and classify products accurately, support quality inspection in the production line.

- Predict and handle complex situations, reduce machine downtime and increase operating efficiency.

- Optimize production processes through data analysis and self-improvement of work performance.

- Coordinate synchronously with other robots, forming a smart robot network in the factory.

Enhanced sensing and sensing capabilities

Another important trend is to develop more precise sensing and interaction capabilities of robots through modern sensor systems:

- Image and machine vision sensors (Vision Sensor): Help robots recognize the surrounding environment, recognize the position, shape of objects and adjust operations precisely.

- Contact sensors (Force & Tactile Sensor): Allow robots to sense force, pressure and contact surfaces.

- Sound sensors: Help robots recognize sounds, noises or voices, thereby increasing the ability to interact with humans and the environment.

- Multi-sensor combination: Robots can simultaneously process images, sounds and tactile feedback to make decisions faster and more accurately.

Future development trends

In the coming years, 4-degree-of-freedom robots will continue to move towards:

- Full automation with the ability to self-identify, self-plan and execute tasks.

- Connect to ERP and MES systems, allowing management, monitoring and optimization of production lines in real time.

- Compact design, reasonable cost, helping small and medium enterprises easily apply robots to production.

- Develop collaborative robots (Cobots), which can work safely in parallel with humans.

Conclusion

4-degree-of-freedom robots are becoming an important foundation in the digital transformation strategy of smart factories. Intech Group is a pioneer in the field of industrial robots and smart automation solutions, providing modern 4-degree-of-freedom robots that are easy to integrate and suitable for all production scales. Contact us now for advice on optimal automatic cargo handling robot solutions, helping your business accelerate on the automation journey.