Transcript Wireless ABS system By: Srej Balázs Pereira Raymond Alejandro Escalada Arto Toppinen Anssi Suhonen Savonia Polytechnic Frame of the presentation  Aim and Problems  Main parts and ideas  Central.

Wireless ABS system
By:
Srej Balázs
Pereira Raymond
Alejandro Escalada
Arto Toppinen
Anssi Suhonen
Savonia Polytechnic
Frame of the presentation
 Aim and Problems
 Main parts and ideas
 Central quad (data collector)
 Sensor and dynamo part (peripherals)
 Possible Solutions:
 Energy storage
 Communication protocol
 Security encryption
 Summary
Aim and problems:
 Main idea is to work out an
absolutely wireless ABS sensor
system
 1st stage of problems:
 How to ensure power supply without wires?
 Realize a safety RF communication
between the peripheries and central data
collector.
 Create interface between the central
computer of the car and the central quad.
Task and problems:
 2nd stage of problems:
 Stopped car: there is no Dynamo effect, no
power supply (battery usage  price, size)
 There are 4 wheels, necessary to use 4 RF
receiver device (safety reasons).
 Transmission loss tolerance is very less for
this system.
Central Quad (transceiver)
 Wireless data collector interface
 Main function of it, is to receive the RF
signals from the peripheral devices
Reproduce the signal and transmit
directly to the central computer in the
car.
 It Contains four RF signal receiver chip
Sensor and dynamo part
 Wireless sensor interface
The dynamo should be light weighted but
efficient enough to provide power supply
for the sensor and the RF interface
In order to implement the wireless
system, we can use the same old
sensors with the dynamo and the RF
interface added to it.
Possible solutions
Energy storage:
 For the case when a car is stopped
necessary to supply the sensor circuits
by battery
 At least necessary to use a capacitor
which can provide enough energy until
the CPU is going to send a break (rollback lock) message and goes to sleep
mode.
Possible solutions
Communication protocol:
The RF communication will solve with
Chipcon cc2510 RF microcontrollers.
Max data rate: 500kbps
Normal payload: in every 250ms
Message
Add-on
+/ID/ TYPE 12bit signals 4bit
Alarm payload: in all critical event
Message
ID/ TYPE 12bit
Deviation
Possible solutions
Security encryption:
 In the used RF device, there is a
encryption / decryption coprocessor. It
gives opportunity to protect the RF
messages. The encryption could be done
at maximum 128 bit.
 Necessary to use encryption to make
safer the communication.
Duty cycle of data
transmission
1. Transmission when
the car is in
motion and
working normally.
2. Transmission in
the emergency
situation of
breaking.
1
250
500
750
t (ms)
250
500
750
t (ms)
2
Emergency
signals
Data Packet Format
Representation of the System
Dynamo and
wireless sensor
interfaces
Central data
collector
interface
Customized
Protocol
System Realization
Wired set-up is replaced by the RF parts
Schematics of the simulator
Available options:
 Accelerometer to measure the
efficiency of suspension
 Temperature sensor
 Pressure sensor to measure the break
fluid pressure
Summary
 Aims of the project: To develop a cost
effective wireless ABS system, in which the
sensor data will be transmitted to the
central circuit wirelessly. Also, to make the
system really wireless the power supply to
the peripheral circuits is derived from the
local dynamos.
 Expected results: The cost of the entire
system should be less than or equal to 8€.
We expect the system to function as
reliably as the original wired system