{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 17:Advanced Electdrical Controls For Fluid Power Systems" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Example 17.1 pgno:610" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The repeatable error of system is in. 0.00138\n" ] } ], "source": [ "# Aim:To determine the system accuracy of electrohydraulic servo system\n", "# Given:\n", "# servo valve gain:\n", "G_SV=0.15; #(in^3/s)/mA\n", "# cylinder gain:\n", "G_cyl=0.20; #in/in^3\n", "# feedback transducer gain:\n", "H=4; #V/in\n", "# weight of load:\n", "W=1000; #lb\n", "# mass of load:\n", "M=2.59; #lb.(s^2)/in\n", "# volume of oil under compression:\n", "V=50; #in^3\n", "# system deadband:\n", "SD=4; #mA\n", "# bulk modulus of oil:\n", "beta1=175000; #lb/in^2\n", "# cylinder piston area:\n", "A=5; #in^2# Solutions:\n", "# natural frequency of the oil,\n", "om_H=A*(((2*beta1)/(V*M))**0.5); #rad/s\n", "# value of open-loop gain,\n", "open_loop=om_H/3; #/s\n", "# amplifier gain,\n", "G_A=open_loop/(G_SV*G_cyl*H); #mA/V\n", "# repeatable error,\n", "RE=SD/(G_A*H); #in\n", "\n", "# Results:\n", "print\"\\n Results: \"\n", "print\"\\n The repeatable error of system is in.\",round(RE,5)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.2 pgno:610" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The repeatable error of system is cm. 0.00352\n" ] } ], "source": [ "# Aim:To determine the system accuracy of in SI units\n", "# Given:\n", "# servo valve gain:\n", "G_SV=2.46; #(cm**3/s)/mA\n", "# cylinder gain:\n", "G_cyl=0.031; #cm/cm**3\n", "# feedback transducer gain:\n", "H=4; #V/cm\n", "# mass of load:\n", "M=450; #kg\n", "# volume of oil:\n", "V=819; #cm**3\n", "# system deadband:\n", "SD=4; #mA\n", "# bulk modulus of oil:\n", "beta1=1200; #MPa\n", "# cylinder piston area:\n", "A=32.3; #cm**2\n", "from math import ceil\n", "# Solutions:\n", "# natural frequency of the oil,\n", "om_H=(A*10**-4)*(((2*beta1*10**6)/(V*10**-6*M))**0.5); #rad/s\n", "# value of open-loop gain,\n", "open_loop=om_H/3; #/s\n", "# amplifier gain,\n", "G_A=open_loop/(G_SV*G_cyl*H); #mA/V\n", "# repeatable error,\n", "RE=SD/(G_A*H); #cm\n", "# rounding off the above answer,\n", "RE=round(RE)+(round(ceil((RE-round(RE))*100000))/100000); #cm\n", "\n", "# Results:\n", "print\"\\n Results: \"\n", "print\"\\n The repeatable error of system is cm.\",RE" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Chapter 17.3 pgno:612" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", " Results: \n", "\n", " The tracking error of system is in. 0.104\n", "\n", " The tracking error of system in SI Unit is cm. 0.264\n" ] } ], "source": [ "# Aim:Refer Example 14-3 for Problem Description\n", "# Given:\n", "# servo valve current saturation:\n", "I=300.; #mA\n", "# amplifier gain:\n", "G_A=724.; #mA/V\n", "# feedback transducer gain:\n", "H=4.; #V/in\n", "# feedback transducer gain in metric units\n", "H1=1.57; #V/cm# Solutions:\n", "# tracking error,\n", "TE=I/(G_A*H); #in\n", "# tracking error,\n", "TE1=I/(G_A*H1); #cm\n", "\n", "# Results:\n", "print\"\\n Results: \"\n", "print\"\\n The tracking error of system is in.\",round(TE,3)\n", "print\"\\n The tracking error of system in SI Unit is cm.\",round(TE1,3)" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }