Industry: • FieldPoint Development of a Glow Plug Endurance … · endurance tests for glow plugs...
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Customer Solutions by G. Giridhar, Application Engineer, Vinod Mathews, CEO, Captronic Systems Bangalore, India The Challenge: Developing automated test equipment to perform accelerated endurance tests for glow plugs and speed up the testing cycle. The Solution: Building a system that performs endurance testing while calibrating and controlling the voltage of power supplies and recording various parameters of up to seven glow plugs simultaneously using FieldPoint distributed I/O modules and LabVIEW software. Glow Plug Usage At low outdoor temperatures and when an engine is cool, fuel in diesel engines insufficiently ignites or does not ignite at all. Glow plugs aid in starting a diesel engine at these low temperatures and ensure a smooth running engine immediately after starting at low speeds. In recent engine models, the glow plugs also continue to glow for up to several seconds after the engine starts to reduce the pollution content in the exhaust. Glow plugs mount in the cylinder head of the diesel engine with the positive connected to the battery and the negative grounded on the engine block. A glow plug consists of a heating resistor element welded in series with a positive temperature (PTC) resistor. When the voltage is applied, the heating resistor heats up and the glow plug tip glows. This PTC resistor also limits the flow of current, which stabilizes the temperature and current of the glow plug. We needed an application to automate the testing of the endurance, durability, and life of the glow plugs at a lower cost. The application needed to perform various functions, including applying recipes of voltages on the plugs for different time periods, testing in a cyclic manner until the plug fails, and ensuring unattended operation. The features offered by LabVIEW and FieldPoint made it possible for us to create this glow plug test system and add additional features to our basic requirements. For example, we were able to use the watchdog features of FieldPoint to program the system to shut down automatically in emergency conditions, such as short circuit or high glow plug temperatures. LabVIEW also gave us the flexibility to control the test system processes and acquire data for tests conducted for several thousands of cycles. The system automatically recovers from power shutdown to complete the balance of any incomplete tests. We can also view test data from any computer on the network. Using LabVIEW and FieldPoint, we were able to develop the Glow Plug Endurance Test System (GPETS) to accelerate the endurance process cycle of the plug. Creating the GPETS The system hardware for the GPETS consists of a personal computer and several FieldPoint modules, including FP-1001 for networking from a remote location, FP-AO-210 for controlling the voltage, FP-AI-110s for acquiring the current and temperature, FP-RLY-420 for switching on the power supply, and FP-RTD-122 for acquiring the jig-temperature. The individual tests were a collection of similar tasks, thus it was evident that the code should be modular. Each task was written to be a self-contained, generic sub-VI. Through the use of these software modules and the state machine programming of LabVIEW, we were able to develop different tests. We were also able to present data in a clear graphical format using LabVIEW graphical interfaces and control options to create an easy-to-use, understandable interface. The GPETS has four main sub-VIs: type program execution, voltage calibration, current calibration, and data entry. These execute in a sequence with the application logging the voltage, current temperature, and number of tests completed until the plug fails. The main panel of this application is the type program execution, which we use to view the user-specified data, start the different endurance programs required for testing the glow plugs, and perform online analysis of the process status of the Industry: Automotive Products Used: LabVIEW ™ • FieldPoint ™ The Glow Plug Endurance Test System (GPETS) developed using National Instruments hardware and software. Development of a Glow Plug Endurance Test System The features offered by LabVIEW and FieldPoint made it possible for us to create this glow plug test system and add additional features to our basic requirements. 02_664_161_101_8.5x10.875.qxd 10/1/02 1:26 PM Page 1
Transcript of Industry: • FieldPoint Development of a Glow Plug Endurance … · endurance tests for glow plugs...
Customer Solutions
by G. Giridhar, Application Engineer,Vinod Mathews, CEO, Captronic SystemsBangalore, India
The Challenge: Developing automated test equipment to perform acceleratedendurance tests for glow plugs and speed up the testing cycle.
The Solution: Building a system thatperforms endurance testing while calibratingand controlling the voltage of power suppliesand recording various parameters of up toseven glow plugs simultaneously usingFieldPoint distributed I/O modules and LabVIEW software.
Glow Plug Usage At low outdoor temperatures and when an engine is cool, fuel in diesel enginesinsufficiently ignites or does not ignite at all. Glow plugs aid in starting a diesel engineat these low temperatures and ensure asmooth running engine immediately afterstarting at low speeds. In recent enginemodels, the glow plugs also continue to glowfor up to several seconds after the enginestarts to reduce the pollution content in theexhaust. Glow plugs mount in the cylinderhead of the diesel engine with the positiveconnected to the battery and the negativegrounded on the engine block.
