Essential Manufacturing

21Machine Vision

Machine vision systems are found in a wide range of applications within industry and they are an important element wherever automation is implemented. This chapter considers the application and operation of machine vision within manufacturing.

21.1 Areas of Application of Artificial Vision

21.1.1 Qualitative and Quantitative Inspection

This large area of application of vision system has many subdivisions. It is an attractive area for investment as, without the use of automation, visual inspection can account for around 10% of the total labour costs of manufactured products. Qualitative inspection involves using the vision system for checking a product on an accept or reject basis by examining its attributes. For example, a flaw in a glass bottle, a crack in a casting or a discoloured fruit on a conveyor would be attributes that would cause these items to be rejected. Other aspects of this would be the detection of foreign bodies such as mice or insects on a conveyor in a food processing plant, verification of a completed task in an assembly sequence or checking the degree of swarf build up on a drill bit. Quantitative inspection involves using the system to measure the dimensional features of a product or component. Examples of this are measuring the width of steel strip coming from a steel mill, gauging the diameter of a shaft during or after turning or inspecting a completed component dimensionally.

21.1.2 Identification

Rather than check an attribute ...