For extending the present capabilities of the robots and to improve their capacities sensors are used in the programmable automation. Specifically the use of sensors makes the programmable automation system reliable, simpler and faster and makes the system suitable for the factory environment.
Sensor needs can be broadly divided into three types. They are:
- Inspecting the parts visually
- Finding parts
- Controlling manipulation
1. Inspecting the parts visually: Here the visual inspection is not done entirely. But the subsets of the Inspection are being performed using the manual techniques rather than by using the machinery methods. So, in order to overcome the manual errors the subsets of the Inspection like qualitative and semi quantitative inspections can be done by using the sensory methods. These sensory methods are used for accurate measurement. These sensory methods are used for detecting the cracks, assessing completeness of the assembly, examining surface finish etc. To avoid lengthy and complex processes which are done by man these sensory methods are used for inspection.
2. Finding Parts: Present industrial methods cannot come up with the advantages of picking process of the parts from a bin which contains many randomly oriented parts. The inability of the past existing robots to adapt random positions has limitations even for material handling and assembly operations. Thus the robots by the use of visual sensors are used for determining the orientation, identity and position for doing visual inspection.
3. Controlling Manipulation: Manipulation of the tools and work pieces for material handling and assembly operations includes many basic operations like inserting, holding, grasping etc and the human manipulations which are very inaccurate and they mostly rely on the sensors for those operations. After assessing which sensor is useful at which place both the sensors are used for controlling manipulation. Therefore visual sensors can be used for positioning the manipulator automatically with precise matching.
So, the sensors are used especially in these three applications.