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UPDATE #11

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In this issue:

FuzzyDesigner provides a new level of capability


The FuzzyDesigner feature within RSLogix 5000 software is an editor that lets you create your own custom fuzzy logic algorithms for use in the Logix5000 family of controllers.

You can create and use as many fuzzy logic add-on instructions as you need – this lets you widely use and distribute your fuzzy logic instructions wherever you want
Fuzzy logic is extremely useful in applications that have a complex process and, because of non-linearities or time-variable responses, it is impossible to model the process mathematically. Often, traditional control methods, such as PID control, cannot provide adequate control for these types of applications. Typically, these processes are still controllable by using and applying the expert knowledge of operators who have learned how the process responds to various input conditions. This is where you can use FuzzyDesigner to encapsulate this knowledge in a usable control algorithm.

FuzzyDesigner Component Library
Input Port – stores fuzzy or crisp input values that can be preprocessed by a user-defined linear digital filter.
Input Linguistic Variable – stores linguistic terms and is used for classifying the actual component input into reference fuzzy sets.
Rule Block – stores rules, performs fuzzy logic inference based on fuzzy rules and computes degrees of fulfillment of consequent variables from degrees of fulfillment of premise variables.
Intermediate Linguistic Variable – is a bridge for logical chaining of rule blocks.
Output Linguistic Variables – stores parameters of linguistic terms and computes an output value from degrees of fulfillment of all terms.
Output Takagi-Sugeno Variable – stores parameters of functional (linear or constant) terms and computes an output value from degrees of fulfillment of all terms.
PID Controller – allows intelligent supervision of the conventional PID controller.
Output Port – stores fuzzy or crisp output values of the fuzzy system.
FuzzyDesigner provides a function block-type environment to create fuzzy logic algorithms. Simple point and click interfaces make it easy to define membership functions or rule block definitions. FuzzyDesigner also provides a set of built-in components that allow the building of hierarchical fuzzy systems easily.Once the custom fuzzy logic algorithm is created, FuzzyDesigner then integrates with Logix controllers using the new add-on instruction feature in RSLogix 5000 software (V. 16 or later). The fuzzy logic algorithm is compiled to an add-on instruction, which can then be imported into any RSLogix 5000 project and used like any other add-on instruction.

You can create and use as many fuzzy logic add-on instructions as needed. This gives an option to widely use and distribute fuzzy logic instructions. The software displays the current values within your fuzzy logic algorithm and lets you to tune membership function values, rule weights and other parameters in the controller, to obtain your desired response.

FuzzyDesigner Process:
1. Design Fuzzy system.
2. Generate add-on instruction.
3. Import and instantiate add-on instruction.
4. Download project to RSLogix 5000.
5. Monitor and tune Fuzzy algorithm.

FuzzyDesigner also provides tools to simulate and evaluate the response of fuzzy logic algorithms. Input value changes can be simulated and monitored to determine how rules will respond. You can also generate two- and three-dimensional mesh plots to graphically show how the fuzzy logic responds to changes in your process.

Fuzzy logic is typically applied in one of three ways, all of which are supported by FuzzyDesigner.
1. Direct fuzzy control algorithm, which uses rule-based control to directly control the process
2. Fuzzy logic algorithm, which acts as a supervisor to a traditional controller
3. Fuzzy logic algorithm, which smoothly blends the outputs from multiple control schemes, each of which is appropriate for different operating conditions of the process

FuzzyDesigner provides a new level of capability for advanced control within our Integrated Architecture. Whether you want to create your own custom fuzzy logic algorithms, or have our services and support organisation offer the expertise to help create a custom solution for you, FuzzyDesigner makes it easy to take advantage of fuzzy logic technology. It is available in Version 16 or later of RSLogix 5000 software and is compatible with the entire family of Logix5000 controllers.

For more information, please e-mail us at: info_update@ra.rockwell.com, ref: FuzzyLogic