AUTOMATION OF ROTOGRAVURE

PRINTING MACHINE

INTRODUCTION Rotogravure runs at 150m/s. Uniform speed of DC drive and tension of the film

is to be maintained for desired output. This cannot be done manually. Tension Controller Circuit is implemented using

load cells and PID controller.

BASIC MODEL

BLOCK DIAGRAM

LOAD CELL An electromechanical type of transducer. Converts mechanical force into electrical signal. The sheet being printed will apply the tension on

load cell. Load cell will concert the tension applied into an

electrical signal.

INSTRUMENTATIONAMPLIFIER A type of differential amplifier which eliminate

the need for input impedance matching and thus make the amplifier particularly suitable for use in measurement and test equipment.

Signal from load cell will be given as input to the instrumentation amplifier.

Instrumentation amplifier will remove the noise and amplify the signal by adjusting suitable gain value.

PID CONTROLLER The proportional-integral-derivative (PID)

controller is a generic control loop feedback mechanism widely used in industrial control systems.

The algorithm involves three separate parameters; the Proportional, the Integral and Derivative values.

The Proportional value determines the reaction to the current error.

Contd.. The Integral determines the reaction based on

the sum of recent errors. The Derivative determines the reaction to the

rate at which the error has been changing. By "tuning" the three constants in the PID

controller algorithm, the controller can provide control action designed for specific process requirements.

Contd.. In our project the output of instrumentation

amplifier is given to PID controller along with the feedback input.

Reference input is also given to PID controller in order to specify the desire tension along with the speed at which the machine is to run.

PID controller will compare the reference voltage and feedback voltage and will bring the feedback voltage closer to reference voltage, which result into control output from PID controller.

MICROCONTROLLERAT89c2051 8-bit microcontroller with 2K bytes

reprogrammable flash memory. Microcontroller will help us to display the output

signals from load cell, PID controller and load cell with proper programming.

DC MOTOR DRIVE The controlled output from PID controller will be

given to motor driver. The drive and control speed of the film cylinder

depending upon the tension applied by the sheet on load cells.

Project By.. Snehil Lodha Kunal Mahadik Datta Remaniche Sagar Salvi