Engine Management System:
Engine management system is now-a-days, used in many of the modem cars.
This car includes many electronic control systems such as microcontrollers for the control of various engine factors.
The main objective of the system is to ensure that the engine is operated at its optimum settings.
The engine management system of a car is responsible for managing the ignition and fuelling requirements of the engine.
The power and speed of the engine are controlled by varying the ignition timing and the Air fue1 mixture.
In modern cars, this is done by microprocessor.
To control the ignition delay, the crank shaft drives a distribution which makes electrical contacts for each spark plug in turn and a timing wheel.
This timing wheel generates pulses - to indicate the crankshaft position.
The microprocessor then adjusts the timing at which high voltage pulses are sent to the distributor so that they occur at right moments of time.
To control the amount of air-fuel mixture entering into a cylinder during the suction stroke, the microprocessor varies the time for which a solenoid is activated to the inlet
valve on the basis of inputs received by the engine temperature and the throttle position.
The amount of fuel to be injected into the air stream can be determined on input from a sensor of the mass rate of air, or computed from other measurements.
The microprocessor then gives as output to control of fuel inject valve.
The system hence consists of number of sensor for observing vehicle speed, Engine temperature, oil and fuel pressure, air flow etc.,
These sensors supplies input signals to the microprocessor after suitable signal conditioning and provides output signals via drivers to actuate corresponding actuators.
Engine Speed Sensors:
The Engine speed sensor is an inductive type sensor used to measure or sense the engine speed. It consists of a coil and a sensor wheel.
When the teeth of the wheel pass through the sensor, the inductance of the coil changes.
This change in inductance produces an oscillating voltage.
Engine Temperature Sensor:
The engine temperature sensor is used to sense the temperature of the engine.
It is usually a thermistor or a thermocouple.
The thermocouple consists of a bimetallic strip or a thermistor whose resistance changes when there is a variation in temperature of the engine.
Hot wire Anemometer:
Hot wire anemometer is used as amass airflow rate sensor in which a heated wire gets cooled when air passes across it.
The amount of coding depends on the mass flow rate.
The oxygen sensor is usually a closed end tube made of zirconium oxide with porous platinum electrodes on the inner and outer surfaces.
When the temperature is above 300˚C the sensor become permeable to oxygen ions so that melt age will be produced between the electrodes.
The various drivers such as fuel injection drivers, ignition coil driver’s solenoid drivers and are used to actuate actuators according to the signal by various sensors.
Analog signals are converted into digital signals by using ADC and are sensed by various sensors which in turn sent to the microcontroller.
The microcontroller compares these input values with the set points stored in its memory and it issues control signals to the corresponding our drivers.
The output signals are converted into analogue signal by using ADC.
The transient protection circuit prevents any sudden surge a rise or far in the power supply in the power supply to the micro controller.
A+12V voltage regulator is used to supply the dc voltage required for the microcontroller
Wireless Surveillance Balloon:
Surveillance generally refers to monitoring or observing a person or a group of people h m a certain distance, frequently.
Surveillance equipment is typically used in warfare and/or in counter-insurgency operations to monitor the activities of an enemy from a distance.
Surveillance equipment may also be used to monitor hazardous situations from a distance, such as for example, as may be associated with chemical hazards, explosive
hazards, and the like, so as to provide advance information to personnel responsible for controlling
Other applications may include search and rescue missions, police operations, and homeland security activities.
Elements of Wireless Surveillance Balloon:
Various essential elements of a wireless surveillance balloon are listed below:
Located in the housing
Communication modules transmit data collected by the sensors
An anchor line which may be adapted to anchor the deployable surveillance balloon to the housing after deployment
A lighter-than-air (LTA) gas source which may be adapted to provide lighter than- air gas for inflation of the surveillance balloon during and / or after deployment
Ancillary components which may facilitate the operation of the system, such as power sources, gas lines, wires, control circuitry, databases, displays, regulators, latches,
springs, levers, gaskets, etc.
Wireless surveillance balloon have been used for various applications like:
Border security (TARS) in military,
Enhancing battlefield situational awareness.
Platform for mounting telecommunication, television. radio transmitters and Broadband equipment Aerial platform for scientific instrument testing,
Aerial platform for weather prediction instruments,
For holding up large-array radio- telescopes.