The level of ruggedness required is dependent upon the environment in which the smart camera is to be deployed. It is important to note that many applications take place in fairly harsh environments. In food inspection applications, for example, the cleaning process washes all parts on the line, including the camera. Smart cameras are available with an IP rating of at least 67, which offers total protection against dust and submersion in water up to 1 m deep (see Figure 3).
Those who have completed a vision application know that vision is often part of a much larger system. Since the primary output of a smart camera is a decision, result, or some other information beyond an image, most smart cameras have built-in I/O to communicate or control other devices in the system. With industrial automation, the smart camera may need to control actuators to sort products; communicate inspection results to a robot controller, PLC, or programmable automation controller (PAC); save images and data to network servers; or communicate inspection parameters and results to a local or remote user interface. With USB and display ports, smart cameras can completely replace PC vision systems where an operator interface is required; the parts are integrated in a single device.
Often, for scientific imaging applications, the vision must integrate with motion stages, data acquisition systems, microscopes, specialized optics, and advanced triggering. As a result, many smart cameras today include I/O such as industrial digital inputs and outputs, encoder inputs for image synchronization, and communication ports.
Models are also available with built-in lighting, however, an integrated light cannot be independently positioned, and the feature is useless if a backlight is used. Built-in light controllers, an available alternative, can modify illumination directly from the smart camera. To effectively communicate to other devices, more and more industrial communication protocols, including DeviceNet, EthernetIP, and serial, are also being supported natively in smart cameras. It is therefore critical to understand how the smart camera will best integrate into an overall system (see Figure 4).
With the capabilities of today’s smart cameras, the adoption of these devices continues to grow, and newer technologies are being integrated that could help accelerate the growth. The devices, for example, are moving into the 3D vision space by providing solutions with multiple image sensors integrated into stereoscope or laser triangulation packages. These days, smart cameras can come in all shapes, sizes, and performance levels, but there is still one attribute that still defines them as smart cameras: the ability to perform image processing and make decisions directly on the camera. It is the decision making that makes a camera smart, and with the potential cost savings, ease of integration, and increasing performance, smart cameras are a cutting-edge option for many vision applications.
This article was written by Carlton Heard, Product Engineer – Vision Hardware and Software, at National Instruments (Austin, TX). For more information, visit http://info.hotims.com/49746-152.