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The above figure is the home page of the VHMS (Vehicle Health Monitoring System).

Whenever the user switches on the system this Home page gets displayed on the HMI display

unit and the vehicle health computation gets started. It has an back button to navigate to previous

 page and stop button to stop the process. Along with these it also has three buttons namely VHR,

 priority tasks, DTC. The back ground VI is designed in such a way that whenever these buttons

ie., controls get activated, the execution jumps to their corresponding subVI and their respective

 page gets displayed on the HMI display unit. The design and function of these subVI’s are

described below.

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Whenever the Vehicle health report button gets activated (user touches VHR button on home

 page) the above page gets displayed on the HMI display unit. This gives the complete status of 

the vehicle and its parts. It displays the health of the important vehicular parts such as Engine,

Emissions, Transmissions, Suspensions and Replacements. The status of these vehicular parts is

divided into three states. Optimum state – it represents that the corresponding vehicular part is in

good condition and no replacement is required.

 Needs servicing - it represents that the corresponding vehicular part is not in good condition and

some servicing or replacement is required. It alarms the user to make the vehicle checked in due

time.

Serious fault - it represents that the corresponding vehicular part is not in good condition and

immediate replacement is required for uninterrupted journey and safety of the user.

Each and every vehicular part status depends on several parameters and parts. Whenever these

controls or buttons gets activated, their corresponding VI gets executed and its page is displayed.

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For example the status of the engine in VHR is not in optimum state. It represents that some partor constituent of the engine is malfunctioning. To know, where the fault has been occurred, the

user has to click on the engine button which displays the above page. As shown in the above

figure the engine efficiency depends on several factors such as, engine temperature, engine load

value, throttle position, intake air temperature, and engine coolant temperature. Along with these

the fuel level indicator and RPM known as speedo meter is placed on this page. The status of 

these indicators represents the status or functioning of those corresponding constituents or parts.

The pedal is a form of potentiometer circuit which controls the throttle position for fuel injection

according to the inlet air. For throttle position manipulation, the vehicle consists of an inbuilt

sensor which has three reference levels. The ECU produces voltage pulses by this sensor whichare received by this sub VI which indicates the position of the throttle.(if voltage equals to 1 then

the throttle is fully closed, if voltage equals to 5 then throttle is fully open, generally the voltage

varies between these values.

the intake air temperature, engine temperature, engine coolant temperature are continuously

monitored. They have some optimum values and the driver gets alarmed whenever these

temperature reaches the optimum values.

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CO,NMHC,THC,NOx, HC+NOx, PM are the major constituents of the emissions in car.

These emissions should be in permissible limits, else they would cause harm to mankind. These

levels change from vehicles running on petrol to those running on diesel. An VI is build to

monitor these exhaust gases.

Petrol Diesel

CO 0.5 1

 NMHC 0 0.1

THC 0 0.068

 NOx 0.08 0.06

HC+NOx 0.17 0

PM 0.005 0.005

The above are the permissible levels of gases in emissions from a car according to a survey in

2008.

The exhaust consists of several gases, of this carbon monoxide is a toxic gas, and hence catalytic

converters are used to convert CO into CO2 to make it less harmful. Hence catalytic converter 

status can be drawn from emissions.

Oxygen sensors are used to send feedback, so as to control the intake of air at the piston during

combustion. For generating feedback these sensors sense this emission levels. Hence oxygen

sensor’s status can be drawn from emissions. 

Hence an VI is developed to detect weather the emissions are in permissible levels or not and

also the status of mufflers, catalytic converters, oxygen sensors are displayed on the HMI unit.

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The transmissions and suspensions are the important factors for load sharing of the car. The major part of 

the transmissions is Auto Transmission Fluid whose life or working efficiency varies on the distance

travelled and working temperature. Its level has to be maintained in optimum values else malfunction

appears in the vehicle. The fuel condition, oil temperature and fuel level are continuously monitored and

the user gets alarmed when they reaches the optimum values.

The suspensions are the one which shares the load of the car equally on the four wheels. If the road is

with heavy bumps, the effect of jumping or shaking is minimized by these springs used for suspension.

The spring rate, wheel rate and weight transfer have certain deviation values, and any overflow of these

deviation reduces the performance of the car, ie., engine efficiency gets affected.

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There are several fluids in the car whose condition effects the car’s efficiency. Of those the

important fluids are Engine fluid, Air fluid, Oil filter, ATF, TX fluid and Brake pad fluid. All

these fluids life gets worsen depending on the distance travelled. More over some of the fluids

life time reduces to half on increase of every 20 degrees. Some fluids have minimum temperature

to be maintained and some others have maximum temperature, where driver has to be alarmed

whenever these temperatures had reached to their min or max values.

As the majority of the fluid life is estimated from the distance travelled, the distance is

calculated by taking the pulse wave from the VSS pin in the car. Four pulses represents one

rotation of the wheel and by multiplying it with pi* radius of wheel/2, we have the distance

travelled. The VI is designed in such a way that depending on the temperature the fluid is

operated, its life time or status is calculated and displayed.

As all fluids have different life times, a set of reset buttons are placed on the page so that, when

an fluid is replaced its distance count has been resetted to zero, where as the other fluids distance

values continue to be accumulated.

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Diagnostic trouble codes are the one which makes VHR perfect. When a problem has occurred in

any of the components of the car the ECU produces trouble codes. These are in large numbersand a VI is build such that the obtained trouble codes are decoded and a message is displayed on

the HMI unit.

All the computations are done by the values obtained from ECU through CAN bus. ECU

receives these values from the internal sensors. What if these internal sensors gets damaged? All

the computations go into flaw. This situation is eradicated by decoding these trouble codes.

When ever the internal sensors gets damaged, corresponding dtc is produced by ECU which is

decoded and displayed as an message and thus making VHR as an error less report.

There are nearly two to three thousands of trouble codes, of which we have taken 30

which are very important and had decoded them.

 p0100, p0115, p0176, p0195, p0200, p0220 , p0230, p0261, p0300, p0320, p0335,

 p0340, p0350, p0382, p0405, p0410, p0420, p0460, p0470, p0480, p0500, p0566, p0654,

 p0700, p0703, p0704, p0725, p0730, p0740, p0745 are some of the trouble codes generated

in ECU.

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For example if p0745 is generated,it means some error has been occurred in pressure

control solenoid.This trouble code is detected and a message will be displayed as “Pressure

Control Solenoid Malfunction” on the HMI display unit.  

Prioritizing tasks is an extraordinary feature of Vehicle Health Monitoring system. It displays

tasks which need serious attention of the user which have to be attended or served first.

Whenever there are more than one problem ie.,more than one part of the car has to be replaced

then the prioritizing task’s helps the user and the work’s man who is servicing the car. 

The prioritizing tasks VI prioritizes all the flaws in the car and displays them in order according

to their priority in descending order. Whenever the car is sent to servicing the work’s man click’s

on the prioritizing task’s control and replaces the malfunctioning parts according to their priority. 

Thus making the VHMS user friendly.