Posts Tagged ‘Final Control Element’
How Can I Correct for Noise Using Internal Filters?
Noise is inevitable. To one degree or another it’s evident in the data of most every production process. Sure it can be absent in academic settings and similar lab environments where simulations often generate sanitized data. However, in the real world of industrial manufacturing noise is a factor that cannot be avoided. Failing to account for or manage noise can be a recipe for – well – failure.
Read MoreWhat is the Purpose of a PID Controller’s Integral Term? Why is PI Control So Widely Used in Industry?
In the realm of process control it makes complete sense that the primary goal is – you guessed it – to control the process. For decades the PID controller has proven a reliable tool for fulfilling that objective. Even so, there are various forms of the controller that can be used and each has its unique performance attributes. In spite of the added complexity associated with the Integral Term the PI controller is the form most widely used in industry.
Read MoreWhat is On-Off Control?
On-Off Control is not a highly sophisticated control method. Even so, examples of its practical, everyday use can be found all around. Look no further than the appliances in your home. Kitchen appliances such as ovens and refrigerators utilize On-Off Control. Similarly the furnaces, water heaters, and air conditioners found in most basements rely on On-Off Control. Although it’s unsophisticated, On-Off Control plays a significant role in our lives.
Read MoreDefault Out-of-the-Box Settings Prevent the PID Controller from Achieving its Goal
Tuning a PID controller doesn’t have to be hard. Whether a practitioner chooses to tune control loops manually or with the help of software, the procedure is relatively straight forward and can produce highly effective results. It can be argued that using software is faster and provides more optimal results than manual tuning, but that’s an argument that largely depends on the economic importance of the PID control loop in question. In the end, the goal is the same: To tune for improved control loop performance.
Read MoreHow Does the Derivative Term Affect PID Controller Performance?
Derivative is the third term within the PID. In mathematical terms the word derivative is defined as the slope of a curve. Seen in the context of strip chart data derivative represents the rate of change in error – the difference between the Process Variable (PV) and Set Point (SP). Like the proportional and integral terms within a PID controller, the derivative term seeks to correct for error. Valuable as the third term can be in maintaining effective control, experience suggests that appropriate uses of derivative are not entirely clear.
Read MoreHow Do I Calculate Gain? What Is the Difference Between Process Gain and Controller Gain?
Among practitioners who tune PID control loops manually most note their focus on calculating the Gain. Process Gain is a model parameter whereas Controller Gain is a tuning parameter. The former describes important aspects of a given process’ dynamic behavior. The later contributes to the PID controller’s responsiveness to disturbances.
Read MoreWhat is Model-Predictive Control?
Model-Predictive Control (MPC) is advanced technology that optimizes the control and performance of business-critical production processes. So is Control Loop Performance Monitoring (CLPM) software. But if both help practitioners to optimize control loop performance, then what’s the difference?
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