A glow plug consists of a heating resistorelement welded in series with a positivetemperature (PTC) resistor. When the voltage is applied, the heating resistor heats up andthe glow plug tip glows. This PTC resistor also limits the flow of current, which stabilizesthe temperature and current of the glow plug.We needed an application to automate thetesting of the endurance, durability, and life of the glow plugs at a lower cost. Theapplication needed to perform variousfunctions, including applying recipes of
voltages on the plugs for different timeperiods, testing in a cyclic manner until theplug fails, and ensuring unattended operation.
The features offered by LabVIEW andFieldPoint made it possible for us to createthis glow plug test system and add additionalfeatures to our basic requirements. Forexample, we were able to use the watchdogfeatures of FieldPoint to program the systemto shut down automatically in emergencyconditions, such as short circuit or high
glow plug temperatures.LabVIEW also gave usthe flexibility to controlthe test system processesand acquire data fortests conducted forseveral thousands of
cycles. The system automatically recoversfrom power shutdown to complete thebalance of any incomplete tests. We can also view test data from any computer on the network. Using LabVIEW and FieldPoint,we were able to develop the Glow PlugEndurance Test System (GPETS) to acceleratethe endurance process cycle of the plug.
Creating the GPETS The system hardware for the GPETS consistsof a personal computer and several FieldPoint
modules, including FP-1001 for networkingfrom a remote location, FP-AO-210 forcontrolling the voltage, FP-AI-110s foracquiring the current and temperature,FP-RLY-420 for switching on the powersupply, and FP-RTD-122 for acquiring the jig-temperature. The individual tests were acollection of similar tasks, thus it was evident that the code should be modular. Each task was written to be a self-contained,generic sub-VI. Through the use of thesesoftware modules and the state machineprogramming of LabVIEW, we were able todevelop different tests. We were also able to present data in a clear graphical formatusing LabVIEW graphical interfaces andcontrol options to create an easy-to-use,understandable interface.
The GPETS has four main sub-VIs: type program execution, voltage calibration,current calibration, and data entry. Theseexecute in a sequence with the applicationlogging the voltage, current temperature, and number of tests completed until the plug fails. The main panel of this applicationis the type program execution, which we use to view the user-specified data, start the different endurance programs required for testing the glow plugs, and perform online analysis of the process status of the
Industry: AutomotiveProducts Used: LabVIEW™ • FieldPoint™
The Glow Plug Endurance Test System (GPETS) developed using National Instruments hardware and software.
Development of a Glow Plug Endurance Test System
The features offered by LabVIEW and FieldPoint madeit possible for us to create this glow plug test systemand add additional features to our basic requirements.
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Customer Solutions
seven glow plug currents, voltages, andtemperatures. The sub-VI also controls datalogging of the date, time, number of cycles,voltage, current, and temperature with respect to time.
The voltage and current calibration sub-VIs control the voltage and current forthe predefined input, which helps us calibratethe power supplies and the acquired outputvoltage and current. The data entry sub-VIsets the parameters for the endurance test,which includes controlling voltage for theglow plug, forced cooling time of a plug bythe air jet, the number of operations, thewarning temperature set point, and theamount of power supply required.
We can enable or disable the DC sourcesaccording to the need for the test, which can depend, for example, on the number of plugs connected. We then know whether or not a glow plug is working or if it is notbeing used. Online graphs are also availablefor voltage versus time, current versus time,and temperature versus time for the sevenglow plugs. We can log the data to a databaseand view the old test data from the typeprogram history. Automatic shut down alsooccurs in case of PC communication failure.
An Independent Test SystemAfter running many tests, this NationalInstruments system has proven to be a very useful tool for testing the endurance,durability, and life period of the glow plugs.On the new LabVIEW system, testing of theglow plugs is done automatically for a three to four week period without requiring humanintervention thanks to features, such asautomatic shutdown in case of emergenciesand restarting operation after power failure.Additionally, FieldPoint makes it possible for us to isolate power supply voltages andcontrols and develop a distributed I/O systemthat can run such a large loop-in-loop controlapplication. We achieved all of this at one-fifth the cost of a dedicated system. ■
For more information, contactG. Giridhar or Vinod MathewsCaptronic Systems,Bangalore, IndiaE-Mail: [email protected]
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After running many tests, this National Instruments system has proven to be a very usefultool for testing the endurance,durability, and the life period of the glow plugs.
User interface for status monitoring of Glow Plug Endurance Test System (GPETS)
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