Posts Tagged ‘FCE’
How Can I Correct for Noise Using External Filters?
Choices, choices. In the realm of process control practitioners are regularly forced to choose between competing options. Consider a PID control loop: Should it be tuned for faster disturbance rejection or tighter Set Point tracking? Should the Derivative Term be used or does the PI configuration provide a sufficiently fast Settling Time? And the choices go on and on. In that sense there are multiple choices for filtering noise too – options that provide very different benefits. Fortunately when it comes to filtering for Signal Noise the choice is typically clear.
Read MoreHow 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 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 Detect Valve Issues and Prevent Failures?
It’s generally known that the behavior of final control elements (FCEs) (valves, air handlers, etc.) change over time. Like most things the dynamics of FCEs are different from the time they’re first installed to the time they’re serviced and ultimately replaced. Sometimes the change in dynamic behavior is subtle. Other times the change is dramatic. Unfortunately that’s the nature of things, and that’s the primary reason why monitoring for valve issues is beneficial.
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 Output Distribution? How Is It Helpful?
Most of us know what it means to give 110%. Whether by a coach urging players to finish strong or a supervisor encouraging staff to hit a project deadline, many of us have been asked to go beyond some normal expectation of output. Even though we’re limited to giving 100%, operating at such a high level can result in great achievements. When that high octane performance level is required for only a brief period the impact on staff can be minimal. If demanded for an extended period, however, the impact can be long lasting and even debilitating. We’re only human, right?
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