Basic information about 4 DOF robots in industrial applications?

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Introduce

Basic information about 4 DOF robots in industrial applications

Robot arms are a mechanical product that is being widely used in the fields of technology and manufacturing, even in healthcare, education or military exploration,…

With its dexterity and flexible manipulation ability, this device is often used when working on non-parallel planes such as machine editing.

Normally, people will rely on the number of axes or rotation points according to structure to classify robots. The 4-step robot arm is made from 4 axes including vertical and horizontal: Base Servo, Hand Servo, Shoulder Servo, Clamp Servo,…

The importance of performance appraisals in optimizing efficiency and productivity

When evaluating performance, you can optimize efficiency and improve production. Proposing appropriate options and selection methods helps improve productivity, improve speed, thereby reducing manufacturing costs.

Aim and objective of the article

Performance analysis helps improve quality
Impact of robot arms in manufacturing industries
Analyze and interpret robot arm data

Overview of 4 DOF Robotic Arm

Definition and basic functions of 4 DOF robots

“Four degrees of freedom robotic arm” is often used to describe a robotic arm system capable of moving in four degrees of freedom or basic degrees of freedom. The four degrees of freedom here refer to the ability to move the arm in the four cardinal directions without constraints. Specifically, four degrees of freedom in this context are typically included

Move up and down (Vibration): The arm can be raised and lowered.
Move left and right (Roll): The arm can rotate around a horizontal axis to move left or right.
Vertical Movement (High Low): The arm can move up and down along a vertical axis
Rotation: The arm can rotate around its axis, commonly known as wrist rotation.

With these four degrees of freedom, the robot arm is capable of performing a variety of tasks and interacting with its surroundings flexibly. This is often used in industrial and medical robotic systems, or in research and development applications.

Composition and structure of a typical 4 DOF robot arm

The structure of the 4-step robot arm includes the following basic parts:

Manipulator

A manipulator is one of the mechanical parts including stitches and joints that are simulated with basic movement capabilities including the wrist moving easily, the hand performing operations and directly completing the work. Details in the arm are connected together by sliding joints and rotating joints so they move more firmly

Control system

This department ensures the task of carrying out operations every time there is a signal. Each activity and function of the 4-level robot arm control system is decentralized into many different levels. They operate from simple, solving general action methods to operating positions, passing points… or complex operations such as kinematic calculations, interpolation, error handling, trajectory establishment…

Currently, to optimize normal movements, 4-step robots will apply servo motor technology. This engine has the function of creating moving force so that machines can operate stably

Management software

This is the programming environment and also the means for the operator to give commands to the robot. The right software needs to have the most appropriate programming language that is user-friendly and easy to use.

Application fields of 4 DOF robots in the industrial field

Industrial robot arms are mechanical devices, pre-programmed with functions similar to human arms. With high flexibility, this device is applied in many different fields, from soldering, painting, assembling printed circuit boards, labeling, supporting material handling, product inspection and testing. experience,…

Robots are used for packaging and product classification, often using parallel robots.
Robots are used to spray paint in car and airplane body factories…
Robots used in plastic injection technology.
Used for loading and unloading and picking up goods.
Used in transporting and relocating products.
Automatic welding robot.
Robots are used in the foundry industry to pour molten metal.

Performance evaluation parameters

Accuracy and precision

In industry, precision is an important concept, especially when measuring and controlling technical parameters during the manufacturing process.

Define:

Accuracy is the ability of a measurement system, device or process to provide results as close as possible to the actual or true value. It is usually expressed in terms of relative or absolute error.

Precision measuring techniques:

Absolute error: This is the difference between the measured value and the actual value, regardless of direction
Relative error: Calculated by dividing the absolute error by the actual value and multiplying by 100 to get a percentage.
Repeatability: Measures the ability of a measuring device to produce the same result when measuring the same value many times under the same conditions.
Reproducibility: Measures the ability of a measuring device to produce the same result when measuring the same value under different conditions.
Linear accuracy: Measures the ability of a measuring device to give results close to the actual value over the entire measuring range.
Dynamic accuracy: Measures the ability of a measuring device to determine an accurate value under dynamic measurement conditions, such as during movement or rapid change.

The importance of accuracy and precision in industrial applications

Accuracy and precision are important factors in calibration to ensure the reliability, integrity and quality of measurements.

Precise measurements yield results close to the true value, while precise measurements show low variability and high repeatability. Both precision and accuracy are essential in many industries, where measurement accuracy and consistency are critical to product quality, safety, and regulatory compliance.

