sensor presentation akhil short

8/3/2019 Sensor Presentation Akhil Short

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Presented By -

Akhil Sharma

Deep Lomesh Shah

Technische Universitt Chemnitz

Master Micro and Nano Systems

Second Semester

Sensors For Active And Passive Security System

Seminar Automotive Sensors

Chair for Measurement and Sensor TechnologyUniv.-Prof. Dr.-Ing. O. Kanoun


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There are two main types of security systems

Active security system Passive security system

Active security systems They work for prevention of crash/accident.e.g. ESP , ABS, ACC, TCS, TPM, EBD, CBC, Headlights, Reflectors,Suspensions, Infrared night vision etc.

Passive security systems They work after the crash has taken placee.g. airbags, seatbelts, laminated windshield, crumple zones, PPS, paddingthe instrumental panel etc.

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Source : Jeopardylabs.com

Source : Google Image


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Anti-Lock Braking System (ABS)

What is ABS ? An anti-lock braking system is a safety system that allows the wheels on

a motor vehicle to continue interacting tractively with the road surface as directedby driver steering inputs while braking.

Therefore, preventing the wheelsfrom locking (that is ceasing rotation)and therefore avoiding skidding.



Source : www.carazoo.com


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Components Of ABS



ABS

Wheel SensorABS Control

Module

Hydraulic Pumpand Pressure

Release Valves

Brake Pipe

ABS comprises of following -


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Components Of ABS



Wheel sensors The speed sensors, which are located at each wheel provideinformation to ABS control module when a wheel is about to lock up.

.ABS Control Module It is an ECU type unit in the car/vehicle which receivesinformation from each individual wheel speed sensor. When a wheel loses tractionthe signal is sent to the controller, the controller will then limit the brake force

(EBD) and activate the ABS modulator which actuates the braking valves on andoff.

Valves There is a valve in the brake pipe of each brake controlled by the ABS.

Pump When a valve reduces the pressure in a pipe, the pump maintains thepressure back to the normal in the pipe.


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Schematic showing ABS inside a vehicle



A : Wheel sensor

B : ABS controlmodule

C : Hydraulic pump &

pressure releasevalves

D : Brake pipe


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Operation Principle



STEP 1: Heavy brakes applied, observe green wheel(A).

STEP 2: ABS control module(B) activated, signal sent to brake pressurevalve(C) to lower the pressure in the corresponding brake pipe(D).

STEP 3: Lowering of pressure in brake pipe(D),causing brake caliper toloosen the grip.

1. Brake caliper

2. Wheel speed sensor

STEP 4: Pressure built up again using hydraulic pump (C).


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.A) Example : Car without ABS onslippery surface.

Without ABS, as driver applies brakes,wheels lock (1). Despite applyingsteering lock, car continues straightahead due to the loss of steeringcontrol (2) and a collision results.


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.A) Example : Car with ABS on slippery surface.

In the diagram above, the driver hits the brakes hard on a slippery surface(1), then steers (2), and successfully manages to avoid the obstacle. ABSprevents the wheels from locking, and this allows you steer.


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Visualising ABS inside the vehicle



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.Visualising ABS


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Autonomous Cruise Control System (ACC)



.What is ACC ?

Autonomous cruise control is an optional cruise control system appearingon some more upscale vehicles / intelligent cars.

Cruise control (sometimes known as speed control or auto cruise) is asystem that automatically controls the speed of a motor vehicle.

These systems use either a radar or lasersetup allowing the vehicle to slow whenapproaching another vehicle andaccelerate again to the preset speed whentraffic allows.

Source: www.popsci.com


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Types Of ACC



.

ACC

Radar Type Laser Type

Laser-based systems aresignificantly lower in costthan radar based systems

However, laser based ACCsystems do not detect and track

vehicles well in adverseweather conditions nor do theytrack extremely dirty (non-reflective) vehicles very well.


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Example



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Source: www.carsp.ca


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User friendly



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Source: Google Image

sensor presentation akhil short

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