Fl For Embedded Systems Applications

Fuzzy Logic for Embedded Systems Applications Ranganath Muthu SSN College of Engineering

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Embedded Systems Applications • • • • • • • •

Fuzzy Anti-Lock Brake System Automotive Engine Control with Fuzzy Logic Adaptive 5-Speed Automatic Transmission Anti-Skid Steering Systems Fuzzy Logic Enhanced Control of an AC Induction Motor with a DSP Fuzzy Logic predicts Aircraft Flight Path Fuzzy Logic in AC Control Adaptive Heating System Control using Fuzzy Logic

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Embedded Systems Applications • Fuzzy Logic Supervisory Control for Coal Power • • • •

Plant Application of Fuzzy Control for Optimal Operation of Complex Chilling systems Fuzzy Logic and Neuro-Fuzzy Data Analysis in a Medical Shoe Monitoring Glaucoma by Means of a Neuro-Fuzzy Classifier Development of a Fuzzy Knowledge-Based System for the Control of a Refuse Incineration Plant

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Embedded Systems Applications • Fuzzy Technology Implemented in Sonar • • • •

Systems Data Analysis of Environmental Data for Traffic Control Truck Speed Limiter Control by Fuzzy Logic Optimization of a Water Treatment System Improved Supervisory Control with the Fuzzy PLC

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Fuzzy Anti-Lock Braking System • ABS ensures optimal vehicle control and minimal • • •

stopping distances during hard or emergency braking irrespective of road and weather conditions. Experts predict that 35% to 50% of all cars built worldwide in five years will have ABS as standard equipment. Electronic control units (ECUs), wheel speed sensors, and brake modulators are major components of an ABS module. Wheel speed sensors transmit pulses to the ECU with a frequency proportional to wheel speed.

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Fuzzy ABS • The ECU then processes this information and regulates • •

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the brake accordingly. Since ABS systems are nonlinear and dynamic in nature they are a prime candidate for fuzzy logic control. Intel & Inform Software Corporation Fuzzy ABS utilizes a high performance, low cost, 16-bit 8XC196Kx architecture to take advantage of improved math execution timing. Uses Fuzzy Rules like "If the rear wheels are turning slowly and a short time ago the vehicle speed was high, then reduce rear brake pressure".

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ABS Block Diagram

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Inputs: 1. The Brake: This block represents the brake pedal deflection/ assertion. This information is acquired in a digital or analog format. 2. The 4 W.D: This indicates if the vehicle is in the 4-wheel-drive mode. 3. The Ignition: This input registers if the ignition key is in place, and if the engine is running or not. 4. Feed-back: This block represents the set of inputs concerning the state of the ABS system. 5. Wheel speed: In a typical application this will represent a set of 4 input signals that convey the information concerning the speed of each wheel. This information is used to derive all necessary information for the control algorithm Outputs: The proposed system shown above has two types of outputs. The PWM signals to control ABS braking, and an Error lamp signal to indicate a malfunction if one exists. 19 December 2008

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Fuzzy Washing Machine • The length of wash time is based on the amount of clothes you • • •

wish to wash and the type and degree of dirt you have. To automate this process, we use sensors to detect these parameters and the wash time is then determined from this data. There is no easy way to formulate a precise mathematical relationship between volume of clothes and dirt and the length of wash time required. There are two inputs: (1) one for the degree of dirt on the clothes and (2) one for the type of dirt on the clothes. These two inputs can be obtained from a single optical sensor.

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• The degree of dirt is determined by the transparency of the • •

wash water. The dirtier the clothes, the lower the transparency for a fixed amount of water. The type of dirt is determined from the saturation time, the time it takes to reach saturation. The fuzzy controller output is the length of the wash time.

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Fuzzy Controller

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Labels and Membership Functions of Input Variable dirtiness

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Labels and Membership Functions of Input Variable type_of_dirt

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Labels and Membership Functions of Output Variable wash_time

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Rules • If saturation time is long and transparency is bad, then wash time should be long.

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Thank You

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