Calibration procedures must be performed carefully using traceable standards, and regular calibration checks must be performed to maintain the accuracy and precision of the measuring instrument. Accurate and precise measurements are indispensable to obtain reliable and trustworthy results, which makes them essential in the field of calibration.

Case studies highlight the impact of accuracy and precision on productivity

Manufacturing industry: In a manufacturing plant, a company is producing precision parts for aerospace applications. The manufacturing process requires high precision and accuracy to meet industry standards. Initially, the company faced challenges in maintaining consistent quality, leading to frequent rejections and rework.

Solution: The company invested in advanced machining tools with greater accuracy and precision. This not only reduces the number of defective components but also increases the overall efficiency of the production line. With improved accuracy, the need for rework is reduced, resulting in significant time and cost savings. Precision in manufacturing also enhances the company’s reputation for providing reliable and high-quality products, leading to increased customer satisfaction and repeat business.

Load capacity

Importance and impact of load carrying capacity in industrial applications

The internal load capacity of a device is an important factor in industrial applications, especially in sectors such as manufacturing, logistics, construction, etc.

The importance and impact of payload capacity in these applications is significant for many reasons:

Use resources effectively:
Cost effective in use
Improve productivity
Construction of equipment with large loads
Ensure safety for workers
Environmental impact
Customizable and adaptable to many heavy-duty jobs
Method of measuring and evaluating the load-bearing capacity of a 4 DOF robot arm

Methods for measuring and evaluating the load-bearing capacity of DOF robot arms include:

Static analysis: attach torque sensors at key points on the robot arm. That way, the resulting sensor indicators can be measured
Dynamic analysis: Calculate inertial parameters of each link in the robot arm, including mass, center of mass and inertia tensor. Use this information to analyze the dynamic behavior of the robot under different loads.
Simulation: Use simulation software to model the robot arm and simulate different loads. This allows you to observe the robot’s response to different loads without physical testing. Ensure that the simulation accurately represents the real-world dynamics of the robot.
Experimental testing: Measure joint angles, velocities and accelerations to evaluate the impact of loading on robot performance.
Load testing: Evaluates the compliance of a robot arm by applying external force and measuring the resulting displacements. A compliant robot can handle the heaviest loads with less impact on accuracy and stability.
Safety factor: Set a safety factor to ensure the robot is not pushed to its absolute limit. This margin of safety helps account for uncertainties in load distribution, environmental conditions, and variations in the robot’s mechanical components.
Long-term operation: Let the robot operate for a long time with different loads to evaluate the durability and reliability of the robot. This type of testing helps identify any problems that may arise during extended use.

Speed and cycle time

Techniques for defining and measuring speed and cycle time

Cycle time is the time required to complete a single manufacturing operation on a unit or batch from start to finish. Therefore, a cycle is a single step in a product manufacturing process, for example welding a part, assembling a part, or finishing a product.

Understanding and managing the time required to complete each operation can be critical to achieving effective production planning and scheduling, ensuring that each step of the manufacturing process is as efficient as possible.

Cycle time (per 1 product) = Processing time / Total amount of goods processed

That means if you have a single workstation that assembles a product from start to finish, that station’s CT is the time of one assembly.

For example, when a CNC machine processes 90 units in an hour, its productivity is 90 units/h and therefore its CT is 60/90 = 0.67 minutes or 40 seconds per unit.

If you are working with batches, CT corresponds to the processing time of the batch. Instead of performing cycle time calculations, simply measure the amount of time it takes to process a shipment.

Cycle time (per batch) = Processing time for one shipment

Optimize speed and cycle time for efficient industrial processes

Optimizing speed and cycle time for industrial processes requires a systematic process, performance and rigorous management. Ways to improve and speed up the cycle include:

Process analysis: Conduct a detailed analysis of the process to identify steps that can be improved. Identify delays and their root causes.
Optimize technology: Apply new and improved technology to replace old technology, especially those that can reduce waiting times and increase production speed. Consider using automation to reduce worker time and increase efficiency.
Optimize production processes: Optimize machinery and equipment layout to minimize travel time and ineffective work. Optimize production schedules to minimize waiting times between process steps.
Schedule management: Optimize employee and equipment work schedules to reduce idle time. Use tracking and management systems to keep production moving without a hitch.
Increased maintenance and upkeep: Ensure that machinery and equipment are properly maintained to avoid breakdowns and reduce downtime. Plan regular maintenance cycles to keep equipment running smoothly.
Risk management: Assess and minimize risks that could disrupt production processes. Develop a contingency plan to handle problems quickly when they occur.
Employee training: Train employees so they understand work processes and can detect and resolve problems quickly.
Monitoring and evaluation: Use a monitoring and evaluation system to monitor performance and identify further improvement opportunities.

