Custom-Tailored Solutions

Tips for Successfully Implementing Machine Vision

The main task for any Machine Vision solution is to reduce a large amount of data (an image of the part) into useful information (presence/absence of features or flaws, dimensional information, etc.). In order to do this in a way that is accurate and repeatable, users of machine vision should be prepared to address important integration issues when solving a vision application. We will discuss the most common issues below. These application integration issues generally fall into the following categories; application feasibility, mechanical design and installation, electrical design and installation, and programming or commissioning.

Application Feasibility

First, we will discuss application feasibility. Customers will work with an Application Engineer to determine if the application is feasible. The application engineer will run through a series of questions to ensure that the Vision System can meet the customer’s requirements. The mechanical space available for the inspection task will be critical in this phase of the project, as it will have a major effect on the lighting and optics that can be used. Since image quality is so important, the lighting design is perhaps the most important aspect of this phase of the application. Other factors that will affect application cost and feasibility include line speeds, part presentation, and vision system communication requirements.

Mechanical Design and Installation

Mechanical design is closely coupled with application feasibility, since mechanical designers often have the part presentation already designed, and the vision system must work with this design. This is not ideal. Ideally, the machine vision application engineer and mechanical designer work hand-in-hand to design a part presentation system. In some more progressive industries, like medical device manufacturing and consumer products, the part itself is often designed with features that aid Machine Vision inspection. PPT VISION has experience with this kind of design, called design for manufacturability, where vision application engineers are involved very early in the product development process.

Three of the most important integration issues for the application’s mechanical design include rigid fixtures for the part lighting and optics, a rigid structure to minimize the relative movement between the optical components, and enclosures to prevent tampering with the optics and lighting after the commissioning process is complete.

Electrical Design and Installation

Electrical designs start with simple designs based on discrete inputs and outputs (I/O), like a photoelectric sensor for triggering the inspection (input) and a solenoid driven reject gate for moving defective parts out of the main assembly line (output). More complex communications involve the Ethernet port built into each IMPACT vision processor, and TCP/IP communications that can span one machine, or an entire factory floor. These more complex communications schemes sometimes involve an integration firm working with machine vision application engineers to design the information flows.

Programming or Commissioning

Finally, programming or commissioning a new Vision System. The final step to commissioning a Vision System is taking the initial program that was used for benchmarking during the Application Feasibility stage and enhancing it to run on the factory floor. This typically includes debugging communications, and adding troubleshooting aids. PPT VISION partners with a large integrator network and would be happy to recommend experienced integrators to any customer who needs help with this phase of the project work. Many customers opt to do this work themselves, and for those customers, we offer training at PPT VISION. If you are interested in this training, conducted by our experienced Application Engineering department, visit www.pptvision.com