Design and Fabrication of Quality Control and Inspection Machine Based on Computer Vision

Quality control and inspection are one of the main processes of any industry where manufactured products undergo quality checks and analysis. The process passes the products for completion only if it fulfills certain quality check tests and criteria predefined. Quality is one of the most important f

Project Title

Design and Fabrication of Quality Control and Inspection Machine Based on Computer Vision

Project Area of Specialization

Mechanical Engineering

Project Summary

Quality control and inspection are one of the main processes of any industry where manufactured products undergo quality checks and analysis. The process passes the products for completion only if it fulfills certain quality check tests and criteria predefined. Quality is one of the most important features of any product. It is the extent to which a product meets the customer or manufacturers requirements. 

Quality control departments try to ensure that these defected products are separated from the good ones via manual inspection. Some quality control methods are also applied to rectify the processes and reduce the defected products in a manufactured process to a minimum. However, the effectiveness of these processes is limited as manual operations are slow, have limited efficiency and often lead to slow production due to the manual inspection. There is a potential to automate this quality control process for industries and make it more efficient and smarter by means of artificial intelligence.

A conceptual illustration of our proposed quality control and inspection machine

We have proposed an automatic quality control and inspection mechanism based on computer vision for the quality control of industrially manufactured products. Our proposed solution consists of a conveyer-based inspection and sorting system. This inspection system will be equipped with sensors and high-definition cameras, mounted on different points along the conveyer system which will take images of the passing products at a preset rate. We have chosen nuts (mechanical fasteners) as our product for inspection as a case study. These images can be used to determine the geometric dimensions of the product passing on conveyer belt using image processing to a great degree of accuracy. Then the dimensional measurement data acquired is compared with the range of acceptable values to sort out defected products from the right ones. This sorting is done with a servo-based mechanism to sort defected products at different levels based on the ones that can be re-processed and the ones that are wasted.

Flow of main operations of inspection and quality control

This data is also used for the overall analysis of the quality of products using Quality control charts which are used in the industry for process control and to evaluate product quality. These quality control charts can reveal the nature of anomaly in the manufacturing process as to whether it is related to human or any machine factor. Hence, the required improvement in the manufacturing process or product can be made using this analysis and evaluations to achieve better product quality.

Project Objectives

1. The design and fabrication of conveyer-based sorting machine with automatic quality control and inspection mechanism using computer vision.
2. To improve the quality control process in industries and SME’s and make it further efficient in terms of operation.

Project Implementation Method

The whole system will be first designed on CAD software (e.g., Solidworks) and then it will be fabricated using some basic principles of Machine Design. This will be an electromechanical system consisting of sensors (e.g., interrupt sensors), cameras and actuators for example stepper motor to drive and control conveyor belt and servo motors will be used to perform sorting operations.

This project requires following things

1. Capturing Images,
2. Algorithm of image processing to acquire useful image,
3. Algorithm for storing data to make quality charts and extracting geometric measurement parameters of nut and then finally comparing them with the desired results. Examples of these parameters are:

• External & Internal Diameters
• Thickness
• Pitch

1. Sorting mechanism to sort out undesired nuts. The sorting mechanism will consist of 2 parts, one for those products that can be reworked and the others which are no longer useful.

Below is the flow chart depicting the flow of operations:

Benefits of the Project

The world is currently going through an enormous phase of the 4th industrial revolution. Development of new technologies has paved way for better products, socio-economic development and most importantly tough market competition for almost every product. In the words of the economists of the 21st century, this phase is a window of opportunity for emerging economies like Pakistan to seize the opportunity to jump-in or leapfrog into the new industries. The application of 4IR technologies to existing industries for trifold advancement and improvement is the only way to excel.

Hence, the scope and benefits of our Quality control and inspection mechanism are enormous in terms of application and outcomes, especially for manufacturing sector and SME’s. Some of the many benefits are given below:

1. The Quality control and inspection mechanism is fully automated and every product is inspected for its compatibility with accepted standards, reducing the need for manpower.
2. Process rectification as the quality charts is analyzed to introduce continuous improvements in the manufacturing operations, reducing defected products in a production facility.
3. The overall quality of the products is improved as there is minimal to no chance of passing a defected product which leads to increased customer satisfaction and better market reputation of the brand.
4. Less time consumed in Quality check and inspection allowing increased productivity of an industry and hence more financial benefit.
5. The efficiency of the automated system will also pave the way for industries to transform the basic infrastructure of their operations to be inline with automation and 4IR technologies for better operations and economics.
6. Can be used in quality control on manufactured surgical items which are a significant export of Pakistan, which adds more value to the product and increases its brand reputation.
7. Can be used in quality control in agricultural produce as well with a change of algorithm. It can be used to separate best quality fruits such as mangoes, oranges from the total produce. Fruit export has a huge share in Pakistan’s economy.

Technical Details of Final Deliverable

Flat Belt Conveyer System

The belt conveyer system is used for delivering the products (inuts) across the shop floor from the start of Quality Control system to the ending point at which the product will be rendered as good if it has passed the quality standards. The conveyor system has the following design specifications, based on extensive literature review:

1. Material to be Conveyed: Nuts (or any discrete/unitary product)
2. Conveyer Belt Length: 45 inches
3. Belt Width: 4.5 inches
4. Total Conveyer Length: 55 inches
5. Total Conveyer Width: 6.14 inches
6. Total Conveyer Height: 10 inches (Frame height: 4 inches, Structure Legs: 6 inches)

The conveyor system has been designed with the objective of facilitating the quality control and inspection operations. Special consideration has been given in terms of length to incorporate the cameras, sensors and sorting mechanism along the length of the conveyor system. Weight is not a consideration here as the nuts are not bulky and the system has been designed such that it can take way more load than actually required (length is more important in this case). The main objective of this conveyor is to provide a length long enough for carrying out all the inspection operations in a smooth manner.

The initial design has been done using calculations and CAD models. The design has been completed as well as fabricated. However, this initial fabrication is just the conveyer system and there are lot of additions and operations to be performed on it before bringing it into operation. It has to be equipped with all the electronics and other mechanisms in the later phases as the project continues.

                                               Conveyer CAD model

                       Our Fabricated Conveyer System Prototype

Image Processing and Quality control systems

The image processing system consists of sensors, cameras, controllers and interfaces to perform its required function. Interrupt sensors indicate the presence of the nut as it enters the conveyer system. The HD camera will start taking images as the nuts pass underneath it at a preset rate. The acquired data will be sent to the raspberry pie processor for processing. The raspberry pie processor processes the images,controls and synchronizes the whole system with each other such as sensors, cameras with the conveyor system. The image data is processed and geometric dimensions data is collected and then used to construct quality control charts such as X-bar chart and p charts.

Sorting mechanism

The sorting mechanism consists of a servo-operated sorting arm that uses input from the raspberry pie processor for operation. When a defected nut or product is analyzed by the processor using the image data, then a signal is generated to the servo mechanism which removes the defected product from the conveyer system to the sorting bins. In this way the sorting operation is carried out and quality control is achieved.

Sorting arms on a conveyer system for sorting defected products on pre-set geometric measurement criteria 

Final Deliverable of the Project

HW/SW integrated system

Core Industry

Manufacturing

Other Industries

Food

Core Technology

Artificial Intelligence(AI)

Other Technologies

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com