Real-life examples show the impact of speed and cycle time on productivity

Increase efficiency. Tracking cycle time helps manufacturers identify inefficiencies and non-value-added activities in their processes and find ways to fix them. Optimize production processes. When tracking time is an ongoing activity, it facilitates continuous improvement, not only by continually comparing process efficiency but also by continually updating benchmarks when results improve.
Workers are notified. The defined cycle times will provide production team members with information about what is expected of them in terms of processing times.
Better production planning. Calculating average processing time allows you to create accurate production schedules based on actual process times.
Higher production rate. Reducing cycle times often correlates with increasing production speeds without affecting product quality.
Reduce implementation time. By improving processing times, customer lead times are reduced as a result.
Improve customer satisfaction. Shorter lead times and the ability to respond quickly to changing customer needs will certainly result in higher customer satisfaction.

Repeatability and reliability

Learn about repeatability and reliability in the context of 4 DOF robotic arms

Repeatability: Repeatability refers to the ability of a robot to return to a specific location accurately when applying the same set of inputs or commands.
Importance: High repeatability is essential for applications where robots need to perform the same task with precision and consistency.
Reliability: Reliability, in the context of 4 DOF robotic arms, refers to the system’s overall dependence on performing tasks consistently without error.
Reliable robot performance is critical, especially in industrial environments where downtime can lead to production delays and increased costs.

Methods and standards for evaluating repeatability and reliability

Evaluation methods and standards play an important role in ensuring repeatability and reliability in various fields, including research, testing and evaluation. Repeatability refers to the ability to obtain consistent results when the same experiment or measurement is conducted multiple times, while reliability indicates the consistency and accuracy of a measurement or assessment tool.

Standardized Operational Procedures (SOP): follow standardized procedures to conduct audits or testing. The SOP provides step-by-step instructions to ensure consistency
Calibration: Regularly calibrate measuring instruments to ensure accuracy and consistency. Calibration helps maintain device reliability by aligning it with a reference standard.
Instrumentation standards: Follow industry or sector-specific standards for equipment selection, use, and maintenance. This ensures that the equipment is used in a standardized manner across different experiments.
Training Program: Provides comprehensive training for individuals involved in data collection or evaluation. Consistent training helps minimize variation caused by human factors.
Randomization: Random assignment of subjects or conditions to minimize bias and control for extraneous variables. Randomization contributes to the reliability of the experimental design.
Statistical methods: Use appropriate statistical methods to evaluate the reliability of data. The intraclass correlation coefficient (ICC), Cohen’s kappa, and Cronbach’s alpha are examples of statistical measures used to quantify reliability.
External validation: Seek external validation of assessments or tests by collaborating with other researchers or organizations. External validation adds credibility and trustworthiness to the findings.

Implications of repeatability and reliability for industrial operations

Reliability plays an important role in measuring and testing product quality. It ensures that measurement and test results are reliable and can be used to evaluate product quality. Below is a description of the role of reliability in quality measurement and testing, how to evaluate reliability, and its application in manufacturing processes.

Performance evaluation techniques

Laboratory testing

Overview of laboratory testing to evaluate performance

Laboratory testing refers to the process of testing and evaluating something in a laboratory under the best conditions. The experimenter obtains the best results that the machine operates from and makes recommendations. reported usage to users

Equipment and procedures used to evaluate various parameters

OEE stands for “Overall Equipment Effectiveness” and is an index used in the manufacturing sector to measure the overall performance of manufacturing equipment or manufacturing processes.

Overall equipment efficiency OEE is used to express the level of efficiency of machinery in percentage terms. The effectiveness of a device is evaluated overall through all three factors: time; quality; and operating speed:

When used as a benchmark, OEE is used to compare the efficiency of a production piece of equipment with industry standards or to compare the efficiency between different shifts on the same piece of equipment.

When used as a baseline, OEE is a parameter that helps track the efficiency over time of a manufacturing equipment while eliminating waste.

In case the OEE score reaches 40%. This result is an alarm bell for this business to immediately start monitoring and improving its production efficiency. A score of 40% is a low score, and most companies can easily improve their scores through simple measures (e.g., tracking downtime causes and addressing each cause at a large scale). smallest to smallest).

In case the OEE score is 60%, this is a typical sign when the Enterprise’s production system needs to improve a few points to achieve a good performance score.

In case the OEE score reaches 85%, those are world-class manufacturers. This is also the long-term goal for many ambitious manufacturing businesses.

A 100% OEE score represents perfect production performance: no downtime; production activities are smooth and fast.

