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{
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{
"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)"
]
},
{
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"execution_count": null,
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|
