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PITOPS PID |
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PID AND ADVANCED CONTROL SUITE OF
TOOLS |
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Click on Downloads to download and examine a full-blown demo of Pitops-PID. |
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Pitops-PID is a comprehensive primary and advanced control simulator and optimizer. With Pitops-PID, you can build simulations to mimic any process in just a few minutes. Unlike competitor software, Pitops-PID works from fast millisecond scan times to seconds, minutes, and multiples of minutes. This allows simulation from super-fast compressor-surge control loops to very slow distillation column online analyzer-based purity control loops. Pitops-PID has many features. An overview list of Pitops-PID features are shown below: |
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Pitops Functions |
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Figure 1 shows the Pitops-PID main simulation screen. Many important process
control parameters can be accessed from a single screen. Pitops-PID has a
very convenient and easy user interface. |
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Figure 1. Transfer Function and Controller Parameters in Pitops-PID |
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Control Objectives and Process Characteristics The optimal tuning of critical loops must take into account the nature of the process, how fast the control valve can be allowed to move, nature of known and unknown disturbances and other custom issues unique to the loop. Pitops-PID allows you to configure a custom simulation quickly and easily. Figure 2 shows a simulation comprising of superimposed disturbances like those seen in the real process. After configuring the disturbances, Pitops-PID optimizes the tuning parameters based on the custom simulation, taking into account the control needs of the loop, which include the following: 1. Typical setpoint changes 2. Typical disturbances 3. Output rate of change consideration 4. Any other custom needs specific to the PID loop 5. Optimize PID tuning to handle control valve stiction or deadband Most other products optimize tuning based on heuristics and error criteria; in contrast, Pitops-PID optimizes based on the precise (custom) process characteristics and control objectives. |
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Figure 2. Configuring disturbances to match the real process |
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Individual P, I and D Contribution Decomposition Pitops-PID decomposes the total controller contribution into the individual proportional, integral and derivative contributions and plots them individually as a function of the time axis. This provides diagnostics which are useful for critical advanced control loops, especially slow loops with long process dead time where use of derivative can significantly improve controller performance. Powerful Multiple Cascade Simulation and Optimization Pitops-PID provides cascade PID simulation and sequential optimization capability to optimize both slave and cascade controllers - see Figure 3. A single, easy-to-use master screen alows you to specify most parameters. Signal Transforms, Analyzer PV Sample Delay and NonLinear Control You can specify slow loops, GC analyzer sample time delay and special transforms like natural logarithms, square and square root to linearize commonly known non-linear processes. These transformations are used for constraint control for distillation column delta pressure to infer column flooding limits and also for tighter control of tall superfractionators where the distillation purities behave non-linearly. Control Simulations in Time Domain Pitops-PID provides calculation procedures and commissioning guidelines to design and implement feedforward controllers. Most other competitor software products run in the discrete (Z) domain. In contrast, Pitops-PID runs completely in the time domain which is easier to understand by people of all skills and experience levels. |
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Figure 3. Cascade Simulation and Control Optimization |
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Feedforward Control Parameter Optimization Pitops provides powerful, easy to use feedforward simulation module. Many skilled control engineers have admitted that they began to truly appreciate some important aspects of feedforward control design only after being exposed to Pitops-PID. Pitops-PID automatically optimizes controller parameters for a closed-loop simulation for a real-plant case configured with a disturbance and feedforward model precisely matching the process dynamics. The feedforward trends in Pitops-PID are shown in Figure 4. Model-Based Controller Design Implementation Powerful model-based control schemes can be built in the DCS using Pitops-PID suite of model-based controller design, see Figure 5 for an illustration. Using regressed, empirical, semi-empirical or rigorous chemical engineering models, effective model-based dynamic controllers can be easily implemented. The procedures show how to build controllers at a fractional cost and effort compared to other options. Pitops-PID is the only tool that any control engineer will ever need in the control room. All simulations can be built very easily in a matter of minutes. This ease of use is unmatched by any other competitor software. Both new and skilled engineers and also DCS technicians/operators have successfully used Pitops-PID with ease and confidence. |
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Figure 4. Feedforward Simulation and Parameter Estimation |
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Figure 5. Internal Model Controller (IMC) and Dead Time Compensation (DTC) |
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Control Valve Stiction/Deadband Pitops optimizes PID tuning parameters to improve control action amidts control valve problems such as stiction and deadband. For control valves with stiction or deadband, Pitops will move the controller settings in the direction of increased proportional and derivative action and reduced integral action. |
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| Click on Downloads to download and examine a full-blown demo of Pitops-PID. | |||
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Copyright © PiControl Solutions LLC. All rights reserved. |
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