Operating time ratio = (Theoretical operating time – Machine downtime) / Theoretical operating time

Performance Ratio = (Ideal cycle time × Total product) / Machine run time

Quality Ratio = Total quality products / Total number of products performed

Advantage

Calculate return on investment
Improve competitiveness
Demonstrate device performance visually
Capture product cost information

Defect

Field experiment

Overview of field testing to evaluate performance

Field testing refers to the process of testing and evaluating an application under real-world conditions outside of a controlled development environment. Testers deploy this approach to both web and mobile apps with the aim of gathering real user feedback and identifying any potential issues or improvements before the official release.

Methods and challenges when conducting field testing

Analyze and interpret data

Data analysis and interpretation techniques in performance evaluation

Performance data is information that shows how well you are achieving your goals and objectives. It can help you identify strengths, weaknesses, opportunities and threats, and guide decision-making and improvement efforts. Interpret your performance data effectively and use it for various purposes

Software tools and algorithms are used to analyze performance data

AWS Glure: Serverless data integration. Serverless Data is a serverless data integration service that helps users easily find, prepare, and aggregate data for analytics, machine learning (ML), and application development
Amazon OpenSearch Service: Log Analytics and Analytical Search A suite of distributed, community-driven, Apache 2.0-licensed, 100% open source search and analytics tools used for a wide range of cases such as real-time application monitoring, log analysis, and website search.
Amazon QuickSight: Embedded, scalable, serverless, machine learning-based BI service built.
Amazon SageMaker: Fully managed service for building, training, and deploying ML models with fully managed infrastructure, tools, and workflows.

Interpret and present performance appraisal results effectively

Steps to interpret effective job evaluation

Case study

Case study 1: Performance evaluation of a 4 DOF robot arm in the automotive industry

Target

Evaluate the accuracy and repeatability of a 4 DOF robot arm in performing specific tasks.
Analyze the efficiency and speed of the robot arm in different operating situations.
Evaluate the reliability and operating time of the robot arm during continuous operation.
Identify potential areas to improve robot arm performance.

Methodology

Task-specific evaluation: Conduct tests for a variety of tasks, such as assembly, welding, and material handling, to evaluate the accuracy and repeatability of the robot arm.
Test speed and efficiency: Measure the time it takes a robot arm to complete specific tasks and evaluate its overall effectiveness.
Reliability assessment: Monitor the performance of the robot arm over an extended period of time to determine its reliability and identify any downtime.
Compare to specifications: Compare the actual performance of the robot arm to the manufacturer’s specifications to confirm its compliance with the design parameters.

Results and analysis

Provides detailed results on accuracy, repeatability, speed and efficiency for each tested task.
Compare actual performance with manufacturer specifications.
Highlight any issues or areas observed for improvement.

Case study 2: Performance evaluation of a 4 DOF robot arm in the electronics industry

Target

Evaluate the accuracy and repeatability of a 4 DOF robot arm in performing specific tasks.
Analyze the efficiency and speed of the robot arm in different operating situations.
Evaluate the reliability and operating time of the robot arm during continuous operation.
Identify potential areas to improve robot arm performance.

Methodology

Test speed and efficiency: Measure the time it takes a robot arm to complete specific tasks and evaluate its overall effectiveness.
Reliability assessment: Monitor the performance of the robot arm over an extended period of time to determine its reliability and identify any downtime.
Compare to specifications: Compare the actual performance of the robot arm to the manufacturer’s specifications to confirm its compliance with the design parameters.

Results and analysis:

Provides detailed results on accuracy, repeatability, speed and efficiency for each tested task.
Compare actual performance with manufacturer specifications.
Highlight any issues or areas observed for improvement.

Conclusion

Summarize the importance of performance evaluation for 4 DOF robotic arms in industrial applications

Increase efficiency. Tracking cycle time helps manufacturers identify inefficiencies and non-value-added activities in their processes and find ways to fix them. Optimize production processes. When tracking time is an ongoing activity, it facilitates continuous improvement, not only by continually comparing process efficiency but also by continually updating benchmarks when results improve.
Workers are notified. The defined cycle times will provide production team members with information about what is expected of them in terms of processing times.
Better production planning. Calculating average processing time allows you to create accurate production schedules based on actual process times.
Higher production rate. Reducing cycle times often correlates with increasing production speeds without affecting product quality.
Reduce implementation time. By improving processing times, customer lead times are reduced as a result.
Improve customer satisfaction. Shorter lead times and the ability to respond quickly to changing customer needs will certainly result in higher customer satisfaction.

Future prospects and advances in performance evaluation of 4 DOF robots

In the future, performance assessment tools will be more developed to help businesses and users easily see the efficiency of the machine. Select equipment suitable for the production process